CosmoView 41: Data from NSF’s NOIRLab Show Earth Trojan Asteroid Is the Largest Found

Astronomers have confirmed the existence of the second known Earth Trojan asteroid and found that it is much bigger than the first. An Earth Trojan is an asteroid that follows the same path around the Sun as Earth does, either ahead of or behind Earth in its orbit. Called 2020 XL₅ the asteroid was discovered by the Pan-STARRS1 survey telescope in 2020, but astronomers were not sure then whether it was an Earth Trojan. The SOAR Telescope operated by NOIRLab in Chile helped confirm that it is an Earth Trojan and found that it is over a kilometer across — almost three times bigger than the other Earth Trojan known.