We Just Discovered 2 Super-Earths

Tuesday, 05 December 2017 - 2:41PM
Tuesday, 05 December 2017 - 2:41PM
We Just Discovered 2 Super-Earths
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Image credit: NASA

In an unprecedented discovery, scientists have just found two rare "super-Earths" right next to one another. 

Researchers have learned that a faraway exoplanet known as K2-18b may be a rare "super-earth" composed of rock, startlingly similar to planet Earth, according to a new study. 

And the exciting discovery doesn't end there. While combing through their data, researchers discovered that K2-18b was situated right next to yet another super-earth, a newly discovered exoplanet named K2-18b that scientists believe is also roughly the same mass as Earth.

"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.

Orbiting within the habitable zone of red dwarf star K2-18, Cloutier says it's more than likely that exoplanet K2-18b has liquid water on its surface.

To make the groundbreaking discovery, Cloutier first had to learn the planet's mass by using radial velocity measurements to determine if K2-18b was a rocky planet with liquid water similar to Earth, or a mostly gaseous planet like Neptune. 

"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," Cloutier said.

While K2-18b and its newly discovered super-Earth nextdoor, K2-18c, are both roughly the same mass as Earth, their similarites may end there. Unlike its neighbor, the newly discovered exoplanet is situated much closer to its star, likely putting it just outside the habitable zone, and as a result, likely doesn't possess liquid water on its surface.

With more than 3,000 exoplanets confirmed by NASA at this point, you might wonder what's so special about finding another one—but it's an incredibly rare phenomenon to confirm an exoplanet, let alone to find two super-Earths sitting right next to each other light years away from Earth.

Cloutier shares that enthusiasm with all the carefully measured passion any scientist worth his weight in life-changing discoveries can muster. 

"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," Cloutier said.

"Once all the boxes were checked it sunk in that, wow, this actually is a planet."