In the skies above Earth, astronomers with the Catalina Sky Survey have spotted what might be a new friend: an asteroid temporarily captured by our planet's gravity, what we call a minimoon.

It's named 2020 CD3, a small chunk of likely carbonaceous rock between 1.9 and 3.5 metres (6.2 and 11.5 feet) in diameter. And here's the kicker - the rock's trajectory indicates it's been in orbit for around three years already.

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