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)
Sunday, August 4, 2013
Today's Astronomy Picture of the Day shows Jupiter's ever-changing moon Io. Thanks to the tidal tug-of-war that is the Jupiter system, there are no (permanent) maps for these territories.