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Marsbugs: The Electronic Astrobiology Newsletter, Volume 11, Number 24, 8 June 2004
Marsbugs: The Electronic Astrobiology Newsletter
Volume 11, Number 24, 8 June 2004
Editor/Publisher: David J. Thomas, Ph.D., Science Division, Lyon College, Batesville, Arkansas 72503-2317, USA.
Marsbugs is published on a weekly to monthly basis as warranted by the number of articles and announcements. Copyright of this compilation exists with the editor, except for specific articles, in which instance copyright exists with the author/authors. Opinions expressed in this newsletter are those of the authors, and are not necessarily endorsed by the editor or by Lyon College. E-mail subscriptions are free, and may be obtained by contacting the editor. Information concerning the scope of this newsletter, subscription formats and availability of back-issues is available at The editor does not condone "spamming" of subscribers. Readers would appreciate it if others would not send unsolicited e-mail using the Marsbugs mailing lists. Persons who have information that may be of interest to subscribers of Marsbugs should send that information to the editor.
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Marsbugs: The Electronic Astrobiology Newsletter, Volume 11, Number 24, 8 June 2004
Articles and News
Page 1DARK ENERGY TIED TO HUMAN ORIGINS
By Robert Roy Britt
Page 1NASA RESEARCHERS CUSTOMIZE "LAB-ON-A-CHIP" TECHNOLOGY TO HELP PROTECT FUTURE SPACE EXPLORERS AND DETECT LIFE FORMS ON MARS
NASA/MSFC release 04-156
Page 2CAUGHT IN THE ACT
Harvard-Smithsonian Center for Astrophysics release 04-23
Page 3NEW MOON SHOT NOT SO COSTLY
From United Press International
Page 3ROCKS TELL TALE OF WARM EARLY ATMOSPHERE—CONTINENTS PLAYED ROLE IN DECAY, RENEWAL OF ANCIENT GREENHOUSE
By Dawn Levy
Page 4METEORITE CRASH TURNED EARTH INSIDE OUT: NEW RESEARCH PAINTS A PICTURE OF WHAT HAPPENED BILLIONS OF YEARS AGO WHEN A DEVASTATING METEORITE CRASHED INTO THE EARTH
By Karen Kelly
Page 5EARLIEST BILATERAL FOSSIL DISCOVERED
By Leslie Mullen
Page 5FLESHING OUT MARTIAN PROTEINS: INTERVIEW WITH RICHARD MATHIES
From Astrobiology Magazine
Announcements
Page 7SQUYRES TO ADDRESS MARS SOCIETY CONVENTION
Mars Society release
Page 7SPACE ENTHUSIASTS, CASSINI SCIENTISTS INVITE PUBLIC TO UA ON JUNE 19
By Lori Stiles
Page 8NEW ADDITIONS TO THE ASTROBIOLOGY INDEX
By David J. Thomas
Mission Reports
Page 9CASSINI-HUYGENS UPDATES
NASA/JPL releases
Page 10MARS EXPLORATION ROVERS UPDATES
NASA/JPL releases
Page 12MARS GLOBAL SURVEYOR IMAGES
NASA/JPL/MSSS release
Page 13MARS ODYSSEY THEMIS IMAGES
NASA/JPL/ASU release
Page 13ROSETTA: MOVING TOWARDS CRUISE PHASE
ESA release
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Marsbugs: The Electronic Astrobiology Newsletter, Volume 11, Number 24, 8 June 2004
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Marsbugs: The Electronic Astrobiology Newsletter, Volume 11, Number 24, 8 June 2004
DARK ENERGY TIED TO HUMAN ORIGINS
By Robert Roy Britt
From Space.com
31 May 2004
Among the most elusive and important questions in science are whether we're alone and what the heck that strange stuff is that's pushing the universe apart. Neither is likely to be answered anytime soon, yet each occupies many great minds and together they drive billions of dollars in research spending every year. Now wouldn't it be really weird if these two seemingly unrelated questions were intimately linked? Strange but possibly true, says Mario Livio, a theorist at the Space Telescope Science Institute (STScI).
