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Of Craters and Erosion: Opportunity Examines "Beagle" (QTVR)
This 360-degree view shows Opportunity's last stop on the now-familiar
surface of Meridiani Planum before reaching different terrains associated
with the very large "Victoria Crater." In the center of the mosaic is
"Beagle Crater," an impact crater about 35 meters (115 feet) wide. On the
far left and wrapping around to the far right, Opportunity's tracks are
visible approaching the crater.
Though it looks relatively fresh in orbital images, from a closer vantage
point Beagle Crater appears moderately eroded. The crater walls are
slumped and the middle of the crater bowl is filled with rippled sand.
However, a slightly raised crater rim remains, and in a few places (for
instance, on the inside left wall), cliffs of outcrop appear to be
preserved in the crater. Ejected rocks from Beagle Crater surround the
rover, many with the distinctive, fine-grained layering commonly seen in
the rocks of Meridiani Planum. Many of these rocks have surfaces smoothed
by wind erosion. Wind erosion also formed the sand drifts nestled among
the rocks.
Because impact craters have well-understood shapes when they form, the
altered appearance of eroded craters gives scientists clues to the
processes that modified them. By observing how filled an impact crater
has become and how worn its edges are, scientists can estimate how long
its surface has been exposed to erosion. The many-sided outline of a
crater such as Beagle and the blocky appearance of its ejecta may also
tell scientists about the strength of the underlying bedrock. Based on
observations such as these, scientists know that Beagle Crater is fresher
than "Eagle" and "Fram" craters near Opportunity's landing site and more
similar in form to "Viking" and "Voyager" craters in the plains to the
north of Beagle.
Opportunity made other observations at Beagle Crater, such as
spectroscopic measurements taken with the panoramic camera and the
miniature thermal emission spectrometer, to help scientists assess the
composition of the rocks and determine whether Beagle Crater was excavated
into the surface rocks of Meridiani Planum or into the ejecta blanket of
Victoria Crater.
Beagle Crater takes its unofficial name from a great ship of exploration,
the HMS Beagle, whose most famous passenger was British naturalist Charles
Darwin. During the Beagle expedition around the world, Darwin conducted
many of the observations that led to his theory of natural selection.
Scientists have unofficially named many rocks and features in the area of
Beagle Crater after the Galapagos Islands and the varieties of finches
Darwin observed there. The name Beagle Crater also commemorates the
European Space Agency's ill-fated Beagle 2 lander, the loss if which is a
reminder of how difficult space exploration can be.
Opportunity took the mosaic of images that make up this 360-degree view of
the rover's surroundings with the panoramic camera on the rover's 901st
through 904th sols, or Martian days (Aug. 6 through Aug. 9, 2006), of
exploration. This is an approximate true-color image combining exposures
taken through the panoramic camera's 753-nanometer, 535-namometer, and
432-nanometer filters.