Red dust of Mars

The red dust particles that "color the Martian sky pink, feed storms that regularly envelop the planet and produce Mars' distinctive red soil" has been imaged by the Phoenix Mars Lander.

[right, from the UA press release: The image on the upper left is from NASA's Phoenix Mars Lander's Optical Microscope. A 3D representation of the same sample is on the right, as seen by Phoenix's Atomic Force Microscope. This is 100 times greater magnification than the view from the Optical Microscope, and the most highly magnified image ever seen from another world. The image shows four round pits, only 5 microns in depth, that were micromachined into the silicon substrate, which is the background plane shown in red. This image has been processed to reflect the levelness of the substrate. A Martian particle -- only one micrometer, or one millionth of a meter, across -- is held in the upper left pit.]