Astronomy Picture Of the Day (APOD)An Avalanche on Mars
What caused this sudden cloud of dust on Mars? An avalanche! The first avalanche imaged in progress on another planet was recorded last month on Mars by NASA's robotic Mars Reconnaissance Orbiter. Visible...
Planets Align Over Australian Radio Telescope Array
Last week, Mercury, Venus, and the Moon all appeared close together in Earth's sky. This picturesque conjunction was caught on camera behind elements of the Australia Telescope Compact Array (ATCA) near the town of Narrabri in rural New South Wales.
CMBR Dipole: Speeding Through the Universe
Our Earth is not at rest. The Earth moves around the Sun. The Sun orbits the center of the Milky Way Galaxy. The Milky Way Galaxy orbits in the Local Group of Galaxies. The Local Group falls toward the Virgo Cluster of Galaxies.
M104 Hubble Remix
The striking spiral galaxy M104 is famous for its nearly edge-on profile featuring a broad ring of obscuring dust. Seen in silhouette against a bright bulge of stars, the swath of cosmic dust lanes lends a hat-like appearance to the galaxy in optical images suggesting the more popular moniker, The Sombrero Galaxy.
Comet over California
Still gracing northern skies, a fading Comet Holmes lies at the top edge of this colorful skyview, recorded on March 4. The reddish emission nebula below it is NGC 1499, also known as the California Nebula for its resemblance to the outline of the state on the US west coast.
Vela Supernova Remnant
The plane of our Milky Way Galaxy runs through this complex and beautiful skyscape. At the northwestern edge of the constellation Vela (the Sails) the 16 degree wide, 30 frame mosaic is centered on the glowing filaments of the Vela Supernova Remnant, the expanding debris cloud from the death explosion of a massive star.
The International Space Station Expands Again
The developing International Space Station (ISS) has changed its appearance again. Last month, the Space Shuttle orbiter Atlantis visited the ISS and added components that included the Columbus Science Laboratory. The entire array of expansive solar panels is visible in this picture taken by the Atlantis Crew after leaving the ISS to return to Earth.
NGC 6334: The Cats Paw Nebula
Nebulae are perhaps as famous for being identified with familiar shapes as perhaps cats are for getting into trouble. Still, no known cat could have created the vast Cat's Paw Nebula visible in Scorpius.
Sand Dunes Thawing on Mars
What are these strange shapes on Mars? Defrosting sand dunes. As spring now dawns on the Northern Hemisphere of Mars, dunes of sand near the pole, as pictured above, are beginning to thaw. The carbon dioxide and water ice actually sublime in the thin atmosphere directly to gas.
Comet Hale Bopp Over Val Parola Pass
Comet Hale-Bopp, the Great Comet of 1997, became much brighter than any surrounding stars. It was seen even over bright city lights. Away from city lights, however, it put on quite a spectacular show. Here Comet Hale-Bopp was photographed above Val Parola Pass in the Dolomite mountains surrounding Cortina d'Ampezzo, Italy.