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 20, 2016
Today's Astronomy Picture of the Day shows two views of the Sun with Mercury in Transit. I tried defocusing my eyes to combine the images into a stereo view, but can't quite manage that.