[House Hearing, 114 Congress]
[From the U.S. Government Publishing Office]
ASTROBIOLOGY AND THE SEARCH FOR LIFE
BEYOND EARTH IN THE NEXT DECADE
=======================================================================
HEARING
BEFORE THE
COMMITTEE ON SCIENCE, SPACE, AND TECHNOLOGY
HOUSE OF REPRESENTATIVES
ONE HUNDRED FOURTEENTH CONGRESS
FIRST SESSION
__________
September 29, 2015
__________
Serial No. 114-40
__________
Printed for the use of the Committee on Science, Space, and Technology
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Available via the World Wide Web: http://science.house.gov
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COMMITTEE ON SCIENCE, SPACE, AND TECHNOLOGY
HON. LAMAR S. SMITH, Texas, Chair
FRANK D. LUCAS, Oklahoma EDDIE BERNICE JOHNSON, Texas
F. JAMES SENSENBRENNER, JR., ZOE LOFGREN, California
Wisconsin DANIEL LIPINSKI, Illinois
DANA ROHRABACHER, California DONNA F. EDWARDS, Maryland
RANDY NEUGEBAUER, Texas SUZANNE BONAMICI, Oregon
MICHAEL T. McCAUL, Texas ERIC SWALWELL, California
MO BROOKS, Alabama ALAN GRAYSON, Florida
RANDY HULTGREN, Illinois AMI BERA, California
BILL POSEY, Florida ELIZABETH H. ESTY, Connecticut
THOMAS MASSIE, Kentucky MARC A. VEASEY, Texas
JIM BRIDENSTINE, Oklahoma KATHERINE M. CLARK, Massachusetts
RANDY K. WEBER, Texas DON S. BEYER, JR., Virginia
BILL JOHNSON, Ohio ED PERLMUTTER, Colorado
JOHN R. MOOLENAAR, Michigan PAUL TONKO, New York
STEPHEN KNIGHT, California MARK TAKANO, California
BRIAN BABIN, Texas BILL FOSTER, Illinois
BRUCE WESTERMAN, Arkansas
BARBARA COMSTOCK, Virginia
GARY PALMER, Alabama
BARRY LOUDERMILK, Georgia
RALPH LEE ABRAHAM, Louisiana
DARIN LAHOOD, Illinois
C O N T E N T S
September 29, 2015
Page
Witness List..................................................... 2
Hearing Charter.................................................. 3
Opening Statements
Statement by Representative Lamar S. Smith, Chairman, Committee
on Science, Space, and Technology, U.S. House of
Representatives................................................ 9
Written Statement............................................ 10
Statement by Representative Eddie Bernice Johnson, Ranking
Member, Committee on Science, Space, and Technology, U.S. House
of Representatives............................................. 11
Written Statement............................................ 12
Witnesses:
Dr. Ellen Stofan, Chief Scientist, NASA
Oral Statement............................................... 14
Written Statement............................................ 17
Dr. Jonathan Lunine, David D. Duncan Professor in the Physical
Sciences, and Director, Center for Radiophysics and Space
Research, Cornell University
Oral Statement............................................... 22
Written Statement............................................ 24
Dr. Jacob Bean, Assistant Professor, Departments of Astronomy and
Astrophysics, Geophysics, University of Chicago
Oral Statement............................................... 30
Written Statement............................................ 32
Dr. Andrew Siemion, Director, SETI Research Center, University of
California, Berkeley
Oral Statement............................................... 37
Written Statement............................................ 39
Discussion....................................................... 50
Appendix I: Answers to Post-Hearing Questions
Dr. Ellen Stofan, Chief Scientist, NASA.......................... 72
Dr. Jonathan Lunine, David D. Duncan Professor in the Physical
Sciences, and Director, Center for Radiophysics and Space
Research, Cornell University................................... 87
Dr. Jacob Bean, Assistant Professor, Departments of Astronomy and
Astrophysics, Geophysics, University of Chicago................ 91
Dr. Andrew Siemion, Director, SETI Research Center, University of
California, Berkeley........................................... 95
ASTROBIOLOGY AND THE SEARCH FOR LIFE
BEYOND EARTH IN THE NEXT DECADE
----------
TUESDAY, SEPTEMBER 29, 2015
House of Representatives,
Committee on Science, Space, and Technology,
Washington, D.C.
The Committee met, pursuant to call, at 10:02 a.m., in Room
2318 of the Rayburn House Office Building, Hon. Lamar Smith
[Chairman of the Committee] presiding.
[GRAPHICS NOT AVAILABLE IN TIFF FORMAT]
Chairman Smith. The Committee on Science, Space, and
Technology will come to order. Without objection, the Chair is
authorized to declare recesses of the Committee at any time.
Welcome to today's hearing, which is called ``Astrobiology
and the Search for Life beyond Earth in the Next Decade.''
Let me make a couple of announcements. One is an
explanation and that is to say that we expect more Members
shortly, but at least on the Republican side, all of our
Members are in a Republican conference that I left early in
order to start on time here, but other Members will be arriving
shortly. And the same may be true of our colleagues on the
other side of the aisle as well.
We have a new member of the Science, Space, and Technology
Committee, and I would like to introduce him. He is Darin
LaHood, the first Member to my left, whose father I served with
in Congress some years ago. Darin LaHood represents a district
in Illinois. He's a former State Senator or serving as a State
Senator when he was elected to Congress. Before that, he was
both a State and Federal prosecutor. So we welcome his many
talents to the Committee. He is going to be serving on two
subcommittees, Research and Technology and Oversight, where he
will be bringing all those legal skills to bear. And so we are
pleased to have him join us today and permanently on this
Committee. Welcome, Darin, to you.
Mr. LaHood. Thank you, Mr. Chairman.
Chairman Smith. I'm going to recognize myself for an
opening statement and then I'll recognize the Ranking Member.
Edwin Hubble once said: ``Equipped with his five senses,
man explores the universe around him and calls the adventure
Science.'' There are few greater adventures than the search for
life beyond Earth.
When the Hubble Space Telescope was launched in 1990,
planets around other stars had not yet been discovered. The
only planets we knew were those that orbited our Sun. Since
1995, however, when the first extrasolar planet was detected,
the rate of discovery of new exoplanets and external solar
systems has been truly remarkable.
Today, with the Kepler Telescope, we have found nearly
2,000 confirmed planets that orbit around other stars in our
galaxy. Of these, 306 lie within the habitable zone of the
stars they orbit--where water could exist--and 14 are almost
the size of the Earth.
Whether life exists beyond Earth, and if so, how humans can
detect it, is a critical question. If definitive evidence of
life is found, it may be the most significant scientific
discovery in human history. The search for life in the universe
is a priority of NASA and the U.S. scientific community.
Seeking habitable planets is one of the three scientific
objectives of the 2010 National Research Council Decadal Survey
on astronomy and astrophysics.
The United States pioneered the field of astrobiology and
continues to lead the world in this type of research. Since the
space program began, NASA has explored the cosmos for life
beyond Earth and has conducted scientific research that
investigates this possibility.
NASA's astrobiology program continues these scientific
endeavors to improve our understanding of biological,
planetary, and cosmic phenomena. Just yesterday, NASA announced
that it identified flowing briny water on Mars. This past
April, NASA's Chief Scientist, Dr. Ellen Stofan, made global
headlines with her prediction that ``we are going to have
strong indications of life beyond Earth in the next decade and
definitive evidence within the next 20 to 30 years.'' And I am
glad that Dr. Stofan has joined us today.
Within our solar system, the question of whether life
exists or existed on Mars continues to capture the public
imagination. In the past year, NASA's Curiosity Rover made
several major scientific discoveries relevant to the search for
life on Mars. Curiosity measured a spike in levels of the
organic chemical methane in the local atmosphere of its
research site. It also detected other organic molecules in
drill samples in a mudstone that once sat at the bottom of a
lake. And Jupiter's moon, Europa, shows strong evidence of an
ocean of liquid water beneath its surface, which could host
conditions favorable to some form of life.
NASA selected nine science instruments for a future mission
to Europa. Two of them are from the Southwest Research
Institute in San Antonio and one from the University of Texas
in Austin. These instruments will help scientists investigate
the chemical makeup of Europa's potentially habitable
environment.
Last July, astronomers, with the help of the Kepler Space
Telescope, confirmed the discovery of Kepler 452-b, the first
near-Earth-size planet in the ``habitable zone'' around a sun-
like star. This discovery marks another milestone in the
journey to find another ``Earth.''
The Transiting Exoplanet Survey Satellite, which will
launch in 2017, and the James Webb Space Telescope, which will
begin in 2018, will help scientists discover more planets with
potential biosignatures in their atmospheres, such as evidence
of oxygen and methane gas. Around the world a relatively small
number of astronomers monitor radio and optical emissions
throughout the universe. They try to filter out the cosmic
noise and interference of satellites and spacecraft to find
anomalies that could represent life.
The search for life beyond Earth also inspires a new
generation of explorers. It motivates students to study math,
science, engineering, and computer science. Just a few months
ago, astronomers confirmed that Tom Wagg, a 15-year-old
student, discovered exoplanet WASP-142b, which orbits a star
approximately 1,000 light years away in the constellation
Hydra.
It is in our human nature to seek out the unknown and to
discover the universe around us. The stars compel us to look
upward and lead us from this world to another. Many Americans
often gaze into the beauty of the night sky in awe; some may
wonder if there is life beyond our pale blue dot.
I thank our witnesses and look forward to hearing their
testimony and particularly about recent developments in the
field of astrobiology and the search for life.
[The prepared statement of Chairman Smith follows:]
Prepared Statement of Committee Chairman Lamar S. Smith
Edwin Hubble once said: ``Equipped with his five senses, man
explores the universe around him and calls the adventure Science.''
There are few greater adventures than the search for life beyond Earth.
When the Hubble Space Telescope was launched in 1990, planets
around other stars had not yet been discovered. The only planets we
knew were those that orbited our Sun.
Since 1995, however, when the first extrasolar planet was detected,
the rate of discovery of new exoplanets and external solar systems has
been truly remarkable.
Today, with the Kepler Telescope, we have found nearly 2000
confirmed planets that orbit around other stars in our galaxy. Of
these, 306 lie within the habitable zone of the stars they orbit-where
water could exist-and 14 are almost the size of Earth.
Whether life exists beyond Earth, and if so, how humans can detect
it, is a critical question. If definitive evidence of life is found, it
may be the most significant scientific discovery in human history.
The search for life in the Universe is a priority of NASA and the
U.S. scientific community. Seeking habitable planets is one of the
three scientific objectives of the 2010 National Research Council
decadal survey on astronomy and astrophysics.
The United States pioneered the field of astrobiology and continues
to lead the world in this type of research. Since the space program
began, NASA has explored the cosmos for life beyond Earth and has
conducted scientific research that investigates this possibility.
NASA's astrobiology program continues these scientific endeavors to
improve our understanding of biological, planetary, and cosmic
phenomena. Just yesterday, NASA announced that it identified flowing
briny water on Mars.
This past April, NASA's Chief Scientist, Dr. Ellen Stofan, made
global headlines with her prediction that ``we are going to have strong
indications of life beyond Earth in the next decade and definitive
evidence within the next 20 to 30 years.'' I am glad Dr. Stofan has
joined us today.
