Not Another Space Article! Thoughts on Extrasolar Planets

The year 1995 was a significant point in the history of science: two scientists at the University of Geneva discovered a planet orbiting the distant star 51 Pegasi. This was the first verified extrasolar planet discovery of the time, and now, twelve years later, over 200 extrasolar planets have been found orbiting other stars.

Although most planets discovered thus far are gas giants many times larger than Jupiter, some searches have turned up planets only a few times the size of Earth. On December 27th of 2006, just a few weeks ago, the first satellite designed specifically to find extrasolar planets was launched. The orbiting telescope, called CoRoT, was put into space by the European Space Agency, and is designed to find planets a few times the size of Earth.

Planet hunts are also in the future of NASA, with the Kepler mission, SIM PlanetQuest, and others. The tentative Terrestrial Planet Finder, or TPF, will search nearby star systems for planets roughly the size of Earth. In the event of the discovery of not only an Earth-sized planet, but chemical signatures of life as well, the age-old question of "are we alone?" would finally be answered. Although planets of a terrestrial-type are the holy grail, the larger cosmic bodies will not be forgotten. Gas giant planets should not be ruled out in the search for other Earths, as moons of several thousand miles in diameter are likely to be found orbiting these giants. Titan, for example, a moon of Saturn, is nearly as large as Mars and has a thick atmosphere. It is conceivable that a hypothetical gas giant could have a moon as large as Earth.

The search for extrasolar planets continues in 2007, and will likely turn up dozens of new worlds. With so many possibilities out there, one can be almost sure that the at least part of the future of humanity will lie in space...

Here are some cool sites on extrasolar planets:

PlanetQuest- http://planetquest.jpl.nasa.gov/index.cfm

The Extrasolar Planets Encyclopaedia-

http://vo.obspm.fr/exoplanetes/encyclo/catalog.php