Scientists Discover A Habitable ‘Super Earth’ — Which May Already Be Hosting ‘Alien’ Life
According to new research published in Nature, a newly discovered “super-Earth” sits just 39 light-years away in another solar system —
and scientists are dubbing it one of the best exoplanets to potentially support alien life.
Its rocky surface and prime location its own solar system mean the exoplanet, LHS 1140b, potentially has liquid water — which means extraterrestrial life is possible too.
In the last year, a number of nearby exoplanets were discovered that scientists believe could be habitable to alien life, such as Proxima b and the seven Earth-sized TRAPPIST-1 planets.
But for many, LHS 1140b, also known as a “super-Earth,” is the most exciting exoplanet discovered yet.
“It’s very interesting to me that we have just discovered a super-Earth right up against that boundary,” said Dittman.
“The fact that the planet is rocky and in its star’s habitable zone also raises its intrigue, because we may now have a planet suitable for the search for life as well.”
Dittman and his team discovered LHS1140b by way of the transit method, in which the light of a star dims as a planet is crossing, or transiting, as viewed by Earth-bound instruments. The research team estimates the planet has a diameter of almost 11,000 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,” Dittman added.
Statistical results suggest that the nearest transiting Earth-sized planet in the liquid-water, habitable zone of an M dwarf star is probably around 10.5 parsecs away4. A temperate planet has been discovered orbiting Proxima Centauri, the closest M dwarf5, but it probably does not transit and its true mass is unknown. Seven Earth-sized planets transit the very low-mass star TRAPPIST-1, which is 12 parsecs away ,but their masses and, particularly, their densities are poorly constrained. Here we report observations of LHS 1140b, a planet with a radius of 1.4 Earth radii transiting a small, cool star (LHS 1140) 12 parsecs away. We measure the mass of the planet to be 6.6 times that of Earth, consistent with a rocky bulk composition. LHS 1140b receives an insulation of 0.46 times that of Earth, placing it within the liquid-water, habitable zone8. With 90 per cent confidence, we place an upper limit on the orbital eccentricity of 0.29. The circular orbit is unlikely to be the result of tides and therefore was probably present at formation. Given its large surface gravity and cool insulation, the planet may have retained its atmosphere despite the greater luminosity (compared to the present-day) of its host star in its youth9,10. Because LHS 1140 is nearby, telescopes currently under construction might be able to search for specific atmospheric gases in the future.