2MASS 2MASS galaxy catalog adaptive optics Alvaro Orsi Andromeda Galaxy Arp 194 asteroid asteroids astronomical event ATLASGAL atomic clock aurora Betelgeuse Big Bang Cassiopeia A Chandra telescope Chandra X-Ray Observatory climate clouds collision comets Comet Tempel-Tuttle computer model computer models computer simulation conjunction Cosmic collision cosmology crater dark matter data manipulation Deep Impact Durham University dust dwarf galaxy Earthshine Echo satellite eclipse exploration extrasolar planet first stars galactic plane galaxies galaxy galaxy cluster galaxy group gamma-ray burst gamma ray burst Ganymede GRB Hayden history hoax Hubble Space Telescope ice ice age impact infrared intermediate skill International Space Station interstellar gas Io Ionized Atoms Jupiter large-scale structure launch LCROSS leap second Leonids LRO lunar magnetic field magnetosphere manhattanhenge Mars Mars Reconnaissance Orbiter meteor meteorite meteor shower microwave Milky Way Galaxy mission Moon MRO multiwavelength imagery NASA neutron star night sky Noctilucent Clouds observation optical planet satellite solar eclipse Solar System space shuttle star star formation Stars sunset Venus