A planet in the distant K2-18 star system could be Earth’s scaled up version or Super Earth, according to a new study.
The exoplanet, referred to as K2-18b, is located in a potentially habitable zone from its host star, which makes it a probable candidate for holding surface liquid water.
Surface liquid water is an important element required for hosting any form of life. Based on the discoveries related K2-18b so far, it could be an exoplanet that may possibly host extraterrestrial life.
That is not all, the team of researchers, from the University of Montreal in Canada and the University of Texas in the United States, who conducted the study with data from the European Southern Observatory, also discovered that the planet has a neighbor. Both exoplanets orbit K2-18, a red-dwarf star in the constellation Leo around 111 light years away.
Next, the research team wanted to understand whether K2-18b was a rocky planet like Earth or a gassy one like Neptune. To do this, the scientists had to first analyze the exoplanet’s mass with the help of radial velocity measurements taken with the High Accuracy Radial Velocity Planet Searcher. The Harps tool measures the radial velocity of stars that is impacted by a planet’s presence.
"If you can get the mass and radius, you can measure the bulk density of the planet and that can tell you what the bulk of the planet is made of," study lead author Ryan Cloutier said.
The experts were able to understand that K2-18b is either primarily a planet, which is rocky and has a small gaseous atmosphere or watery with a thick top layer of ice. At present, the scientists are not able to distinguish between the two options; however, they feel more data can be collected with the help of the James Webb Space Telescope.
James Webb Space Telescope
The JWST, which is lined up for a tentative 2019 spring launch, will help the team observe the atmosphere of the planet and find whether it is covered in water or has a substantial atmosphere. The space telescope is geared toward obtaining a range of data to help scientists study the solar system, exoplanets, and the early universe.
René Doyon, the paper co-author, feels that there is a high demand to use JWST so one has to be careful while selecting which exoplanets to study. K2-18b, however, is now among the most exciting bets for atmospheric study. Therefore, it is going to be near the top of the JWST target list, according to Doyon.