Within our solar system, the question of whether life exists or
existed on Mars continues to capture the public imagination.In the past
year, NASA's Curiosity Rover made several major scientific discoveries
relevant to the search for life on Mars.
Curiosity measured a spike in levels of the organic chemical
methane in the local atmosphere of its research site. It also detected
other organic molecules in drill samples from a mudstone that once sat
at the bottom of a lake.
And Jupiter's moon, Europa, shows strong evidence of an ocean of
liquid water beneath its surface, which could host conditions favorable
to some form of life.
These instruments will help scientists investigate the chemical
makeup of Europa's potentially habitable environment.
Last July, astronomers, with the help of the Kepler Space
Telescope, confirmed the discovery of Kepler 452-b, the first near-
Earth-size planet in the ``habitable zone'' around a sun-like star.
This discovery marks another milestone in the journey to find another
``Earth.''
The Transiting Exoplanet Survey Satellite, which will launch in
2017, and the James Webb Space Telescope, which will begin in 2018,
will help scientists discover more planets with potential biosignatures
in their atmospheres--such as evidence of oxygen and methane gas.
Around the world a relatively small number of astronomers monitor
radio and optical emissions throughout the universe. They try to filter
out the cosmic noise and interference of satellites and spacecraft to
find anomalies that could represent life.
The search for life beyond Earth also inspires a new generation of
explorers. It motivates students to study math, science, engineering,
and computer science.
Just a few months ago, astronomers confirmed that Tom Wagg, a 15
year old student, discovered exoplanet WASP-142b, which orbits a star
approximately 1,000 light years away in the constellation Hydra.
It is in our human nature to seek out the unknown and to discover
the universe around us. The stars compel us to look upward and lead us
from this world to another. Many Americans often gaze into the beauty
of the night sky in awe, some may wonder if there is life beyond our
pale blue dot.
I thank our witnesses and look forward to hearing their testimony
and particularly about recent developments in the field of astrobiology
and the search for life.
Chairman Smith. And now I will recognize the gentlewoman
from Texas, Eddie Bernice Johnson, the Ranking Member, for her
opening statement.
Ms. Johnson of Texas. Thank you very much, Mr. Chairman,
and good morning. Let me welcome our distinguished panel of
witnesses today. I do look forward to your testimony.
I want to welcome Mr. LaHood to the Committee and simply
say that the first week of this month I visited the Curiosity
team in France, and the excitement is beyond measure.
Administrator Bolden stated in the preface of NASA's
Strategic Plan that ``when we explore the solar system and the
universe, we gain knowledge about the dynamics of the Sun and
the planetary system and whether we are alone.''
With respect to the question of whether we are alone, the
search for life beyond Earth is a topic this Committee has
devoted a lot of attention to over the past two years. I don't
know if we plan on taking up life somewhere else. I don't know
where our Chairman wants to go, but I'm interested in following
him.
I understand that the purpose of today's hearing is to get
another update on that topic. It is my hope that our witnesses
will also take some time to discuss how their research
activities can be used to help foster excitement in our young
people and spur them to pursue careers in science, technology,
engineering, and math. That's important because these young
people are the future science and technological leaders and
innovators who will be critical to our nation's growth and
progress going forward. While it's exciting to search for
intelligent life elsewhere in the universe, I hope we don't
neglect nurturing the intelligent life we have right here in
our country.
As a final note, I want to recognize that this is a return
visit by Dr. Lunine. One year ago he and Governor Mitch Daniels
testified before the Committee on their National Research
Council panel's report entitled ``Pathways to Exploration: A
Review of the Future of Human Space Exploration.'' And that was
completed pursuant to the NASA Authorization Act of 2010. I
highly recommend that our newer colleagues on the Committee and
in the rest of the Congress as a whole for that matter read
this report, as I found it to be objective in its endorsement
of the goal of sending humans to Mars and thoughtful in its
recommendations for an exploration program to send humans to
the surface of Mars, a central goal established by this
Committee in the House-passed NASA Authorization Act of 2015.
And with that, I again want to thank our witnesses and I
yield back. Thank you.
[The prepared statement of Ms. Johnson of Texas follows:]
Prepared Statement of Committee Ranking Member
Eddie Bernice Johnson
Good morning and welcome to our distinguished panel of witnesses. I
look forward to your testimony.
Administrator Bolden stated, in the preface of NASA's Strategic
Plan, that when we explore the solar system and the universe, we gain
knowledge about the dynamics of the Sun and the planetary system and
whether we are alone.
With respect to the question of whether we are alone, the Search
for Life Beyond Earth is a topic this Committee has devoted a lot of
attention to over the past two years. I understand that the purpose of
today's hearing is to get another update on that topic. It is my hope
that our witnesses will also take some time to discuss how their
research activities can be used to help foster excitement in our young
people and spur them to pursue careers in Science, Technology,
Engineering, and Mathematics.
That's important, because those young people are the future science
and technological leaders and innovators who will be critical to our
Nation's growth and progress going forward. While it's exciting to
search for intelligent life elsewhere in the universe, I hope we don't
neglect nurturing the intelligent life we have right here in this
country now.
As a final note, I want to recognize that this is a return visit by
Dr. Lunine. One year ago, he and Governor Mitch Daniels testified
before this Committee on their National Research Council panel's report
titled "Pathways to Exploration: A Review of the Future of Human
Exploration" that was completed pursuant to the NASA Authorization Act
of 2010.
I highly recommend that my newer colleagues on the Committee, and
in the rest of the Congress as a whole for that matter, read this
report as I found it to be objective in its endorsement of the goal of
sending humans to Mars, and thoughtful in its recommendations for an
exploration program to send humans to the surface of Mars--a central
goal established by this Committee in the House-passed NASA
Authorization Act of 2015.
With that, I again want to welcome our witnesses to today's
hearing, and I yield back.
Chairman Smith. I thank the Ranking Member for those nice
comments.
Let me introduce our witnesses. Our first witness is Dr.
Ellen Stofan, NASA's Chief Scientist. She serves as principal
advisor to NASA Administrator Charles Bolden on the agency's
science programs and science-related strategic planning and
investments. This is Dr. Stofan's second term at NASA, as she
recently held a number of senior scientist positions at the Jet
Propulsion Laboratory. Dr. Stofan is the recipient of the
Presidential Early Career Award for Scientists and Engineers.
She earned her bachelor's degree from William and Mary and her
master's and doctorate degrees in geological sciences from
Brown University.
Our second witness today is Dr. Jonathan Lunine, the
Director of the Cornell Center for Astrophysics and Planetary
Science at Cornell University, where he specializes in
astrobiology. Dr. Lunine has extensive experience in the search
for life on other planets. He worked as an interdisciplinary
scientist on the Cassini mission, which showed that one of
Saturn's moons may host micro-bio life, and on the James Webb
Space Telescope, which will study the origins of life in the
near future. Dr. Lunine received his bachelor's degree in
physics and astronomy from the University of Rochester and his
master's and Ph.D. in planetary science from the California
Institute of Technology.
Our third witness is Dr. Jacob Bean, Assistant Professor of
Astronomy and Astrophysics at the University Of Chicago. Dr.
Bean also is the leader of the Bean Exoplanet Group, which uses
telescopes to detect and characterize exoplanets. Dr. Bean's
work has used the Hubble and Spitzer telescopes to make
breakthroughs in astrobiology, which include the measurement of
the first spectrum of a super-Earth planet. Dr. Bean also
develops new instruments for exoplanet detection and
characterization and is helping to design the giant Magellan
telescope, which will soon be the world's largest telescope.
Dr. Bean received his undergraduate degree in physics from the
Georgia Institute of Technology and his Ph.D. in astronomy from
the University of Texas in Austin.
Our final witness today is Dr. Andrew Siemion. Dr. Siemion
is an astrophysicist at the University of California Berkeley
and served as Director of the U.C. Berkeley Center for Search
for Extraterrestrial Intelligence Research. Dr. Siemion's
research interests include studies of time variable celestial
phenomena, astronomical instrumentation and SETI, and Dr.
Siemion also is a leader of the Breakthrough Listen Initiative,
a ten-year, $100 million initiative to search for
extraterrestrial life that is possibly the most comprehensive
search for alien communications to date. Dr. Siemion received
his Ph.D. in astrophysics from the University of California at
Berkeley.
We welcome you all. You're clearly experts in the field.
And, Dr. Stofan, you begin.
TESTIMONY OF DR. ELLEN STOFAN,
CHIEF SCIENTIST, NASA
Dr. Stofan. Thank you. I'm pleased to appear before the
Committee to discuss astrobiology and the search for life
beyond Earth. If I could have the first slide, please.
[Slide.]
NASA's science missions are providing strong evidence of
possible habitable environments beyond Earth. With future
technology and instruments currently under development, we will
explore the solar system and beyond, and could indeed, perhaps
in as little as 10 to 20 years, discover some form of life,
past or present.
Our search is making amazing progress. When I was a Ph.D.
student, scientists certainly suspected that planets might be
commonplace in the universe, but we have not found evidence of
a single one. Twenty years ago, we found evidence of such a
planet, and today, thanks to NASA's space missions and ground-
based telescopes, we have identified nearly 5,000 planets
orbiting other stars, and we now believe that that the vast
majority of stars in the universe have planets around them. In
July, the Kepler mission confirmed the first near-Earth-size
planet in the ``habitable zone'' around a sun-like star,
Kepler-452b.
On Mars, a series of NASA missions culminating in the
Curiosity Rover, which touched down in Gale Crater nearly three
years ago, have allowed us to make fundamental discoveries.
Next slide.
[Slide.]
We now know that Mars was once a water world much like
Earth, with clouds and a water cycle, and indeed some running
water currently on the surface. For hundreds of millions of
years, about half of the northern hemisphere of Mars had an
ocean, possibly a mile deep in places.
Indeed, we now know that we live in a soggy solar system,
and undoubtedly, in a soggy universe. For instance, Jupiter
lies outside the habitable zone and we would expect water there
to be frozen. Yet we now have evidence of liquid oceans on
three moons of Jupiter under the icy crusts of those worlds.
And using the Hubble and Spitzer Space Telescopes, we have
found signs of water in the atmospheres of planets around other
stars.
So what lies ahead in the next decade of exploration? I'd
like to describe just some of the highlights. Life as we know
it requires water, liquid water, that's been stable on the
surface of a planet for a very long time. That's why Mars is
our primary destination in the search for life in our solar
system. The Mars 2020 Rover mission will study Martian rocks
and soils to understand past habitable conditions on Mars and
to seek signs of ancient microbial life. If we do find evidence
of life on Mars, it will likely be fossilized microorganisms
preserved in the rock layers. The Mars 2020 Rover will begin
the search, but as a field geologist, I can tell you it's going
to be hard to find. That's why I believe it will take human
explorers who can move quickly and make intuitive decisions on
their feet to really identify it, and in doing so, inspire that
next generation of explorers.
Over the next decade, our journey to Mars involves the
development of a commercial crew capability for low-Earth
orbit, the Space Launch System and Orion, to go beyond low-
Earth orbit and an asteroid redirect mission.
Beyond Mars, the President's fiscal year 2016 budget
request supports the formulation and development of a new
mission to the Jovian moon Europa. If I could have the next
slide.
