English: Hadriacus Mons lies on the northeast edge of the Hellas impact basin. It numbers among a handful of similar low volcanic structures (originally called paterae, after the Latin word for dish) in the cratered highlands next to Hellas. The others are Tyrrhenus (also on the northeast) and Amphitrites, Peneus, and Pityusa (all on the southwest of Hellas). Hadriacus and its neighbors also show a different volcanic style than later volcanos such as Olympus Mons and the others in Tharsis and Elysium. Hadriacus's low slopes, wide structure, and heavily scored flanks suggest that it is made of easily eroded materials. Scientists call such volcanic debris "pyroclastic," from the Greek meaning fire-broken. The image is a mosaic of infrared frames taken during daytime by the Thermal Emission Imaging System (THEMIS) on NASA's Mars Odyssey orbiter. Circling Mars every two hours, THEMIS scans the surface in five visible and 10 infrared bands. The smallest details it can record at infrared wavelengths are 100 meters (330 feet) wide; at visible wavelengths, THEMIS has imaged selected regions at 18-meter (59 feet) resolution.
Some of the features in this image are annotated in Wikimedia Commons.