Read the full article at
NASA RESEARCHERS CUSTOMIZE "LAB-ON-A-CHIP" TECHNOLOGY TO HELP PROTECT FUTURE SPACE EXPLORERS AND DETECT LIFE FORMS ON MARS
NASA/MSFC release 04-156
1 June 2004
Imagine a huge laboratory filled with people and equipment shrinking to fit on a small chip—the size of a dime. Scientists on Earth use labs on chips for medical tests and other research. Marshall Center scientists are customizing these chips for use in space. One day they may be used in devices to detect contaminates, and rovers may use them to identify life on Mars.
With a microscope and computer monitor, researchers at NASA's Marshall Space Flight Center in Huntsville, AL, watch fluorescent bacteria flow through tiny, fluid highways on a dime-sized lab on a chip. Lab-on-a-chip technology allows chemical and biological processes—previously conducted on large pieces of laboratory equipment—to be performed on a small glass plate with fluid channels, known to scientists as microfluidic capillaries.
"We are studying how lab-on-a-chip technology can be used for new tools to detect bacteria and life forms on Earth and other planets and for protecting astronauts by monitoring crew health and detecting microbes and contaminants in spacecraft," explains Dr. Helen Cole, project manager for the Lab-on-a-Chip Applications Development program.
The chips are made with the same micro-fabrication technique used to print circuits on computer chips. Chemicals and fluid samples can be mixed, diluted, separated, and controlled using channels or electrical circuits embedded in the chip. On Earth, some basic lab-on-a-chip technology approaches are being used for commercial, medical diagnostic applications, such as an in-office test for strep throat, or modern in-home pregnancy tests. These applications conduct a test and yield results in a short time, with a hand-held portable device containing a simple chip design.
"NASA requires complex lab-on-a-chip technology, so scientists can conduct multiple chemical and biological assays or perform many processes on a single chip," says Cole. "Current commercial devices are not designed to work in space, so we are developing a set of unique chips along with a corresponding miniaturized controller and analysis unit."
Labs on chips are manufactured in many shapes and sizes and can be used for numerous applications—from medical tests to water quality monitoring to detecting the signatures of life on other planets. The eight holes on this chip are actually ports that can be filled with fluids or chemicals. Tiny valves control the chemical processes by mixing fluids that move in the tiny channels that look like lines, connecting the ports. Scientists at NASA's Marshall Space Flight Center in Huntsville, AL, designed this chip to grow biological crystals on the International Space Station. Through this research, they discovered that this technology is ideally suited for solving the challenges of the Vision for Space Exploration. For example, thousands of chips the size of dimes could be loaded on a martian rover looking for biosignatures of past or present life. Other types of chips could be placed in handheld devices used to monitor microbes in water or to quickly conduct medical tests on astronauts. Image credit: NASA/MSFC/D. Stoffer.
NASA researchers are developing complex, portable microarray diagnostic chips to test for all the genes and DNA responsible for determining the traits of a particular organism, detect specific types of organisms, or use biosensor-like probes such as antibodies to detect molecules of interest. By applying this technology in laboratories and in the field where organisms live in extreme environments on Earth, astrobiologists can compare Earth-life with that which may be found on other planets.
"The micro array chip system developed to go to Mars will be lightweight, portable and capable of detecting organic molecules," says Dr. Lisa Monaco, the project scientist for the Lab-on-a-Chip Applications Development program. "This instrumentation can easily be adapted for monitoring crew health and their environment."
Since the chips are small, a large number of them can be carried on a Mars rover to search for life or on carried on long-duration human exploration missions for monitoring microbes inside lunar or martian habitats.
"We need customized microarray chips to find and characterize life at remote places on Earth, Mars, and other places in the solar system," says Dr. Andrew Steele, a scientist at the Carnegie Institution of Washington, a private research organization. Steele, the principal investigator for the Modular Assays for Solar System Exploration (MASSE) project, is working with Marshall scientists and engineers to develop the technology and instruments needed to analyze samples quickly and produce images of samples.
"When astrobiologists study life in extreme environments—whether it lives deep in the ocean, in Antarctica, or on Mars—they need a handheld device or something that can fit on a small robot," Steele explains. "We also need to be able to analyze the tests as quickly as possible within periods from 1 to 24 hours. Marshall is one of just a few places in the world developing these specific technologies for space and exploration applications and has unique experience in miniaturizing these instruments and designing them for the harsh space environment."
