18. Mars

18. Mars

Courtesy of NASA/JPL/Malin Space Science Systems

http://mpfwww.jpl.nasa.gov/gallery/volcanoes/20020418a.html


This image shows two martian volcanoes, Ceraunius Tholus (lower) and Uranius Tholus (upper). Impact craters on the slopes of these volcanoes indicate they are old an inactive.
The crater at the summit of Ceraunius Tholus is about 25 km (15.5 miles) across. Remains of an ancient flow can be seen on the northern slope.