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)
Wednesday, January 6, 2016
Comets, Comet Dust
Today's Astronomy Picture of the Day combines several plates to catch two comets (and a lucky meteor fall—some comet dust, maybe?) in one view.