Last year, astronomers on the hunt for potentially dangerous near-Earth asteroids spotted something unusual. A space rock, now dubbed 2024 PT5 made several close passes by Earth, not quite orbiting our planet,

For a brief, but exciting, time last year, Earth had two moons. A small asteroid lingered close to our planet in its orbit around the Sun, temporarily caught by Earth’s gravity to become a far away mini-moon. A closer look at the space rock reveals a rather familiar origin: Earth’s mini-moon might actually be a broken-off piece of our regular Moon.

2024 PT5 is the second near-Earth asteroid scientists suspect was ejected from the moon's surface, the first being 469219 Kamo'oalewa, which a different team of scientists have traced to an old impact crater on the far side of the moon.

A near-Earth object was likely ejected into space after an impact thousands of years ago. Now it could contribute new insights to asteroid and lunar science.