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, April 20, 2016
Today's Astronomy Picture of the Day shows an Einstein Ring. One galaxy allows the light of another (more distant) galaxy to bend around it, allowing the fortuitous imaging of objects that would otherwise be missed.