Mars Polar Lander and Deep Space 2 Landing Sites

The Mars Polar Lander is targeted for a site on the martian south polar layered deposits at 76 degrees south, 195 degrees west, about 800 km (500 miles) from the south pole. Uncertainties in the spacecraft trajectory give a 200 km x 20 km (124 x 12.4 miles) ellipse on the surface which represents the most likely (99% confidence) landing area. The images at right show the ellipse superimposed on a mosaic of the martian terrain. The elevation of this area is 4000 meters above the martian reference level and the daily temperature variation at the site is expected to be between -60 and -5 degrees C (-76 to +23 F). In Mars' southern hemisphere this is the end of spring, the Sun will be above the horizon continuously at these latitudes. During the winter the landing area is covered with a thin layer of carbon dioxide frost, by the time of the landing the frost should have sublimed away as the polar cap recedes for the summer. However, it is believed that a record of the climate may be contained in the layering of the deposits in this region, and studying this record is one of the main goals of the Mars Polar Lander. The Deep Space 2 (DS2) Mars Microprobes are targeted to land nearby, at 73 degrees S, 210 degrees W, in similar terrain (see image directly below).

The lander is scheduled to touch down on 3 December 1999 at 20:15 UT Earth Received Time (3:15 p.m. EST), the DS2 probes will impact at nearly the same time. The first signals from the lander will reach Earth at 20:39 UT (3:39 p.m. EST). After landing there will be a 45 minute communications session consisting mainly of information on the health and engineering state of the lander and may include a low-resolution black and white image. Later that night there will be another communications session which could include color lander camera images as well as pictures taken by the Mars Descent Imager. Data from the DS2 probes will also be received Friday evening. There will be a press briefing on Saturday at 07:30 UT (2:30 a.m. EST). Communications sessions on Saturday could include a stereo image mosaic of the soil near the robot arm and the first sounds from the Mars microphone. Most of these events will be covered on NASA Television.
The NM-DS2 target site is at the center of
this Viking 2 Orbiter image. The image is
approximately 140 km across.

These images were taken by the Mars Global Surveyor MOC (Mars Orbiter Camera) and show high resolution views of the terrain near the Mars Polar Lander site. The image at left is an area within the landing ellipse showing the layered deposits and generally smooth ridged terrain characteristic of the region. The area was still covered by frost at the time the image was taken, some dark spots are visible where the frost is beginning to sublime as the Sun heats it. The image is 2700 meters (1.7 miles) across each edge and the illumination is from the lower right. The image at right shows polar layered material at 73 S, 225 W, not far from the Deep Space 2 touchdown sites. The deposits were presumably formed by layers of dust transported by the atmosphere and deposited over thousands or millions of years. It is assumed that this layering also underlies the Mars Polar Lander and Deep Space 2 sites. The smallest layers visible in this image are a few meters thick, the image is 1.5 km (0.9 miles) across and is illuminated from the lower right.

Mosaic of the south polar cap of Mars

Images and Data from Mars Polar Lander

Timetable of events for landing day

Press Release on landing events and media coverage

Press Release on the landing site

Mars Polar Lander home page at NSSDCA

Deep Space 2 home page at NSSDCA

Mars Home Page

More on the landing site - Mars Polar Lander Website
Timeline of coverage of the landing - JPL
Current Temperatures at the Landing Site - USGS

NASA Official: Dr. Ed Grayzeck, edwin.j.grayzeck@nasa.gov
Last Updated: 18 December 2001, DRW