## EXERCISE 2 "FEELING DIRT OR SOIL AT THE LANDER 1 SITE"

• Images of footpads 2 and 3 of Viking Lander 1 were acquired in July of 1976.
• These images are high-resolution images composed of "pixels". Each pixel measures 0.04 degrees across.
• Each pixel contains 64 levels of brightness information (6 bit data).
• The display software assumes 256 levels of brightness information (8 bit data).
• Camera 2 image of Lander 1 (Frame 12A001/000) shows footpad 3 (at right) and surrounding area on Sol 0 (the sol of landing).
• Footpad 3 penetrated 0.036 m into the soillike material.

• Camera 1 image of Lander 1 (Frame 11A079/012) shows footpad 2 (at left) and surrounding area on Sol 12 (a Sol is a lander event day).

• Footpad 2 is buried and penetrated 0.16 m into a different soillike material. A small depression within the larger depression marks the the buried footpad rim.
• Each footpad is shaped like an inverted sailor's hat with a radius near 0.21 m and a crown near 0.1 m.
• Assume that all three footpads (footpad 1 is hidden from the cameras) were moving vertically downward at 2.30 m/s when they touched the surface.
• The mass of the spacecraft is 611 kg.
• What do you think the soillike materials are like?
• Hints:
• Calculate the spacecraft masses per unit area for the footpads.