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Chandra shows Saturn's rings sparkling with X-rays CHANDRA PHOTO RELEASE Posted: July 5, 2005
As the image shows, the X-rays in the ring mostly come from the B ring, which is about 25,000 kilometers wide and is about 40,000 kilometers (25,000 miles) above the surface of Saturn (the bright white inner ring in the optical image). There is some evidence for a concentration of X-rays on the morning side (left side, also called the East ansa) of the rings. One possible explanation for this concentration is that the X-rays are associated with optical features called spokes, which are largely confined to the dense B ring and most often seen on the morning side. Spokes, which appear as radial shadows in the rings, are due to transient clouds of fine ice-dust particles that are lifted off the ring surface, and typically last an hour or so before disappearing. It has been suggested that the spokes are triggered by meteoroid impacts on the rings, which are more likely in the midnight to early morning hours because during that period the relative speed of the rings through a cloud of meteoroids would be greater. The higher X-ray brightness on the morning side of the rings could be due to the additional solar fluorescence from the transient ice clouds that produce the spokes. This explanation may also account for other Chandra observations of Saturn, which show that the X-ray brightness of the rings varies significantly from one week to the next. |
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As excitement builds for the first space shuttle launch in over two years, this comprehensive video selection captures the major pre-flight events for Discovery and her seven astronauts.
Administrator Mike Griffin is the sole witness testifying before the House Science Committee in this hearing on the future of NASA. (2hr 01min 09sec file)
One day before beginning the space shuttle Flight Readiness Review, Administrator Mike Griffin gives a televised address to agency workers and answers questions. (26min 09sec file)
The Stafford-Covey Task Group holds a news conference from NASA Headquarters following the panel's final public hearing on the space shuttle program. (55min 58sec file)
The 18th Progress resupply ship launched to the International Space Station is guided to docking with the Zvezda service module's aft port via manual control from commander Sergei Krikalev. A problem thwarted plans for an automated linkup.
The House Science Committee, Subcommittee on Space and Aeronautics, begins its hearing on the International Space Station. (29min 59sec file)
House members question Expedition 11 crew member John Phillips living on the International Space Station. (16min 33sec file)
The hearing continues with questioning by House members of former station astronauts Peggy Whitson and Mike Fincke. (31min 33sec file)