Kepler Finds 3 Smallest Exoplanets

Just this December, NASA announced they had confirmed Kepler's detection of the two smallest exoplanets ever discovered, Kepler 20 e and Kepler 20 f, orbiting around the star Kepler 20, located 950 light years from Earth in the Lyra constellation. Both planets were estimated to be roughly the size of Earth, Kepler 20 f, being the largest of the two with an estimated diameter of around 13,200 km. Well, It's a mere month later now and it appears that three new planets have arisen to take the title of smallest known exoplanets for themselves.

Found orbiting the small red dwarf star KOI-961, which is located 130 light years from Earth, in the Cygnus constellation. KOI-961.01, KOI-961.02 and KOI-961.03 (I know, I wish they'd find a better way of naming these things too) are all believed to be rocky planets about the same size as Earth, the smallest of the three being about the size as Mars. So not only are the planets in this trio the smallest exoplanets yet discovered. But they now join the ranks of the very short list of confirmed exoplanets that are believed to be rocky worlds like our own, as well.

As for the BIG question that's always on every one's mind whenever any extra solar planet is discovered. According to NASA, the proximity to which these newly discovered worlds are believed to orbit their parent star, would it impossible for them to maintain surface liquids, and therefore -unlikely homes for life.

-CAINE-

Image Credit: NASA/JPL
VIA: jpl.nasa.gov

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.

Kepler Finds it's First Circumbinary Planet (Insert Obligatory Star Wars Refernce Here)

NASA's Kepler mission has announced the first direct detection of a circumbinary planet – a planet orbiting two stars- in a binary star system designated Kepler-16, located 200 light-years from Earth. While potential planets have previously been detected in other binary systems, Kepler-16b, as this newest exoplanet is now known, is the first confirmed planet to have been observed orbiting both it's parent stars.

A binary star system, as the name suggests, is a system with two stars orbiting around a common center of mass. Because from our vantage point on Earth, each of the two stars regularly passes in front of the other during their orbit, Kepler-16 is classified as an eclipsing binary.

Observations of Kepler-16 showed a drop in light from the system, not only when the stars eclipsed one another, as expected, but also a when neither star was eclipsing the other, indicating the presence of a much smaller 3rd object orbiting around them. By measuring the gravitational tug applied to the stars by this third objects, scientists were able to estimate it's mass, and Kepler-16b, as the new planet is now known, is believed to be a cold, uninhabitable world, about the size of Saturn, comprised of gas and rock.

Though Kepler-16b may be a cold, gaseous world -incapable of harboring any Jedi resistance fighters -or even sand people. As Kepler's Principal investigator William Borucki points out, the confirmation of a planet orbiting in a binary system - which are much more common than the single star system in which we reside-

"confirms a new class of planetary systems that could harbor life," and "Given that most stars in our galaxy are part of a binary system, this means the opportunities for life are much broader than if planets form only around single stars. This milestone discovery confirms a theory that scientists have had for decades but could not prove until now."


-CAINE-

Source: NASA.gov
VIA: GGB on tumblr