Cape Canaveral: Astronomers from NASA`s Kepler project have discovered a mini planet which is the smallest known world outside our solar system.
The planet is the innermost of three circling a yellow star similar to the sun and is named Kepler-37.
Thomas Barclay, who works with NASA`s Ames Research Center in Mountain View, California, was quoted as telling a news agency, "We see very large planets and they`re uncommon. Earth-sized planets seen to be pretty common, so our guess is that small planets must be even more common”.
The smaller the planet, the more difficult it is to find.
Kepler-37b, as well as two sibling planets, were discovered with a NASA space telescope of the same name, which studies light from about 150,000 sun-like stars.
Kepler-37b flies about 10 times closer to its star than Earth circles the sun, which gives it a surface temperature of about 800 degrees Fahrenheit (427 degrees Celsius).
Mercury is the closet planet to the sun in our solar system, so scientists compared Kepler-37b to a mini Mercury.
The little planet, which is slightly larger than Earth`s moon, has two somewhat larger siblings. Kepler-37c, which is slightly smaller than Venus, circles the trio`s parent star in 21 days and Kepler-37d, about twice the size of Earth, orbits in 40 days.
The Kepler telescope works by detecting slight dips in the amount of light coming from target stars caused by orbiting planets passing by, or transiting, relative to the observatory`s line of sight. The smaller the planet, the less pronounced the dip.
Of the 833 confirmed planets found beyond the solar system, 114 were discovered by the Kepler science team, according to the project`s website. Nearly 3,000 more Kepler candidate planets are being analyzed.
(With Agency inputs)