NASA Solarsystem Collection

Uranius Tholus

This Viking orbiter image shows Uranius Tholus, one of the smaller volcanos in the Tharsis region of Mars. It is only 60 kilometers across and 3 kilometers higher than the surrounding plains.

In comparison with Olympus Mons, the greater number of impact craters near Uranius Tholus implies that it is substantially older than Olympus Mons. One such crater in the top center of the image has been flooded by lava from the surrounding plains. Because this crater must have formed after the volcano but before the plains, the plains must be younger than the volcano. (This is an example of using superposition relationships to determine the relative age of a series of features by determining which features lie on top of other features.) This area is believed to be more than 3 billion years old.

This image was taken by NASA's Viking 1 orbiter in 1977.

*Image Credit*: NASA

Solar System Exploration

SSE

Space

NASA

National Aeronautics and Space Administration

JPL

Jet Propulsion Laboratory

Planets

Mars

Crater

Viking

Viking 1 Orbiter

Jet Propulsion Laboratory

Mars

Jet Propulsion Laboratory (JPL)

1977

1977

SPD-SLRSY-831

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