Taking a SMART sidelong look at Peak of Eternal Light
Three-dimensional views of the mountainous terrain surrounding a “Peak of Eternal Light” near the Moon’s south pole have been released by the European Space Agency. Dr Detlef Koschny will present the images at the European Planetary Science Congress in Münster on Friday 26th September.
Images taken by the AMIE camera carried by ESA’s SMART-1 mission have been used to create digital elevation model of the peak, which is almost continuously exposed to sunlight.
“AMIE is not a stereo camera, so producing a 3-D model of the surface has been a challenge,” said Dr Koschny. “We’ve used a technique where we use the brightness of reflected light to determine the slope and, by comparing several images, put together a model that produces a shadow pattern that matches those observed by SMART-1.”
AMIE took a total of 113 images of the peak, located close to the rim of the Shackleton Crater which lies on the lunar south pole. In all but four of the images, the peak was illuminated by sunlight. This is of particular interest in planning future manned missions to the Moon, as it would mean that solar panels could be used almost constantly to generate an electricity supply for a lunar base.
In addition, the shadowed craters nearby are in constant darkness and may hold water ice deposited over millennia by cometary impacts and hydrogen and oxygen particles contained in the solar wind. This potential water supply would also be a vital resource for any lunar base.
The team, led by Dr Björn Grieger of ESA’s European Space Astronomy Centre in Madrid, selected five of the AMIE images showing the peak illuminated from different angles. They mapped all the pixels onto a grid, defining the bright and dark areas. The data from the five images were then compared to produce estimates of the slope angles and the rendered elevation model was iteratively adjusted to produce a shadow match. The original AMIE images were then projected onto the retrieved model. To clearly visualise the topography, the elevation has been exaggerated five times.
SMART-1 orbited the Moon between November 2004 and September 2006, covering a full seasonal cycle. The resolution of the AMIE images is about 50 metres per pixel.
Click on images for high-resolution versions
Figure 1. Clementine mosaic of lunar south pole showing possible landing sites. The “Peak of Eternal Light is marked in red. Credit: PJ Stooke
Figure 2. Selected Amie Images of the peak superposed onto Clementine mosaic. Credit: ESA/SMART-1/Space-X (Space Exploration Institute)
Figure 3. Digital elevation map. Credit: ESA/SMART-1/Space-X (Space Exploration Institute)
Figure 4. View of “Peak of Eternal Light” from the rim of the Shackleton Crater. The peak is along the ridge in the centre of the image. The possible landing sites 1 & 2 from the Clementine mosaic are in the bottom right hand corner of the image. Credit: ESA/SMART-1/Space-X (Space Exploration Institute)
Figure 5. View of “Peak of Eternal Light”. The Shackleton Crater is just off the image on the right hand side. Potential landing site 4 from the Clementine mosaic is on the left hand ridge of the peak. The small crater in the centre of the image is about 1 kilometre across. Credit: ESA/SMART-1/Space-X (Space Exploration Institute)
Figure 6. The “Peak of Eternal Light” is in the background of the image. The crater in the foreground is about 5 kilometres across. Potential landing site 5 is just to the left of the main crater, near the small crater on the rim. Credit: ESA/SMART-1/Space-X (Space Exploration Institute)
EUROPEAN PLANETARY SCIENCE CONGRESS
EPSC 2008 is organised by Europlanet, the European Planetology Network in association with the European Geosciences Union and the Westfälische Wilhelms Universität, Münster.
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The objectives are to:
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2) initiate a long-term integration of the European planetary science community;
3) improve European scientific competitiveness, develop and spread expertise in this research area;
4) improve public understanding of planetary environments.
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