These great hollow globes of artificial super-metals, and artificial transparent adamant, ranged in size from the earliest and smallest structures, which were no bigger than a very small asteroid, to spheres considerably larger than the Earth. (Olaf Stapledon, STAR MAKER)
Monday, February 15, 2016
Today's Astronomy Picture of the Day shows light-colored deposits (salts left by retreating water?) on Mars as imaged by the THEMIS instrument on the venerable Mars 2001 Odyssey orbiter.