Second moon spotted by astronomers
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Earth might have a second moon - but not for long!
Astronomers in the US first spotted a small object moving across the sky and over several weeks observatories across the world worked out its orbit and found it was gravitationally bound to Earth.
A moon is a celestial body or satellite that makes an orbit around a planet.
It's believed that the new moon - which is about the size of a car - is most likely an asteroid caught by Earth's gravity as it passed by.
The two objects cannot move apart, because gravity will eventually pull them back together which is why the object continues to circle the Earth.
The tiny 'moon' has been circling our planet once every 47 days.
Its size may be why the International Astronomical Union's Minor Planet Center doesn't call it a moon, but a 'temporarily captured object'.
Although it's only just been discovered, researchers think the mini-moon has been orbiting Earth for three years and will be flung out of its orbit in April 2020 - so definitely not competition for the Moon.
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