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, June 5, 2017
Today's Astronomy Picture of the Day helps you plan your observing plans for the next few months. Or, in my case, what I'll be missing under the semi-permanent all-sky cloud filter.