In a new find, scientists have discovered two exoplanets that they believe is the scaled-up version of Earth. The newly discovered Super-Earth called K2 18b has also a sister planet named K2 18c. Both K2 18b and K2 18c orbit a red-dwarf parent star called K2-18 and these two rocky planets are believed to be moving in the habitable zone, as per the researchers.
This new discovery was done with the help of data collected by the European Southern Observatory (ESO) and the research was carried out by a group of scientists from the University of Texas and the University of Montreal. lead author Ryan Cloutier, a PhD student in U of T Scarborough’s Centre for Planet Science, U of T’s Department of Astronomy and Astrophysics, and Université de Montréal Institute for research on exoplanets (iREx) said, “”Being able to measure the mass and density of K2-18b was tremendous, but to discover a new exoplanet was lucky and equally exciting.”
The red dwarf K2-18 is situated almost 111 light years away from earth in the Leo constellation. The planet K2-18b was first discovered in 2015 and at that time scientists expected it be orbiting in its host stars habitable zone, thus indicating to have liquid water, a vital component for the possibility of life as we know it. But know when the researchers tried to find out whether K2-18b is a scaled-up version of Earth (mostly rock), or a scaled-down version of Neptune (mostly gas), they got some surprising information.
Apart from getting to know that K2-18b is a scaled up version of Earth, which means it’s mostly icy and rocky, scientists also were able to discover another neighboring exoplanet K2-18c which doubled their excitement. While collected data regarding K2-18b, Cloutier came across some unusual signal in addition to the signal received from K2-18 and K2-18b.
“When we first threw the data on the table we were trying to figure out what it was. You have to ensure the signal isn’t just noise, and you need to do a careful analysis to verify it, but seeing that initial signal was a good indication there was another planet,” informed Cloutier. Sharing his experience about discovering a new exoplanet, Coulter said, “It wasn’t a eureka moment because we still had to go through a checklist of things to do in order to verify the data. Once all the boxes were checked it sunk in that, wow, this actually is a planet.”
Now, coming to the K2-18b, the researchers informed that they calculated the mass of the planet using radial velocity measurements taken with High Accuracy Radial Velocity Planet Searcher (HARPS) using s 3.6m telescope at La Silla Observatory, in Chile. According to Cloutier, if one can get the mass and radius, one can measure the bulk density of the planet, and that can tell what the bulk of the planet is made of. HARPS’ mass measurement data, after being put through machine learning, suggested that the K2-18b is either a mostly rocky planet with a small gaseous atmosphere – like Earth, but bigger – or a mostly water planet with a thick icy layer over it, as reported by the study. Scientists expect that the picture will be clearer when the K2-18b will be studied with the help of James Webb Space Telescope (JWST), which is scheduled to launch in 2019.