K2-18b's newly found super-Earth status comes after a slew of other recent, rocky planet-related discoveries. Dubbed K2-18c, the planet is also a Super Earth, though because of its proximity to its star it's not likely that liquid water could exist on its surface, which makes it a lot less appealing to humans. At that time they noticed that the super-Earth was orbiting the dwarf-star within its habitable zone. Scientists, aside from two regular signals that they received every 39 days from the star's rotation and every 33 days from the planet's orbit, discovered a third signal which they received every nine days, which was the first indication that there might be another planet close to K2-18b.
The astronomers found that K2-18b has a mass about 8 times that of Earth. Both the planets revolve around the red-dwarf star K2-18, which is 111 light years from Earth.
"And so we sort of know that, for this planet, it's got about the right temperature that it could have liquid surface water".
To do that, Cloutier and his fellow researchers used data from the High Accuracy Radial Velocity Planet Searcher on the European Southern Observatory's 3.6-meter telescope in La Silla Observatory, Chile.
"Once all the boxes were checked it sunk in that, wow, this actually is a planet", he said.More news: United States defense chief calls for deepening anti-terror cooperation with Pakistan
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Using sophisticated machine-learning techniques, the team figured out the planet could well be an Earth-like planet made mostly of rock and with a gaseous atmosphere.
"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 head researcher Ryan Cloutier, a PhD student in U of T Scarborough's Centre for Planet Science. However, scientists weren't sure whether the planet had a rocky or terrestrial surface like Earth or if it was more like a Neptune kind of planet, which consists of gas and ice.
Current technology prevents us from being able to definitively say which one it is but the fact that it could be either is a huge leap forward in our understanding of this distant solar system. This super-Earth-K2-18c-unfortunately, is a much poorer candidate for life.
Engineers inspect the James Webb Space Telescope after cryogenic testing in Houston, November 19, 2017. "But 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".
"K2-18b is now one of the best targets for atmospheric study, it is going to the near top of the list", Rene Doyon, from Universite de Montreal Institute in Canada, added.
"When we first threw the data on the table we were trying to figure out what it was".