Sunrise on Mercury / R. Silverberg -- Before Eden / A.C. Clarke -- Seeds of the dusk / R.Z. Gallum -- The black pits of Luna / R.A. Heinlein -- Crucifixus etiam / W.M. Miller, Jr. -- Desertion / C.D. Simak -- Pressure / H. Harrison -- The planet of doubt / S.G. Weinbaum -- One Sunday in Neptune / A. Panshin -- Wait it out / L. Niven.