Earlier this year, a minimoon was found orbiting Earth by a group of astronomers. The minimoon has now drifted away but astronomers said that more such minimoons will be found orbiting Earth in the future.
The minimoon was first spotted by astronomers at the Catalina Sky Survey in Arizona. The astronomers spotted a dim object called 2020 CD3 in February but they were not sure whether it was a a minimoon or an artificial object like a rocket booster. But Grigori Fedorets at Queen’s University Belfast and his team used several telescopes to observe the object closely in order to find out more about its composition and other details.
Fedorets and his team found that the celestial body had a diameter of about 1.2 metres and it was probably made of silicate rock. “Based on simulations, the average capture time for minimoons is only nine months, so this was captured for a longer time than is expected,” says Fedorets. “But this object flew very close to the [regular] moon, and that put it into a more stable orbit.”
According to astronomers Minimoon or 2020 CD3 drifted out of the orbit of Earth in March, but the researchers are hopeful that once the Vera C. Rubin Observatory is completed in Chile it will help in detecting many more objects like it.
“We could detect a minimoon once every two or three months in the best-case scenario. In the worst case scenario, maybe once a year,” Fedorets was quoted as saying by newscientist.com.