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Hurricane Ivan
Cameras on the International Space Station see Hurricane Ivan as the orbiting complex flies over the powerful storm. (3min 05sec file)
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Friday's Genesis update
On Friday, Sept. 10, officials hold a news conference from Utah to update reporters on the recovery operations to salvage the Genesis sample return mission. (44min 47sec file)
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Genesis recovered
Workers recover the Genesis solar wind samples from the impact crater and take the equipment into a facility for examination. (2min 08sec file)
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Tour of KSC hurricane damage
Martin Wilson, manager of the Thermal Protection System Facility, gives a tour of the highly damaged building at Kennedy Space Center in the wake of Hurricane Frances. (2min 31sec file)
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Inside the VAB
Go inside Kennedy Space Center's hurricane-battered Vehicle Assembly Building and also see the damage to the 52-story tall facility's roof. (2min 51sec file)
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Post-impact news briefing
Officials hold a post-landing news conference in Utah a couple hours after Genesis returned to Earth on Sept. 8. (40min 52sec file)
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Capsule first spotted
Powerful tracking cameras spot the Genesis capsule for the first time a couple hundred thousand feet above Earth, prompting applause in the control centers. But just moments later, that joy turned to heartbreak. (1min 02sec file)
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Genesis crash lands
The Genesis sample return capsule tumbles through the sky and impacts the desert floor in Utah after its speed-slowing chute and parafoil failed to deploy for a mid-air recovery by a helicopter. (2min 29sec file)
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This slow-motion video shows the Genesis capsule slamming into the ground. (1min 06sec file)
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Aerial views of crater
Aerial views show the Genesis capsule half buried in the Utah desert floor after its landing system suffered a failure. (1min 53sec file)
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Recovery helicopters
The primary and backup recovery helicopters take off with escort from a Blackhawk in preparation for the mid-air retrieval of Genesis. (1min 01sec file)
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The original plan
Animation shows how the Genesis spacecraft was supposed to return. Expert narration provided by JPL entry, descent and landing expert Rob Manning. (5min 29sec file)
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Tuesday's hurricane news briefing
The Kennedy Space Center director and 45th Space Wing commander from Cape Canaveral Air Force Station hold a news conference Tuesday to describe damage from Hurricane Frances. (46min 15sec file)
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Footage of KSC damage
This movie takes you on a tour of hurricane damage to Kennedy Space Center's Vehicle Assembly Building, shuttle tile manufacturing facility and press site. (3min 11sec file)
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Dark matter 'superstructure' revealed by Chandra
Posted: September 14, 2004

A nearby galaxy cluster is facing an intergalactic headwind as it is pulled by an underlying superstructure of dark matter, according to new evidence from NASA's Chandra X-ray Observatory. Astronomers think that most of the matter in the universe is concentrated in long large filaments of dark matter and that galaxy clusters are formed where these filaments intersect.

A Chandra mosaic of images of the Fornax galaxy cluster reveals that the vast cloud of ten-million-degree Celsius gas surrounding the cluster core has a swept-back cometary shape that extends for more than half a million light years. This geometry suggests that the hot gas cloud is moving through a larger, but less dense cloud of gas, creating a ram pressure, or intergalactic headwind. Credit: NASA/CXC/Columbia U./C.Scharf et al.
A Chandra survey of the Fornax galaxy cluster revealed a vast, swept-back cloud of hot gas near the center of the cluster. This geometry indicates that the hot gas cloud, which is several hundred thousand light years in length, is moving rapidly through a larger, less dense cloud of gas. The motion of the core gas cloud, together with optical observations of a group of galaxies racing inward on a collision course with it, suggests that an unseen, large structure is collapsing and drawing everything toward a common center of gravity.

"At a relatively nearby distance of about 60 million light years, the Fornax cluster represents a crucial laboratory for studying the interplay of galaxies, hot gas and dark matter as the cluster evolves." said Caleb Scharf of Columbia University in New York, NY, lead author of a paper describing the Chandra survey that was presented at an American Astronomical Society meeting in New Orleans, LA. "What we are seeing could be associated directly with the intergalactic gas surrounding a very large scale structure that stretches over millions of light years."

The infalling galaxy group, whose motion was detected by Michael Drinkwater of the University of Melbourne in Australia, and colleagues, is about 3 million light years from the cluster core, so a collision with the core will not occur for a few billion years. Insight as to how this collision will look is provided by the elliptical galaxy NGC 1404 that is plunging into the core of the cluster for the first time. As discussed by Scharf and another group led by Marie Machacek of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., the hot gas cloud surrounding this galaxy has a sharp leading edge and a trailing tail of gas being stripped from the galaxy.

"One thing that makes what we see in Fornax rather compelling is that it looks a lot like some of the latest computer simulations," added Scharf. "The Fornax picture, with infalling galaxies, and the swept back geometry of the cluster gas - seen only with the Chandra resolution and the proximity of Fornax - is one of the best matches to date with these high-resolution simulations."

Over the course of hundreds of millions of years, NGC 1404's orbit will take it through the cluster core several times, most of the gas it contains will be stripped away, and the formation of new stars will cease. In contrast, galaxies that remain outside the core will retain their gas, and new stars can continue to form. Indeed, Scharf and colleagues found that galaxies located in regions outside the core were more likely to show X-ray activity that could be associated with active star formation.

The wide-field and deep X-ray view around Fornax was obtained through ten Chandra pointings, each lasting about 14 hours. Other members of the research team were David Zurek of the American Museum of Natural History, New York, NY, and Martin Bureau, a Hubble Fellow currently at Columbia.

NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for NASA's Office of Space Science, Washington. Northrop Grumman of Redondo Beach, Calif., formerly TRW, Inc., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass.