Figure 1
Click on image for larger version
Eberswalde Delta contains river meanders, which indicate that flowing
water was present for an extended period of time, not just the weeks
required to explain the catastrophic flood channels.
Shown here are two red-blue color anaglyphs in which you can view the
topography with red-blue glasses (blue filter over your right eye). This
anaglyphs shows a relatively large area but with 3x reduction of spatial
scale (75 cm/pixel), and figure 1 is a sample at full resolution (25
cm/pixel).
The former river channels are high rather than low, which is called
inverted relief. Coarse gravel was deposited in the stream channel, which
later proved more resistant to erosion than the materials outside the
channel, creating this inverted relief.
Meanders are formed when a river channel gradually erodes the outer banks,
increasing the curvature of the channel. Eventually the river decides to
take a short cut, cutting off a meander, as shown here. This produces what
are called oxbow lakes.
(We previously released image PSP_1334_1560, including color, but acquired
a later image (PSP_1534_1560) over this same area but from a different
viewing angle to provide stereo coverage.)
Observation Geometry
Image PSP_001534_1560 was taken by the High Resolution Imaging Science
Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter
spacecraft on 23-Nov-2006. The complete image is centered at -23.8 degrees
latitude, 326.4 degrees East longitude. The range to the target site was
267.8 km (167.3 miles). At this distance the image scale is 26.8 cm/pixel
(with 1 x 1 binning) so objects ~80 cm across are resolved. The image
shown here has been map-projected to 25 cm/pixel and north is up. The
image was taken at a local Mars time of 03:42 PM and the scene is
illuminated from the west with a solar incidence angle of 67 degrees, thus
the sun was about 23 degrees above the horizon. At a solar longitude of
139.9 degrees, the season on Mars is Northern Summer.
NASA's Jet Propulsion Laboratory, a division of the California Institute
of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for
NASA's Science Mission Directorate, Washington. Lockheed Martin Space
Systems, Denver, is the prime contractor for the project and built the
spacecraft. The High Resolution Imaging Science Experiment is operated by
the University of Arizona, Tucson, and the instrument was built by Ball
Aerospace and Technology Corp., Boulder, Colo.