Everybody on the surface died. About 100,000 died in orbit when the explosion occured. About 20,000 people survived the detonation of Earth aboard spaceships and orbiting colonies and hotels; about half of them died before making their way to any place safe. 10,000 desperate humans made their way to the Moon and the colonies established on it, seeking Hope to go on living.

The colonies were established by many nations. Before the disaster they housed a total of under 15,000 people, a few thousand pets, and enough crops to feed 20,000 people. Before the disaster the Lunar Colonies imported 100 tons of raw materials from Earth every week. You can imagine the strife caused by the arrival of the survivors. Friendly society was nearly extinguished by the flood.

L.U.C.Y., the Lunar United Colony Youth, was a group of idealists who felt that the only solution to the shared problem of Humanity was Mars. So they left to establish a new colony on the Red Planet as the Moon drifted towards the Outer Solar System.