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Last Updated: Friday August 20 2010 13:36 GMT

Is the moon getting smaller?

cracks in the moon

Scientists reckon the moon is shrinking after seeing big cracks on its surface.

They're called fault lines and they look a bit similar to the cracks in the ground that happen when there's a massive earthquake.

Experts say it shows that the surface of the moon is shrinking because its centre is getting colder.

Objects often get smaller as they get colder, but scientists don't know how long this has been happening to the moon.

Fourteen new cracks have been spotted in lunar photos like the one above.

Dr Marek Kukula

Dr Marek Kukula is an astronomer

It's thought the moon has contracted by about 100 metres sometime over the last billion years.

The moon is around 4.5 billion years old so it won't be disappearing too soon!