Earth has a second ‘tiny’ moon for now

Astronomers have recently discovered a new “mini-moon” looping around the Earth.

The astronomers, who discovered the object last February 15, said the mini-moon will likely leave the Earth’s orbit sometime in April as it shoots off into the distant solar system or burns up in our planet’s atmosphere just like other space rocks.

Called “2020 CD3,” the tiny moon was discovered by astronomers Kacper Wierzchos and Theodore Pruyne at the NASA-funded Catalina Sky Survey at the University of Arizona.

“BIG NEWS. 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,” Wierzchos wrote as a caption to an image of the mini-moon, which he uploaded on Twitter.

https://twitter.com/WierzchosKacper/status/1232460436634656769?s=19

Wierzchos said the mini-moon, which has been trapped by Earth’s gravity for about three years already, is a car-sized piece of carbonaceous rock with a diameter between 1.9 to 3.5 meters.

“The object has a diameter between 1.9 – 3.5 m assuming a C-type (carbonaceous) asteroid albedo,” Wierzchos said in his long post.

He noted that discovering a new mini-moon is a “big deal” because it was the second asteroid to orbit the Earth out of one million known asteroids.

“But it’s a big deal as out of ~ 1 million known asteroids, this is just the second asteroid known to orbit Earth (after 2006 RH120, which was also discovered by the Catalina Sky Survey),” Wierzchos said.

https://twitter.com/WierzchosKacper/status/1232461141256749057?s=19

The “2006 RH120,” which was the first known asteroid to orbit the Earth, was discovered in September 2006.

It has orbited the Earth for 18 months.

According to Wierzchos, since the 2020 CD3’s distance to Earth varies, so does its orbital period or the time it takes to circle Earth.

He said the existence of the second mini-moon has only been publicly announced by the International Astronomical Union’s Minor Planet Center (MPC) on February 25 after the center and other astronomers confirmed their find.