[Slide.]
We estimate that Europa has twice as much water as the
Earth's oceans, and Hubble has observed plumes of water at one
of Europa's poles. A Europa mission could potentially, among
other things, analyze these water plumes to determine the
composition of those oceans.
Beyond our solar system, there are countless other worlds
that could harbor life. In 2017, NASA will launch the
Transiting Exoplanet Survey Satellite to look for rocky planets
near the habitable zone of the closest stars. Next slide.
[Slide.]
We will then use the James Webb Space Telescope to analyze
the atmospheres of some of these planets. The President's
fiscal year 2016 budget request also supports the pre-
formulation of a Wide Field Infrared Survey Telescope with the
capability of directly imaging planets around the nearest stars
and analyzing their atmospheres.
Since Earth remains, for now, the only instance of an
inhabited planet, the search for life also requires that we
further develop our understanding of life on Earth. Through our
research here, we have learned that life is tough, tenacious,
metabolically diverse, and highly adaptable to local
environmental conditions. Astrobiologists have discovered life
in numerous extreme environments and in extraordinary forms
from bacteria that consume chemicals that would be toxic to
most other life, to microbes that live under high levels of
radiation.
Perhaps even more interesting is the possibility that life
could exist in the absence of liquid water. That's why
scientists are interested in exploring some of the more unusual
places in our solar system and beyond, such as Saturn's moon
Titan, where it rains liquid methane and ethane. Could such an
environment harbor life? We don't know yet.
Ultimately, of course, the search for life is a
crosscutting theme in all of NASA's space science endeavors,
bringing together research in astrophysics, Earth science,
heliophysics, and planetary science. Astrobiology is guided by
a community-constructed roadmap generated about every five
years with the next roadmap slated for release later this year.
In addition, in April NASA announced the formation of an
initiative dedicated to the search for life on planets outside
our solar system. The Nexus for Exoplanet System Science is an
interdisciplinary effort that connects top research teams and
provides a synthesized approach in the search for planets with
the greatest potential for harboring life.
From research, to our knowledge of where to go and what to
look for, to the capabilities of finding it both within our
solar system and beyond, we are making great discoveries.
Thank you for the opportunity to testify today.
[The prepared statement of Dr. Stofan follows:]
[GRAPHICS NOT AVAILABLE IN TIFF FORMAT]
Chairman Smith. Thank you, Dr. Stofan.
Dr. Lunine.
TESTIMONY OF DR. JONATHAN LUNINE,
DAVID D. DUNCAN PROFESSOR
IN THE PHYSICAL SCIENCES, AND DIRECTOR,
CENTER FOR RADIOPHYSICS AND SPACE RESEARCH,
CORNELL UNIVERSITY
Dr. Lunine. Thank you, Chairman Smith, Ranking Member
Johnson, and members of the committee. Thank you for the
opportunity to present my views on the search for life beyond
Earth. These views are my own and they come from 30 years of
working in the field of planetary science at various
institutions in the United States and abroad.
One of the most important outcomes of the last two decades
of solar system exploration is the identification of four
bodies in our solar system that appear capable of harboring
life. These bodies possess a particular set of characteristics
that make them the best leads in the search for life beyond the
Earth. And if I could have the first slide, the first of these
bodies is Mars.
[Slide.]
In its first billion years, Mars had abundant liquid water,
stabilized and protected by a much denser atmosphere than the
tenuous shell we see today. During this time, life might have
begun, survived for a while on the surface, and then was
extinguished or retreated underground as the atmosphere was
lost. If I could have the second slide----
[Slide.]
The second of these objects is Jupiter's moon Europa. It's
a body the size of our own moon. It has a very large saltwater
ocean, twice the water that we have in our own ocean. This
ocean is in contact with a rocky core and abundant sources of
energy. As yet, we don't know whether organic molecules exist
inside of this ocean, but we strongly suspect that they are
there. Equally important, we don't know how far beneath
Europa's surface the ocean lies. Knowing that will allow a
strategy to be formulated for searching for life there.
[Slide.
Next slide is Titan, a Saturnian moon that's larger than
the planet Mercury and the only moon in our solar system to
host a dense atmosphere of nitrogen and methane. Cassini and
its lander Huygens have revealed methane clouds, rain, gullies,
river valleys, and methane/ethane seas, and so we cannot resist
asking whether some biochemically novel form of life might have
arisen in this exotic frigid environment. Titan is a test for
the universality of life as an outcome of cosmic evolution. To
quote the historian Stephen Pyne, ``What the Galapagos Islands
did for the theory of evolution by natural selection, Titan
might do for exobiology.''
[Slide.]
Finally, next slide, Enceladus has surprised us. This small
Saturnian moon has a large plume of material emanating from a
series of fractures in its south polar region. Make a list of
requirements for terrestrial-type life--liquid water, organics,
minerals, energy, chemical gradients--and Cassini has found
evidence for all of them in the plum of Enceladus.
So how do we actually find the signs of life in these
bodies? The evidence will not be entire living organisms. Much
more likely is that we will detect signatures that indicate
that life is at work or was at work in these environments. In
contrast to nonbiological processes, biology is built from a
very limited, selected set of molecules, and so if we can
recognize patterns in the makeup of organic molecules and their
isotopes, we then have strong evidence of biology at work.
At Mars, finding sources of methane and measuring their
isotopes is one way to get at this question. Another is to seek
well-preserved organic materials in the soil to see if they
record the signatures of biology. And the Mars 2020 Rover will
do the heavy lifting here.
For Europa, the Europa mission now in development will
provide the essential information needed to decide, among other
things, whether organics and water are welling up through the
cracks on the surface and whether plumes exist and can be
measured. Doing this mission, doing it now is absolutely
crucial to any general strategy for the search for life.
For Titan, the search to target one of the great methane/
ethane seas by dropping a capsule capable of floating across
the surface. We don't know what kind of biochemistry we're
looking for here and so a generalized search for patterns and
molecular structures and abundances that indicate deviation
from abiotic chemistry is appropriate.
And finally, Enceladus provides us with the most
straightforward way to look for life. Merely flying through the
plume of Enceladus, as Cassini has done multiple times, with
modern instrumentation intended to detect the signatures of
life, is sufficient to do the search.
The long flight times in the outer solar system in
particular dictate the planning for missions to Enceladus,
Europa, and Titan must begin now and must be pursued with vigor
if they're to happen in the next two decades. It is remarkable
that we have found four destinations in our own solar system
where life may actually exist or have existed for quite some
time in the past and now is the time to actually go search for
the life.
Thank you.
[The prepared statement of Dr. Lunine follows:]
[GRAPHICS NOT AVAILABLE IN TIFF FORMAT]
Chairman Smith. Thank you, Dr. Lunine.
And Dr. Bean.
TESTIMONY OF DR. JACOB BEAN,
ASSISTANT PROFESSOR,
DEPARTMENTS OF ASTRONOMY
AND ASTROPHYSICS, GEOPHYSICS,
UNIVERSITY OF CHICAGO
Dr. Bean. Mr. Chairman and Members of the Committee, good
morning, and thank you for the opportunity to serve as a
witness for this important hearing.
My testimony today will be focused on the topic of
exoplanet spectroscopy in the context of the search for life
beyond Earth. The main point I want to convey is that an
expanded exoplanet exploration program with a flagship
exoplanet spectroscopy space telescope as its centerpiece could
answer one of humanity's most fundamental questions: Is there
life elsewhere in the universe?
Extrasolar planets, or exoplanets for short, are planets
outside our solar system that orbit stars other than our Sun.
This year marks just the 20th anniversary of the first
detection of an exoplanet orbiting a sun-like star, but
progress in the field has been rapid in the intervening years.
In particular, the launch of NASA's Kepler telescope in 2009
has revolutionized the field. The Kepler mission has advanced
to the point that it is now focused on finding Earth-size
planets orbiting their host stars in the so-called ``habitable
zone,'' which is the distance at which the temperature on the
surface of a terrestrial planet could be right for liquid water
to be present.
A handful of Earth-size habitable-zone exoplanets have been
found over the last few years. These discoveries have grabbed
the attention of the scientific community and the public
because they suggest that Earth-like planets may exist around
relatively nearby stars, and that we therefore have it within
our grasp to search for life on other worlds in our lifetimes.
The next step towards determining if there are any truly
habitable planets or even inhabited planets is to study the
atmospheres of candidate worlds using the technique of
astronomical spectroscopy. Planetary atmospheres are a key
factor controlling the habitability of a planet because they
are reservoirs of biogenic elements and regulators of planetary
surface conditions. Furthermore, planetary atmospheres can be
influenced by interactions with a biosphere, and thus may be a
marker of life itself absent direct observation or
communication.
Astronomers have made progress revealing the nature of the
atmospheres of hot, gas giant-type exoplanets using the Hubble
and Spitzer Space Telescopes and the ground-based Keck and
Gemini telescopes. These investigations have yielded
constraints on the abundances of key chemical species, the
identification of clouds, and the determinations of temperature
maps.
Astronomers eagerly await the launch of the James Webb
Space Telescope in 2018. Among its many new important
capabilities, the Webb telescope will dramatically extend the
reach of exoplanet spectroscopy. It may even have the
capability to determine the presence of major molecules like
water and carbon dioxide and measure the temperatures of Earth-
size exoplanets atmospheres. However, Webb will be hard-pressed
to detect evidence for life, only made possible with fortuitous
planets, extraordinary performance of the instrument, and large
amounts of biosignature gases in the planets themselves.
A flagship space telescope with next-generation optics will
likely be needed to detect evidence for life on other Earth-
like exoplanets. The astrophysics community is currently
ramping up for a Decadal Survey that will prioritize large
space missions to follow the Webb telescope.
At the wise urging of NASA leadership, the community is
currently developing concepts for telescopes that could take
spectra of Earth-like exoplanets in preparation for the decadal
selection process. The top-priority space telescope from the
previous Decadal Survey, currently dubbed WFIRST-AFTA will have
capabilities that lay a foundation for a future life-finder
telescope. One of the science goals of the WFIRST-AFTA mission
is to obtain improved statistics on the frequency of
potentially habitable planets. In addition, NASA is currently
considering including an exoplanet spectrometer on the
telescope. This instrument would not have the capability to
make measurements for Earth-like planets but it would advance
the science and technology in that direction.
As a final point, it is important to keep in mind that a
future life-finder mission cannot be a success in the absence
of other projects. The need for comprehensive knowledge to
confront the question of life on other planets is why I think
that ultimately an expanded program in exoplanet exploration
would be the best way forward. Although a flagship space
telescope would be the crown jewel, this program should be
driven by the question of life rather than the construction of
a single facility. It would take courage and perseverance by
scientists, government leaders, and the public all working
together to act on this vision and see it through, but our
ability to rise to this kind of challenge is what makes America
exceptional.
From the Apollo program through the Voyager, Hubble, and
Mars Rover programs, with the recent stunning success of the
New Horizons mission to Pluto, and today with the launch of the
Webb telescope just a few years away, our country leads the way
in projects that are lasting milestones of space exploration.
The search for life beyond our planet represents the next great
space exploration challenge that would continue this legacy.
Mr. Chairman and members of the committee, thank you again
for the opportunity to be here as a witness, and I'd be happy
to take questions.
