An international team of astronomers using NASA's Hubble Space Telescope has devised a new method for measuring perhaps the greatest puzzle of our universe dark energy. This mysterious phenomenon, discovered in 1998, is pushing our universe apart at ever-increasing speeds. The team's results appear in the August 20, 2010 issue of the journal Science.

A long-exposure Hubble Space Telescope image shows a majestic face-on spiral galaxy located deep within the Coma Cluster of galaxies, which lies 320 million light-years away in the northern constellation Coma Berenices. The galaxy, known as NGC 4911, contains rich lanes of dust and gas near its center. These are silhouetted against glowing newborn star clusters and iridescent pink clouds of hydrogen, the existence of which indicates ongoing star formation. Hubble has also captured the outer spiral arms of NGC 4911, along with thousands of other galaxies of varying sizes. The high resolution of Hubble's cameras, paired with considerably long exposures, made it possible to observe these faint details.

A beautiful new image of two colliding galaxies has been released by NASA's Great Observatories. The Antennae galaxies, located about 62 million light-years from Earth, are shown in this composite image from the Chandra X-ray Observatory (blue), the Hubble Space Telescope (gold and brown), and the Spitzer Space Telescope (red). The imaging data were taken in 1999, 2003, 2004, and 2005. The Antennae galaxies take their name from the long antenna-like "arms," seen in wide-angle views of the system. These features were produced by tidal forces generated in the collision.