Another nearby planet found that may be just right for life

Apr 20, 2017, 08:52
Another nearby planet found that may be just right for life

So are a group of seven mostly Earth-sized planets in or near the habitable zone found circling a star called Trappist-1 earlier this year, but it in a different direction.

A light year is the distance light travels in a year - almost six trillion miles.

'We could hardly hope for a better target to perform one of the biggest quests in science - searching for evidence of life beyond Earth'.

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.

The exoplanet, which has been (rather unimaginatively) named LHS 1140b, orbits right in the middle of the red dwarf's habitable zone (HZ) - the region of space around a star in which a planet could potentially sustain liquid water on its surface. In short, super-Earth LHS 1140b is among the most exciting known subjects for atmospheric studies.

In what has been described as one of the most important discoveries of its kind in the past decade, the existence of Planet LHS1140b - about 40 per cent bigger than Earth - will be revealed today in the prestigious journal Nature by the Harvard-Smithsonian Centre for Astrophysics. It's here, researchers say, where we might find the best chance in our search for life. But if LHS 1140b was able to withstand the brunt of its star's radiation, it's possible signs of life are lurking there. That make this place an exciting candidate in the search for life outside our Solar System.

The vast site, containing as much water as all of Earth's seas, could also potentially be a habitat for life.

The star LHS 1140 is also a red dwarf, but it's old enough to have settled down. 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. "This star that LHS 1140b orbits seems to be quiet, so it's not going to damage the planet's atmosphere or anything on its surface", Dittmann explained.

Artist's impression of the super-Earth exoplanet LHS 1140b. Charbonneau said recent studies show that the Trappist planets may not be rocky like Earth, while Trappist discoverer Michael Gillon said the newest planet has such intense gravity that its atmosphere may be smooshed down so telescopes can't get a good look at it.

For alien life to exist on a planet, it must have liquid surface water and retain an atmosphere.

Furthermore, they established that LHS 1140b receives an insolation of 0.46 times that of Earth.

Using just a 12-inch telescope - a high-end one you can purchase at astronomy stores or online - Thiam-Guan Tan from Perth, Australia, managed to provide the final confirmation that the researchers had correctly calculated the orbital period of the planet. The scientists used the MEarth-South telescope array to monitor the brightness of the star LHS 1140, starting in 2014.

An analysis of the resulting data determined that the planet orbits the star every 25 days, at a distance well within Mercury's orbit around our own sun (roughly 7.4 million miles).

Given all these possibilities, Dittmann and his team are eager to keep studying this planet with more ground-based telescopes, as well as the space-based Hubble telescope.

Two giant telescopes under construction in Chile might be powerful enough, if aimed at 1140b, to recognize any oxygen molecules of the sort that animals need to breathe, assuming 1140b is swathed in oxygen.