It's only Monday, but I'm going out on a limb and predicting that this will stand as the nature photo of the week. The image, courtesy of Veres Viktor, via NASA, shows a mysterious "night-shining cloud" over Budapest, Hungary on June 15. Such clouds apparently form in high in the Earth's atmosphere. Scientists still don't know much about them and have launched a satellite to study them. From our perspective they are amazing. Go here for details.