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)
Sunday, April 28, 2019
The Iron World
Today's Astronomy Picture of the Day is a short video showing the color-enhanced full globe of our innermost planet: Mercury, as imaged by the MESSENGER vehicle after it's very successful mission.