Most habitable planets may lack dry land

This artist's impression shows the exoplanet LHS 1140b, which orbits a red dwarf star 40 light-years from Earth and may be the new holder of the title "best place to look for signs of life beyond the Solar System".

The name is LHS 1140b. 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.

With thousands of planets now confirmed, each day we get a little closer to that futuristic "Star Trek" mission credo "to explore unusual new worlds, to seek out new life and new civilizations".

The study's main author, Jason Dittmann, with the Harvard-Smithsonian Centre for Astrophysics, said that this is the "most interesting" exoplanet that he's seen in the last decade.

Whether there is actually water on the planet or not depends on the composition of its atmosphere and other factors, including the presence of a magnetic field, such as the one Earth has, but the most important thing is for the planet to "fulfil the requirements to have water", which means that it must be in its star's habitable zone, Murgas said. Releasing the results of their preliminary research of LHS 1140b in this week's Nature, Dittmann is hopeful at the prospect of finding life on this distant planet, a feat which has yet to be reached by the scientific community. The exoplanet is in the Cetus constellation, which is relatively close at just 40 light years away.

More news: Trapped Mosul civilians could face worst catastrophe of Iraq conflict, United Nations warns

In the new work, Simpson finds that the Earth's finely balanced oceans may be a effect of the anthropic principle - more often used in a cosmological context - which accounts for how our observations of the Universe are influenced by the requirement for the formation of sentient life. At this point, there's still much to learn about the planet, but it's definitely a starting point for newer, more powerful telescopes.

In August 2016, a solitary habitable planet was found orbiting Earth's nearest star, Proxima Centauri. But LHS 1140b's large mass could make the study of its potential atmosphere tricky. It is in the so-called Goldilocks zone of its parent star, meaning its temperature is just right to have liquid water on the planet's surface. At the moment, our hopes rest on the telescopes now under construction in Chile which are due to be completed soon, whilst NASA's James Webb Space Telescope, which should be operational in 2018, is also expected to provide some support. LHS-1140b, as the new planet is known, however, particularly excited scientists due to the possibility of carrying out an analysis of its atmosphere with the help of existing telescopes. If initial on-Earth investigations indicate there are signs of life on the planet, the next step would naturally be to dispatch a probe. "Future observations might enable us to detect the atmosphere of a potentially habitable planet for the first time".

"LHS 1140 spins more slowly and emits less high-energy radiation than other similar low-mass stars", points out Astudillo-Defru.

Outside astronomers have already put this new planet near the top of their must-see lists for new ground and space-based telescopes.

  • Myrtle Hill