The Mars Phoenix Lander has managed to take its first images of Martian dust from its atomic force microscope. This is about 100 times more detailed than images taken from its optical microscope. And unlike an optical microscope which gathers light bounced off a sample to get an image, an atomic force microscope actually moves a sharp tip up and down along the surface of the sample. An 3-dimensional image of the sample is constructed by measuring how much the tip went up and down at each position.
Using the atomic force microscope, Phoenix managed to image a single particle of Martian dust held in a pitted silicon substrate. It’s incredible that we can see such microscopic samples on another planet. Below is also embedded a video graciously provided by NASA and its partners in the Phoenix mission which roughly illustrates how the microscope works