[The prepared statement of Dr. Bean follows:]
[GRAPHICS NOT AVAILABLE IN TIFF FORMAT]
Chairman Smith. Thank you, Dr. Bean.
And Dr. Siemion.
TESTIMONY OF DR. ANDREW SIEMION,
DIRECTOR, SETI RESEARCH CENTER,
UNIVERSITY OF CALIFORNIA, BERKELEY
Dr. Siemion. Chairman Smith, Ranking Member Johnson, and
Members of the Committee, thank you for the opportunity to
testify today.
Searches for Extraterrestrial Intelligence, SETI
experiments, seek to determine the distribution of advanced
life in the universe through detecting the presence of
technology, usually by searching for electromagnetic radiation
from communication technology, but also by searching for
evidence of large-scale energy usage or interstellar
propulsion. Technology is thus used as a proxy for
intelligence. If an advanced technology exists, so, too, does
the advanced life that created it.
We know of no way to directly detect intelligent life, but
if other intelligent life exists and possesses a technological
capability similar to our own, we could detect their technology
using the techniques of modern astronomy. Large radio
telescopes such as the Green Bank Telescope in West Virginia
and the Arecibo Observatory in Puerto Rico are superb
facilities for a wide range of astronomy, including pulsar
studies that test Einstein's theory of general relativity,
mapping the gas in nearby galaxies, and probing the earliest
epochs of the universe. In addition, these facilities are among
the world's best in searching for the faint whispers of distant
technologies.
A variety of radio study experiments are underway at both
the Green Bank Telescope and the Arecibo Observatory, including
some that allow us to observe in parallel with other
astronomers without interfering with their work, a technique we
call ``piggyback observing.'' Several other U.S. and
international radio telescopes are also currently being used
for radio study, including the private Allen Telescope Array in
northern California, the Low-Frequency Array in Europe, and the
Murchison Widefield Array in Australia.
Many radio study searches are taking advantage of the
wealth of new information on our galaxy's exoplanet population
now being revealed by missions such as NASA's Kepler
spacecraft.
In a very exciting new project, a group based at the
University of California San Diego are using the Lick
Observatory near San Jose to conduct a search for pulsed lasers
in the near-infrared, wavelengths just a hair longer than
optical light but much better at penetrating the dusty space
between the stars.
These SETI experiments are funded by a combination of
government and private sources, including notable contributions
from the John Templeton Foundation. Ensuring that facilities
like the Green Bank Telescope, Arecibo, and the Lick and Keck
Observatories continue to exist as world-class astronomical
facilities is critical to their continued use in SETI
experiments.
One of the most exciting prospects for SETI in the next
decade is the Breakthrough Listen initiative, a $100 million,
ten-year effort funded by the Breakthrough Prize Foundation
that will conduct the most sensitive, comprehensive, and
intensive search for advanced intelligent life on other worlds
ever performed.
I have an animation I would like to show you illustrating
some components of Breakthrough Listen.
[Slide.]
Here, we see the Milky Way Galaxy, a galaxy that we now
know hosts tens of billions of planets in the habitable zone of
their star, planets that might have liquid water on their
surface. If intelligent life arose on some of these planets and
developed radio technology, the emissions from their technology
would proceed at the speed of light out into the Milky Way. But
for how long? Life may arise, it may develop intelligence, and
finally, a communicative technology. But that final stage may
only last for a few thousand years. But the evidence of their
technology, the bubble of their electromagnetic radiation, will
continue to propagate throughout the galaxy and could
eventually be detectable at the Earth.
With Breakthrough Listen, we will conduct deep observations
for these types of emissions from 1 million of the nearest
stars to the Earth that will be at least 10 times more
sensitive than ever performed. These observations will cover at
least five times more of the radio spectrum than any previous
experiment. We will conduct these observations using the Green
Bank Telescope in West Virginia, as well as the Parkes Radio
Telescope in Australia.
It is undoubtable that the next decade will be an
incredibly exciting time for astrobiology. Data provided by
missions like the Transiting Exoplanet Survey Satellite and the
James Webb Space Telescope virtually guarantee dramatic new
insight into exoplanet science, including identifying and
characterizing some of the nearest exoplanets to the Earth. At
the same time, we will continue to learn more about the
development of life on Earth and the potential for life
elsewhere in our own solar system. If history is any guide,
these discoveries will only heighten our imagination about the
possibilities for advanced life elsewhere in the universe.
Thank you.
[The prepared statement of Dr. Siemion follows:]
[GRAPHICS NOT AVAILABLE IN TIFF FORMAT]
Chairman Smith. Thank you, Dr. Siemion.
As you might guess, we all have thousands of questions and
we're somewhat limited in our time by five minutes, but, Dr.
Stofan, I'd like to address a couple of questions to you.
One, I am absolutely astounded by the announcement by NASA
that briny water may be on the surface of Mars. Is that the
case? When the Mars Curiosity Rover reported no evidence of
water, I thought that was the end of it, but if we have this
water on the surface of Mars, why is it we do not have any
photographs of that water?
Dr. Stofan. Indeed, the new results that we just got show
that the recurring slope lineae, these features that are on the
sides of some craters on slopes, seasonally over time it seems
that water melts----
Chairman Smith. Right.
Dr. Stofan. --briny water carries those materials down
slope, and we've finally been able to put all the evidence
together, including chemical observations, to say, okay, that's
really what's forming these things, which we're incredibly
excited about.
The problem is these features are very transient. There's
not a whole lot of water that's carrying those salts and so
it's very hard to see with the resolution of spacecraft that we
see. But again, we can certainly trace of the chemical
signatures.
We also, at the Phoenix landing site, were able to see the
evidence of liquid water, including a little droplet on the
spacecraft. So, you know, water is there on Mars. It's not in
huge abundance right near the surface but we know it's at the
poles, we know it's under----
Chairman Smith. When will we have evidence of liquid water?
Anytime soon?
Dr. Stofan. I'm afraid I can't answer exactly when will
have--we feel that the evidence we showed yesterday is
certainly good evidence of liquid water, but you have to
understand that those water--when it's flowing on the surface,
it's very, very hard to detect.
Chairman Smith. Okay. Thank you.
Next question is where are we in your opinion most likely
to detect any kind, any form of life, even if it's bacteria or
microbes or whatever? Is it going to be Mars? Is it going to be
Europa? Is it going to be an exoplanet? Is it going to be some
technological communication? Where do you think the best
prospects lie?
Dr. Stofan. Well, I certainly believe that it's going to be
Mars, and I think, as you heard from me and you heard from Dr.
Lunine, we're very optimistic about the 2020 Rover and its
potential for looking for signs for ancient microbial life.
Now, again, that's----
Chairman Smith. Okay.
Dr. Stofan. --not the most exciting in a lot of people's
terms to find fossilized microbes, but that's--or the
signatures----
Chairman Smith. Yes.
Dr. Stofan. --that those microbes existed, but I'm really
optimistic, but again, I think it's going to take humans on the
surface of Mars to really get at the definitive evidence to
study that liquid water----
Chairman Smith. That we're talking about.
Dr. Stofan. --that we want to see.
Chairman Smith. Okay. Thank you, Dr. Stofan.
Dr. Lunine, how would you rank the various--you--let me
start again. You mentioned four locations: Mars, Europa, Titan,
and Saturn--one of Saturn's moons Enceladus. Was that in order
of likelihood or do you have a preference or a prediction as to
where we might most likely find evidence of some form of life?
Dr. Lunine. Well, that was actually in order moving outward
from the Sun----
Chairman Smith. Oh, okay.
Dr. Lunine. --so there was no implied--or, you know, the
question is whether in any environment that can support life
does life actually begin, does it form? And I don't know the
answer to that and no one else does----
Chairman Smith. Okay.
Dr. Lunine. --and that's why in my view we need to look at
all of these bodies where there is very strong evidence,
compelling evidence of what's called a habitable environment,
an environment where life could actually be sustained. So----
Chairman Smith. And when we find out what the thickness of
the ice is on Europa, that's the time to send a probe there I
gather?
Dr. Lunine. Yes. There's a lot of ground work that has to
be done on Europa. We don't know if there are organic
molecules.
Chairman Smith. Okay.
Dr. Lunine. The Europa mission will tell us whether there
are fresh organics in the cracks.
Chairman Smith. Okay.
Dr. Lunine. If there are, that would be the place to go.
Chairman Smith. Thank you. Dr. Bean, when do you think we
will have the capability of detecting biosignatures in the
atmospheres of exoplanets?
Dr. Bean. Yeah, so as I mentioned, I think the James Webb
Space Telescope, which is planned to launch in 2018, will be
our first chance----
Chairman Smith. Right.
Dr. Bean. --to do that. If we get lucky and we find the
kind of planets orbiting very nearby stars, then we may be able
to search for biosignature gases----
Chairman Smith. With James Webb?
Dr. Bean. Yes.
Chairman Smith. And not before? You think it's going to
take----
Dr. Bean. Definitely not before.
Chairman Smith. Okay. I'm going to ask you also what do you
think the odds are of actually finding a biosignature, say, in
the next ten years. Well, let me ask you, likely or unlikely?
Dr. Bean. I'd say that's unlikely, but we are optimistic
that we can take----
Chairman Smith. You can say----
Dr. Bean. --important steps towards doing that over the
next 10 years.
Chairman Smith. Okay. Thank you. Dr. Bean, I was hoping
you'd be a little bit more optimistic than that, but anyone
want to give a one out of three, one out of four? What would
you say?
Dr. Bean. One out of five.
Chairman Smith. One out of five, that's better than
otherwise. Okay. Thank you, Dr. Bean.
And, Dr. Siemion, last question for you. Could you briefly
tell us the advantages and disadvantages of radio and optical
astronomy? I know we're trying both. You seemed to focus a
little bit more on radio in your comments, but there's
advantages and disadvantages to both, and do you have a
preference or not, and if so, what are the advantages and
disadvantages?
Dr. Siemion. Yeah, I think you're absolutely right that
historically SETI has concentrated on the radio portion of the
electromagnetic spectrum.
Chairman Smith. Yeah.
Dr. Siemion. But as we've developed technology on Earth
that allows us to communicate at optical wavelengths, we've----
Chairman Smith. Yes.
Dr. Siemion. --moved some of our efforts in SETI to those
wavelengths as well. The truth is is that we don't know what
part of the electromagnetic spectrum we might eventually
receive, some signal or some evidence of a technological
civilization elsewhere. So it behooves us to search as much of
that spectrum as we can, and that's why we focus on both the
radio and the optical.
Chairman Smith. Okay. Thank you, Dr. Siemion.
My time is expired but, Dr. Bean, just a quick comment. You
know that 20 percent is actually pretty high considering how
historic that would be, and I think we all would agree it might
be the most interesting news in, say, the last 100 years, so
that 20 percent is something I think is not insignificant. So I
appreciate your comments.
The Ranking Member, the gentlewoman from Texas, is
recognized for her questions. And let me say, going back to her
opening statement, that it's not often that the Chairman hears
the Ranking Member say she's going to follow the Chairman, so I
just wanted to----
Ms. Johnson of Texas. If you go to Mars.
Chairman Smith. All yours.
