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)
Friday, May 4, 2018
Today's Astronomy Picture of the Day shows Messier 101 in the constellation of Ursa Major. As you look at this beautiful spiral seen from above, can you spot other extra-galactic objects in the field of view?