[meteorite-list] Crater Lichtenberg and Young Lunar Basalts Tracked by SMART-1

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Fri Mar 3 13:23:28 2006
Message-ID: <200603031753.k23HriS20602_at_zagami.jpl.nasa.gov>

http://www.esa.int/SPECIALS/SMART-1/SEMQ0SMVGJE_0.html

Crater Lichtenberg and young lunar basalts tracked by SMART-1
European Space Agency
2 March 2006

This animation, made from images taken by the Advanced Moon Imaging
Experiment (AMIE) on board ESA's SMART-1 spacecraft, illustrates a
special pointing mode, the so-called 'target-tracking' mode.
 
[Map showing location of the crater Lichtenberg]

The images show crater Lichtenberg in the Oceanus Procellarum region on
the Moon, centred on an area located at 66.8? West, 32.6? North.

The AMIE camera obtained the images from a distance of between 2064 and
2162 kilometres with a ground resolution of between approximately 186
and 195 metres per pixel.

Most of the time, the SMART-1 spacecraft points exactly downwards to the
Moon, so-called 'nadir-pointing'. This animation illustrates a pointing
mode called the 'target-tracking' mode.

As the spacecraft moves around the Moon, it is commanded to keep
pointing at the same target for a certain period of time, even though it
moves over the lunar surface faster than 900 metres per second (or 3260
kilometres per hour). In this particular case, the distance between the
target and the spacecraft changes by 100 kilometres every six minutes.

The prominent crater in the lower right of the image is crater
Lichtenberg, with a diameter of 20 kilometres. There is a height
difference between inner crater floor and surrounding lava plain of 1300
metres.

The actual target of this observation was the 'ghost' crater on the
lower left of Lichtenberg. This is almost hidden by overflowed lava from
Oceanus Procellarum. The SIR infrared spectrometer on board SMART-1 was
measuring the composition of this area during these measurements.

[Crater Lichtenberg]

This area is of high geological interest and it was selected for the
study of the most recent lunar volcanism. It is thought to contain the
youngest basalts on the lunar surface, with an age of about 'only' 1000
million years.

>From geological mapping, scientists know that there are very young
basalts around crater Lichtenberg*, but how old are they really, and how
long was lunar "mare" volcanism active?

Recent data show that lunar volcanism was active for at least 2000
million years from 4000 million years ago, ceasing at about 2000 million
years. In Oceanus Procellarum, it is thought that these basalts are the
very youngest basalts on the lunar surface with an age of probably less
than 1000 million years. This should be compared with the age of the
Moon at about 4500 million years.

[3D anaglyph view of crater Lichtenberg]

The first and last images have been used to create a 3D anaglyph image
that can be viewed with red/green glasses (red on the left eye). Note
that the crater floor actually lies below the surrounding lava plain.
The USGS topographic map can be used to compare the heights.

Crater Lichtenberg is named after the German physicist Georg Christoph
Lichtenberg (1742-1799), who was a professor at the University of
Goettingen, Germany.

*Reference: Wilhelms, D.E., (1987). Geological history of the Moon. US
Geol. Surv. Special Paper 1348
 
 
For more information:
 
Jean-Luc Josset, SPACE-X Space Exploration Institute
E-mail: jean-luc.josset _at_ space-x.ch

Bernard H. Foing, ESA SMART-1 Project Scientist
E-mail: bernard.foing _at_ esa.int
Received on Fri 03 Mar 2006 12:53:42 PM PST