Ocean Origins on Earth - Ocean Worlds: The Story of Seas on Earth and Other Planets - page 31

fig. 4. Craters on the eastern limb and far side of the Moon, imaged by the Apollo
16 spacecraft in 1972.
There was, it has been suggested, one last such event that has been
called the Late Heavy Bombardment, which is thought to have taken
place some 3.9 billion years ago as the orbits of Jupiter and Saturn
readjusted, perturbing the orbits of many of the asteroids near to them
and sending them shooting across the solar system. A model for such
a profound reordering in the solar system—a far cry from early ideas
of stable planetary orbits—was proposed by scientists working in
Nice, France, in 2007 (hence it is now know as the 'Nice model'). This