MARS
True-color image (click to enlarge) of Martian surface from the Viking 2 mission. Click here for more.
Image (click to enlarge) of Mars from the Hubble Space Telescope. Click here for more.
Strange surface features, imaged from the Mars Global Surveyor. Click on each image for more info and for instructions on how to find the images from the original MGS maps...
face or natural rock formation?
glass tubes or dunes?
trees or frost?

More on Mars...

The NASA Mars Clock