Andromeda up close, second genesis and Gedanken in astrobiology

Welcome! "Alien Life" tracks the latest discoveries and thoughts in the various elements of the famous Drake Equation. Here's today's news:
g Stars - NASA's Spitzer Space Telescope has captured a stunning infrared view of Messier 31, the famous spiral galaxy also known as Andromeda. Andromeda is the most-studied galaxy outside our own Milky Way, yet Spitzer's sensitive infrared eyes have detected captivating new features, including bright, aging stars and a spiral arc in the center of the galaxy. See article.
g Abodes - No one knows when life first established a firm foothold on Earth. Ask around in the scientific community, though, and you'll probably hear that the surface of early Earth, before about 3.8 billion years ago, was too hostile an environment for even a lowly microbe to set up shop. The main problem, as the conventional argument goes, was that between around 4.1 and 3.8 billion years ago, comets and asteroids were constantly bombarding Earth. The disastrous effects of these impacts would have rendered the Earth's surface uninhabitable. Not necessarily so, say a team of astrobiologists who are studying the oldest known sedimentary rocks on Earth. See article. Note: This article is from 2000.
g Life - If life originated on Earth, rather than being brought here from somewhere else, the question then arises as to whether life may have arisen more than once. If that is the case, then it is of interest to ask what evidence might exist for such a second genesis of life. See article.
g Intelligence - Scientists digging in a remote Indonesian cave have uncovered a jawbone that they say adds more evidence that a tiny prehistoric Hobbit-like species once existed. See article.
g Message - How many technically advanced civilizations exist in our galaxy? With this essay by Steven Soter, Scientist-in-Residence in the Center for Ancient Studies at New York University, Astrobiology Magazine initiates the first in a series of "Gedanken" or thought, experiments - musings by noted scientists on scientific mysteries in a series of "what if" scenarios. See article.
g Cosmicus - Once hotel companies start to build and operate orbital accommodation, they're going to be endlessly improving it, and competing to build more and more exotic facilities. One of the areas in which they'll compete will be in building zero-G sports centers. Basically, the bigger these are the more interesting the opportunities they'll provide. See article.
g Learning - Here’s a neat, interactive Web site that shows how gravity works with different solar system configurations. See site.
g Imagining - Here’s a neat site that draws upon the history of science fiction for examples: "Let’s Build an Extraterrestrial".

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