- 1958: Invaders from Earth/Across Time, Ace Mass market paperback, 169 pp.
- 1959: Utopia Grossband #105, Mass market paperback, in German as Griff nach dem Ganymed
- 1968: Invaders from Earth, Avon Mass market paperback, 142 pp.
- 1970: A Robert Silverberg Omnibus (The Time Hoppers/Invaders from Earth/Master of Life and Death), Sidgwick & Jackson Hard cover book
- 1972: Invaders from Earth, Hawthorne Hard cover book
- 1977: Invaders from Earth, Sidgwick & Jackson Hard cover book
- 1978: Science Fiction Special #30, Sidgwick & Jackson Mass market paperback
- 1979: Invaders from Earth, Panther Mass market paperback, 143 pp.
- 1980: Invaders from Earth and To Worlds Beyond, Ace Mass market paperback
- 1983: Opration Ganymde, Fleuve Noir Mass market paperback, in French
- 1987: Invaders from Earth, Tor Mass market paperback, ISBN 0-812-55464-7, 190 pp.
- 1990: Invasores Terrestres, Mass market paperback, ISBN 972-21-0076-9, in Portuguese
- 2000: Fictionwise, Fictionwise Online
- 2001: Invaders from Earth, FoxAcre Mass market paperback, ISBN 096717838X, 149 pp.
- 2001: Invaders from Earth, Rosetta Online
(from Tor 1987)
Earth's colony on Ganymede is under attack. The people of Earth demand reprisal, and the United Nations must take action to protect the interests of the people.
But Ted Kennedy is worried. He has been to Ganymede and seen the "people"; and knows a truth too terrifying to reveal. Only he can convince the leaders of Earth that they are victims of a hoax. His life may be forfeit, but he is determined to live long enough to stop the INVADERS FROM EARTH
[None on record]