Don't worry: this story is not about the imminent destruction of Earth again. On the contrary: asteroids like 2020 XL5, discovered in 2020, are exciting because they could provide insights into Earth's early past. 2020 XL5 is a so-called Trojan, as astronomers confirm now in the science magazine Nature (the assumption existed already before): An asteroid which accompanies Earth in its orbit. If one considers only the system from sun and planet, there are several places, at which the attractive forces of planet and sun cancel each other out. These are the so-called Lagrange points. Objects residing there can…