Earth Has a New Moon, Sort Of

It's about the size of a big sectional sofa

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It's that teeny, tiny speck in the middle of the picture.

Griffin Frame, Staff Writer

As we all know, our planet Earth has just one moon, something we don’t think about that often. You look in the sky, and there it is. It hasn’t changed in our lifetime, but what would you think if we got another moon?

Recently, scientists discovered a new object orbiting Earth, a new asteroid that some are calling a mini- moon. The asteroid is in the size range of 1.9 – 3.5 m (6.23 – 11.48 ft) and is called 2020 CD3. The asteroid was discovered in the Catalina Sky Survey. 

Check out the Twitter feed: “BIG NEWS (thread 1/3). Earth has a new temporarily captured object/Possible mini-moon called 2020CD3. On the night of Feb. 15, my Catalina Sky Survey teammate Teddy Pruyne and I found a 20th magnitude object. Here are the discovery images,” said astronomer Kacper Wierzchos. Link here

Scientists say 2020CD3 has an erratic orbit and in the future will eventually leave our planet’s sphere of influence.

“The orbit shows evidence that the asteroid likely entered the orbit  three years ago,” Wierzchos said.

This is the second asteroid to get captured by Earth’s gravitational field and orbit us, and there’s even a term for it – Temporary Captured Object (TCO). This is not a common occurrence.

“The reason TCOs are so rare, is that it takes a very precise vector [speed and direction] to be pulled in by Earth’s gravitational pull, and to not impact or fly out in a new direction,” Pruyne said.

The object has a diameter between 1.9 – 3.5 meters assuming a C-type asteroid albedo. But even though it’s small, “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),” said Wierzchos.