BEIJING, Feb. 26 (Xinhuanet) -- A mini planet that is the smallest of more than 800 extra-solar planets was found beyond solar system, U.S. scientists said on Tuesday.
The planet, known as Kepler-37b, was discovered with a NASA space telescope and is one of three circling a sun-like star located in the constellation Lyra, about 210 light years away.
Kepler-37b flies about 10 times closer to its sun-like star than Earth circles the sun, which gives it a surface temperature of about 427 degrees Celsius.
Mercury is the closet planet to the sun in solar system, so scientists compared Kepler-37b to a mini Mercury.
"This is the first time we've been able to probe the smallest range, smaller than anything we have in our solar system," said Thomas Barclay, with NASA's Ames Research Center in Mountain View, California.