For the first time, astronomers have discovered a planet outside our solar system that is potentially habitable with Earth-like temperatures - a find researchers described on Tuesday as a big step in the search for life in the universe.
"This is the most Earth-like planet yet, even if it's not an Earth," astrophysicist Steve Maran told Associated Press Television.
Located by scientists working at the European Space Observatory facilities at La Silla Paranal Observatory in Chile, the star Gliese-581 apparently has a rotating planet.
The planet is just the right size, might have water in liquid form, and in galactic terms is relatively nearby at 120 trillion miles away.
But the star it closely orbits, known as a "red dwarf," is much smaller, dimmer and cooler than our sun.
There is still a lot that is unknown about the new planet, which could be deemed inhospitable to life once more is known about it.
"It's an incremental advance in what we're learning about planets and stars," Maran said.
Maran also said that a new research instrument at the European Southern Observatory was able to show trace of the planet through a "wobble" pattern of the red dwarf sun.
The planet was discovered by the European Southern Observatory's telescope in La Silla, Chile, which has a special instrument that splits light to find wobbles in different wave lengths.
Those wobbles can reveal the existence of other worlds.
"That's something really very slow by the standards of outer space, and it's a great technological achievement to detect it," Maran said.
There are still a lot of questions that scientists need to ask.
The results of the discovery have not been published but have been submitted to the journal Astronomy and Astrophysics.
Red dwarfs are low-energy, tiny stars that give off dim red light and last longer than stars like our sun.
Until a few years ago, astronomers did not consider these stars as possible hosts of planets that might sustain life.