"These planets orbit quite close to their stars, so they're quite hot," said Kepler science team leader William Borucki of NASA's Ames Research Center in Moffett Field, Calif., who made the announcement at the American Astronomical Society meeting in Washington, D.C.
Launched last year, the $591 million Kepler eyeballs about 156,000 stars within 3,000 light-years of Earth for planets, according to a study in the upcoming Science journal. (One light-year is 5.9 trillion miles.)
All of the planets, which orbit their stars once within every four days' time because of their closeness, bake at temperatures above 2,240 degrees Fahrenheit. "Certainly they are no places to look for life. That will be coming later," Borucki said.
Kepler detects planets by spotting light-dipping eclipses, or "transits," of stars by their companion planets. Four of the newly detected planets are 1.3 to 1.5 times wider than Jupiter in our solar system, while the last one, dubbed Kepler-4b, is only about 0.6 times as wide as Jupiter and weighs only about 8% as much.
Analyses of the stars around which the planets orbit reveal that only about one-third release more solar blasts than our sun, says team scientist Natalie Batalha of San Jose (Calif.) State University. "That is good news for exobiology (alien life) and good news for planet detection," says astronomer Caty Pilachowski of Indiana University-Bloomington. "Kepler is going to find a lot of planets."
Opening a new chapter in planet hunting, scientists reported Monday that they had discovered five worlds orbiting nearby stars by using the Kepler space telescope.