Meet Earth's Closest Rocky Neighbor Outside the Solar System

NASA's Spitzer telescope discovers rocky exoplanet 21 light-years away.

ByABC News
July 31, 2015, 12:19 PM
This artist's concept shows the silhouette of a rocky planet, dubbed HD 219134b. At 21 light-years away, the planet is the closest outside of our solar system that can be seen crossing, or transiting, its star.
This artist's concept shows the silhouette of a rocky planet, dubbed HD 219134b. At 21 light-years away, the planet is the closest outside of our solar system that can be seen crossing, or transiting, its star.
NASA/JPL-Caltech

— -- Earth's closest rocky neighbor outside of the solar system has been confirmed using NASA's Spitzer telescope.

The alien rocky planet has been named HD 219134b and is 1.6 times the size of Earth, according to NASA. What makes this exoplanet special is it's 21 light-years away from Earth, while most other exoplanets that have been located are hundreds of light years away.

In fact, it's so close that the star that the exoplanet orbits is visible to the naked eye, in the constellation Cassiopeia, NASA officials said.

While the exoplanet was first discovered using the Italian Galileo National Telescope in the Canary Islands, Spitzer has taken infrared measurements, allowing scientists to learn more about the exoplanet's size and confirm its rocky terrain.

The exoplanet is transiting in front of its star, making it an ideal body for scientists to study and a potential gold mine of scientific data, according to NASA scientists.

"Transiting exoplanets are worth their weight in gold because they can be extensively characterized," Michael Werner, project scientist for the Spitzer mission, said in a statement on Thursday. "This exoplanet will be one of the most studied for decades to come."

One thing scientists know they won't find though is alien life. According to NASA, the exoplanet rotates too close to its star, making it unable to sustain life.