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)
Tuesday, February 27, 2018
Today's Astronomy Picture of the Day shows a river of water, a river of light (the Milky Way) and a river of dust (zodiacal light). The third is created by dust from comets passing near Jupiter. That is a lot of comets!