Last Quarter Moon (NASA, International Space Station, 08/22/11) (by NASA’s Marshall Space Flight Center)
Comet Hale-Bopp, C1995 O1, sports two tails here: a blue ion tail and a white dust tail. Both are formed by material ejected from the nucleus, which is mostly water ice and dust. The ice is heated by the comet's approach to the sun, going directly from a solid to a gas, bypassing the liquid form. As the material from the nucleus is ejected it forms a gigantic cloud around the nucleus which we see as the coma. It then separates into the blue ion gas tail and the dust tail.
An annular eclipse is seen beside the Tokyo Sky Tree tower in Tokyo's Sumida Ward at 7:34 a.m. on May 21. This composite photo was created using different exposure levels taken at the same place. (Satoru Sekiguchi)
Comet Lovejoy on December 23, 2014. Photo by Gerald Rhemann. The wonderful New Year’s comet – Comet C/2014 Q2 Lovejoy