The Marshall Center team is collaborating with scientists at other NASA centers and at universities to design chips for many applications, such as studying how fluidic systems work in spacecraft and identifying microbes in self-contained life support systems. To make customized chips for these various applications, NASA has an agreement with the U.S. Army's Microdevices and Microfabrication Laboratory at Redstone Arsenal in Huntsville. The lab-on-a-chip research is funded by NASA's Biological and Physical Research Enterprise through the Marshall Center's Microgravity Science and Applications Division. More information about space research is available on the Internet at
Read the original news release at
An additional article on this subject is available at
CAUGHT IN THE ACT
Harvard-Smithsonian Center for Astrophysics release 04-23
2 June 2004
How old is too old? Pro football players tend to peak in their late 20s, and few continue their careers beyond the age of 35. For young stars, the peak age for planet formation is around 1 to 3 million years. By 10 million years old, their resources are exhausted and they retire to a life on the stellar "main sequence."
Using telescopes on the ground and in space, a team of astronomers led by Lee W. Hartmann and Aurora Sicilia-Aguilar (Harvard-Smithsonian Center for Astrophysics) is studying Sun-like stars in their waning formative years, within clusters older than previously explored. They seek to refine our understanding of planet formation by studying dusty protoplanetary disks around such stars. Their results, presented today at the 204th meeting of the American Astronomical Society in Denver, Colorado, better define the time span during which planets might form.
"While the planets that may be forming cannot be detected directly," said Sicilia-Aguilar, "we can see changes in the circumstellar dusty accretion disks caused as the planets sweep up and accumulate mass. The data also has shown dramatic differences between stars of 3 and 10 million years of age: the younger stars frequently have dusty disks capable of forming planets, while such disks are essentially absent in the older population."
The team used data from the Smithsonian Institution's Whipple Observatory telescopes, the WIYN telescope at Kitt Peak National Observatory, and from the Spitzer Space Telescope (the latter made available as part of the Guaranteed Time Program of Infrared Array Camera PI Giovanni Fazio), to make these findings.
"We are trying to understand the evolution of protoplanetary disks around stars not too different from the Sun," said team leader Lee W. Hartmann. "Many stars about 1 million years old have disks, but by 10 million years, almost none have disks. We are trying to find stars at an in-between age and 'catch them in the act' of forming planets."
Circumstellar dust disks enshroud young stars, and astronomers understand this to be a common feature of stellar evolution and of possible planetary system formation. The initial protoplanetary disks contain the gas and dust that provide the raw materials for the formation of later planetary systems.
"After stars form planets in their disks and clear out most of the material—either by accretion onto the star, accretion onto planets, or ejection—small amounts of dust can remain in so-called 'debris disks.' Most or all of this debris dust is thought to be continuously generated by the collision of small bodies, much like the zodiacal light in our solar system," said Hartmann.
The team is presenting the first identification of low mass stars in the young clusters Trumpler 37 and NGC 7160. (These clusters are loose associations of stars that have formed together in the comparatively recent past.)
"The cluster members confirm the age estimates of 1 to 5 million years for Tr37 and 10 million years for NGC 7160," said Sicilia-Aguilar. "We do find active accretion in some of the stars in Tr37. The average accretion rate is equivalent to swallowing up 10 Jupiter masses in a million years. This is consistent with models of viscous disk evolution. In comparison, we have detected no signs of active accretion so far in the older cluster NGC 7160, suggesting that disk accretion ends within 10 million years. This probably coincides with the major phase of giant planet formation."
Like pro football players, young stars also peak early. Most planets form when stars are 1 to 3 million years old. By 10 million years, the dusty disk is gone and planet formation ends, as shown in this artist's rendering. Image credit: David A. Aguilar, Harvard-Smithsonian Center for Astrophysics.
Trumpler 37 is of more immediate interest, said Hartmann, because we hope to find stars with Jupiter-size planets that are still accumulating material from the disks, so the disks are not completely cleared out yet. However, there may be a few objects in the 10 million-year-old cluster NGC 7160 that are also still forming their giant planets. Not all disks evolve at the same rate.
