LHS 1140b orbits in the habitable region or "Goldilocks zone" around a faint red dwarf star named LHS 1140.
An global team of scientists has announced the discovery of a new "super-Earth" exoplanet (a planet with more mass than Earth, but not quite as big as our gas giants) that could represent our best chance of finding life outside of our solar system.
This artist's impression shows the exoplanet LHS 1140b, which orbits a red dwarf star 40 light-years from Earth and may be astronomers' best chance at finding alien life.
This also allowed them to be sure that the planet is rocky, said HARPS team member Nicola Astudillo-Defru, because HARPS is the most precise instrument that can measure the "wobble" of the planet as the star tugs on it. That's another box you can check off on the "likely to support life" chart.
Astronomers have found roughly 20 Earth-sized planets that might support liquid water, according to a database maintained by the University of Puerto Rico at Arecibo. At that distance, it receives about half as much sunlight from its star as Earth.
The super-Earth and its parent star are located in the constellation Cetus, the Whale, 39 light years from the Sun, thus - relatively speaking - putting it in our galactic "neighbourhood", according to Felipe Murgas, the coauthor of the study and a researcher with Spain's Canary Islands Institute of Astrophysics.
Scientists believe that one of the major factors that governed the emergence of life on Earth was the presence of liquid water, and so telescopes target distant worlds capable of harboring this precious resource when searching for the hallmarks of life beyond our planet. Whilst Venus may sometimes be described as Earth's twin, it's pretty far from it, and with a surface temperature exceeding 880 degrees Fahrenheit (470 degrees Celsius), it's probably not the best environment in which to search for life.
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. This process could take 40 million years, Dittman said. They were also able to help him discover its orbit, which is 25 days, as well as the planet's mass and density.
LHS 1140b may seem like it's ideal now, but that wasn't always the case. During that time, the habitable zone of the star would be much further out, which means that LHS 1140b was exceptionally heated.
But if the planet can shield and hide its water source from this heat, it would be saved, Dittman said.
The habitable zone is also dependent on the type of star the planet orbits.
But if it's too far, any water will freeze, as is seen on Mars.
LHS 1140b's host star spins slower and emits less radiation, unlike the TRAPPIST-1 star. That suggests the planet is dense enough to be rocky. Other signs it could be habitable would be nitrogen molecules.
The scientists aren't wasting any time following up with observations: the next transit (where the planet crosses in front of the star) will occur on October 26 and they've booked several telescopes in Chile to search for signatures of oxygen molecules in the planet's atmosphere.
"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. They want to confirm the existence of the planet's atmosphere and find out if it has molecular oxygen or water, and if it's similar to Earth.
"This planet will be an excellent target for the James Webb Space Telescope when it launches in 2018, and I'm especially excited about studying it with the ground-based Giant Magellan Telescope, which is under construction", said co-author David Charbonneau of the CfA.