1 / 39

Surface Features on Mars

Surface Features on Mars. Dr. Joshua Bandfield Mars Space Flight Facility Arizona State University. Mars has Many Types of Surface Features. Craters Volcanic Features Channels Layers Wind Features. 2. Choosing a Research Topic.

hazina
Télécharger la présentation

Surface Features on Mars

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

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

  2. Mars has Many Types of Surface Features • Craters • Volcanic Features • Channels • Layers • Wind Features 2

  3. Choosing a Research Topic • The features to be studied need to be a good size for study with THEMIS data • 100’s of kilometers is too big, 10 meters is too small • A single THEMIS image should capture the feature • We can’t do studies that require taking many images • We can use other images taken already, however • THEMIS needs to be the correct type of data to use to lead to a conclusion • Sizes, shapes, textures 3

  4. Choosing a Research Topic • There are other types of data are available that will help solve the problem • Other THEMIS images already collected can be used to help answer the question • Higher and lower resolution images available from other spacecraft can help as well 4

  5. Impact Craters • Craters on Mars have a number of important features: • Ejecta • Density (how many on a surface) • Morphology (shape) 5

  6. All THEMIS visible images are ~18 km across Crater Ejecta • Ejecta are the materials that get thrown out of a crater when a meteorite hits the surface • Sometimes the ejecta will look 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 6 Crater in Elysium Planitia 18N, 136E

  7. Rampart Craters • Rampart craters have distinct ejecta that look like it flowed across the surface • This is probably due to ice or liquid water present in the subsurface when the crater formed Rampart Crater in Acidalia Planitia 28N, 319E 7

  8. Orcus Patera 16N, 183E Ares Vallis 16N, 330E Modified Craters • Craters can be eroded by wind and water or flooded with lava 8

  9. Crater Density Older Surface • The relative age of the surface of Mars can be determined by figuring out the crater density (the number of craters on a surface) • Young surfaces will have few craters • Old surfaces will have many craters Younger Surface Kasei Vallis 25N, 287E 9

  10. Crater Morphology Central Peak • The morphology (shape) of a crater will look different based on how old and how large the crater is • Large craters have central peaks or rings and slumping walls • Old craters are eroded and have ‘softer’ features Slumps 10 Arabia Terra 18N, 6E

  11. THEMIS and Craters • THEMIS is good for observing crater shapes and sizes for smaller craters • This is good to see how craters are shaped and how they are modified • Crater densities can be used to date the relative ages of surfaces • If the ages are very different! 11

  12. Volcanic Features • We see evidence for lots of volcanoes and lava flows on Mars • Olympus Mons (shown in the picture) is a shield volcano the size of the state of Arizona! 12 Olympus Mons 18N, 230E (Wide Angle)

  13. 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 13

  14. Volcanoes • Mars has many volcanoes that are usually one of three types: • Shield volcanoes (these can be huge!!) • Cones • Patera Apollinaris Patera -10N, 174E (Wide Angle, ~100 km across) 14 Biblis Patera 2N, 237E

  15. Isidis Planitia 12N, 90E Cones • These are small, steep sided volcanoes • Only ~100 m across 15

  16. THEMIS and Volcanoes • THEMIS can observe the shape of smaller volcanoes • This can determine the type of volcano • Different lava flows can be mapped • The relative dates of the flows can often be determined from the image 16

  17. Channels • Channels on Mars can be large or small • Outflow channels were formed by massive floods in the past • Valley networks were formed by trickles of water in the past Valley Networks on Alba Patera 44N, 242E 17

  18. Channels • Outflow channels on Mars were formed by catastrophic floods • The water came from underground Ares and Tiu Valles 15N, 330E (Wide Angle, ~1500 km across) Outflow Channels in Elysium Planitia 22N, 126E 18

  19. Hale Crater -35N, 324E Gullies Formed recently by liquid water! 19

  20. Aureum Chaos -3N, 331E Chaos Terrain • Chaos terrain is often at the head of the outflow channels where the ground collapsed Wide Angle (~500 km across) 2N, 340E 20

  21. THEMIS and Channels • THEMIS can observe many water related surface features • The size and shape of valley networks • The flood size can be estimated from chaos terrain and outflow channels • Where gullies occur and their size and shape 21

  22. Candor Chasma -7N, 290E Layers • There are many kinds of layered rocks on Mars • We don’t know how all of them formed 22

  23. Finely Layered Deposits • Formed by ash from volcanoes or by sediments deposited in water Layers in Becquerel Crater 22N, 353E 24

  24. Polar Layered Deposits • Alternating layers of water ice and dust • These layers record Mars’ climate history 23 South Pole Layered Deposits -82N, 306E

  25. THEMIS and Layers • THEMIS can determine the size of some layered deposits • The thickness and number of layers can be determined from images • The shape of the layers can sometimes help find out how they formed 25

  26. Wind Eroded Features in Tharsis -5N, 200E Wind Features • Mars is an aeolian (wind driven) planet • Wind Erosion • Dunes • Wind streaks • Dust devils • Dust mantled surfaces 26

  27. 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 27

  28. Wind Streaks • Wind streaks form behind topographic features (such as crater rims) • Dust can be deposited or scoured in a wind streak 28 Syrtis Major 0N, 72E

  29. Dust Devils • Dust devils pick dust up in to the atmosphere • They can act like vacuum cleaners and leave dust-free tracks behind them Dust Devil Tracks in Argyre Planitia -47N, 318E 29

  30. Martian Dust • Mars’ atmosphere is always dusty • Sometimes there are dust storms that cover the entire planet! • Many surfaces are covered with a mantle of dust Dust Storm Near Mars’ North Pole 30

  31. THEMIS and Wind Features • THEMIS can use wind features to determine wind directions on the surface of Mars • Images can tell whether a surface is sandy, rocky, or dusty 31

  32. Mars’ North Pole Mars’ South Pole Polar Caps • Mars’ polar caps are made of solid CO2 (dry ice) and water ice 32

  33. Polar Caps • There are many strange landforms in the Martian poles Swiss Cheese Terrain Mars’ South Pole 33

  34. Valles Marineris 34

  35. Melas Chasma -9N, 282E Coprates Chasma -15N, 302E Valles Marineris • The Grand Canyon of Mars • Large enough to stretch across the entire United States! • Landslides, dunes, layers 35

  36. Mars Maps • Zoom in to see details • Also see: http://pubs.usgs.gov/imap/i2782/i2782_sh1.pdf 36

  37. The Martian Dichotomy • Mars has a northern hemisphere with few craters (the northern lowlands) • The southern hemisphere is older and heavily cratered (the southern highlands) • Nobody really knows how this dichotomy formed! 37

  38. Northern Lowlands Dichotomy Boundary Cratered Highlands Mars’ Dichotomy • The global dichotomy can be seen in the global elevation map 38

  39. Alba Patera Olympus Mons Ascraeus Mons Pavonis Mons Arsia Mons Tharsis • Tharsis is a huge (1/3 of the planet) volcanic region on Mars • There are many lava flows and shield volcanoes 39

More Related