Houston Astronomical Society Home Observing Guide Contact Us	Observing Guide the Atmosphere   Jonathan's Space Report 7/15/2007: The Space Report ("JSR") is issued about twice a month. It describes all space launches, including both piloted missions and automated satellites  Noctilucent Clouds Follow the progress of AIM, a satellite devoted to the study of "night-shining" clouds. These unusual clouds form in the mesosphere. The mesosphere is not only very cold (-125 C), but also very dry--"one hundred million times dryer than air from the Sahara desert." Nevertheless, NLCs are made of water. The clouds consist of tiny ice crystals about the size of particles in cigarette smoke. Sunlight scattered by these crystals gives the clouds their characteristic blue color.	Web Resources 8/5/07 Photosynth views of Space Shuttle Endeavour preparation for launch Space Station, as seen from the ground