Exoplanets Everywhere: Kepler's ongoing Search for Other Worlds

When an object of a significant enough size passes in front of any star within Kepler's field of view (that's about 150,000, in case you were wondering), it causes a dip in the magnitude of light being emitted by the star. Revealing, not only the presence of any extrasolar planets around said star, but also the distance at which those planets orbit their parent star. This method of detection is commonly referred to as the transit method, and like any other method of detecting such planets, requires multiple observations for confirmation.


Found Orbiting the class G star Kepler 22, which is located around 600 light years from Earth in the Cygnus constellation. Planet Kepler 22b, was found to have a 290 day orbital cycle, which places the planet within what we have defined as the habitable zone of its parent star; which is lower in mass, and cooler than our own sun. But there's a catch. While the planet's diameter is estimated to be around 2.4 times that of Earth's, the actual mass of the planet is impossible to determine based on Kepler's observations alone. So it's impossible to say weather or not Kepler 22b is a rocky planet like Earth, or gaseous ball like Jupiter and Saturn. But if it is a world like our own, and assuming that it also has the proper atmosphere Kepler 22b would have an estimated average surface temperature of around 72 degrees F. Which would make it not only the most Earth-like world yet discovered, but also the most likely home for life as we know it outside of our own solar system. The prospect is obviously tantalizing.

To date, scientists have confirmed the existence of over 500 exoplanets * using Kepler, The Hubble Space Telescope, and various other observational techniques. As time goes on, even more discoveries will be made, and long term observations will slowly scratch all of the potential candidates off Kepler's list; possibly resulting in the confirmed discovery of several thousand more worlds orbiting stars light years away from our own. And while it will likely be some time before we ever definitively confirm that conditions on one those planets is conducive to life. The apparent abundance of stars with planetary systems would seem to suggest that it's only a matter of time before we do. And even if we can't say for certain that there's life on any of those planets, to think that we live in a time when discovering worlds in other star systems has become common place, is astonishing, to say the least.

-CAINE-

Source: NASA1, NASA2
Image credit: Kepler 11- NASA/Tim Pyle, Kepler 20e, 20 f, and 22b- NASA/Ames/JPL-Caltech

*The exact number of confirmed exoplanets was actually kind of hard to nail down, The Extrasolar Planets Encyclopedia claims 716. But the most common figure I found was in the 500-600 range.