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Marsbugs: The Electronic Astrobiology Newsletter, Volume 11, Number 16, 13 April 2004
Marsbugs: The Electronic Astrobiology Newsletter
Volume 11, Number 16, 13 April 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 http://www.lyon.edu/projects/marsbugs. 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 16, 13 April 2004
Articles and News
Page 1 FOR THE SAKE OF LAND AND CLIMATE, COAXING SOIL TO SOAK UP CARBON
Pacific Northwest National Laboratory release
Page 2 ASTRONOMERS TAKE SEARCH FOR EARTH-THREATENING SPACE ROCKS TO SOUTHERN SKIES
By Lori Stiles
Page 3 STARFIELD OF DREAMS: THE ASTROBIOLOGY SCIENCE CONFERENCE, 2004
By Leslie Mullen
Page 3 WEB-BASED PROGRAM CALCULATES EFFECTS OF AN EARTH IMPACT
By Lori Stiles
Page 4 DELAYED GRATIFICATION ZONES
By Leslie Mullen
Page 6 MODERN MARS: LATEST SPACECRAFT FINDINGS REDEFINE FUTURE MISSIONS
By Leonard David
Page 6 NASA RADAR AIDS HIGH-TECH DIGS
By Rosemary Sullivant
Page 7 A BLACK BOX FOR PEOPLE
By Karen Miller
Page 8 HOW LONG DOES IT TAKE FOR EARTH'S MAGNETIC FIELD TO REVERSE? LONG-DEBATED, A FIRM ANSWER IS NOW ON THE HORIZON
National Science Foundation release
Page 8 ASTROBIOLOGY: ASKING BIG QUESTIONS TO LEARN SCIENCE
By Edna DeVore
Page 8 DANGEROUS SPACE ROCKS UNDER WATCH
From Reuters and CNN
Page 8 EXPERIMENT HARNESSES STATE-OF-THE-ART SEQUENCING TECHNOLOGY TO DETECT LIFE ON MARS
By Robert Sanders
Page 10 CAN SETI PROBE FOR PROBES? INTERVIEW WITH SCOT STRIDE
From Astrobiology Magazine
Announcements
Page 13 ERRATUM: DOWN THAT LONG DUSTY TRAIL
Corrections by Corien Bakermans
Page 13 NEW ADDITIONS TO THE ASTROBIOLOGY INDEX
By David J. Thomas
Mission Reports
Page 13 CASSINI SIGNIFICANT EVENTS
NASA/JPL release
Page 14 CASSINI: TWO STORMS CAUGHT IN THE ACT ON SATURN
NASA/JPL release 2004-098
Page 15 NASA EXTENDS MARS ROVERS' MISSION
NASA/JPL release 2004-097
Page 16 MARS GLOBAL SURVEYOR IMAGES
NASA/JPL/MSSS release
Page 17 MARS ODYSSEY THEMIS IMAGES
NASA/JPL/ASU release
Page 17 ROSETTA STATUS REPORT: ONGOING COMMISSIONING ACTIVITIES
ESA release
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Marsbugs: The Electronic Astrobiology Newsletter, Volume 11, Number 16, 13 April 2004
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Marsbugs: The Electronic Astrobiology Newsletter, Volume 11, Number 16, 13 April 2004
FOR THE SAKE OF LAND AND CLIMATE, COAXING SOIL TO SOAK UP CARBON
Pacific Northwest National Laboratory release
1 April 2004
In a novel approach to stalling global warming while reinvigorating nutrient-depleted farmland, chemists have found they can promote soil's natural ability to soak up greenhouse-gas carbon dioxide from the surrounding air. Experiments led by Jim Amonette at the Department of Energy's Pacific Northwest National Laboratory in Richland, WA, and reported today at the American Chemical Society national meeting, show that maintaining a proper alkalinity plus frequent wetting and drying cycles can coax soil to retain more carbon.
"Globally, soils contain four times as much carbon as the atmosphere, and half of the soil carbon is in the form of organic matter," said Amonette, a PNNL senior research scientist. Until about 30 years ago, soil tillage released more carbon dioxide to the atmosphere than burning of fossil fuels. Some agricultural soils have lost a third of their carbon from tillage.
"These carbon-depleted soils are a tremendous potential reservoir for carbon that can help slow the increase in atmospheric carbon dioxide," Amonette said. "The amount of carbon added to soil in a year is incredible. Today, 99 percent of it comes out the top as carbon dioxide. If we can increase the fraction that is retained in soil by even a small amount, it will make a huge difference."
