The first known Earth Trojan asteroid has been discovered rotating the sun in Earth's orbit.
"2010 TK7," as it has been named, is 1,000 feet wide and travels about 48 million miles from and in direct line with Earth.
Trojans are a unique classification of asteroids, defined by their ability to share an orbit in direct line with a planet. 2010 TK7 is the first known Trojan to Earth. This newly found asteroid poses no threat to Earth because it simply follows the same path, and will never collide with Earth. Researchers say it has a well-defined orbit path and will never come closer to Earth than 15 million miles.
Spotted by NASA's Widefield Infrared Survey Explorer (WISE) satellite, a team led by Martin Connors of Athabasca University in Alberta, Canada first discovered the asteroid last year.
"The object has an unusual orbit that takes it farther away from the sun than what is typical for Trojans," Connors said. "WISE was a game-changer, giving us a point of view difficult to have at Earth's surface."
Beginning in Jan. 2010 before commencing in Feb. 2011, the WISE telescope scanned the entire sky in infrared light, according to a press release from NASA. The team of astronomers led by Connors took a closer look using an addition to the WISE mission called NEOWISE, which focuses on near-Earth-objects (NEO) like asteroids and comets. The project, in the end, found 132 previously unknown near-Earth-objects, including 2010 TK7.
The presence of Trojans is not a new concept. The first Trojan was discovered in 1906 near Jupiter and scientists have suspected Earth Trojans for some times now. It was not discovered before due to the brightness of sun and the daytime sky hiding it, according to Connors.
Researchers say that due to how close this Trojan is to Earth is valuable for it can be probed to identify the rare metals present inside the rock.