April 7: NASA's Mars Odyssey spacecraft was launched from Cape Canaveral Air Force Station at 11:02 a.m. EDT. If all continues to go well, the craft will make the 286-million-mile journey and enter Mars orbit on October 24. Once there, Mars Odyssey will spend more than two years looking for signs of water with powerful ground-penetrating telescopes.
A Mars Odyssey MSFC, NASA, 5 June 2001.
2001 Mars Odyssey homepage at JPL, NASA.
Return to the Red Planet by Henry Bortman, NASA's Astrobiology Institute [publicized] 11 April 2001.
Mars Odyssey Begins Journey to Red Planet by Jim Banke, Space.com, 7 April 2001.
Life on Mars! is a related CA webpage.
April 6:
Tagish Lake meteorite contains few amino acids. Reports at recent science conferences say that the carbon-rich meteorite that fell in British Columbia in January 2000 has few of the organic compounds that characterize most carbonaceous meteorites. Instead, much of the carbon in this meteorite is found in large honeycomb-shaped molecules of carbon and hydrogen. Furthermore, the meteorite is unusually fragile, has a high concentration of stardust grains from interstellar space and has clays that could have formed only in the presence of liquid water. Dr. Sandra Pizzarello, a faculty research associate in the chemistry department at Arizona State University says, "I don't know quite what to make of it." We are curious to know more.
Kenneth Chang, "Scientists Find Twinge of Disappointment in Meteorite" [text], The New York Times, 6 April 2001.
Comets... is a related CA webpage. Its What'sNEW section points to seven earlier news items about Tagish Lake.
April 2:
Carbon dioxide made gullies on Mars? A team from the University of Arizona thinks so. The small channels were discovered last summer in high-resolution images from the Mars Global Surveyor orbiter camera. They are found mainly at high latitudes near Mars' south pole, on slopes facing away from midday sunlight. Notably, the gullies always start about 100 meters below the top of the cliff. According to a report in today's Geophysical Research Letters, all of these details are consistent with the CO2 theory.
Liquid CO2, Not Water, Likely Created Martian Gullies by Don Musselwhite et al., UniSci.com, 2 April 2001.
Life on Mars! is a related CA webpage.
March 30:
A giant comet with a very large orbit cannot be explained by existing theories of comet formation. The supercomet, 2000 CR105, was first spotted in February 2000 and is some 400 kilometers wide. Brett Gladman and colleagues at the Observatoire de la Côte d'Azur, France, say the comet's highly elliptical orbit takes it as far as 58.2 billion kilometers from the sun. The orbit's nearest point is 6.6 billion kilometers from the sun, still far outside Neptune's orbit. Astronomers are wondering if an undiscovered distant planet could have pulled the comet into its high orbit. Or, if Neptune once had a much more eccentric orbit, it could have provided the tug. Astronomers will now seek other similar comets. [Thanks CCNet.]
Signs of a Hidden Planet? by Govert Schilling, Academicpress.com, 28 March 2001.
Comets... is a related CA webpage.
March 28:
British mission may return first Mars sample. The mission, which could launch in 2009 if approved by the European Space Agency, is designed to cost well under the $1 billion that NASA had allotted for a similar mission that presently is on indefinite hold. According to the preliminary plan, a probe aboard a Mars orbiter would be dropped through Mars' atmosphere, slowed by parachutes and cushioned on impact with the surface by airbags. An arm would drill down a meter or so for a 200-gram core sample and place it in a canister. A small rocket engine would then send the probe back into orbit where it would bleep for detection and undergo "laser-range control" retrieval by the orbiter. The orbiter would return to Earth within the next two years, when orbital mechanics were most favorable. [Thanks CCNet.]
Mars Rock Return Mission Planned by British, by Robin Lloyd, Space.com, 27 March 2001.
Life on Mars! is the related CA webpage.
March 19:
Did a chunk of ice fall to Earth from a comet? On 6 March, a piece of ice crashed through the roof of a house in Harbord, Australia. About 12 inches in longest dimension, it was too large for a hailstone. Now NASA has taken a sample to California for testing. A similar ice fall in Meliana, Spain, last January was found to be of earthly origin. [Thanks CCNet.]
Flying ice block may have alien origin, Daily Telegraph, Sidney, Australia, 17 March 2001.
Comets... is a related CA webpage.
March 16: [From the 32nd Lunar and Planetary Science Conference.]
Meteors could carry life from one solar system to another. "About one meteorite ejected from a planet belonging to our Solar System is captured by another stellar system every 100 million years," Jay Melosh of the University of Arizona told the Lunar and Planetary Science Conference in Houston this week. And Russell Vreeland of West Chester University of Pennsylvania says it would be quite possible for meteorites to carry well-protected organisms over interstellar distances.
All Aboard the Meteor Express of Life, by Jeff Hecht, SpaceDaily, 17 March 2001.
Or could they? Melosh's own conclusion is much more pessimistic than the reports on his work. Read his article submitted to the Proceedings of the Rubey Symposium, May 2002. [Thanks, Ron Mcghee.]
H. J. Melosh, "Exchange of Meteorites (and Life?) between Stellar Systems" [PDF], revised Aug 2002.
New Mars. Maria Zuber, deputy lead for Mars Global Surveyor' Mars Orbiter Laser Altimeter, says, "From my perspective, pretty much every six months you have a new Mars. ...If you had studied Mars 20 years ago and you came to this meeting today, you would think that people were talking about a different planet that wasn't the one you studied."
Scientists Evaluate a 'New Mars', by Leonard David, Space.com, 14 March 2001.
Life on Mars! is a related CA webpage.
March 14: [More from the human genome sequence announcements.]
Intronless paralogs: "Retrotransposition of processed mRNA transcripts into the genome results in functional genes, called intronless paralogs, or inactivated genes (pseudogenes)," Science says. We note that, if a gene is installed in pieces, the creation of an intronlelss paralog could complete the process, after which the original, interrupted allele could become corrupted or deleted with no harm. Craig Venter et al. report finding 298 examples of interrupted and intronlelss paralog pairs, including 97 intronless, full-length, functional human genes.
J. Craig Venter et al. "The Sequence of the Human Genome" [abstract], p 1304-1351 v 291, Science, 16 Februrary 2001.
Introns... is a related CA webpage.
Transposons as a creative force. The number of recognized examples of beneficial human genes apparently installed by transposons has grown. The International Human Genome Sequencing Consortium identified 27 more, bringing the total to 47. They note that transposon installation into the human genome seems to have happened primarily in two episodes, both more than 50 million years ago.
International Human Genome Sequencing Consortium, "Initial sequencing and analysis of the human genome" [abstract], p 860-921 v 409, Nature, 15 Februrary 2001.
Frederic Bushman, "New Genes Created from Transposon Fragments," p 323-235, Lateral DNA Transfer, Cold Spring Harbor Laboratory Press, 2002.
Transposon insertion and the immune system is the topic of What'sNEW, 25 August 1998.
The human genome..., What'sNEW, 12 February 2001.
Viruses... is a related CA webpage. [Next-What'sNEW about HGT-Prev]
March 12:
Nature features astrobiology in a special Insight section with seven articles pertaining to life in the cosmos. The transfer of life from one planet to another after impacts is considered a realistic possibility in several of the articles. The search for "aliens" gets a lot of attention, as do extremophiles. Sean B. Carroll's article about the evolution of complexity was especially interesting to us. "We do not understand why the actual complexity realized in evolution is far less than what seems to be possible genetically," he observes. But he does not doubt that random processes, perhaps driven by some bias toward complexity, can produce sustained evolutionary progress.
Nisbet and Sleep consider all kinds of possibilities for the origin of life and photosynthesis, and we welcome their emphasis on the role of gene transfer. They conclude with a plea for the rejection of creationism, saying, "Judeo-Christian thought must accept convincing evidence from nature." The evidence that life on Earth was formerly simpler than now is convincing, we agree. That life originates and advances by Darwinian evolution, without input, is another matter. We wish this difference, and the panspermia alternative to Darwinism and creationism, received more notice.
An ad at the front of the section announces The International Journal of Astrobiology, coming from Cambridge University Press.
E. G. Nisbet and N. H. Sleep, "The habitat and nature of early life," p 1083-1091 v 409 Nature, 22 February 2001.
Sean B. Carroll, "Chance and necessity: the evolution of morphological complexity and diversity," p 1102-1109 v 409 Nature, 22 February 2001.
Evolution vs Creationism is a related CA webpage.
March 7:
Comet Hale-Bopp is still actively shedding gas and dust, almost 2 billion kilometers from the sun, despite the low temperature there. Ordinarily, comets actively shed material only when they are within 4-5 hundred million kilometers from the sun, where it can warm them. Hale-Bopp's orbit places it deep in the southern sky, where it is being tracked by the European Southern Observatory.
Visiting with an Old and Active Friend: La Silla Telescope Views Comet Hale-Bopp at 2 Billion Kilometres, European Southern Observatory, 6 March 2001.
Comets... is a related CA webpage.
March 7:
The 32nd Lunar and Planetary Science Conference will be held March 12-16, at the NASA Johnson Space Center in Houston, Texas. More than 1100 papers will be presented on topics pertaining to astrobiology, asteroids, Europa and Jupiter, extraterrestrial life, Ganymede and Io, Martian glaciers, Martian volcanoes, Martian water, Mercury, the Tagish Lake Meteorite and Venus. Whether the magnetites in the Mars meteorite ALH 84001 are sufficient to prove that there was life on Mars is sure to be discussed. [Thanks, Ron Baalke and Frances Westall.]
32nd Lunar and Planetary Science Conference, 12-16 March 2001.
Life on Mars! is a related CA webpage.
March 6:
Microbes survive after a simulated meteorite impact. One way for microorganisms to escape a planet is to be blasted off by a high-speed impact. But would the shock of such an impact kill them all? Now a team from Germany has investigated whether microorganisms could survive a pressure shock comparable to that which some martian meteorites appear to have experienced. In experiments using explosives, spores of Bacillus subtilis HA 101 were subjected to a peak shock pressure of 32 GPa between two quartz plates. Their survival rate reached 10^-4. The experimenters conclude, "bacterial spores may survive an impact-induced escape process in a scenario of interplanetary transfer of life." [Thanks, CCNet.]
G. Horneck, D. Stoffler, U. Eschweiler and U. Hornemann, "Bacterial spores survive simulated meteorite impact," p 285-290 v 149 n 1, Icarus, January 2001.
Can the Theory Be Tested? is a related CA webpage.
March 5:
Influenza epidemics are four times more likely during solar maxima. A Canadian team of a solar physicist, a phsician and an epidemiologist compared flu and solar records dating back to 1729 and found a statistically significant connection. Although the results were compelling, the team offered no explanation for the effect. The report adds plausibility to the earlier suggestion by Hoyle and Wickramasinghe that increased solar radiation might enhance the penetration of space-borne germs into Earth's atmosphere. [Thanks, CCNet.]
Flu epidemics coincide with solar eruptions..., Margaret Munro, National Post, Canada, 2 March 2001.
Influenza from Space? is a related CA webpage.