Amonette's experiments promoted the activity of tyrosinase, a common enzyme that catalyzes soil's natural "humification" process. This process involves the gradual incorporation of carbon from dead plants and microbes into stable organic matter called humus, which is responsible for the dark color in many soils. Tyrosinase increases the reaction rate between oxygen and humus precursors, such as phenols and hydroxybenzoic acids, to form quinones. The quinones react with amino acids released by soil microbes to form complex, durable molecules called humic polymers.
"Because humic polymers are less easily degraded by microbes than the precursor molecules, they survive to diffuse into small pores in soil aggregates where they are stabilized for decades, if not centuries," Amonette said.
The humification rate depends on many factors: enzyme stability, moisture, alkalinity, oxygen availability, microbial population and the physical properties of different soils. Amonette's experiments were designed to weigh the importance of these many factors and to learn ways they might be manipulated to increase humification.
In the lab, Amonette assembled 72 elaborate plastic-tube configurations he likens to "those Russian nesting dolls," matrioshkas. The tubes allowed Amonette to control individual moisture levels and oxygen availability. Each soil sample was placed between the inner and outer walls of water-tight but gas-porous concentric cylinders. These were placed inside yet a larger "chimney" tube to control the humidity as well as the type of gas and its flow rate.
Amonette was particularly interested in identifying soil components and soil additives that might improve tyrosinase's natural ability to promote humification. He found that an alkaline, porous material called "fly ash," a byproduct of coal combustion, "speeds up the normal humification process by promoting the reaction of the quinones with the amino acids and providing small pores to protect humic polymers," he said. "Frequent cycles of wetting and drying appear to be important, too, for fostering a rich microbial community that supplies many of the humic precursors and for aiding the formation of soil aggregates."
Amonette is eager to put his results to the test where it matters most-in the field. He will get his wish in May, when he travels to a field outside of Charleston, SC. There, he and collaborators from the U.S. Forest Service and Oak Ridge National Laboratory will plant 72 pots containing various controlled mixtures of soil and catalysts.
PNNL is a DOE Office of Science laboratory that solves complex problems in energy, national security, the environment and life sciences by advancing the understanding of physics, chemistry, biology and computation.
Read the original news release at http://www.pnl.gov/news/2004/04-25.htm.
ASTRONOMERS TAKE SEARCH FOR EARTH-THREATENING SPACE ROCKS TO SOUTHERN SKIES
By Lori Stiles
University of Arizona release
6 April 2004
The hunt for space rocks on a collision course with Earth has so far been pretty much limited to the Northern Hemisphere. But last week astronomers took the search for Earth-threatening asteroids to southern skies. Astronomers using a refurbished telescope at the Australian National University's Siding Spring Observatory discovered their first two near-Earth asteroids (NEAs) on March 29. NEAs are asteroids that pass near the Earth and may pose a threat of collision.
Siding Spring Survey (SSS) astronomer Gordon Garradd detected a roughly 100-meter (about 300-foot) diameter asteroid and 300-meter (about 1,000-foot) diameter asteroid in images he obtained with the 0.5-meter (20-inch) Uppsala Schmidt telescope. SSS partner Robert H. McNaught confirmed both discoveries in images he took with the Siding Spring 1-meter (40-inch) that same night.
The 100-meter asteroid, designated 2004 FH29, makes a complete orbit around the sun every 2.13 years. It missed Earth by 3 million kilometers (1.9 million miles), or 8 times the Earth-to-moon distance, yesterday, traveling at 10 km per second (22,000 mph) relative to Earth. The 300-meter asteroid, designated 2004 FJ29, orbits the sun about every 46 weeks. It came within 20 million kilometers (12 million miles), or within 52 lunar distances of Earth, last Tuesday, March 30, traveling at 18 km per second (40,000 mph) relative to Earth. Neither object poses a direct threat of colliding with Earth.
Had the asteroids not missed, damage from their impacts would have depended on what kind of rock they're made of. The 100-meter object likely would mostly burn up in Earth's atmosphere in an airblast equivalent to 10 megatons of TNT, comparable to the 1908 explosion above the Tunguska River valley in Siberia, McNaught said. The 300-meter rocky asteroid likely would reach Earth's surface, dumping the equivalent of 1,400 megatons of TNT energy into Earth's atmosphere, he added. That's comparable to 200 Tunguskas, or 24 times the largest thermonuclear bomb explosion, a 58 megaton Soviet bomb exploded in 1961.
The new survey is a joint collaboration between the University of Arizona Lunar and Planetary Laboratory and ANU's Research School of Astronomy and Astrophysics. It is funded by NASA's Near-Earth Object Observation Program, a 10-year effort to discover and track at least 90 percent of the one kilometer (six-tenths of a mile) or larger NEOs with the potential to become impact hazards.
