Reasons For Theorizing
Discoveries regarding extrasolar planets were first published in 1989 raising the prospect of whether life (as we know it or imagine it) could be supported on other planets. It is currently believed that for this to happen a planet must orbit in a relatively narrow band around its parent star, where temperatures are suitable for water to exist as a liquid. This region is called the habitable zone.
The most Earth-like exoplanets yet found, Gliese 667Cc and Gliese 581g (disputed), have masses larger than Earth's and orbit red dwarf stars in the habitable zone. All currently known smaller extra solar bodies orbit pulsar PSR 1257+12.
The sensitivity of current detection methods makes it difficult for scientists to search for terrestrial planets smaller than this. To allow smaller bodies to be detected, NASA was studying a project called the Terrestrial Planet Finder (TPF), a two-telescope concept slated to begin launching around 2014. However, Congressional spending limits under House Resolution 20 passed on January 31, 2007 by the U.S. House of Representatives and February 14 by the U.S. Senate have all but canceled the program.
Prior to TPF's cancellation, astrophysicists had begun speculating about the best places to point the telescope in order to find Earth-like planets. While life on earth has formed around a stable yellow dwarf, solar twins are not as common in the galaxy as red dwarf stars (which have a mass of less than one-half that of the Sun and consequently emit less heat), or bigger, brighter blue giants. In addition, it is estimated that more than a quarter of all stars are at least binary systems, with as many as 10% of these systems containing more than two stars (trinary etc.)—unlike our own sun, which has no companion. Therefore it may be prudent to consider how life might evolve in such environments. Such speculation may still be of use should a future planet-finding telescope be launched, and possibly for NASA's Kepler mission.
Read more about this topic: Aurelia And Blue Moon
Famous quotes containing the words reasons for, reasons and/or theorizing:
“Adolescents, for all their self-involvement, are emerging from the self-centeredness of childhood. Their perception of other people has more depth. They are better equipped at appreciating others’ reasons for action, or the basis of others’ emotions. But this maturity functions in a piecemeal fashion. They show more understanding of their friends, but not of their teachers.”
—Terri Apter (20th century)
“With what reason remains he reasons ill.”
—Samuel Beckett (1906–1989)
“From the outset, the Christian was the theorizing Jew, the Jew is therefore the practical
Christian, and the practical Christian has become a Jew again.”
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