KEEPING A LOW PROFILE. Tyrrhena Mons is one of a handful of low-elevation, easily eroded volcanos that lie next to the Hellas impact basin. Among the oldest known volcanos on Mars, Tyrrhena shows marked differences from large and lofty volcanos such as Olympus Mons. It's not even 2 km high compared to Olympus' more than 20 km, and instead of being made from flows of hard, basaltic lava, Tyrrhena was built from numerous explosive eruptions that spewed mostly cinders and ash. This view looks north from an altitude of about 20 kilometers (12 miles); no vertical exaggeration. (A 1.2 MB version of the image is available.) Image credit: NASA/JPL/Arizona State University, R. Luk.
To explore Tyrrhena Patera further, check out Not the Typical Mars Volcano.