Astronomers say they have for the first time spotted a planet beyond our own in what is sometimes called the Goldilocks zone for life: Not too hot, not too cold. Juuuust right.
Not too far from its star, not too close. So it could contain liquid water. The planet itself is neither too big nor too small for the proper surface, gravity and atmosphere.
It's just right. Just like Earth.
The new planet sits smack in the middle of what astronomers refer to as the habitable zone, unlike any of the nearly 500 other planets astronomers have found outside our solar system. And it is in our galactic neighborhood, suggesting that plenty of Earth-like planets circle other stars.
Finding a planet that could potentially support life is a major step toward answering the timeless question: Are we alone?
Scientists have jumped the gun before on proclaiming that planets outside our solar system were habitable only to have them turn out to be not quite so conducive to life. But this one is so clearly in the right zone that five outside astronomers told the Associated Press it seems to be the real thing.
Life on other planets doesn't mean E.T. Even a simple single-cell bacteria or the equivalent of shower mold would shake perceptions about the uniqueness of life on Earth.
But there are still many unanswered questions about this strange planet. It is about three times the mass of Earth, slightly larger in width and much closer to its star — 14 million miles vs. 93 million. It's so close to its version of the sun that it orbits every 37 days. And it doesn't rotate much, so one side is almost always bright, the other dark.
Temperatures can be as hot as 160 degrees or as frigid as 25 below zero, but in between — in the land of constant sunrise — it would be "shirt-sleeve weather," said co-discoverer Steven Vogt of the University of California at Santa Cruz.
It's unknown whether water actually exists on the planet and what kind of atmosphere it has. But because conditions are ideal for liquid water, and because there always seems to be life on Earth where there is water, Vogt believes "that chances for life on this planet are 100 percent."
The findings, announced by the National Science Foundation on Wednesday, are being published in Astrophysical Journal.