Earth had two moons, but one was destroyed in giant collision: new theory

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A new theory has come up that the earth might once have had two moons, the one that shines at night today and a smaller companion, which was destroyed in a slow collision between the two satellites.

While the side of the moon facing the Earth has relatively low and flat topography, the side facing away is high and mountainous with a much thicker crust.

Scientists have proposed different theories to explain this lack of symmetry. One leading idea is that gravitational tidal forces reshaped the moon’s crust and made it lopsided.

But the new theory builds on the ‘giant impact’ model that explains the moon’s creation.

Many experts believe a Mars-sized object collided with the Earth early in the solar system’s history, ejecting debris that was later drawn together by gravity to form the moon.

The ‘second’ moon is also thought to have been generated by the giant impact, remaining in orbit for tens of millions of years.

The two moons collided relatively slowly, according to the theory.