Andrew Yee[_1_]
August 23rd 07, 04:53 AM
ESA News
http://www.esa.int
22 August 2007
SMART-1 diagnoses wrinkles and excess weight on the Moon
Owing to SMART-1's high resolution and favourable illumination conditions
during the satellite's scientific operations, data from Europe's lunar
orbiter is helping put together a story linking geological and volcanic
activity on the Moon.
The combination of high-resolution data from SMART-1's AMIE micro-camera and
data from the US Clementine mission is helping scientists determine the
tectonics of the Moon's giant basins and the history of volcanic flooding of
mid-sized craters, inside and around the lunar basins.
"Thanks to low-elevation solar illumination on these high-resolution
images", says SMART-1 Project Scientist Bernard Foing, "it is now possible
to study fine, small-scale geological features that went undetected
earlier."
The study provides new information on the thermal and tectonic history of
the Moon and the processes following the formation of the large basins.
There are approximately 50 recognizable lunar basins more than 300 km in
diameter. They are believed to be created by the impact of asteroids or
comets during the Lunar Late Heavy Bombardment period, 350-750 million years
after the formation of the Moon. Some of these basins (mostly on the near
side) were then filled in by lava originating from volcanic activity.
Combining information from SMART-1 and Clementine makes it possible to
assess the link between fine geological structures, identified for the first
time with AMIE's high resolution, and the chemical composition of the study
area. These fine geological structures form due to local mascon (mass
concentration) or because of the thermal effects in the area related to
volcanic activity. This deforms the crust giving it the appearance of being
'overweight' or 'wrinkled'.
The Humorum basin is an 'ideal', circular, compact and moderately thick
basin that was created by a simple impact event, showing a thin crust and
mass concentration within a small area (from Clementine topography and
gravity data).
The Procellarum basin, or Oceanus Procellarum, is a large, extended, complex
basin that is moderately thick and shows no mass concentration. It may have
been formed by faulting associated with the formation of the adjacent
Imbrium crater (3.84 thousand million years ago), rather than by a
'gargantuan' impact.
The Humorum basin shows concentric graben, or elongated, trench-like
erosional features around the edge of the basin. These are formed as the
crust is deformed due to the presence of a mascon (mass concentration or
'local overweight').
"Lunar crust is like a fragile skin, wrinkled due to local mascons or its
thermal history", says Bernard Foing, "as doctors, we searched for these
skin-imprints but some may be masked underneath the last layers of basalt."
For the first time, strike-slip faults have been observed with SMART-1 in
the Humorum basin. These are faults where the rupture is vertical and one
side slides past the other. An example is the San Andreas fault along the
western United States. However, there is no multi-plate tectonic activity on
the Moon.
Procellarum is an extended basin, where the crust is thin enough to allow
magma to arise from under the surface, 4 to 2 thousand million years ago.
SMART-1 images do not show geological faults, or surfaces where the rock
ruptures due to differential movement, in the Procellarum basin.
Procellarum shows wrinkle ridges that are not distributed radially around
the basin. Due to their location, they do not seem associated with mascon
tectonics, but are mostly results of thermal and mechanical deformation
resulting from volcanic activity -- basalt extruded by the lava causes
compression in the area. The Procellarum basin contains the youngest basalt
found on the Moon so far, up to 2 thousand million years old.
Different 'pulses' of volcanic activity in lunar history created units of
lava on the surface. The flooding of mid-sized craters with lava due to
volcanic activity in the region is reflected in the mineralogical map.
Differences in the mineralogical composition provide a tool to study the
geological history of the region. Flooded as well as unflooded craters are
found in the region, reflecting the evolution of volcanic activity with
time.
"This analysis shows the potential of the AMIE camera", says Jean-Luc
Josset, Principal Investigator for the AMIE camera, "and we are still
analysing other datasets that make use of the varying illumination
conditions during the operation of SMART-1 over one and half years".
Notes for editors:
The results reflected in the article appear in 'Coupling between impacts and
lunar volcanism for Humorum and Procellarum basins' by S. Peters, B. Foing,
D. Koschny, A. Rossi and the SMART-1 AMIE team, presented at the European
Planetary Science Congress on 22 August 2007.
Stefan Peters performed this work while he was a trainee at the Research and
Scientific Support Department at ESA's European Space Research and
Technology Centre.
For more information:
Bernard H. Foing, ESA SMART-1 Project Scientist
Email: Bernard.Foing @ esa.int
Stefan Peters, Vrij Universiteit, Amsterdam
Email: Speters @ rssd.esa.int
Jean-Luc Josset, SMART-1 AMIE Principal Investigator, Space-X Space
Exploration Institute
Email : Jean-Luc.Josset @ space-x.ch
[NOTE: Images supporting this release are available at
http://www.esa.int/esaSC/SEMCXRWZK5F_index_1.html ]
http://www.esa.int
22 August 2007
SMART-1 diagnoses wrinkles and excess weight on the Moon
Owing to SMART-1's high resolution and favourable illumination conditions
during the satellite's scientific operations, data from Europe's lunar
orbiter is helping put together a story linking geological and volcanic
activity on the Moon.
