The Opportunity rover (pictured below) landed on Mars in 2004 and has been actively exploring the planet ever since. It is powered by solar cells. As the rover travels across the Martian surface, it kicks up dust, which accumulate on its solar cells. The amount of dust that it kicks up depended on the composition of the surface it was traveling over - a rockier surface kicks up less dust than a softer surface. When planning a path for the rover to follow, scientists need to know how far it might travel before too much dust accumulates on its solar panels.
The scientists have mapped out a 100-km path for the rover to follow (shown below) and have collected satellite data about the composition of the Martian surface at various points along the route using a LiDAR Spectrometer.
Approximate the amount of dust accumulated on the rover’s solar panels?
Composition | Position along path (km) | Amount of dust per distance traveled (mg/km) |
Very sandy | 0 | 6 |
Moderately sandy | 20 | 3.5 |
Slightly sandy | 40 | 2.5 |
Slightly rocky | 60 | 2 |
Moderately rocky | 80 | 1.5 |
Very rocky | 100 | 1 |