... Cave with Aurora Skylight . ... Yes, but have you ever seen aurora from a cave? ... What's happened to our Sun? ... In this beach and skyscape from Alicante, Spain, July's Full Moon shines in the dark blue twilight, its reflection coloring the Mediterranean waters. ... Ou4: A Giant Squid Nebula . ... 3D Homunculus Nebula . ... The Moon Eclipses Saturn . ... A Blue Bridge of Stars between Cluster Galaxies . ... Why is there a blue bridge of stars across the center of this galaxy cluster? ...