Surface Features on Mars Dr. Joshua Bandfield Mars Space Flight Facility Arizona State University

Mars has Many Types of Surface Features Impact Craters Volcanic Features Fluvial/Water-Related Features Layers Aeolian/Wind Features 2

All THEMIS visible images are ~18 km across Crater Ejecta Material that gets thrown out of a crater when a meteorite hits the surface Sometimes looks rougher than the surrounding terrain Most THEMIS images are taken during the afternoon and the sun is shining from the left side of the image 7 Crater in Elysium Planitia 18N, 136E

Rampart Craters Have distinct ejecta that looks like it flowed across the surface Probably due to ice or liquid water in the subsurface when crater formed Rampart Crater in Acidalia Planitia 28N, 319E 8

Crater Morphology Morphology (shape) will look different based on age and size: Large craters: Central peaks, rings and/or slumping walls Old craters: Eroded and have ‘softer’ features 3 ‘types’ of craters: Preserved Modified Destroyed Central Peak Slumps 9 Arabia Terra 18N, 6E

Modified Craters Craters can be eroded or modified by: Wind Water Lava Orcus Patera 16N, 183E Ares Vallis 16N, 330E Modified Craters Craters can be eroded or modified by: Wind Water Lava 10

Volcanic Features Many types of surface features are associated with volcanoes: Volcanic structures Lava flows Calderas Lava Tubes/Channels Olympus Mons (shown here) is a shield-like volcano the size of the state of Arizona! 13 Olympus Mons 18N, 230E (Wide Angle)

Volcanics on Mars Volcanic activity has dominated the surface of Mars Ascraeus Mons Pavonis Mons Arsia Mons Alba Patera Olympus Mons Volcanic activity has dominated the surface of Mars Tharsis is a huge (1/3 of the planet) volcanic region that consists of 3 shield-like volcanoes Olympus Mons, Alba Patera and other small volcanoes are evident in this area 14

Lava Flows There are many lava flows on Mars of all ages These are similar to lava flows that we see in places like Hawaii, but can be much larger! Daedalia Planum -26N, 232E 15

Apollinaris Patera Caldera Multiple basins in the caldera Channels along the flank Lat: 9.3 S Lon: 174.4 E THEMIS Day IR Mosaic 18 6

Dust Devil Tracks Dust devils pick dust up in to the atmosphere They can act like vacuum cleaners and leave dust-free tracks behind them Argyre Planitia -47N, 318E 35

Wind Streaks Wind streaks form behind topographic features (such as crater rims) Dust can be deposited or scoured in a wind streak 36 Syrtis Major 0N, 72E

Dunes Dunes are wind blown piles of sand Sand dunes on Mars are often dark because they are made of basaltic sand Sand Dunes in Kaiser Crater -47N, 19E 37

Surface Features on Mars Impact Craters Volcanic Features Fluvial/Water-Related Features Layers Aeolian/Wind Features 39

Mars Maps Mars Regions Zoom in to see details Also see: http://pubs.usgs.gov/imap/i2782/i2782_sh1.pdf 40