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)
Thursday, March 3, 2016
Today's Astronomy Picture of the Day shows the close encounter between our Moon and Jupiter. If you look carefully, you can spot four more moons in the field of view: Callisto, Io, Ganymede and Europa (attempt no landings there).