The Menace from Earth — Robert A. Heinlein

From Cavernous Cities Beneath The Surface of The Moon...Earth seems a sinister planet hanging in the sky. But to the Pluto colony, Earth Satellite Base holds the only possible reprieve from a terrifying death sentence. And on Earth itself, alien intelligence prowls the skies, kidnapping people for its own inhuman amusement.

This is the day past tomorrow. Time has ended and man has begun his endless journey out into the universe.