Ms. Johnson of Texas. Thank you very much, Mr. Chairman.
Dr. Lunine, today, we are speaking primarily about
astrobiology that can be carried out robotically. However,
humans will one day return to deep space and carry out
scientific exploration on bodies such as Mars. To that end, it
has been over a year since the National Academies released the
Pathways to Exploration study, which you co-authored. That
report found that the horizon goal for human space exploration
is Mars, and as you may know, this Committee agrees with that.
Has NASA been in discussions with you on the results of that
report? And if so, what is the status of the response of that
report and how can this Committee be helpful?
Dr. Lunine. Well, the NASA Advisory Committee did actually
have a session at one of their meetings on the subject of our
report, and one of our committee members, Mary Lynne Dittmar,
was there and had a dialogue with the committee and also folks
from NASA, including Bill Gerstenmaier. So I think there's some
dialogue and thinking going on. I look forward to having more
dialogue with NASA on the report. I think it's still very fresh
and has a lot to contribute to the question of how and when
humans will move beyond low-Earth orbit, and so I look forward
to that dialogue.
Ms. Johnson of Texas. Good. In your view, what if any of
the issues does this Committee and the Congress need to
address?
Dr. Lunine. In the context of that report?
Ms. Johnson of Texas. Yes.
Dr. Lunine. Well, you know, to quote from that report, we
were concerned about the question of flight rates in the near
term and the question of how the destinations or pathways might
be chosen, and I still think those are the key operative
elements in the recommendations from our report.
Ms. Johnson of Texas. Thirty years from now, elementary
school children will be leading the scientific exploration of
the solar system and beyond. Our knowledge of other bodies near
and far will have changed. Humans may have visited Mars and
even the two of us here in this Committee won't be around. But
life beyond Earth may have been detected by then. So I would
like to ask all the panel members, as we think about where we
are today and where we might be 30 years from now, is there
anything that Congress should be considering to ensure that
today's schoolchildren are well-equipped to lead a new era that
can include knowledge of life beyond Earth?
Dr. Stofan. I'm a strong believer that NASA plays an
incredibly important role in inspiring the next generation. And
Charlie Bolden loves to say that everything we do at NASA is
about STEM education. Every time we launch a rocket, every time
we do something like encountering Pluto, we are inspiring the
next generation to want to explore, to question why. And I
would like to see NASA stay on the steady course we have been
with obviously this Committee's support to continue that
exploration and move forward with moving humans out beyond the
low-Earth orbit.
Dr. Lunine. This nation has done some incredible things in
exploring the solar system. One example that excites school
kids is the Cassini spacecraft can actually probe the large
methane seas of Titan and determine their depths and their
composition by sending radio signals through those seas as it
flies by Titan. And so we're actually doing ocean exploration a
billion miles away from the Earth, and that's only one example.
School kids are fascinated by that. They want to be a part of
it. And in order for them to be a part of it, we have to have
continuity in exploration. We have to continue these wonderful
missions so that there isn't effectively a generation-long gap
in these discoveries.
Dr. Bean. To get back at Chairman Smith's earlier question
about putting a number on the chance of finding life, I want to
emphasize that scientific process is a step-by-step, deliberate
process, and so being able to maintain, like Jonathan said, a
continuity in funding these programs and continuing this
deliberate approach I think is extremely important.
Dr. Siemion. I think the only thing that I have to add to
what my other panel members have said is is that the search for
life I think has a particularly compelling aspect to it for
young people, and I think to the extent that that can be
highlighted and taken advantage of to encourage more young
people to enter careers into space and science and technology
is wonderful.
Ms. Johnson of Texas. Thank you very much. My time is
expired.
Chairman Smith. Thank you, Ms. Johnson.
The gentleman from Texas, Mr. Babin, the Chairman of the
Space Subcommittee, is recognized for his questions.
Mr. Babin. Yes, sir. Thank you, Mr. Chairman. And welcome
all of you panelists. We appreciate and it's very, very
fascinating to hear your testimony.
In my district, Texas 36, the Johnson Space Center
Astromaterials Curation facility provides the services for all
return planetary materials that do not require planetary
protection laboratories. This facility has been in operation
since the Apollo lunar samples were returned. In the next
decades we anticipate missions to collect samples from the
Moon, from Mars, from comets, and from asteroids. Each of these
new sample collections will require new curation laboratories
while the facilities for the older collections will require
routine maintenance and upgrades.
Samples to be returned from Mars pose even greater
challenges due to special planetary protection requirements.
Dr. Stofan, what steps is NASA taking to upgrade its curation
facilities and protect against the transfer of viable organisms
from Earth to celestial bodies, which may harbor life?
Dr. Stofan. We have two different committees at NASA,
certainly, the Planetary Protection Group where we take these
issues extremely seriously both for forward contamination of
Mars and the backward contamination for when we eventually
return samples to the Earth. So that's one aspect of where we
are certainly doing research. We're doing testing of all our
Mars spacecraft in the planetary protection area.
We also have another group where we reach out into the
community and bring experts in to advise us on our curation. I
had the opportunity just this past year to tour the facility
down at Johnson. It's extremely--it's an amazing facility. It's
really fun to be able to go there and look at the Apollo lunar
samples, the meteorites we've returned from Antarctica. And we
take that facility, its preservation, and its eventual
expansion as we move eventually towards bringing samples back
from Mars. So we certainly work closely with the community to
understand what is needed and to make sure we will eventually,
when we do return samples from Mars, we will have a plan in
place.
Mr. Babin. Thank you very much.
And this is directed to everyone. What proportion of
astrobiology research in the United States is funded directly
or indirectly by NASA? Does anyone know? Okay.
Dr. Stofan. No. We at NASA can certainly take that question
for the record.
Mr. Babin. Um-hum.
Dr. Stofan. I will say I was just talking with someone a
few weeks ago. I was at a conference at Ames Research Center
where we were thinking about climate on extrasolar planets, and
it's one of the reasons, as I mentioned in my testimony, that
this whole area of astrobiology is an amazing one and it
actually makes me think it'll be a little hard to pull the
number out. We can certainly get you a number on the exact
funding--
Mr. Babin. Okay.
Dr. Stofan. --but when you're thinking about, for example,
habitable conditions on stars, you have to be doing
heliophysics to understand stars, the wind--that solar wind,
the interior of the planet, does it have a magnetosphere that
then protects that atmosphere from being stripped away? The
work we do here on Earth to understand extremophiles, planetary
science, we're pulling from so many disciplines, which is to me
what makes this area of science in particular so incredibly
exciting and fruitful. It's truly interdisciplinary.
Mr. Babin. Absolutely. Okay. And also what are the most
important technological advancements that are needed to further
astrobiology research and what advancements should be our
highest priority to continue this?
Dr. Lunine. Well, I'll take one crack at this. And I don't
want to prioritize these, but one in my area is to develop
miniaturized instrumentation that can detect the chemical signs
of life and also detect biological activity. The smaller the
instruments, the easier it's going to be to send them to the
planets.
Dr. Bean. From the standpoint of studying exoplanets, I
talked in my testimony about building a very large space
telescope as a flagship mission. That's a very high-tech thing
that we have to do to take direct images of planets that we can
take spectra from and look for the signatures of biosignature
gases. That involves the construction of large space
telescopes, rockets to put those telescopes into orbit,
instrumentation to block the blinding glare of the stars those
planets orbit, and perhaps even the manned spaceflight program
to service those telescopes or even construct the telescopes in
orbit.
Mr. Babin. Thank you.
Dr. Siemion. I think in the search for extraterrestrial
intelligence, the low-hanging fruit is very much digital signal
processing technology, so improving our ability to process the
very, very high data rate streams that are produced by radio
telescopes and some optical telescopes, and also developing
receiver technology for radio telescopes that allow us to use
old facilities in new ways.
Mr. Babin. Right, thank you. Mr. Chairman, I yield back the
balance of my time. Thank you, panelists.
Chairman Smith. Thank you, Mr. Babin.
The gentlewoman from Connecticut, Ms. Esty, is recognized
for her questions.
Ms. Esty. Thank you, Mr. Chairman, and thank you, Ranking
Member Johnson, for holding today's fascinating hearing. And
thank you to all of you.
I joined millions of Americans on Sunday night watching the
Blood Moon and a Blue Moon earlier this year, and I have to
tell you, in the district like mine in Connecticut,
schoolchildren are incredibly inspired and excited by these
developments. And many of us here on this panel share a
commitment to STEM education. And so it's in part through that
lens I would like to proceed with my questions.
Congratulations, Dr. Stofan, incredibly exciting
announcement yesterday. And we look forward to understanding
what that means. And as you can hear, we've already had
questions today.
Dr. Stofan, you spoke earlier about the need to have human
exploration on Mars to really understand and to make those
subtle intuitive judgments that are necessary. Do you
anticipate that yesterday's announcement and the discovery
proceeding that changes in any way the priorities of the
ordering of that? And help us understand our role as decision-
makers on helping to set priorities that are keeping up with
the developing science.
Dr. Stofan. You know, I think one of the most exciting
things about yesterday is the fact that we now know there's
near-surface liquid water on Mars. And so this idea that
Jonathan Lunine mentioned in his testimony of--you know, again,
because of this length of water--time that we know that water
was stable on Mars, that's what makes scientists think that
Mars is the place where life maybe could have evolved because
not only did you have liquid water but you had the time to
allow the chemical reactions to take place.
The exciting thing about knowing there's near-surface water
is saying maybe there could still be life forms on Mars today
deep underground, several meters below ground where the cosmic
radiation that affects Mars would not affect them, but the idea
that it's potentially accessible to be studied by, again,
astronauts and laboratories on the surface of Mars. And again,
as a field geologist, somebody who likes to go out in the field
and crack open rocks, I just have this strong bias that it's
going to take humans, laboratories a lot of work because,
again, when you're--it's one thing if you're looking for
something large. If you're looking for something small, it's
going to take time and it's going to take effort, and that's
why I think humans are so critical. And that's why NASA has
chosen to be on this path. And I think the findings from
yesterday convince us we're on the correct path.
Ms. Esty. Thank you. And I have to confess I have a son who
did astrophysics and did exoplanet things, so I have a
personal--I know he has a personal interest in discovering if
this manned mission is going to keep up with his fourth-grade
project from, you know, about 15 years ago.
Dr. Lunine, I was particularly struck by your comment that
a key issue is whether in a habitable environment life actually
does develop, which is sort of the opposite of where we start.
We started with this search is there any life out there, and
now it seems to me you're asking a very different question,
which is we see a lot of components that we would think ought
to lead to life; does it lead to life or does it not? What are
the technological breakthroughs you see us needing to support--
to answer that somewhat different question? It seems to me
that's a different question than I certainly would have thought
about five years ago.
Dr. Lunine. Well, it's a different question but it's a
related question. We really have no laboratory model for how
life began on the Earth. No one has done this in the
laboratory. And so one of the reasons for going out to
environments in our solar system where the conditions for life
are apparently there and possible is to see whether life
actually began, essentially to do the experiment in the field
instead of in the laboratory. And the critical things we need
for that are devices to analyze abundances of amino acids,
fatty acids, to look for patterns in other molecules that might
be part of an exotic biochemistry, for example, on Titan.
