WASHINGTON — An orbiting NASA telescope is finding whole new worlds of possibilities in the search for alien life, spotting more than 50 potential planets that appear to be in the habitable zone.
In just a year of peering out at a small slice of the galaxy, the Kepler telescope has discovered 1,235 possible planets outside our solar system. Amazingly, 54 of them are seemingly in the zone that could be hospitable to life — that is, not too hot or too cold, Kepler chief scientist William Borucki said.
Until now, only two planets outside our solar system were even thought to be in the "Goldilocks zone." And both those discoveries are highly disputed.
Fifty-four possibilities is "an enormous amount, an inconceivable amount," Borucki said. "It's amazing to see this huge number because up to now, we've had zero."
The more than 1,200 newfound celestial bodies are not confirmed as planets yet, but Borucki estimates 80 percent of them will eventually be verified. At least one other astronomer believes Kepler could be 90 percent accurate.
After that, it's another big step in proving that a confirmed planet has some of the basic conditions needed to support life, such as the proper size, composition, temperature and distance from its star. More advanced aspects of habitability such as atmospheric conditions and the presence of water and carbon require telescopes that aren't built yet.
Just because a planet is in the habitable zone doesn't mean it has life. Mars is a good example of that. And even if some these planets are found to contain life, it may not be intelligent life; it could be bacteria or mold or some kind of life form people can't even imagine.
Kepler has also identified a solar system with at least six small planets orbiting their sun — all lined up on a disc-like plane similar to our own.
The planets — called exoplanets because they are outside the Earth's solar system — are believed to be gaseous rather than rocky and so unable to support life, but the discovery of a system with so many planets and all orbiting in a manner similar to planets in our system has created great excitement.
"This is a remarkable system and a very exciting sign of what else is to come," said Jonathan Fortney, a member of the Kepler science team from the University of California at Santa Cruz.
All the celestial bodies Kepler looks at are in our Milky Way galaxy, but they are so far away that traveling there is not a realistic option. In some cases it would take many millions of years with current technology.
But what Kepler is finding in distant parts of the galaxy could be applied to exploring closer stars, astronomers say.
"Our grandchildren will have to decide what's the next step," Borucki said at a NASA news conference. "Do they want to go there? Do they want to send a robot?"
Before Wednesday, the count of confirmed planets outside the solar system stood at 519. That means Kepler could triple the number. And those findings are from Kepler's scanning of just one four-hundredth of the night sky, so the actual number of planets out there is presumably hundreds of times greater, Borucki said.
That is exciting to astronomers, since the more planets there are, the greater the odds that life exists elsewhere in the universe.
Yale University astronomer Debra Fischer, who wasn't part of the Kepler team but serves as an outside expert for NASA, said the new information "gives us a much firmer footing" to hope for worlds that could harbor life.
"I feel different today, knowing these new Kepler results, than I did a week ago," Fischer said. She said Kepler "has blown the lid off of everything we know about extrasolar planets."