After billions of years, it looks like the moon found some temporary company in the form of a "mini-moon" that recently entered the Earth's orbit.
The discovery was made the night of Feb. 15 by Senior Research Specialist Kacper Wierzchos and Research Specialist Theodore Pruyne, both with the Catalina Sky Survey at the University of Arizona College of Science.
Wierzchos tweeted enthusiastically Tuesday that the "mini-moon" is called 2020 CD3 and out of the nearly 1 million known asteroids, it’s the second known asteroid in history to orbit Earth. The first was called 2006 RH120 and was also discovered by the Catalina Sky Survey.
The "mini-moon" is about 6 to 11 feet across and entered the Earth’s orbit about three years ago, Wierzchos said in his tweet. For comparison, the moon has a radius of 2,158.8 miles, according to NASA.
The International Astronomical Union’s Minor Planet Center cataloged the asteroid Tuesday where it says the “object is temporarily bound to Earth” and that “no link to a known artificial object has been found.”
Derek Buzasi, professor of physics at Florida Gulf Coast University, said he doesn't expect the refrigerator-sized asteroid to stay in Earth's orbit for longer than another month or two. However, he's excited about the discovery as it could mean big things for astronomers in the future.
"We know this happens all the time but finding them is very hard," he said. "It's a reminder that something that size can get close to us and it's worthwhile to invest the relatively small amount of money to find them."
Buzasi said that obtaining samples of small, close asteroids and bringing them to Earth is much more beneficial to astronomers than sending over robotic explorers to large asteroids. Studying these rocky asteroids can help scientists learn more about the primordial solar system.
But unfortunately, by the time June rolls around, our "mini-moon" will probably be long gone.
According to NASA, there are more than 200 known moons in our solar system. Most of them orbit big planets like Saturn and Jupiter, which have 82 and 79 moons respectively.
Follow Adrianna Rodriguez on Twitter: @AdriannaUSAT.