Part of the problem is that it's not entirely clear what we
want to look for in some environments. In other environments
like Mars, Europa, Enceladus it's very clear what we want to
look for. So chemical analysis is critical and the ability to
get out to these planets and sample planets and moons and
sample them is also critical.
Ms. Esty. Thank you. And if we might be able to follow up
afterwards with some more detail because, again, our job is in
part to try to set funding priorities and they need to take
into account these changes, so I think, Dr. Stofan, your
comments about the near-surface presence of water compared
with, say, Europa where it's so deep and that presents harder
technological challenges may help guide us with the--as I'm
afraid we have to say the not-enough money that we have to do
this research. I wish we had more, but with what we have, we
want to make sure it has the most impact and rely on your
judgment in guiding us. Thank you all very much.
Chairman Smith. Um-hum. Thank you, Ms. Esty.
The gentleman from Louisiana, Mr. Abraham, is recognized.
Mr. Abraham. Thank you, Mr. Chairman.
I'm one of those teenagers that rushed home to see the
original Star Trek with William Shatner and Leonard Nimoy, so
this is fascinating. Like the Chairman said, we have a million
questions.
Dr. Stofan, like you, I'm of the opinion you're going to
have to have boots on the ground so to speak to finally answer
the questions. So let's bring it a little bit closer to home.
You referenced the possible meteor asteroid in Antarctica. I'm
assuming you're referencing the Allan Hills meteor back in,
what, '84 I think it was when it was discovered.
And if we go to a synthetic biology topics such as XNA as
opposed to DNA, RNA, would our funding be more appropriate in a
realistic term as to funding projects in that realm as opposed
to, you know, something that maybe 100 years off as far as time
travel or space travel is concerned?
Dr. Stofan. Well, I certainly think that this is a multi--
as I said, it's a so interdisciplinary that you really need a
multipronged approach. And so I think that's what NASA has
developed by saying we do need boots on the ground. I
personally think it's achievable that we meet the President's
goal of getting humans in the Mars vicinity in the 2030s. I
think it's completely doable. And in the meantime of course
continuing our robotic exploration like we're doing with the
Mars 2020, moving with the Europa mission to go and explore
Europa.
So I don't think it's an either/or; I think it's an
``and.'' We need to do the technology research here on the
ground. We need to do biological research, and certainly
synthetic biology is an amazing expanding field at this point
in time. But I think it's all of those things together that
help us move forward scientifically and help us refine
scientific questions as we move forward.
Mr. Abraham. And you've got DARPA, you've got USAR MED
you've got NASA, you've got all these agencies looking for
other life forms, doing research on genetic engineering and
those types of deals. Is there any one agency that is
spearheading or that these other agencies report to? Is there
any hurding of the cat so to speak where this research can come
under one big umbrella and people talk to other agencies and
actually come up with some formulations?
Dr. Stofan. Well, I think in the area of astrobiology this
is why community roadmaps like the Astrobiology Community
Roadmap that is coming out this year--because in my mind, going
to the community, whether it's through the Decadal Survey
process through the Academies, the astrobiology roadmap is
going out to the community, who--in general, the scientists
know where all the funding streams are coming from. They're the
ones who are truly pulling and doing this multidisciplinary
work. So when you get the community together and say here are
the priorities, here are the areas that we think have the most
potential for advancement in the next five to ten years, it's
that voice of the scientific community that I think helps
guide----
Mr. Abraham. But is there one voice at this point or is
anybody at the top of the heap so to speak?
Dr. Stofan. In astrobiology I would argue that NASA is
really guiding what we're doing and what the next steps are. We
certainly work closely with other agencies, though.
Mr. Abraham. Does NASA have any rules or regulations that
they foresee that would limit or harness this potential
breakthrough? I mean I could see where with what we have
available even now with some of the genetic engineering that,
you know, some of this stuff could turn out to be kind of bad
stuff.
Dr. Stofan. We certainly don't have any regulatory
authority but I'd have to take that question for the record
because I don't know the answer to it.
Mr. Abraham. Okay. Thank you.
Dr. Lunine, just a quick comment on what you had spoken
with the Congressman earlier about potential life developing in
an environment. Just a personal question: What is your theory
on panspermia, the bringing of life forms into our Earth
atmosphere on an asteroid or meteor?
Dr. Lunine. I think that panspermia has occurred certainly
between the Earth and Mars. We know that materials are
exchanged between those two planets. We have the Allan Hills
meteorite. And there are some good studies that have been done
that show that amino acids will survive the trip to the Earth
through the atmosphere on an asteroid and possibly bacteria as
well, so there may well have been extensive exchange of life
and biological materials between the Earth and Mars,
particularly in the early history of the solar system when
impacts were more frequent.
Mr. Abraham. Okay. Thank you, Mr. Chairman. I yield back.
Chairman Smith. Thank you, Mr. Abraham.
The gentleman from Virginia, Mr. Beyer, is recognized.
Mr. Beyer. Thank you, Mr. Chairman. I thank all of you for
coming today. It's a fascinating hearing. Mr. Chairman, thank
you very much for structuring this. And I look forward to our
Science, Space, and Technology CODEL for low-Earth orbit. I'm
counting on you to assist me in this.
To go quickly, Dr. Siemion, you know, for years we had the
PCs at our home following SETI, doing the analysis of the work,
and it was fun. We have no successful conclusion yet. I'm
fascinated by the $100 million for the Breakthrough project.
But what happens when we discover extraterrestrial
intelligence? Do we have a plan about what happens next?
Dr. Siemion. Well, I'll just mention that--so SETI at home,
the program on PCs, is still around and you're all welcome to
download it. It runs on cellular telephones now, as well as
home PCs.
I think a lot of people have put a lot of thought into what
to do when we potentially eventually discover intelligent life
or any kind of life beyond the Earth. I think there will be a
range of reactions. I think for my part my personal opinion is
that probably the most common reaction will sort of be I sort
of--I told you so. I think many people probably believe that
life is out there and maybe even intelligent life, and
certainly the more we learn about the exoplanet population and
water on Mars and these kinds of things I think reinforced with
people the possibility. But the truth is is that we really
don't know for now, and I think to see what the reaction will
actually be we'll probably have to wait and see.
Mr. Beyer. It'd be interesting to have protocols in place
for when we finally get the breakthrough, what do we say back
and the like so--yeah.
And, Dr. Lunine, you talked about Titan and all the methane
and ethane and all that, and I sort of basically understand
that most elements only come from the explosion of stars, so
you'll get the carbon, but are methane and ethane--can they
develop other than biologically?
Dr. Lunine. Yes. Actually, methane is a very simple organic
molecule, and so it occurs in many environments, in
interstellar clouds, in--they're in comets. It's measured
there. And so these are evidently sources of methane that are
not from biology. It's simple to make in the laboratory, for
example, and carbon is very abundant, as you alluded to, as one
of the products of stellar nucleosynthesis.
So we think that Titan is--has an enormous inventory of
methane that is not biological, that was produced by abiotic
sources. And the ethane that is also part of that system was
produced from the methane, and that's something that Cassini
has confirmed for us by measuring the places in the atmosphere
where the ethane is produced from the methane by ultraviolet
chemistry. So Titan is a huge repository of abiotic methane.
Now, from those and other organic molecules, does some form
of life occur on the surface or arise in the seas of Titan?
That's the part we don't know.
Mr. Beyer. All right. Thank you.
Dr. Stofan, I think this is for you but maybe Dr. Lunine.
Dr. Abraham talked about the panspermia, and I know there was a
project that evolved out of Harvard or MIT a few years ago
trying to replicate the early origin of life on Earth, you
know, the primordial soup, organic soup thing. Is there much
evidence that--or any evidence that life on Earth may have
started someplace else?
Dr. Stofan. You know, we just don't know the answer to
that. You know, we know--what we do know is that life evolved
very rapidly here on Earth after conditions stabilized. And
again, that's a factor that makes us optimistic that there's
life elsewhere in the solar system knowing that life arose
relatively rapidly here.
But we honestly don't know if, again, did Mars--you know,
bacteria come from Mars, bacteria from Earth go to Mars? We
just don't know that, and that's why it's so critical we think
to continue this search for life on Mars, the other bodies of
our solar system to answer that very question.
Mr. Beyer. Great, thank you.
Dr. Bean, you're--it's fascinating your photos of Enceladus
and the fissure, and the--I was trying to--if you could go a
little deeper on--are those gases that are being released
from--through the fissure that----
Dr. Bean. So I think that would be more appropriately
addressed to Dr. Lunine if you want to--
Mr. Beyer. Okay. Was it--I'm sorry.
Dr. Lunine. Yeah, that's okay. I think it was my slide.
So----
Mr. Beyer. Okay, great.
Dr. Lunine. --in the case of Enceladus, those fissures at
the south pole have jets of gas and ice emanating from them,
and those jets merged to make this a very large plume that was
discovered by Cassini. We did not know of the existence of this
plume until the Cassini mission. And once the plume was
discovered, Cassini was directed to actually fly through the
plume multiple times and sample the material in the plume with
its instruments. One of the important lessons that we get from
this is that these flagship missions with large numbers of
instruments are able to respond very flexibly to new
discoveries. The instruments actually tasted the material in
the plume or designed it to sample the atmosphere of Titan, but
once the plume was discovered, Cassini could actually use those
same instruments to tell us what the plume is made of.
Mr. Beyer. Okay, great. Thank you very much. Chairman, I
yield back.
Chairman Smith. Thank you, Mr. Beyer.
The gentleman from Florida, Mr. Posey, is recognized.
Mr. Posey. Thank you, Mr. Chairman, and thank the witnesses
for their testimony today.
I just wonder if each of you would give me your definition
of life.
Dr. Stofan. I think it's a something the scientific
community really struggles with. You know, certainly there are
signs that everybody agrees on, you know, something that is
self-replicating, something that consumes a something and
excretes something else, but the problem is life here on Earth,
what we've learned from doing research here on Earth is that
life and the boundary of what's not life and what is life is a
little blurry, and that's why this is going to be so
challenging to go find life on other planets.
Dr. Lunine. Life is a self-replicating system that
undergoes evolution or mutation and which also seeks to
minimize its local entropy, maximize its order in the sense
that chemically we use a very small fraction of the possible
compounds that can be produced from carbon, and the fact that
we're alive is because we can take in large amounts of
nutrients, process them to make this very small, specific set
of molecules that build our structure, control energy in and
out, control the information needed to build these other
molecules, and then we expel the rest. So for me as--with my
physics background, it's a very high order, very low entropy in
a chemical system.
Dr. Bean. I would say that astronomers use a very basic
definition of life because the information that we can get when
we study the atmospheres of exoplanets will also be very basic.
And so we use a very Earth-centric, even human-centric point of
view for life, and that's the thing that we're looking for
evidence for in the atmospheres of other worlds.
Dr. Siemion. I guess there's some advantage to going last
on a question like that. I don't know that I have a lot to add
to what Dr. Stofan, Lunine, and Bean said. I certainly
appreciate the thermodynamic definition of life that Dr. Lunine
articulated. I guess maybe the only thing that I would add to
that is that I think many of us in the astrobiology community
assume that life is something that we'll know when we see it,
and hopefully that's true, but we're not sure. And it's quite
possible that the first life that we encounter beyond the Earth
will be very different than any kind of life that we have on
Earth.
