2. Earth Telescope View of Mars (0°N,43°W)
This 1988 image from the Lowell Observatory was obtained at the start of spring in the southern hemisphere, so the southern polar cap is prominent. Valles Marineris is the narrow feature protruding to the left of the dark region in the center of the image. Because of the obscuring effects of the Earth's atmosphere, even the best groundbased telescopes usually can resolve features no smaller than about 300 kilometers across when Earth and Mars are closest to one another.
Photo by Leonard MartinRight click here to download a high-resolution version of the image (8.81 MB)