A composite image of Olympus Mons on Mars, the tallest known volcano and mountain in the Solar System. This image was created from black-and-white imagery from the USGS's Mars Global Digital Image Mosaic and color imagery acquired from the 1978 visit of Viking 1.Image credit: United States Geological Survey
 | This picture of the day has been featured on Portal:Solar System. |
 | This picture of the day has been featured on Portal:Outer space. |