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Two Saturn-sized planets discovered

By Michelle Kessler, USA TODAY

NASA's Kepler telescope, launched from Cape Canaveral in March 2009, has discovered two Saturn-sized planets orbiting another star, officials announced today.

The discovery is the first confirmed of another system with multiple planets using the methods employed by Kepler, which measures tiny changes in the brightness of stars as planets cross in front of it, NASA said.

Dubbled Kelper 9b and 9c, the planets are the size of Saturn and orbit close around a star like our sun, more than 2,000 light years away in the constellation Lyra.

Researchers have also identified a possible third planet, not yet confirmed, believed to be the size of a super-Earth, with a radius about 1.5 times Earth's.

NASA could confirm within weeks the existance of the third planet, which would be the smallest yet observed by radius outside our solar system.

Kepler's mission is to search for planets similar in size to Earth that orbit in "habitable" zones where life could be possible.

The observatory, now about 18 million miles from Earth in orbit around the sun, continuously monitors a patch of sky that includes more than 150,000 stars.

More than 473 planets outside our solar system, called "exoplanets," have been discovered since 1995. Another group of planets was discovered by European scientists earlier this week.


Why fish don't freeze in the Arctic Ocean
Stunning deep-sea images from Indonesia