[meteorite-list] Shackleton Crater: SMART-1's Search for Light, Shadow and Ice at Lunar South Pole

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Fri Oct 20 12:44:51 2006
Message-ID: <200610201644.JAA23497_at_zagami.jpl.nasa.gov>

http://www.esa.int/SPECIALS/SMART-1/SEMP7QOFHTE_0.html

Shackleton crater: SMART-1's search for light, shadow and ice at lunar
South Pole

European Space Agency
20 October 2006

This image, taken by the advanced Moon Imaging Experiment (AMIE) on
board ESA's SMART-1 spacecraft, shows crater Shackleton on the Moon.
 
AMIE obtained this image on 13 January 2006 - close to the time of lunar
southern Summer - from a distance of 646 kilometres over the surface and
with a ground resolution of 60 metres per pixel.

Shackleton crater lies at the lunar South Pole, at 89.54?? South latitude
and 0?? East longitude, and has a diameter of 19 kilometres.

SMART-1 monitored this area almost every orbit. This will allow to
produce very high resolution maps of the area as well as illumination
maps. The long shadows that surround the crater make it very hard to
observe. The analysis of the data obtained allowed a very detailed map
of its rim, surrounding ejectas and craters.

SMART-1 also made long repeated exposures to see inside the shadowed
areas. The purpose was detecting the very weak reflected light from the
crater rims, and therefore study the surface reflection properties
(albedo) and its spectral variations (mineralogical composition). These
properties could reveal patchy ice surface layers inside the crater.

On the 2-kilometre wide inner edge of the crater ridge, at times barely
visible from Earth, astronomers using ground radio-telescopes have
recently reported they were not able to detect a distinctive signature
of thick deposits of ice in the area. Earlier measurements by NASA's
Lunar Prospector reported of hydrogen enhancement over large shadowed
areas.

"We still do not know if this hydrogen is due to enhanced trapping of
solar wind, or to the water ice brought on the Moon by the bombardment
of comets and asteroids," says Bernard Foing, ESA's SMART-1 Project
Scientist. "These bodies may have deposited on the Moon patchy layers of
ice filling about 1.5 percent of the areas in permanent shadow, down to
one metre below the surface."

"We need to analyse all remote sensing data sets consistently. Future
lander and rover missions to the Moon will help in the search and
characterisation of lunar polar ice, both on the surface and below the
subsurface," Foing continues. "In any case, one day we may even be able
to simply combine the implanted hydrogen and the oxygen extracted from
lunar rocks to produce clean water, like we do in laboratory experiments
on Earth."

The crater is named after Ernest Shackleton (1874-1922), an explorer
famous for his Antartic expeditions.
 
Note to editors
 
Launched in September 2003, SMART-1 ended its mission through lunar
impact on 3 September 2006. The huge data sets it provided are and will
be analysed by lunar and planetary scientists, and provide a very
important legacy in the history of lunar exploration.
 
 
For more information
 
Bernard H. Foing, ESA SMART-1 Project Scientist
Email: bernard.foing _at_ esa.int

Jean-Luc Josset, AMIE Principal Investigator, SPACE-X Space Exploration
Institute
Email: jean-luc.josset _at_ space-x.ch
Received on Fri 20 Oct 2006 12:44:48 PM PDT