Each spacecraft covers the entire planet in 12 orbits. In this figure, we compare a recent dust storm on Mars with one that occurred earlier this year on Earth. The top image shows a martian north polar dust storm observed on 29 August 2000. The region on the right side of the Mars picture includes the north pole. The bottom image shows a terrestrial dust storm, seen in a SeaWiFS image , acquired on 26 February 2000.
Dust storms play an important role in governing the climate of Mars.
The rare, global storms alter the planet's total heat balance and promote variations in seasonal frost formation and dissipation, and greatly affect the distribution of water vapor. Local and regional storms, especially those in the polar regions, affect the rate at which seasonal frost evolves, and control local and regional weather patterns. On Earth, dust storms are also being recognized as contributing to environmental change, potentially influencing seasonal meteorology and the health of biological communities .