Status Report

NASA Mars Picture of the Day: Mars Exploration Rover (MER-B) Opportunity Landing Site

By SpaceRef Editor
January 24, 2004
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Mars Global Surveyor Mars Orbiter Camera

MGS MOC Release No. MOC2-615, 24 January 2004

MOC/THEMIS Mosaic (click here for 25 m/pixel view)

MGS MOC Wide Angle View
MGS MOC Narrow Angle View

all images credit: NASA/JPL/Malin Space Science Systems

The second Mars Exploration Rover (MER-B),
Opportunity, is set to land on Mars around 9:05 p.m. Pacific
Standard Time today, 24 January 2004 (25 January 2004 UTC).
Above are shown three perspectives on the Opportunity landing
site, which is an ellipse in Meridiani Planum
approximately 87 km (54 mi) long by 11 km (6.8 mi) wide. All images
are oriented with north up and east to the right. The lander
will be coming through the atmosphere from the west/southwest,
roughly following the long axis of the ellipse. It is most likely
to touch down somewhere near the center of the ellipse.

The first image (top)
is a mosaic of MGS MOC and Mars Odyssey Thermal Emission
Imaging System visible images (THEMIS-VIS). The THEMIS-VIS
instrument provides pictures with a spatial resolution of
18 meters per pixel (~59 ft/pixel); the MOC images used in
the mosaic have
resolutions ranging from 1.4 m/pixel to 12 m/pixel. A total
of 15 THEMIS-VIS images were used to form the background,
on which 61 MOC high resolution images were mosaiced. These
data were acquired over a period spanning parts of
3 Mars years between April 1999 through January 2004.
These pictures were acquired not only in different years,
but in different seasons, so the illumination
angle, overall brightness, and patterns of ephemeral windblown
dust and, in some cases, dark dust
devil streaks, are different from image to image within the mosaic.

The second image (bottom, left) is a Mars Global Surveyor (MGS)
Mars Orbiter Camera (MOC) red wide angle view obtained
in November 2003 as part of an on-going effort to monitor
the weather at the landing site. The wide angle view provides a
sense of the regional context. The third image (bottom, right) is
a 1.8 m/pixel (6 ft/pixel) view near the center of the landing
ellipse. It was also acquired by MOC in November 2003, and
covers an area 3 km (1.9 mi) wide. The light-toned, somewhat
circular features are believed to be either the location of
ancient, buried, nearly-filled meteor impact craters or
the eroded remains of craters that formed in bedrock that has
long since been removed from the region.

The Opportunity landing site in Meridiani Planum was selected to
provide access, it is hoped, to materials bearing the iron
oxide mineral, hematite. Hematite was detected in this region
by the Thermal Emission Spectrometer (TES) on MGS. This mineral
is suspected of providing a clue that liquid water may have
once played a role in the region. The dark-toned materials
of Meridiani Planum cover a lighter-toned substrate that may
consist of layered rock. Small ridges have formed in the dark
material in some parts of the landing ellipse, but no one
will know until the first images are returned, exactly what
features will be present at the Opportunity site. One thing
is certain: no previous Mars lander has ever gone to a
setting like Meridiani Planum. The landscape is almost certain
to be different than the Viking 1, Viking 2, Mars Pathfinder,
and Spirit sites.

Sunlight illuminates the wide and narrow angle views, and
each image in the mosaic, from the left. The
THEMIS instrument
is operated by a team at Arizona State University
; the
camera was built by Malin Space Science Systems (MSSS), which also
operates the MGS MOC
Opportunity will land in the mid-afternoon, local time, on Mars.
At the same time, Mars Global Surveyor will pass over the site and
listen for a transmission of Opportunity’s entry, descent, and landing data.
These data will be relayed back to Earth by the MOC.
For more information about the Mars Exploration Rovers, visit
NASA/JPL’s Mars Exploration Program Web site.
For more information about the work that Malin Space
Science Systems and MGS MOC are doing in support of the
rover missions, see:
For information about how MSSS will use
this mosaic of the landing site to help find
Opportunity after it touches down, see
Finding MERs.
MER landing site weather reports are located at:
For a 10 meter per pixel view of the landing site mosaic, download
this (BIG!!) 24.4 MByte file: MER_B_Ellipse_10m.gif.

Malin Space Science Systems and the California Institute of Technology
built the MOC using spare hardware from the Mars Observer mission.
MSSS operates the camera from its facilities in San Diego, California.
The Jet Propulsion Laboratory’s Mars Surveyor Operations Project
operates the Mars Global Surveyor spacecraft with its industrial
partner, Lockheed Martin Astronautics, from facilities in Pasadena,
California and Denver, Colorado.

SpaceRef staff editor.