When astronomers detect what they suspect is an NEA, they immediately must take additional images to confirm their discovery, McNaught said. Surveys often have to suspend their NEA searches and spend observing time confirming NEAs, or they risk losing them altogether because follow-up observations were made too late, he added.
The SSS plan is to use the 1-meter (40-inch) telescope for part of the month to quickly confirm suspect asteroids detected with the Uppsala, freeing the smaller telescope to continue it searches.
"Our confirmation strategy worked beautifully on our first try," McNaught said.
The Uppsala Schmidt telescope was built in the 1950s for Uppsala Observatory in Sweden. It was sited at Stromlo as the Uppsala Southern Station to make wide field photographs of the southern sky. Increasing light pollution from Canberra led to its relocation to Siding Spring, near Coonabarabran in New South Wales, in 1982. Despite its high quality optics, the telescope drifted into disuse because it used photographic film rather than modern electronic detectors and had to be operated manually.
In 1999, McNaught and Stephen M. Larson of UA’s Lunar and Planetary Laboratory joined in an effort to refurbish and upgrade the Uppsala telescope. Larson had similarly just overhauled a manually operated, photographic wide-field Schmidt telescope in the Santa Catalina Mountains north of Tucson for his Catalina Sky Survey (CSS), part of the NASA-funded program to spot and track asteroids headed toward Earth.
The SSS builds on telescope control, detector technology and software developed for the CSS in Tucson. During the upgrade, the Uppsala was completely reconditioned, and fitted with computer control, a large format (16 megapixel) solid state detector array, and extensive support computers and software that detects objects moving against background stars.
Larson said his reaction to the SSS milestone was "one of relief, since it took several years to make the telescope and facility modifications. Now the real work begins."
Larson and Catalina Sky Survey team member Ed Beshore worked on commissioning the Uppsala telescope during the past few months. Commissioning a telescope is like commissioning a ship: you have to get all the parts working and working together, and adjust things so they perform as expected.
"We actually achieved 'first light' last summer, with good images from the start," Larson said.
McNaught and Garradd will operate SSS about 20 nights each month. They suspend operations when the week around full moon brightens the sky, making faint object detection difficult.
The Catalina telescope, which Larson and his team upgraded again in May 2000, features new optics that give it a 69 centimeter (27-inch) aperture and a new, more sensitive camera. In addition to Larson and Beshore, Eric Christensen, Rik Hill, David McLean, and Serena Howard operate CSS.
Both CSS and SSS telescopes can detect objects as faint as 20th magnitude, close to sky background level generated by scattered city light and auroral glow that brightens Earth’s upper atmosphere.
Read the original news release at http://uanews.org/cgi-bin/WebObjects/UANews.woa/4/wa/SRStoryDetails?ArticleID=8916.
Additional articles on this subject are available at:
http://www.spacedaily.com/news/deepimpact-04d.html
http://spaceflightnow.com/news/n0404/09asteroid/
http://www.universetoday.com/am/publish/asteroid_search_looks_south.html.
STARFIELD OF DREAMS: THE ASTROBIOLOGY SCIENCE CONFERENCE, 2004
By Leslie Mullen
From Astrobiology Magazine
7 April 2004
The possibility of finding alien life is tantalizingly close. The recent discovery of ancient water features on the surface of Mars suggests life could have once existed right next door. Discoveries of planets in other solar systems hint at the potential for life in the far reaches of our galaxy, and scientists predict that within a decade we will discover Earth-like worlds orbiting distant stars.
Over 700 scientists and engineers from around the world pondered these and other topics last week at the 2004 Astrobiology Science Conference at NASA's Ames Research Center in Mountain View, California. Discussions ranged from the smallest forms of life, including viruses, to the evolution of the most intelligent life we know of so far—human beings—to the possibility of contacting advanced aliens in other solar systems.
Many scientists said if we do find alien life, it will be a microbe. Earth is a microbial world, and nearly every biosphere on the planet teems with life in this miniscule form. Microbial life on Earth has evolved to live comfortably in extreme environments such as scalding heat, frigid cold, and acid solutions. Microbes even can survive the radiation and vacuum of space. Although microbes have not yet been discovered beyond Earth, the universe is infused with the organic building blocks of life.
While astrobiologists try to figure out where life could thrive beyond Earth, the origin of life on our own planet remains a mystery. Scientists discussed drilling projects that aim to reach subsurface life. These projects may not only help shed light on the origins of life here on Earth, but could indicate places where life may exist on Mars.
Cornell University's Steve Squyres, lead scientist for the Mars rovers team, gave an overview of the progress made by the Spirit and Oppportunity rovers. Squyres seemed confident that the chemical signatures and features discovered by the rover Opportunity were indicative of a flow of salty water that once existed on the martian surface, and he hinted at new evidence to come that could confirm that theory.