Astronomy Picture Of the Day (APOD)X Ray Rainbows
A drop of water or prism of glass can spread out visible sunlight into a rainbow of colors. In order of increasing energy, the well known spectrum of colors in a rainbow runs red, orange, yellow, green, blue, indigo, violet.
Spirals On Edge
Spiral galaxies viewed face-on display a grand design, with graceful spiral arms traced by bright star clusters and glowing stellar nurseries. When seen edge-on, their appearance is very different but no less striking as their central regions bulge and dark cosmic dust lanes appear silhouetted against starlight from flattened galactic disks.
Space Station Shows Off New Robot Arm
The International Space Station (ISS) continues to grow. Last month, the crew of the Space Shuttle Endeavor delivered new Logistics Modules and installed the new Canadarm2 on the growing outpost. The ISS -- complete with its new arm -- was photographed 400 kilometers above planet Earth by the Space Shuttle Endeavor crew soon after they undocked.
GRO J1655 40: Evidence for a Spinning Black Hole
In the center of a swirling whirlpool of hot gas is likely a beast that has never been seen directly: a black hole. Studies of the bright light emitted by the swirling gas frequently indicate not only that a black hole is present, but also likely attributes.
One Hundred Kilometer Terrain on Venus
Even the hot and cracked surface of Venus has rolling hills. Although never actually photographed from up-close, images of the Venusian surface like that shown above have been constructed in recent years by digitally merging distant photographs with height-sensitive radar. Isolated above is a 100-kilometer wide swath inside a volcanic region known as Yavine Corona.
The Pleiades Star Cluster
It is the most famous star cluster on the sky. The Pleiades can be seen without binoculars from even the depths of a light-polluted city. Also known as the Seven Sisters and M45, the Pleiades is one of the brightest and closest open clusters.
Shepard Flies Freedom 7
Forty years ago today (May 5, 1961), at the dawn of the space age, NASA controllers "lit the candle" and sent Alan Shepard arcing into space atop a Redstone rocket. The picture shows the pressure-suited Shepard before launch in his cramped space capsule dubbed "Freedom 7".
Protoplanetary Survivors in Orion
The Orion Nebula is a nuturing stellar nursery filled with hot young stars and their natal clouds of gas and dust. But for planetary systems, the active star-forming region can present a hazardous and inhospitable birthplace.
Far Side of the Sun
You may think it's impossible to see through the Sun, but maps of the Sun's far side are now made routinely by instruments on board the sun-staring SOHO spacecraft. This is one such map from April 12.
Planet Building in HD 100546
More than 100 billion boulders may be swarming in the disk around nearby star HD 100546. In a scene thought similar to the early years of our own Solar System, ever larger rocks are growing by colliding and accreting dust as the messy business of planet formation appears to be underway.