Did our Solar System once have another planet?

by Ker Than

NEW YORK: The fiery demise of a fifth rocky planet in our Solar System might have led to a flurry of asteroid impacts that pockmarked the Moon and Earth billions of years ago.

The Late Heavy Bombardment (LHB) is a relatively brief period, about 3.9 billion years ago, when wayward space projectiles heavily pelted the Moon and inner planets. Craters from that chaotic time are still visible on the Moon, but have been erased from Earth, where the crust is continually recycled.

Try as they might, astronomers have not yet been able to pin down a cause for the bombardment.

craters on the Moon better match asteroids from the Asteroid Belt, located beyond the orbit of Mars.

a long-lost, fifth rocky planet called 'Planet V' was the trigger that upset the gravitational balance of the belt

Planet V's orbit was between that of Mars and the Asteroid Belt,

NASA's Apollo missions, that scientists were able to date the Late Heavy Bombardment