Jacques van Oene
July 26th 05, 02:52 PM
Erica Hupp/Dolores Beasley
Headquarters, Washington July 26, 2005
(Phone: 202/358-1237/1753)
Carolina Martinez
Jet Propulsion Laboratory, Pasadena, Calif.
(Phone: 818/354-9382)
Preston Dyches
Space Science Institute, Boulder, Colo.
(Phone: 720/974-5859)
RELEASE: 05-201
CASSINI FINDS RECENT AND UNUSUAL GEOLOGY ON ENCELADUS
NASA's Cassini spacecraft has obtained new detailed images of the south
polar region of Saturn's moon Enceladus. The data reveal distinctive
geological features and the most youthful terrain seen on the moon. These
findings point to a very complex evolutionary history for Saturn's
brightest, whitest satellite.
Cassini's July 14 flyby brought it within 109 miles of the surface of the
icy moon. The close encounter revealed a landscape near the south pole
almost entirely free of impact craters. The area is also littered with
house-sized ice boulders carved by tectonic patterns unique to Enceladus.
These features set the region apart from the rest of the moon.
As white as fresh snow, Enceladus has the most reflective surface in the
solar system. Previous Cassini flybys revealed Enceladus, in contrast to
Saturn's other icy moons, has lightly cratered regions, fractured plains and
wrinkled terrain.
The new findings add to the story of a body that has undergone multiple
episodes of geologic activity spanning a considerable portion of its
lifetime. The moon's southern most latitudes have likely seen the most
recent activity.
These same latitudes may also bear the scars of a shift in the moon's spin
rate. If true, this speculation may help scientists understand why Enceladus
has a tortured-looking surface, with pervasive crisscrossing faults, folds
and ridges. The most remarkable images show ice blocks, about 33 to 328 feet
across in a region that is unusual in its lack of the very fine-grained
frost that seems to cover the rest of Enceladus.
"A landscape littered with building-sized blocks was not expected," said Dr.
Peter Thomas, an imaging-team member from Cornell University, Ithaca, N.Y.
"The minimal cover of finer material and the preservation of small, crossing
fracture patterns in the surrounding areas indicate that this region is
young compared to the rest of Enceladus."
False color composites of this region, created from the most recent images,
show the largest exposures of coarse-grained ice fractures seen anywhere on
the satellite, which also supports the notion of a young surface at southern
latitudes. Some of the latest images may hint at the answer. The images
revealed additional examples of a distinctive "Y-shaped" tectonic feature on
Enceladus. In this unusual element, parallel ridges and valleys appear to
systematically fold and deform around the south polar terrains.
"These tectonic features define a boundary that isolates the young, south
polar terrains from older terrains on Enceladus," noted Dr. Paul
Helfenstein, an associate of the imaging team also at Cornell University.
"Their placement and orientation may tell us a very interesting story about
the way the rotation of Enceladus has evolved over time and what might have
provided the energy to power the geologic activity that has wracked this
moon."
The apparent absence of sizable impact craters also suggests the south pole
is younger than other terrain on Enceladus. These indications of youth are
of great interest to scientists who have long suspected Enceladus as one
possible source of material for Saturn's extensive and diffuse E ring, which
coincides with the moon's orbit. Young terrain requires a means to generate
the heat needed to modify the surface. Other Cassini instrument teams are
working to understand data about temperature, composition, particles and
magnetic field. Together with image interpretation, these data can create a
more complete picture.
The Cassini-Huygens mission is a cooperative project of NASA, the European
Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory
(JPL), a division of the California Institute of Technology in Pasadena,
manages the mission for NASA's Science Mission Directorate. The imaging
operations center is based at the Space Science Institute in Boulder, Colo.
These Cassini images are available on the Web at:
http://www.nasa.gov/cassini
http://saturn.jpl.nasa.gov
http://ciclops.org
-end-
--
--------------
Jacques :-)
www.spacepatches.info
Headquarters, Washington July 26, 2005
(Phone: 202/358-1237/1753)
Carolina Martinez
Jet Propulsion Laboratory, Pasadena, Calif.
(Phone: 818/354-9382)
Preston Dyches
Space Science Institute, Boulder, Colo.
(Phone: 720/974-5859)
RELEASE: 05-201
CASSINI FINDS RECENT AND UNUSUAL GEOLOGY ON ENCELADUS
NASA's Cassini spacecraft has obtained new detailed images of the south
polar region of Saturn's moon Enceladus. The data reveal distinctive
geological features and the most youthful terrain seen on the moon. These
findings point to a very complex evolutionary history for Saturn's
brightest, whitest satellite.
Cassini's July 14 flyby brought it within 109 miles of the surface of the
icy moon. The close encounter revealed a landscape near the south pole
almost entirely free of impact craters. The area is also littered with
house-sized ice boulders carved by tectonic patterns unique to Enceladus.
These features set the region apart from the rest of the moon.
As white as fresh snow, Enceladus has the most reflective surface in the
solar system. Previous Cassini flybys revealed Enceladus, in contrast to
Saturn's other icy moons, has lightly cratered regions, fractured plains and
wrinkled terrain.
The new findings add to the story of a body that has undergone multiple
episodes of geologic activity spanning a considerable portion of its
lifetime. The moon's southern most latitudes have likely seen the most
recent activity.
These same latitudes may also bear the scars of a shift in the moon's spin
rate. If true, this speculation may help scientists understand why Enceladus
has a tortured-looking surface, with pervasive crisscrossing faults, folds
and ridges. The most remarkable images show ice blocks, about 33 to 328 feet
across in a region that is unusual in its lack of the very fine-grained
frost that seems to cover the rest of Enceladus.
"A landscape littered with building-sized blocks was not expected," said Dr.
Peter Thomas, an imaging-team member from Cornell University, Ithaca, N.Y.
"The minimal cover of finer material and the preservation of small, crossing
fracture patterns in the surrounding areas indicate that this region is
young compared to the rest of Enceladus."
False color composites of this region, created from the most recent images,
show the largest exposures of coarse-grained ice fractures seen anywhere on
the satellite, which also supports the notion of a young surface at southern
latitudes. Some of the latest images may hint at the answer. The images
revealed additional examples of a distinctive "Y-shaped" tectonic feature on
Enceladus. In this unusual element, parallel ridges and valleys appear to
systematically fold and deform around the south polar terrains.
"These tectonic features define a boundary that isolates the young, south
polar terrains from older terrains on Enceladus," noted Dr. Paul
Helfenstein, an associate of the imaging team also at Cornell University.
"Their placement and orientation may tell us a very interesting story about
the way the rotation of Enceladus has evolved over time and what might have
provided the energy to power the geologic activity that has wracked this
moon."
The apparent absence of sizable impact craters also suggests the south pole
is younger than other terrain on Enceladus. These indications of youth are
of great interest to scientists who have long suspected Enceladus as one
possible source of material for Saturn's extensive and diffuse E ring, which
coincides with the moon's orbit. Young terrain requires a means to generate
the heat needed to modify the surface. Other Cassini instrument teams are
working to understand data about temperature, composition, particles and
magnetic field. Together with image interpretation, these data can create a
more complete picture.
The Cassini-Huygens mission is a cooperative project of NASA, the European
Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory
(JPL), a division of the California Institute of Technology in Pasadena,
manages the mission for NASA's Science Mission Directorate. The imaging
operations center is based at the Space Science Institute in Boulder, Colo.
These Cassini images are available on the Web at:
http://www.nasa.gov/cassini
http://saturn.jpl.nasa.gov
http://ciclops.org
-end-
--
--------------
Jacques :-)
www.spacepatches.info