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 9, 2016
Today's Astronomy Picture of the Day is a short video showing the appearance and disappearance of a supernova in a galaxy some 80 million light years away. For a brief time, one supernova can outshine all the other stars in its parent galaxy.