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Earth Picks Up An Extra Moon — For Now

A pair of astronomers have discovered a second moon circling the Earth, thanks to observations by the Catalina Sky Survey in Tucson.

How many moons does Earth have?

It depends on when you ask.

For months or years, a Volkswagen-sized rock has circled our world roughly every four months.

Astronomers believe the object, unpoetically labelled "2020 CD3," is one of many space rocks that zip past us; this one just happened to get caught in our gravity.

Other objects are known or suspected to engage in a gravitational dance with Earth, but are not satellites per se.

But another temporary moon did visit 14 years ago: a fridge-sized asteroid called 2006 RH120.

Like its predecessor, CD3 eventually will leave Earth behind — a mere planetary pit stop on its journey through the solar system.

Nicholas Gerbis was a senior field correspondent for KJZZ from 2016 to 2024.