Dwarf Galaxies in the Coma Cluster
In visible light images, more than a thousand galaxies are seen to lie within a volume about 20 million light-years across in the rich Coma Galaxy Cluster. But infrared images of the Coma Cluster are now being used to add thousands more to the Coma's galaxy count in the form of previously undiscovered dwarf galaxies.
This composite combines infrared Spitzer Space Telescope image
data (red and green) with visible light Sloan Sky Survey data (blue) for the central part of the cluster. Over 1 degree wide, the field is dominated by two giant elliptical galaxies in blue. Still, many of the small green smudges are identified as dwarf galaxies, roughly comparable to the Small Magellanic Cloud. Dwarf galaxies are thought to form first, providing building blocks for larger galaxies. The well-studied, friendly, Coma Cluster is 320 million light-years away.
Image Credit: NASA, JPL-Caltech, SDSS, Leigh Jenkins, Ann
* A Atlantis *
Atlantis Lifts Off!
Photographers crowd around the countdown clock to capture the successful launch of Space Shuttle Atlantis from Launch Pad 39A. The shuttle is delivering a new segment to the starboard side of the International Space Station's backbone, known as the truss. Three spacewalks are planned to install the S3/S4 truss segment, deploy a set of solar arrays and prepare them for operation. STS-117 is the 118th space shuttle flight, the 21st flight to the station, the 28th flight for Atlantis and the first of four flights planned for 2007. Image credit: NASA/Jim Grossmann
Photographers crowd around the countdown clock to capture the successful launch of Space Shuttle Atlantis from Launch Pad 39A. The shuttle is delivering a new segment to the starboard side of the International Space Station's backbone, known as the truss. Three spacewalks are planned to install the S3/S4 truss segment, deploy a set of solar arrays and prepare them for operation. STS-117 is the 118th space shuttle flight, the 21st flight to the station, the 28th flight for Atlantis and the first of four flights planned for 2007. Image credit: NASA/Jim Grossmann