A photo of Mars from NASA's Viking spacecraft, which launched in 1975.
This Mars photo from ESA's Mars Express spacecraft was taken on Dec. 15, 2012, and beamed to Earth on Dec. 18. The spacecraft was 9.761 kilometers from Mars at the time.
This new image of Mars taken by NASA's Mars Reconnaissance Orbiter shows an optical illusion. What appears to be trees rising from the Martian surface are actually dark streaks of collapsed material running down sand dunes due to carbon dioxide frost evaporation. The image was released in Jan. 2010.
Some believe we could 'terraform' Mars to make it more like Earth, eliminating the need for protective habitats for future human colonizers.
(Left) This 1894 map of Mars was prepared by Eugene Antoniadi and redrawn by Lowell Hess. (Right) A Hubble Space Telescope photo of Mars shows the modern view of our neighboring planet.
A comparison of the sizes of planets Venus (left), Earth and Mars.
Mars' 3.7 billion-year-old Eberswalde crater can be seen here in relief. The crater offer more proof that liquid water once flowed on Mars.
Hubble image of Mars taken on October 28, 2005. This image shows a 930-mile long dust storm raging across the equator.
Mars' largest moon Phobos, as seen during a recent flyby performed by the European spacecraft Mars Express.
The ESA spacecraft Mars Express took this image of Phobos on March 7, 2010. This image has been enhanced for seeing features in the less-illuminated part of the moon.
This image was acquired by the Mars Express High-Resolution Stereo Camera on 17 May 2010 and shows a part of the northern polar region of Mars at the northern hemisphere summer solstice.
NASA has selected Gale crater as the landing site for the Mars Science Laboratory mission.
Photo taken of the Gandhi face geologic feature by the Mars Reconnaissance Orbiter.
Valles Marineris, the grand valley of Mars, extends over 1,800 miles (3,000 kilometers) long, spans as much as 370 miles (600 kilometers) across, and plunges as much as 5 miles (8 kilometers) deep.
The original 'Face on Mars' image taken by NASA's Viking 1 orbiter, in grey scale, on July, 25 1976. Image shows a remnant massif located in the Cydonia region.
A view of Mars' three large Tharsis Montes volcanoes, which lie in a straight line. Olympus Mons, the largest known volcano in the solar system, is at upper left.
Phoenicis Lacus has an area of 8100 sq km (59.5 x 136 km), which corresponds to the size of Corsica. This image was obtained on July 31, 2010 using the High-Resolution Stereo Camera (HRSC) on ESA's Mars Express spacecraft.
The mounds shown here, located in the Southern Acidalia Planitia, range in size between 20 and 500 meters in diameter.
Bull's-eye impact crater.
Melting glaciers spawned rivers on Mars as recently as several hundred million years ago. This image shows a river that sprang from a past glacier from an unnamed crater in Mars’ middle latitudes. Full Story.