Astronomers discover Earth-like planet orbiting nearby star

The star Gliese 581 hosts an Earth-size planet (foreground) that orbits in the star's habitable zone
The star Gliese 581 hosts an Earth-size planet (foreground) that orbits in the star's habitable zone

MAUNA KEA, Hawaii (HawaiiNewsNow) – 11 years of painstaking observations have paid off for a team of astronomers working at the Keck Observatory atop Mauna Kea on the Big Island. They announced Wednesday the discovery of a planet that has several similarities to Earth.

Astronomers consider Gliese 581g to be a "potentially habitable" planet. It is about 30% larger than the Earth, but its distance from its star indicates that its surface temperature may be similar to that of Earth. Its mass is great enough that observers think it is capable of supporting an atmosphere. Scientists believe that these combination of factors could mean that the planet has water in both liquid and vapor forms, a critical prerequisite for life to potentially form.

Gliese 581g is one of six planets discovered orbiting Gliese 581, a red dwarf star in the constellation Libra. It is 20 light years from our solar system, around 117 trillion miles away. There are two other planets in the system that are at the hot and cold edges of the "habitable zone", one of these planets is also considered to be potentially capable of supporting life.

A team of planet hunters from several universities made the discovery after hundreds of precise observations over the last 11 years. Nader Haghighipour of the University of Hawaii was one of the key members of the team. The relative swiftness of this and other recent planet discoveries has given scientists optimism that there may be multitudes of Earth-like planets in the universe.

Artwork by Lynette Cook.

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