Books about Life on other planets -- Fiction (sorted by popularity)
- Eight Keys to Eden Mark Clifton 167 downloads
- Slave Planet Laurence M. Janifer 165 downloads
- Star Ship Poul Anderson 159 downloads
- Woman's touch Evelyn E. Smith 158 downloads
- Med Ship Man Murray Leinster 155 downloads
- The Planet Savers Marion Zimmer Bradley 144 downloads
- The Gods of Mars Edgar Rice Burroughs 144 downloads
- The great illusion Manly Banister 139 downloads
- The Masked World Jack Williamson 139 downloads
- Bleekman's Planet Randall Garrett and Robert Silverberg 135 downloads
- This World Is Taboo Murray Leinster 133 downloads
- Pariah Planet Murray Leinster 129 downloads
- Cultural Exchange Keith Laumer 121 downloads
- The Virgin of Valkarion Poul Anderson 120 downloads
- No-Risk Planet Stephen Marlowe 117 downloads
- A Matter of Protocol Jack Sharkey 115 downloads
- Spacerogue Robert Silverberg 114 downloads
- The Chemically Pure Warriors Allen Kim Lang 113 downloads
- Citadel of Lost Ships Leigh Brackett 110 downloads
- Tiger by the Tail Poul Anderson 110 downloads
- Phantom Out of Time Nelson S. Bond 107 downloads
- Rockabye, Grady David Mason 106 downloads
- An Earthman on Venus (Originally titled "The Radio Man") Ralph Milne Farley 105 downloads
- The Desert and the Stars Keith Laumer 104 downloads
- Sword of the Seven Suns Gardner F. Fox 104 downloads