The combination of high-resolution data from SMART-1's AMIE micro-camera and
data from the US Clementine mission is helping scientists determine the
tectonics of the Moon's giant basins and the history of volcanic flooding of
mid-sized craters, inside and around the lunar basins.
"Thanks to low-elevation solar illumination on these high-resolution
images", says SMART-1 Project Scientist Bernard Foing, "it is now possible
to study fine, small-scale geological features that went undetected
earlier."
The study provides new information on the thermal and tectonic history of
the Moon and the processes following the formation of the large basins.
There are approximately 50 recognizable lunar basins more than 300 km in
diameter. They are believed to be created by the impact of asteroids or
comets during the Lunar Late Heavy Bombardment period, 350-750 million years
after the formation of the Moon. Some of these basins (mostly on the near
side) were then filled in by lava originating from volcanic activity.
Combining information from SMART-1 and Clementine makes it possible to
assess the link between fine geological structures, identified for the first
time with AMIE's high resolution, and the chemical composition of the study
area. These fine geological structures form due to local mascon (mass
concentration) or because of the thermal effects in the area related to
volcanic activity. This deforms the crust giving it the appearance of being
'overweight' or 'wrinkled'.
The Humorum basin is an 'ideal', circular, compact and moderately thick
basin that was created by a simple impact event, showing a thin crust and
mass concentration within a small area (from Clementine topography and
gravity data).
The Procellarum basin, or Oceanus Procellarum, is a large, extended, complex
basin that is moderately thick and shows no mass concentration. It may have
been formed by faulting associated with the formation of the adjacent
Imbrium crater (3.84 thousand million years ago), rather than by a
'gargantuan' impact.
The Humorum basin shows concentric graben, or elongated, trench-like
erosional features around the edge of the basin. These are formed as the
crust is deformed due to the presence of a mascon (mass concentration or
'local overweight').
"Lunar crust is like a fragile skin, wrinkled due to local mascons or its
thermal history", says Bernard Foing, "as doctors, we searched for these
skin-imprints but some may be masked underneath the last layers of basalt."
For the first time, strike-slip faults have been observed with SMART-1 in
the Humorum basin. These are faults where the rupture is vertical and one
side slides past the other. An example is the San Andreas fault along the
western United States. However, there is no multi-plate tectonic activity on
the Moon.
Procellarum is an extended basin, where the crust is thin enough to allow
magma to arise from under the surface, 4 to 2 thousand million years ago.
SMART-1 images do not show geological faults, or surfaces where the rock
ruptures due to differential movement, in the Procellarum basin.
Procellarum shows wrinkle ridges that are not distributed radially around
the basin. Due to their location, they do not seem associated with mascon
tectonics, but are mostly results of thermal and mechanical deformation
resulting from volcanic activity -- basalt extruded by the lava causes
compression in the area. The Procellarum basin contains the youngest basalt
found on the Moon so far, up to 2 thousand million years old.
Different 'pulses' of volcanic activity in lunar history created units of
lava on the surface. The flooding of mid-sized craters with lava due to
volcanic activity in the region is reflected in the mineralogical map.
Differences in the mineralogical composition provide a tool to study the
geological history of the region. Flooded as well as unflooded craters are
found in the region, reflecting the evolution of volcanic activity with
time.
"This analysis shows the potential of the AMIE camera", says Jean-Luc
Josset, Principal Investigator for the AMIE camera, "and we are still
analysing other datasets that make use of the varying illumination
conditions during the operation of SMART-1 over one and half years".
Notes for editors:
The results reflected in the article appear in 'Coupling between impacts and
lunar volcanism for Humorum and Procellarum basins' by S. Peters, B. Foing,
D. Koschny, A. Rossi and the SMART-1 AMIE team, presented at the European
Planetary Science Congress on 22 August 2007.
Stefan Peters performed this work while he was a trainee at the Research and
Scientific Support Department at ESA's European Space Research and
Technology Centre.
For more information:
Bernard H. Foing, ESA SMART-1 Project Scientist
Email: Bernard.Foing @ esa.int
Stefan Peters, Vrij Universiteit, Amsterdam
Email: Speters @ rssd.esa.int
Jean-Luc Josset, SMART-1 AMIE Principal Investigator, Space-X Space
Exploration Institute
Email : Jean-Luc.Josset @ space-x.ch
[NOTE: Images supporting this release are available at
http://www.esa.int/esaSC/SEMCXRWZK5F_index_1.html ]