'Super Earth' Planet Discovered, May Be Habitable

The “Super Earth” is a mere 42 light-years away, and is one of six planets that orbit its star. A team led by Mikko Tuomi from the University of Hertfordshire in England announced the discovery of the planet, HD40307G, in the journal Astronomy and Astrophysics.

HD40307G was found to be in the habitable zone, reports Space.com. Astronomers like to use the Goldilocks analogy for the hospitable zone. In order for life to be sustained on a planet, the temperature needs to be just right, neither too hot or too cold. HD40307G was one of three newly discovered planets orbiting its star.

HD40307G is dubbed a “Super Earth” due to its size, reports USA Today. HD40307G weighs seven times as much as Earth but moves faster, taking 200 days to orbits its star. Astronomers detect  planets by measuring the gravitational wobbles as the planet passes a parent star. Each planet has its own gravitational pull and astronomers can measure how much of a wobble these planets cause on the sun they are orbiting. In this case, astronomers had already recorded the wobble caused by three “Super Earths.”

The Super Earths previously discovered orbited too closely to their parent star, so were too hot to support liquid water.

The astronomers were examining previously collected data of the star HD40307, which is slightly smaller than our own sun, and its planets. The data was collected using the High Accuracy Radial velocity Planet Searcher (HARPS) at La Silla Observatory in Chile. HARPS was also used to detect an Earth-sized planet in Alpha Centauri.

It's still too early to determine if HD40307G could sustain life or the what type of planet it is. Speaking to Space.com, Tuomi said “the truth at the moment is that we simply do not know whether the planet is a large Earth or a small, warm Neptune without a solid surface."

Still, astronomers are excited about the discovery of HD40307G. Speaking to USA Today, Sara Seager, an MIT astronomer who was not part of the team that discovered the planet, said, "To me this discovery stands out as adding to the tip of the iceberg ... where we will get to an almost everyday occurrence of finding potentially habitable planets!”