Serene Scene
May 21, 2012
Even in a peaceful looking scene such as this one of Saturn and its moon Tethys, the Cassini spacecraft reveals clues about how Saturn is ever-changing. Saturn's northern hemisphere still shows the scars of the huge storm that raged through much of 2011 . And, day by day, the shadows cast by the rings on the planet's southern hemisphere are growing wider as the seasons progress toward northern summer. The moon, Tethys, appears above the rings to the left of the center of the image. This moon is 660 miles, or 1,062 kilometers across.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate in Washington. The Cassini orbiter and its two on board cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo.
For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov or http://www.nasa.gov/cassini. The Cassini imaging team homepage is at http://ciclops.org.
Janus' Craters
May 7, 2012
Shadows darken parts of some of Janus' large craters as Cassini takes a close look during its flyby of this irregularly shaped moon on March 27, 2012. This small moon is only 111 miles wide (179 km). The image was taken in visible light with the Cassini spacecraft narrow-angle camera. The view was acquired at a distance of approximately 28,000 miles (45,000 km) from Janus.
The Tale Continues...
April 16, 2012
The brightly reflective moon Enceladus appears before Saturn's rings while the larger moon Titan looms in the distance. Enceladus, which is 313 miles wide (504 km), is in the center of the image. Titan (3,200 miles wide, 5,150 km) can faintly be seen in the background beyond the rings. This view looks toward the anti-Saturn side of Enceladus and the Saturn-facing side of Titan. The northern, sunlit side of the rings is seen from just above the ring plane. The image was taken in visible green light with the Cassini spacecraft narrow-angle camera on March 12, 2012. The view was acquired at a distance of approximately 600,000 miles (1 million km) from Enceladus
Merging Galaxy Cluster Abell 520
This composite image shows the distribution of dark matter, galaxies, and hot gas in the core of the merging galaxy cluster Abell 520, formed from a violent collision of massive galaxy clusters.
The Necklace Nebula
A giant cosmic necklace glows brightly in this NASA Hubble Space Telescope image. The object is a recently discovered planetary nebula, the glowing remains of an ordinary, Sun-like star. The nebula consists of a bright ring, measuring 12 trillion miles across, dotted with dense, bright knots of gas that resemble diamonds in a necklace. The knots glow brightly due to absorption of ultraviolet light from the central stars.
A pair of stars orbiting very close together produced the nebula. About 10,000 years ago one of the aging stars ballooned to the point where it enveloped its companion star. This caused the larger star to spin so fast that much of its gaseous envelope expanded into space. Due to centrifugal force, most of the gas escaped along the star's equator, producing a dense ring. The embedded bright knots are the densest gas clumps in the ring. The stars are furiously whirling around each other, completing an orbit in a little more than a day. (For comparison, Mercury, the closest planet to the Sun, takes 88 days to orbit the Sun.)
The Necklace Nebula is located 15,000 light-years away in the constellation Sagitta (the Arrow). In this composite image, taken on July 2, 2011, Hubble's Wide Field Camera 3 captured the glow of hydrogen (blue), oxygen (green), and nitrogen (red).
Clear and Hazy Gas Layers in Uranus' Atmosphere
Hubble Space Telescope has peered deep into Uranus' atmosphere to see clear and hazy layers created by a mixture of gases. Using infrared filters, Hubble captured detailed features of three layers of Uranus' atmosphere. Hubble's images are different from the ones taken by the Voyager 2 spacecraft, which flew by Uranus 10 years ago. Those images - not taken in infrared light - showed a greenish-blue disk with very little detail. The infrared image allows astronomers to probe the structure of Uranus' atmosphere, which consists of mostly hydrogen with traces of methane. The red around the planet's edge represents a very thin haze at a high altitude. The haze is so thin that it can only be seen by looking at the edges of the disk, and is similar to looking at the edge of a soap bubble. The yellow near the bottom of Uranus is another hazy layer. The deepest layer, the blue near the top of Uranus, shows a clearer atmosphere. Image processing has been used to brighten the rings around Uranus so that astronomers can study their structure. In reality, the rings are as dark as black lava or charcoal.
Jupiter
The above photo is a great picture of Jupiter taken by Hubble.
Hour-Glass Nebula
This Hubble telescope snapshot of MyCn18, a young planetary nebula, reveals that the object has an hourglass shape with an intricate pattern of "etchings" in its walls. A planetary nebula is the glowing relic of a dying, Sun-like star. The results are of great interest because they shed new light on the poorly understood ejection of stellar matter that accompanies the slow death of Sun-like stars. According to one theory on the formation of planetary nebulae, the hourglass shape is produced by the expansion of a fast stellar wind within a slowly expanding cloud, which is denser near its equator than near its poles.
Here is a photo of Hubble:
CREDITS: NASA and affiliates including ESA, CFHT, CXO, M.J. Jee (University of California, Davis), and A. Mahdavi (San Francisco State University), JPL-Caltech/Space Science Institute
