Astronomers have found what could be an “expanded” version of our home planet, located in the habitable zone of its star, capable of sustaining alien life on its surface.
According to the new research, based on data from the European Southern Observatory (ESO), and published in the peer-reviewed scientific journal Astronomy & Astrophysics:
Astronomers found that the potential life-supporting planet, which orbits the red-dwarf star K2-18, also has a neighbor planet called K2-18c. Located in the Leo constellation, about 111 lightyears away from Earth, the Super-Earth planet was first discovered in 2015. Found orbiting the dwarf star’s theoretical habitable zone, the planet became a prime candidate for researchers looking for planets that can theoretically support life.
Astronomers at the University of Texas and the University of Montreal used the HARPS spectrograph on ESO’s 3.6-meter telescope at the La Silla Observatory, Chile, to find K2-18b, an exoplanet – possibly a Super Earth – a planet that eerily resembles our world, but is much, much bigger.
According to experts, K2-18b orbits its star within the habitable zone, making it an ideal candidate to house water in a liquid state on its surface, a fundamental element for the presence of life as we know it. The exoplanet which most likely contains the necessary elements for life as we know it completes an orbit to its star every 33 days.
Furthermore, scientists found that this Super-Earth has a neighboring planet called K2-18c, which could be another rocky planet.
However, the proximity of this last world to its star rules out any possibility that it is capable of sustaining life as we know it.
Both exoplanets orbit the red dwarf K2-18, located 111 light years from Earth, in the constellation Leo.
“Being able to measure the mass and density of K2-18b was tremendous, but to discover a new exoplanet was lucky and equally exciting,” said lead author Ryan Cloutier, from the University of Montreal.
In order to find out whether K2-18b was a ‘larger’ version of Earth (mostly rock) or a reduced version of Neptune (mainly gas), the researchers had to first determine the mass of the planet, using radial velocity measurements taken with HARPS.
“If you can obtain the mass and the radius, you can measure the apparent density of the planet and that can tell you what the bulk of the planet is made of,” Cloutier explains.
Scientists found the K2-18b is either a rocky planet that has a gaseous atmosphere – like Earth, but bigger – or is mostly a planet made of water with a thick layer of ice on top of it.
“With the James Webb Space Telescope (JWST) we can probe the atmosphere and see whether it has an extensive atmosphere or it’s a planet covered in water,” Mr. Cloutier explained.
The JWST, which will be launched in 2019, will be valuable for the compilation of a series of data to study the solar system, the early universe, and exoplanets.
Journal article link: https://arxiv.org/abs/1707.04292
Featured image: Artist’s illustration of planet K2-18B, and its neighboring planet K2-18. Image Credit: Alex Boersma