Earth has an extra companion, a Trojan asteroid that will hang around for 4,000 years

In 2020, astronomers thought they’d found something incredible: the second so-called Earth Trojan asteroid ever seen. Now, a new team of researchers has confirmed that it’s real.

Trojan asteroids are small space rocks that share their orbit with a planet, circling whatever host star that planet does in a stable orbit. While we have spotted Trojan asteroids around other planets in our solar system and others, until now only one of these objects, called 2010 TK7, has been confirmed to orbit along the same path as Earth. In a new study, researchers confirmed that an asteroid spotted in 2020, called 2020 XL5, is the second object of its kind, called an Earth Trojan asteroid. Think of it as an extra companion to Earth, albeit a very tiny one.