"Thus we expect eventually to find out more about the frequency of debris disks, and the rate at which the dust in such disks is removed, by studying the 10-million-year-old cluster NGC 7160 and comparing it to Trumpler 37," said Hartmann.
In addition to Sicilia-Aguilar and Hartmann, team members include Cesar Briceno (Centro de Investigaciones de Astronomia), James Muzerolle (University of Arizona), and Nuria Calvet (Smithsonian Astrophysical Observatory). This work was supported by NASA grant NAG5-9670.
Headquartered in Cambridge, MA, the Harvard-Smithsonian Center for Astrophysics (CfA) is a joint collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. CfA scientists, organized into six research divisions, study the origin, evolution and ultimate fate of the universe.
A high-resolution image to accompany this release is available online at
Contacts:
David Aguilar, Director of Public Affairs
Harvard-Smithsonian Center for Astrophysics
Phone: 617-495-7462
Fax: 617-495-7468
E-mail:
Christine Pulliam
Public Affairs Specialist
Harvard-Smithsonian Center for Astrophysics
Phone: 617-495-7463
Fax: 617-495-7016
E-mail:
Read the original news release at
Additional articles on this subject are available at:
NEW MOON SHOT NOT SO COSTLY
From United Press International and SpaceDaily
2 June 2004
NASA's plan to fulfill President George W. Bush's space exploration effort suggests the agency will have to spend about $64 billion over the next 15 years to send U.S. astronauts back to the moon. Although the price tag—projected in fiscal year 2003 dollars—excludes several elements of the Bush space plan, it is far less than the hundreds of billions critics of the proposal have suggested it would cost. The estimate is based on National Aeronautics and Space Administration budget data compiled in an analysis completed May 10 by the Congressional Research Service. A copy of the analysis, which has been seen by only a few members of Congress, was obtained by United Press International.
Read the full article at
ROCKS TELL TALE OF WARM EARLY ATMOSPHERE—CONTINENTS PLAYED ROLE IN DECAY, RENEWAL OF ANCIENT GREENHOUSE
By Dawn Levy
Stanford University release
2 June 2004
If a time machine could take us back 4.6 billion years to the Earth's birth, we'd see our sun shining 20 to 25 percent less brightly than today. Without an earthly greenhouse to trap the sun's energy and warm the atmosphere, our world would be a spinning ball of ice. Life may never have evolved.
But life did evolve, so greenhouse gases must have been around to warm the Earth. Evidence from the geologic record indicates an abundance of the greenhouse gas carbon dioxide. Methane probably was present as well, but that greenhouse gas doesn't leave enough of a geologic footprint to detect with certainty. Molecular oxygen wasn't around, indicate rocks from the era, which contain iron carbonate instead of iron oxide. Stone fingerprints of flowing streams, liquid oceans and minerals formed from evaporation confirm that 3 billion years ago, Earth was warm enough for liquid water.
Now, the geologic record revealed in some of Earth's oldest rocks is telling a surprising tale of collapse of that greenhouse—and its subsequent regeneration. But even more surprising, say the Stanford scientists who report these findings in the May 25 issue of the journal, Geology, is the critical role that rocks played in the evolution of the early atmosphere.
"This is really the first time we've tried to put together a picture of how the early atmosphere, early climate and early continental evolution went hand in hand," said Donald R. Lowe, a professor of geological and environmental science who wrote the paper with Michael M. Tice, a graduate student investigating early life. NASA's Exobiology Program funded their work. "In the geologic past, climate and atmosphere were really profoundly influenced by development of continents."
The record in the rocks
To piece together geologic clues about what the early atmosphere was like and how it evolved, Lowe, a field geologist, has spent virtually every summer since 1977 in South Africa or Western Australia collecting rocks that are, literally, older than the hills. Some of the Earth's oldest rocks, they are about 3.2 to 3.5 billion years old.
"The further back you go, generally, the harder it is to find a faithful record, rocks that haven't been twisted and squeezed and metamorphosed and otherwise altered," Lowe says. "We're looking back just about as far as the sedimentary record goes."