IMPACT! |
Lunar
CRater Observation and Sensing Satellite (LCROSS) |
Crater Impact Characteristics
The primary goal of LCROSS was to measure the concentration of water
ice (ice to dust ratio) in permanently shadowed lunar regolith.
Setting constraints on water ice set a fiducial for the LRO
studies of hydrogen neutrons, that were expected to have water ice
as a source. Several important processes occur when a body strikes
the lunar surface, including the initial impact, ejecta and plume
dispersion, and the exposure of fresh subsurface (Figure 1). Continuously
monitoring the impact events at a variety of spatial (m to km to
exosphere scales) and temporal scales (sec to minutes to days) allowed
us to understand lunar impact processes and assess the likelihood
that water ice, due to impacts occurring within the permanently
shadowed target crater, may be distributed non-uniformly.
Figure 1 The life cycle of a lunar impact and associated
time and special scales. The LCROSS measurement methods are “layered”
in response to the rapidly evolving impact environment.
Click to Enlarge
Click to Enlarge
The upper stage of the launch vehicle (about the weight
of a large SUV) impacted into the South Pole of the Moon
at over 9,000 km/h (5,600 mph).
The impact excavated a crater about 1/3 of a football field wide
and about the depth of the deep end of a swimming pool.
The amount of material (dust and probably ice) ejected could fill
ten school buses, or ten Space Shuttle cargo bays. The plume was expected
to reach nearly 50 km high (over 30 miles)!
|
IR still of Centaur Crater |
Watch
an animation of a meteoroid hitting the Moon’s surface.
Visit
the NASA Mission Site @ http://www.nasa.gov/lcross
|
