This
story was updated 12:35 p.m. EDT.
WASHINGTON
— A NASA probe slammed into the moon Friday, in a bid to blast out a curtain of
debris in which scientists hope to detect signs of water ice.
The $79
million LCROSS spacecraft, preceded by its Centaur rocket stage, impacted
the lunar surface at the large south pole crater Cabeus at 7:31 a.m. EDT
(1131 GMT) in what NASA Chief Scientist Jim Garvin called "the ultimate
physics experiment."
"We
keep finding evidence that there is water [on the moon]," NASA
Administrator Charles Bolden told SPACE.com here. To find more with LCROSS
"would be incredibly good news. It would be another place we can send
humans," he added. Bolden said he had been following the last steps of the
mission throughout the night.
The LCROSS
probe beamed live
images of the moon as its Centaur rocket stage headed for impact before
making its own death plunge four minutes later. The two probes have crashed,
mission managers assured, but whether LCROSS caught the much touted flash of
the Centaur's impact was not immediately clear.
"I can
certainly report there was an impact," NASA's principal investigator Tony
Colaprete told reporters after the $79 million lunar crashes. "We saw the
impact, we saw the crater ... we have the data we need to actually address the questions
we set out to address."
The target
crater became larger and larger, with its bumpy relief becoming clearer, in the
broadcast images as LCROSS sped toward the moon. There were gasps and then
claps from the Newseum crowd here as the viewing screen filled with the image
of the crater and then went white. Laughs followed as the Flight Director at
Ames confirmed the successful impact and then proudly stood up in a televised
broadcast.
Mission
scientists watched the crash primarily from the probe's operations center at
NASA's Ames Research Center in Moffett Field, Calif., but astronomers and
amateur skywatchers also tuned in at observatories and other sites around the
world — including here at the Newseum, where more than 300 people watched the
NASA impact broadcast on a huge 40-foot screen.
"This
is the biggest screen I've ever seen," said one of the scores of people in
the crowd of NASA employees, members of the press and public, including several
bleary-eyed children.
Among the
crowd were Apollo 11 astronaut Buzz Aldrin and Chip Cronkite, the son of late
CBS TV news anchor Walter Cronkite, to whom the mission is dedicated.
"We
hope this is just the first of many oases we find," Cronkite said.
NASA
launched LCROSS — short for Lunar Crater Observation and Sensing Satellite —
and the powerful Lunar Reconnaissance Orbiter (LRO) in June to hunt for evidence
of water and ice on the lunar surface.
Ice on
the moon
Scientists
think that pockets of water ice might exist in the permanently shadowed craters
of the lunar south pole — thought to potentially be the coldest places in the
solar system. Water has already
been detected on the moon by a NASA-built instrument on board India's now
defunct Chandrayaan-1 probe and other spacecraft, though it was in very small
amounts and bound to the dirt and dust of the lunar surface.
NASA plans to
return astronauts to the moon by 2020 for extended missions on the lunar
surface. Finding usable amounts of ice on the moon would be a boon for that
effort since it could be a vital local resource to support a lunar base.
Even if
LCROSS does not turn up clear proof of water ice, that would be a major find,
mission scientists said. It could mean that ice on the moon is not as uniformly
distributed as suspected, or that water exists in concentrations too low to be
measured by LCROSS instruments — which would have repercussions for its value
as a resource to astronauts, they added.
The LCROSS
impact was also watched
by several satellites that normally monitor Earth and spacecraft like the
Hubble Space Telescope, Sweden's Odin observatory and LCROSS's sister spacecraft, the LRO
probe, which were due analyze the debris after the impact to look for signs of
water ice.
"All
eyes are on LCROSS today," Bolden said during remarks before the impact.
The crashes
were expected to kick up tons of moon dirt and carve a new crater within the
60-mile (98-km) wide Cabeus. That new crater could be as large as 66 feet (20
meters) wide and 13 feet (4 meters) deep. In a pass over the lunar south pole
later today, LRO will image the LCROSS impact crater.
Some 350
tons of moon dirt was expected to be blasted nearly 6.2 miles (10 km) above the
lunar surface. Unlike past moon crashes by other probes, like Japan's recent
Kaguya mission, LCROSS slammed into the lunar surface at a steep angle and was
slated to kick material up high enough to be illuminated by the sun as seen
from Earth and other spacecraft.
Seasoned
skywatchers on Earth equipped with 10 to 12-inch telescopes had a chance to spot
the crash on their own, if they knew where to look.
"There's
not going to be these grand, spectacular images of ejecta flying, kind of what
you've seen in animations or cartoons," Colaprete told reporters Thursday. "It's
going to be more of a muted shimmer of light, but that muted shimmer of light
contains all the information we need to answer our questions."
Scientists
don't know yet whether or not they've detected water in the LCROSS ejecta, as
it is expected to take some time to analyze the data.
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