Mr. Posey. Thank you. This question is for each of you. If
you could pick a mission, this person would say I want a
mission that will do this, achieve this, you know, what
particular type of mission would you choose?
Dr. Stofan. You know, I'm going to go with the geologists
on the surface of Mars looking--you know, cracking open lots of
rocks looking for life. That's my big payoff mission.
Dr. Lunine. So I would go with the Europa mission, and the
reason for that is we have so much tantalizing evidence that
Europa is a habitable environment but there are missing pieces,
including whether there are organics and where to actually go
search for life. And I personally--and I think we have been
waiting since 1998 for a mission to follow up on the Galileo
orbiter Discovery of the ocean under Europa. And so from my
point of view I think it's a critical mission to do and I would
make that my number one right now.
Dr. Bean. So I would like to see a large space telescope
that can take spectra of other Earth-like planets orbiting
nearby stars, something very similar to the previously proposed
and discussed Terrestrial Planet Finder mission, or TPF, which
you may have heard about. I think the advantage of studying
extrasolar planets is that we have a chance to look for--to do
an experiment so to say on how life arises on terrestrial
planets in a variety of environments. So that's what I would
like to see.
Dr. Siemion. I'm not sure what list I'm choosing from here,
but as a radio astronomer and someone interested in SETI, I
think it would--I'd be remiss to not suggest that it would be
wonderful to put a radio telescope on the far side of the Moon.
That region of the Moon is protected from radio frequency
interference from the Earth, something that confuses us in SETI
experiments and allows us to observe at very, very low
frequencies very effectively.
Mr. Posey. Y'all make the choices really tough, don't you?
Following up on the last answer, some people think because
we've been to the Moon, we shouldn't return to the Moon.
There's some--obviously some strategic reasons for going there
for future transportation as a steppingstone to Mars, but I'd
like to ask each of you your opinion of whether or not we still
have a lot to learn from our own Moon?
Dr. Stofan. I chaired the Inner Planets Panel for the last
Planetary Science Decadal Survey, and in--listed in the New
Frontiers collapse of missions is a mission to look at the
terrain around the south pole of the Moon where we think the
lunar mantle has come very close to the surface to help us
understand the origin of the Moon and what that tells us about
the origin and evolution of our own planet. So scientifically,
we certainly have lots of outstanding questions about the Moon
that the scientific community has articulated through the
Decadal Surveys.
Dr. Lunine. The Moon contains the geologic record of the
first 2 billion years of the history of the Earth, and that
record has been more or less lost on the Earth because the
Earth has been so active. And so that is for me the critical
aspect of the scientific value of the Moon. That's the time
when life began on Earth, and to understand what was happening
geologically, we can do no better than turn to the Moon.
Dr. Bean. I'd like to answer the question in terms of human
spaceflight. Dr. Stofan and Dr. Lunine, you gave great
scientific answers, but for me, if we can combine science with
the human element, I think that's a very powerful thing. That
will reach out to the public. That will excite our
schoolchildren to follow math and science, and so for me that's
an exciting ``yes'' to that question.
Dr. Siemion. I think I would agree with Dr. Bean. I think a
manned mission to the Moon would be a wonderful steppingstone
to future missions to perhaps Mars.
Mr. Posey. I want to thank y'all again for your testimony.
It's really been wonderful and I think everyone enjoyed it.
Thank you, Mr. Chairman.
Chairman Smith. Thank you, Mr. Posey.
The gentleman from California, Mr. Bera, is recognized for
his questions.
Mr. Bera. Thank you, Chairman, and Ranking Member. And I
really want to thank both the Chairman and Ranking Member for
this topic. You know, it comes at a very timely time--and the
witnesses.
You know, as a child growing up in Southern California at
the heart of the aerospace industry in the '60s and '70s, you
know, the space race captivated us, the Apollo missions,
Apollo-Soyuz, Skylab, going to the space shuttle. And, you
know, as someone who went into the sciences and became a
doctor, you know, it really was pivotal in, you know, fostering
our curiosity. I mean if we think about who we are as a race,
as human beings, we are naturally curious. We are natural
explorers and we want to find those answers.
And I think it's incredibly important, the work that NASA
is doing, the work that our scientists are doing and fostering
the imagination of the next generation. I think we need to do
more of that in fact because, you know, in listening to some of
the--your testimony, as well as how you answer the questions,
we don't know what life is going to look like. We don't know
what we are going to discover. We don't know what frequencies
we should be listening for. But we do know that something is
out there, and if we don't, you know, continue to push our
imagination, if we don't continue to--we don't know how we're
going to get to Mars, let alone how we're going to send a human
being to Mars and bring them back, but we do know if we
challenge ourselves, we will discover that. We will--we always
have. And I think that is the importance of what we're doing
here on the Science and Technology Committee but also in
Congress and also working with our colleagues around this world
because this is not just a U.S. mission; it is a human mission
to find and discover, you know, where we came from, how life
evolved, but also how life becomes extinct as well, as we're
looking at these planets, the impacts of those discoveries on,
you know, what is affecting our own planet right now as we deal
with climate change, as we deal with a changing atmosphere.
Those discoveries will help us manage our own issues on our
planet.
I'll ask a quick question of each of the panelists, and
each of you can answer this. In explaining why it is important
to search for life beyond our planet, beyond just the
philosophical elements, if you were to explain this to an
elementary school student or the public in general, how might
you put why this is such an important endeavor? And we'll start
with Dr. Stofan.
Dr. Stofan. You know, I certainly always mention this fact,
that ever since I think there have been people looking up at
the sky, we've wondered are we alone, and so there is that huge
philosophical piece. The other piece I like to talk about is,
you know, when we find life, does it have RNA? Does it have
DNA? Is its cell structure like our cell structure? And then
how can we take that information and look back at life here on
Earth and try to understand better how life here involved, what
the conditions are? And so to me you do get a tremendous
learning about life in general by finding life on other
planets.
Obviously also I try to point out to audiences if they
don't buy the science and the philosophy stuff, I try to point
out to them that when we do great human endeavors, whether
it's, you know, exploring the Moon, building the next great
telescope, we challenge technology. We bring good technology
jobs to this country. We move this country forward in our
reputation both internationally and at home. And I think
there's that inspiration part of just doing really hard things,
accomplishing great things, which this country has demonstrated
so ably that were so capable of.
And I will say I also like to tell schoolchildren when I go
and talk to them, I say oh, my gosh, you guys have so much work
to do. We have 5,000 planets we need you to go study. You know,
we've got entries and landings for humans on Mars. You guys
better grow up and get to work. We need help.
Mr. Bera. Great.
Dr. Lunine. This might be a philosophical answer so I
apologize for violating the ground rule, but, you know, for the
last 500 years we've lived in a kind of a Copernican worldview
where the Earth was not the center of the universe or even the
solar system; it's a planet in the solar system. The Sun is not
at the center of the galaxy; it's just a common star in the
galaxy. The galaxy is one of hundreds of billions of galaxies
in the cosmos, and yet we are singular. I mean life and
intelligent life and ourselves at the moment we know of no
other form of life, intelligent life, and the Copernican
worldview would say they're all over the place. And it's
crucial to test that because if that turns out not to be the
case, that's going to shatter our worldview.
Dr. Bean. So my answer would be more along the lines--of
course, those are excellent reasons why we want to do that, and
finding out the answer would he absolutely fascinating and
change our worldview. But I think also the process of doing it
tells us a lot about ourselves, tells us about our hopes and
dreams and about, you know, how we can work together as a
country and as a society and the world. So for me I want to
emphasize the process of looking for that answer, whatever the
answer may be, if it's a positive or a negative. But the
process--through the process we find out a lot about ourselves.
Dr. Siemion. So I may be a bit biased but I think that life
is the most interesting property of the universe, the idea that
somehow in this largely mechanical universe that we live in,
that we understand to great detail, some sort of an organism
came to be that could question its own existence, that could
wonder about the universe itself and where it came from. You
know, if we don't understand that, then I think we don't
understand perhaps one of the most fundamental properties of
the universe that we live in, and so we must answer that
question.
Mr. Bera. Great. Thank you.
Chairman Smith. Thank you, Dr. Bera. And just to follow up
on that question if other Members will allow me, just real
quickly, yes or no, do you think intelligent life does exist
elsewhere in the universe? Dr. Stofan?
Dr. Stofan. Maybe.
Chairman Smith. Okay. Dr. Lunine?
Dr. Lunine. Mr. Chairman, am I allowed to answer by saying
I honestly don't know?
Chairman Smith. No, that's a legitimate answer. Members of
Congress should give that more often themselves. Dr. Bean?
Dr. Bean. I don't know either.
Chairman Smith. And Dr. Siemion? I'm not asking you if you
know; I'm just asking you if you think.
Dr. Siemion. I also don't know but I think it would be
incredibly strange if we were the only example of intelligent
life in the universe. And----
Chairman Smith. Okay.
Dr. Siemion. --I'll quote Stephen Hawking just very, very
briefly, someone much smarter than I am. A universe in which
intelligent life only exists in one place and a universe in
which intelligent life potentially exists in many, many places
are very, very different places.
Chairman Smith. Very good. Thank you, Dr. Siemion.
We'll go now to a gentleman from California, Mr. Swalwell,
for his questions.
Mr. Swalwell. Thank you, Chair. And thank you to our
panelists. Congratulations. I have to say it's refreshing to
have a hearing about something so big, so exciting and further
than the eye can see, and so, you know, in Washington it gets
quite frustrating here. It feels like we are so focused on just
very small, incremental things and people at home get quite
frustrated that that seems to rule the day here. But the work
that you're doing is so important, so big, and will inspire so
many future scientists. So congratulations.
I had the opportunity to go with the Chairman and a few
others to Antarctica. One of your colleagues, John Gunderson,
joined us on a trip and he told us as we went through the
McMurdo Dry Valleys, that that area--and he was excited to be
on that trip and visit that area because it most closely
resembled what we believe many of the parts of Mars to be. And
so this discovery is another step forward in that effort.
As far as the water that has been discovered, do we believe
it could support life? Is it too salty? Do we know enough about
its properties to make that conclusion yet? Dr. Stofan?
Dr. Stofan. It certainly makes us concerned that that water
in particular had a lot of perchlorates in it and salts, and so
based on--you know, and this is where everything we say--you
know, based on what we know about life on Earth, that would not
be a very habitable type of water. That being said, what we
know about the Earth is like this. What could be is like that.
So fundamentally we don't know.
Mr. Swalwell. Great. Any other thoughts from the panelists
on that question?
Dr. Lunine. Well, just very briefly, if I talk about the
possibility of looking for exotic biochemistries on Titan, I'd
better not say that life is impossible in the perchlorate
solutions on Mars, which would be a lot easier to imagine the
biochemistries. So, yes, terrestrial life as we know it,
bacteria, et cetera, would all be sterilized by that solution.
But is there a form of life that has evolved to live in that
solution? That would be very interesting but not impossible.
Mr. Swalwell. And speaking of sterilizing, according to the
New York Times, ``NASA has no plans to examine closely any of
these places which may contain water or could be potentially
habitable places out of fear of contaminating them with Earth's
microbes.'' So sterilizing probes is expensive. Do you think
it's time to reexamine this approach so we can follow up on
this latest discovery?
