subject: Green men on the red planet? [print this page] In addition to that, Waechter observes that geophysical probes can return useful scientific information that can help to explain how the Mars planet evolved. He explains that "understanding the geology of a planet or of a region involves knowing the material composition as a function of depth. This is the type of information that various types of geophysical probes can provide. From this information scientists can piece together possible models to explain how and when the various layers formed."
