## EXERCISE 1 "MODELING THE SURFACE OF MARS"

It was possible to prepare colored maps (see Lander 1 Surface Material Map or Lander 2 Surface Material Map) showing rocks in front of the landers because each lander had two cameras (separated by about 0.822 m) so that azimuths and elevations or rocks seen in the pictures could be used to located the rocks.

Lander 1 Surface Material Map (135,350 Bytes)
Lander 2 Surface Material Map (167,798 Bytes)

Maps are important because they usually record more useful information than we can remember. Examples of maps include house plans, street maps, road maps, landscape plans, etc. Can you remember all of those rocks?

Print one copy each of both Surface Material Maps (printouts can be black and white).

Shape globs of reddish-brown clay to match the rocks and place the globs on appropriate places on the maps. Each rock is about half as tall as it is wide.

Do you have a microrover that you want to test? Then make a full-scale model. This is just what engineers at the Jet Propulsion Laboratory have done to test the Mars Pathfinder Microrover.

Layout a rectangular grid 10 m by 19 m and place markers (stakes) at 1 m intervals along edges. Label the markers according to the maps (0, 1, 2...10). Stretch strings from the markers on each side (Y = 1 to Y = 1, etc. ) and (X = 5 to X = 5 etc.) all at once or one at a time.

Use the rock files on rock locations and sizes to place rocks in the full-scale model according to their coordinates (Y and X). Use the Lander 1 Rock File, (26,508 Bytes), for the Lander 1 site and the Lander 2 Rock File, (30,540 Bytes), for the Lander 2 site.

Say, how much does a rock weigh on Earth? They are dense so that big "babies" weigh a lot. On Earth, densities of some rocks may be near 2,500 kg/m^3 (and weigh about 156 pounds per cubic foot); others are less dense while others are more dense.

Do some calculations for the weight of the big rocks. Maybe you will want to use styrofoam or plastic bags filled with ballast for the big rocks.

For the far fields without fine material, assume that the areas between the larger rocks have the same concentrations of small rocks as the near fields.

Place powders where the maps say fine materials and garden soil where the maps say soillike materials.

Now you can test your microrovers.

Can you drive in a straight line?
How fast can you drive?