Dr. Stofan. You know, I think the scientific community
right now, not just in the United States but around the world
is--you know, because obviously planetary protection is
something that's governed by international policies and
procedures, we want to make sure that if we find life on Mars,
we know that we've found life that is Martian life, not
contamination we brought from the Earth.
And so certainly in areas where there are water, we need to
be cautious, extremely cautious as we move towards exploring
them. However, those areas could potentially be the most
interesting areas to explore. And so I think the scientific
community is certainly going through a process right now of
saying, okay, right now, we don't think that's the place to run
to and potentially contaminate so let's take a really measured,
very scientific approach to how we might get at exploring those
regions. Obviously, when we eventually send humans to Mars,
that's going to lead to much likely broader-scale
contamination, and so I think it's important as we lead up to
sending humans to Mars we try to keep Mars as pristine as we
can.
Mr. Swalwell. Great. And finally, 38 million Californians
are wondering: Can we get that water to California?
Dr. Stofan. Certainly the California drought is something
that NASA is very concerned about. We've been using our
satellites to do what we can to help to certainly monitor with
the GRACE data. And we've certainly seen the alarming reduction
in the amount of water in the aquifers. And we've been working
on some projects with farmers in California that have--and some
pilot projects that have reduced water usage by as much as 30
percent. So NASA is trying to help.
Mr. Swalwell. That's great. Thank you. I yield back. Thank
you, Chairman.
Chairman Smith. Thank you, Mr. Swalwell.
The gentlewoman from Maryland, the Vice--excuse me, the
Ranking Member of the Space Subcommittee is recognized for her
questions.
Ms. Edwards. Thank you very much, Mr. Chairman, and thank
you to the members.
I was sort of curious. I don't know if Mr. Foster had a
chance to--we were kind of speculating over here as to whether
there's value in doing the kind of marking of all of these
different sources to determine whether there was at some point
sort of one general dispersion so that there is a relationship
between potential life that we might detect one place and
another, and so I don't know if that kind of work is going on.
And I wondered, Dr. Lunine, if you could speak to that.
Dr. Lunine. Sure. I'd be happy to. I assume you're talking
about in our solar system?
Ms. Edwards. Yes.
Dr. Lunine. So there's been quite a lot of work done of
course to understand how frequently material has been exchanged
between the Earth and Mars, as I alluded to, but also for
Europa, is it possible to get material from Europa to the Earth
and vice versa? And then Enceladus and Titan. And the answer is
that the farther out you go, the less likely it is. So the most
recent studies that have been done, which are all computer
models, say that the chance of cross contamination between the
Saturn system and the Earth is very, very small, and the chance
of contamination between Europa and the Earth is a little bit
higher but still relatively small.
So one of the advantages of going to the outer solar
system, in addition to exploring Mars, is that we may be going
to habitable environments which have not been contaminated by
either the Earth or Mars, and so if we find life there or the
signs of life, we have somewhat higher assurance that that life
had an independent origin of life on Earth, which of course is
one of the important questions. Could life have begun more than
once in our own solar system? And that's one of the attractions
of going to the outer solar system.
Ms. Edwards. So then that leads me to another question.
And, Dr. Lunine and Dr. Bean, in a 2007 National Academies
report called ``The Limits of Organic Life in Planetary
Systems,'' there was a caution against searching for a model of
life that's based on the model that we know here on Earth and a
conclusion that life is possible in forms different from those
on Earth. And so I wonder if you could talk to me about the
recommendations that came from the report to further inform
investigations to detect and identify possible forms of life
and other planetary environments?
And I think, Dr. Lunine, in your testimony, in your
prepared statement you asked whether the seas of Titan should
be included in our search for life because of the Titan's use
of methane as a working fluid in place of water? So I guess my
question is to what extent would missions to Titan and other
potentially habitable environments be able to investigate
habitats of life forms that are different--that may be
different from those on Earth?
Dr. Lunine. So the 2007 report came out very strongly in
favor, as you noted, of looking in environments that had the
general conditions for habitability: energy, liquid, organic
molecules, and that if in fact those environments were found
not to have a form of life, that that would tell us that
there's something indeed very special about liquid water. And
so that was I think one of the recommendations, as I recall, of
that report.
The challenge of course is how to look for biochemistry in
a methane/ethane liquid. What do we actually look for? There's
no guideline that terrestrial biology gives us except for the
guideline that life will be very selective in the chemical
compound that it uses for catalysts, for building structures,
and so on. And so therefore, if we go back to Titan, for
example, with a boat or a submarine or whatever to explore
these seas, if we find that the organic molecules in the seas
are just like what's in the atmosphere, you know, basically
everything, that's not going to be very promising in terms of
life. But if there's a suite of particular molecules and
structures that are made over and over again, then that might
suggest that if not life itself, at least a chemical evolution
toward life is happening in those seas. Beyond that, it's hard
to say very much because we have our one example of life on the
Earth.
Now, just very briefly, in places like Enceladus and
Europa, which have very Earth-like environments, we would
expect that many of the basic molecules that terrestrial life
uses like amino acids, which are abundant in the cosmos, that
we would see that in life in those environments.
Ms. Edwards. Dr. Bean, in the time remaining.
Dr. Bean. Right. In the context of the search for life on
extrasolar planets, astronomy, my field, is a very discovery-
driven field. We want to build space telescopes and instruments
that are designed to be able to answer a question and we
inform, you know, the design of those instruments with what we
know about on Earth. But we also know that we're going to find
unexpected things and so we want to have as flexible of
instruments as possible and we want to make as complete a
characterization of these planets as we can.
Just to give you an example, the Hubble Space Telescope and
the Spitzer Space Telescopes were never designed to look in the
atmospheres of extrasolar planets, but that has become one of
the most impactful things that those telescopes have done just
because they were built with a suite of instruments that were
very flexible. And so we have to benchmark our design for these
instruments based on what we know, and what we know is limits
of the Earth. But we also want to remain open-minded and
flexible and do this complete characterization of the planets
to try to answer this question in as holistic away as possible.
Ms. Edwards. And I've greatly exceeded my time.
Chairman Smith. Thank you, Ms. Edwards.
The gentleman from Colorado is recognized for his questions
not with trepidation but with curiosity and expectation because
I'm never sure where he's going to go with his questions. But
he is recognized.
Mr. Perlmutter. And, Mr. Chairman and to the Ranking
Member, I've served on a lot of committees in the Congress, and
this Committee is by far the most exciting, stimulating,
energizing committee in the Congress. And as I'm sitting down
here and looking up at the top row and reading Tennyson, ``For
I dipped into the future, far as human eye could see, saw the
vision of the world, and all the wonder that would be.''
Listening to you all, that's what this is about. This is--this
gives me goose bumps. The versatility of your instruments or
your minds to say, you know what, this was really intended to
do that but we could use it for this. And I just enjoy this
Committee.
So--and Dr. Bera talked about the challenge and the desire
of all of us to explore. I mean I have some differences with
the Chairman on prioritizing and actually funding because I see
what you all do and your research and your service to be
investments in the future, and that will pay for a long time to
come. And I don't think it's a zero-sum game pitting the
astronomers against the physicists and all that stuff. And I
don't think the Chairman does either, but I really would like
to see us move forward obviously with the Orion project and get
humans to Mars.
And with that, I'm going to yield to my friend from
Maryland for her questions.
Ms. Edwards. And I thank the gentleman from Colorado. We
pulled a fast one on the Chairman there.
Dr. Stofan, I just had one question about how you're
planning to use the Astrobiology Roadmap that's going to be
released later this year and a year later than initially
thought. Will it be a major vehicle that NASA is going to use
to establish priority and--priorities? And then what kind of
challenges did the agency face that caused a one-year delay to
the issuance of the roadmap?
Dr. Stofan. The Astrobiology Roadmap that again will come
out shortly, the reason that it's taken longer is because this
science is evolving so rapidly and how the scientific community
looks at it, bringing in all these multiple disciplines that
want to have a voice in astrobiology because you might have
thought ten years ago if you're a heliophysicist that nothing
you do has anything to do with astrobiology. All of a sudden
you say, wait, I can actually contribute. And so that's been--
the reason for the delay of the roadmap is we've just been
trying to get the best science from the scientific community,
get it properly reviewed, and get it out as soon as we can. And
so we're happy that it's done and it's about ready to go.
How we use those roadmaps is--definitely comes in several
different ways. Basically, when anybody then proposes to NASA,
whether it's to do research, to do a mission, they then say
here's how my mission that I'm proposing maybe to a competitive
line at NASA. Here's how I'm consistent with the goals of what
the community is saying. And then we can use that at NASA and
say is this really high priority? Because we look to the
community through these community roadmaps, through the decadal
process to say what is the best science, what's the latest
science, the most up-to-date science, and then how can we use
that to inform our decision-making?
Ms. Edwards. So just really quickly, is there a plan to
have the National Academies review the roadmap as well?
Dr. Stofan. I don't know that. I can take that for the
record.
Ms. Edwards. All right. And with that, I will yield back to
the gentleman from Colorado and just say I am--I do get a
little bit concerned with these, you know, constant discoveries
which are really great and we find incredibly fascinating, that
the public then becomes numb to it in a way that would harm us
in terms of making sure that you have the resources that you
need.
And with that, I yield back to the gentleman----
Mr. Perlmutter. Thanks.
Ms. Edwards. --from Colorado.
Mr. Perlmutter. And to the Chairman and the Ranking Member,
the thing that I enjoy about this is we are so--looking so
forward and towards the future. And tonight, I don't know if
you talked about The Martian or not, but the thing that is so
fun about that book, one, he's a wise guy; and two, in that
book, it's about problem-solving, whether it's math or
engineering or physics or biology.
And that's what is so enjoyable about this Committee and
about the panels that come and speak to us because I see you
all as looking to the future and solving problems, and I just
thank you for that. And I thank the Chairman and the Ranking
Member for this Committee because it gives me energy every time
I come in here.
Chairman Smith. Thank you, Mr. Perlmutter. You actually
beat me in quoting Alfred Lord Tennyson because I was going to
end by doing that. However, just to add one more tidbit of
information here, this quote that you see behind us on the wall
is from a poem called Locksley Hall and of course written by
Alfred Lord Tennyson who lived from 1809 to 1892. I have the
entire poem right here. It's multiple pages but that is a
wonderful excerpt of it.
That brings us to the end of our hearing, which was
obviously informative and exciting to all of us. And let me
just simply add that when we think that we're somehow limited
in what we might explore or what we might detect elsewhere in
the cosmos, I think it's helpful to remember that we here in
the United States went from the Wright Brothers to Apollo in 66
years. In 1903 we had the Wright Brothers. We had two guys
flying a contraption a couple hundred feet, 20 feet above the
ground. Sixty-six years later, we had 12 people walking on the
Moon over several years. And any country that can do that can
certainly continue to explore and learn from that exploration,
and who knows, maybe even detect some form of life elsewhere.
So thank you all for being here, most enjoyable hearing,
and I thank the Members who are here as well. And we stand
adjourned.
[Whereupon, at 11:42 a.m., the Committee was adjourned.]
Appendix I
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Answers to Post-Hearing Questions
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