Nearby earth-like planet may be just right for life


A planet is considered habitable when it's in an area where liquid water might exist.

Still, he said he's confident that astronomers will find a habitable planet soon, be it LHS 1140b or another.

The MEarth facility first noticed the telltale sign of a dip in light as the exoplanet passed in front of its star. The planet itself is 1.4 times larger and 6.6 times more massive than Earth, and the principal investigators of the study published today in Nature believe it to be rocky. Those dimensions strongly suggest that the world is rocky like Earth too. But finding a super-Earth with a rocky composition is pretty rare, and the fact that it's in the habitable zone makes the discovery even sweeter.

The following content is co-posted from the Harvard-Smithsonian Center for Astrophysics.

That candidate is an exoplanet orbiting a red dwarf star 40 light-years from Earth-what the global team of astronomers who discovered it have deemed a "super-Earth". By measuring how much light this planet blocks, the team determined that it is about 11,000 miles in diameter, or about 40 percent larger than Earth. But they're not always ripe for life.

Follow-up observations studied the star's "wobble" caused by a gravitational tug of war with the planet and confirmed the presence of a super-Earth. A problem with these smaller stars is that they tend to blast their systems with frequent flares of radiation in the earlier part of their lives.

"With this planet and TRAPPIST-1, our list is growing larger and larger, and when the next telescopes are built it's just going to completely change everything", he said. Those planets are smaller than this one, but they're thought to be rocky too.

This habitable zone is also known as the "Goldilocks" zone, taken from the children's fairy tale.

But with a mass around seven times greater than the Earth, and hence a much higher density, it implies that the exoplanet is probably made of rock with a dense iron core.

But the star that Dittmann found is a bit more intriguing since it's fairly quiet.

Its star also emits less radiation than many other red dwarfs, making the planet more likely to have preserved an atmosphere. That's not the case for this star. One of the key similarities between it and our own orb that we call home is that it "receives similar amounts of energy from its star that Earth does from the Sun, which means it may have liquid water on its surface".

The joint exercise revealed a small, dim star circled by a small, tubby planet. That makes it much it easier to see and study this planet, since it's not completely overpowered by intense starlight.

But for a planet that's orbiting a star about 800,000 years away from us in the constellation of Cetus, how do we know such details? Figuring out the gases in that atmosphere could paint a picture of what conditions are like on the surface below. "It turns out it was lurking there all along", says Dittmann, now at MIT.

"It's just incredible what these amateurs are capable of", said Dittmann.

More observations using the Hubble Space Telescope are underway and the researchers are already using everything they can to study the planet and its atmosphere.

Researchers believe it may be one of the best candidates for a closer look in the future by the James Webb Space Telescope, which NASA will launch in 2018.

LHS 1140b's dense metal core, however, might mean that it was covered by an ocean of magma during its host star's insane youthful period.

"We are multiplying opportunities for looking for the place where life may have emerged elsewhere in the Universe", he said.