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Hill-climbing Mars rover
The Mars Exploration Rover Spirit has reached the summit of Husband Hill, returning a spectacular panorama from the hilltop in the vast Gusev Crater. Scientists held a news conference Sept. 1 to reveal the panorama and give an update on the twin rover mission.
Planes track Discovery
To gain a new perspective on space shuttle Discovery's ascent and gather additional imagery for the return to flight mission, NASA dispatched a pair of high-flying WB-57 aircraft equipped with sharp video cameras in their noses.
Rocket booster cams
When space shuttle Discovery launched its two solid-fuel booster rockets were equipped with video cameras, providing dazzling footage of separation from the external fuel tank, their free fall and splashdown in the sea.
Discovery ferried home
Mounted atop a modified Boeing 747, space shuttle Discovery was ferried across the country from Edwards Air Force Base, California, to Kennedy Space Center, Florida.
Shuttle tank returned
Shuttle fuel tank ET-119 is loaded onto a barge at Kennedy Space Center for the trip back to Lockheed Martin's Michoud Assembly Facility in New Orleans. The tank will be used in the investigation to determine why foam peeled away from Discovery's tank on STS-114 in July.
Delta 4 launch delayed
Launch of the GOES-N weather observatory aboard a Boeing Delta 4 rocket is postponed at Cape Canaveral, Florida.
Mars probe leaves Earth
The Mars Reconnaissance Orbiter lifts off aboard a Lockheed Martin Atlas 5 rocket from Cape Canaveral's Complex 41.
Launch pad demolition
Explosives topple the abandoned Complex 13 mobile service tower at Cape Canaveral Air Force Station. This video was shot from the blockhouse roof at neighboring Complex 14 where John Glenn was launched in 1962.
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Deep Impact comet mission producing surprises
NASA NEWS RELEASE
Posted: September 6, 2005
Painting by the numbers is a good description of how scientists create pictures of everything from atoms in our bodies to asteroids and comets in our solar system. Researchers involved in NASA's Deep Impact mission have been doing this kind of work since the mission's July 4th collision with comet Tempel 1.
"Prior to our Deep Impact experiment, scientists had a lot
of questions and untested ideas about the structure and
composition of the nucleus, or solid body of a comet, but we
had almost no real knowledge," said Deep Impact principal
investigator Michael A'Hearn, a professor of astronomy at
the University of Maryland, College Park, Md. "Our analysis
of data produced by Deep Impact is revealing a great deal,
much of it rather surprising."
This composite image was built up from scaling all images from Deep Impact to 5 meters/pixel, and aligning images to fixed points. Each image at closer range, replaced equivalent locations observed at a greater distance. The impact site has the highest resolution because images were acquired until about 4 sec from impact or a few meters from the surface. Arrows A and B point to large, smooth regions. The impact site is indicated by the third large arrow. Small arrows highlight a scarp that is bright due to illumination angle, which shows the smooth area to be elevated above the extremely rough terrain. The scale bar is 1 km and the two arrows above the nucleus point to the sun and the rotational axis of the nucleus. Celestial north is near the rotational pole. Credit: NASA/JPL/UMd
For example, comet Tempel 1 has a very fluffy structure that
is weaker than a bank of powder snow. The fine dust of the
comet is held together by gravity. However, that gravity is
so weak, if you could stand on the bank and jump, you would
launch yourself into space.
Another surprise for A'Hearn and his colleagues was the
evidence of what appears to be impact craters on the surface
of the comet. Previously two other comets had their nuclei
closely observed, and neither showed evidence of impact
"The nucleus of Tempel 1 has distinct layers shown in
topographic relief ranging from very smooth areas to areas
with features that satisfy all the criteria for impact
craters, including varying size," A'Hearn said. "The problem
in stating with certainty that these are impact craters is
that we don't know of a mechanism by which some comets would
collide with the flotsam and jetsam in our solar system,
while others would not," he added.
According to A'Hearn, one of the more interesting findings
may be the huge increase in carbon-containing molecules
detected in spectral analysis of the ejection plume. This
finding indicates comets contain a substantial amount of
organic material, so they could have brought such material
to Earth early in the planet's history when strikes by
asteroids and meteors were common.
Another finding is the comet interior is well shielded from
the solar heating experienced by the surface of the comet
nucleus. Mission data indicates the nucleus of Tempel 1 is
extremely porous. Its porosity allows the surface of the
nucleus to heat up and cool down almost instantly in
response to sunlight. This suggests heat is not easily
conducted to the interior and the ice and other material
deep inside the nucleus may be pristine and unchanged from
the early days of the solar system, just as many scientists
"The infrared spectrometer gave us the first temperature map
of a comet, allowing us to measure the surface's thermal
inertia, or ability to conduct heat to the interior," said
Olivier Groussin, the University of Maryland research
scientist who generated the map.
It is this diligent and time consuming analysis of spectral
data that is providing much of the "color" with which Deep
Impact scientists are painting the first ever detailed
picture of a comet. For example, researchers recently saw
emission bands for water vaporized by the heat of the
impact, followed a few seconds later by absorption bands
from ice particles ejected from below the surface and not
melted or vaporized.
"In a couple of seconds the fast, hot moving plume
containing water vapor left the view of the spectrometer,
and we are suddenly seeing the excavation of sub-surface ice
and dust," said Deep Impact co-investigator Jessica
Sunshine, with Science Applications International
Corporation, Chantilly, Va. "It is the most dramatic
spectral change I've ever seen."
These findings were published in the September 9 issue of
the journal Science, and presented at the Division for
Planetary Sciences meeting in Cambridge, England. Mission
scientists are filling in important new portions of a
cometary picture that is still far from finished.
Additional coverage for subscribers:
IMPACT MOVIES FROM MOTHERSHIP (NARRATED) PLAY
RIDE ALONG AS THE IMPACTOR SLAMS INTO TARGET PLAY
LEAD SCIENTISTS PRESENTS LATEST RESULTS PLAY
POST-ENCOUNTER NEWS BRIEFING DIAL-UP | BROADBAND
LISTEN TO NEWS CONFERENCE MP3
DEEP IMPACT SMASHES INTO COMET PLAY
NARRATION OF IMPACTOR'S FINAL IMAGES PLAY
IMPACT PICTURES EXPLAINED BY COMET EXPERT PLAY
POST-IMPACT NEWS CONFERENCE DIAL-UP | BROADBAND
LISTEN TO POST-IMPACT NEWS CONFERENCE MP3
"DEEP IMPACT: THE MISSION" MOVIE PLAY
"DIGGING OUT THE SCIENCE" PLAY
RECAP OF IMPACTOR DEPLOY ACTIVITIES PLAY
PREVIEW OF THE ENCOUNTER TIMELINE PLAY
LEARN MORE ABOUT THE SPACECRAFT PLAY
SCIENCE DATA FROM COMET OUTBURSTS PLAY
MISSION ENGINEERING BRIEFING DIAL-UP | BROADBAND
PRE-IMPACT SCIENCE BRIEFING DIAL-UP | BROADBAND
MORE: DEEP IMPACT VIDEO COLLECTION!