Thursday, April 19, 2007

Habitable zones around M- and K-type stars, nanonauts and ‘The Embedding’

Welcome! “Alien Life” tracks the latest discoveries and thoughts in the various elements of the famous Drake Equation. You may notice that this and future entries are shorter than usual; Career, family and book deal commitments have forced me to cut back some of my projects. Now, here’s today’s news:
g Stars - Low mass M- and K-type stars are much more numerous in the solar neighborhood than solar-like G-type stars. Therefore, some of them may appear as interesting candidates for the target star lists of terrestrial exoplanet (i.e., planets with mass, radius, and internal parameters identical to Earth) search programs like Darwin (ESA) or the Terrestrial Planet Finder Coronagraph/Inferometer (NASA). The higher level of stellar activity of low mass M stars, as compared to solar-like G stars, as well as the closer orbital distances of their habitable zones, means that terrestrial-type exoplanets within HZs of these stars are more influenced by stellar activity than one would expect for a planet in an HZ of a solar-like star. See http://www.liebertonline.com/doi/pdfplus/10.1089/ast.2006.0127.
g Abodes - Scientists have found one of the largest fields of seafloor vents gushing super-hot, mineral-rich fluids on a mid-ocean ridge that, until now, remained elusive to the ten-year hunt to find them. See http://www.sciencedaily.com/releases/2007/04/070413151129.htm.
g Life - The biologically destructive effects of atmospheric transit can generate entirely novel and improved endolithic habitats for organisms on the destination planetary body that survive the dispersal filter. The experiment advances our understanding of how island biogeography works on the interplanetary scale. See http://www.liebertonline.com/doi/pdfplus/10.1089/ast.2006.0038.
g Intelligence - The first primate to get rocketed into space and to be cloned, the rhesus monkey, has now had its genome sequenced, promising to improve research into health and yield insights into human evolution. See http://www.livescience.com/humanbiology/
070412_rhesus_monkeys.html
.
g Message - When the Voyager 1 and 2 spacecraft were launched in 1977, they each included a gold-plated phonograph record (a "golden record") of natural sounds, greetings in human voices, and a variety of music. The record cover has symbolic instructions that show how to use and understand the record, though scientists still debate whether other civilizations will be able to decipher them. For info on Voyager’s golden record, see http://voyager.jpl.nasa.gov/spacecraft/goldenrec.html. For an explanation of the record cover diagram, see http://voyager.jpl.nasa.gov/spacecraft/goldenrec1.html. For an interactive module that contains greetings, sounds, and pictures included on the record (requires Flash plug-in), see http://www.jpl.nasa.gov/flash/voyager_record/index_voyager.html.
g Cosmicus - Engineers are designing a new breed of planetary explorers: tiny, shape-shifting devices that can be carried on the wind like dust but can also communicate, fly in formation and take scientific measurements. 'Smart dust' may one day provide a unique method of studying locations interesting to astrobiology, such as Mars and Venus. See http://www.astrobio.net/news/modules.phpop=modload
&name=News&file=article&sid=2304mode=thread&order
=0&thold=0
.
g Learning - With creationism and intelligent design continuing to battle evolution for supremacy in our schools, here’s a quality site that considers the science that supports the theory of evolution — from the National Academy of Sciences. See http://bob.nap.edu/readingroom/books/creationism/.
g Imagining - Like stories about communicating with aliens? Scour your used bookstore for Ian Watson’s “The Embedding” (1973).
g Aftermath - While formal principles have been adopted for the eventuality of detecting intelligent life in our galaxy, no such guidelines exist for the discovery of non-intelligent extraterrestrial life within the solar system. Current scientifically based planetary protection policies for solar system exploration address how to undertake exploration, but do not provide clear guidance on what to do if and when life is detected. Considering that Martian life could be detected under several different robotic and human exploration scenarios in the coming decades, it is appropriate to anticipate how detection of non-intelligent, microbial life could impact future exploration missions and activities, especially on Mars. See http://www.seti.org/atf/cf/{B0D4BC0E-D59B-4CD0-9E79-113953A58644}/m_race_guidelines.pdf.