A ‘mini-moon’ the size of hippopotamus is orbiting Earth for three years now

Many planets have multiple moons, but Earth has just one. However, for a brief time, a ‘mini-moon’ will keep Earth company.

The extraterritorial body is actually an asteroid called 2020CD3. Its diameter is between 1.9-3.5 m, which is roughly a size between a cow and a hippopotamus.

The new ‘moon’ has been temporarily bound to the Earth. It was discovered on Tuesday by Minor Planet Centre at International Astronomical Union. The centre is the official organization for naming, studying, and analysing all minor planetary and extra-planetary bodies in the solar system.

Scientists involved with the discovery, Kacper Wierzchos, said: “Earth has a new temporarily captured object/Possible mini-moon called 2020 CD3. On the night of Feb. 15, my Catalina Sky Survey teammate Teddy Pruyne and I found a 20th magnitude object.”

He explained that the discovery was a monumental event as there are nearly 1 million known asteroids but this is only the second in the known history of space studies to orbit Earth. Before this, 2006 RH120 was known to have orbited Earth briefly. That was also a discovery of the Catalina Sky Survey.

But what causes these mini-moons or asteroids to the Earth’s orbit? It’s a combination of the Earth’s gravity with the moon and sun’s gravitational pull. These forces simultaneously combined create a kind of irregular orbit on which the moon or asteroid can adhere to.

According to the astronomer, the mini-moon probably entered the Earth’s orbit around three years ago. As for the future, it can be expected to stay around from October 2020 to May 2021.

So far, little is known about the asteroid. However, during the next year, it is expected to come closer to the Earth. The closeness should give a chance to make clearer and more detailed observations and help assess its origin.