University of Michigan - Department of Astronomy


updated: 04/19/2000

Martian Surface Features - Worksheets

Preview Questions

  1. What is Mars' orbital period? What is the tilt of its rotation axis? What is the radius of Mars? What is the escape velocity from the planet (in km/s) and how does it complare to the Earth?

  2. What does the word "albedo" mean? Explain the correlation between albedo features and terrain on the moon.

  3. What do the red lines on the topographic map represent?

Worksheet Section

Note: Please write in complete paragraphs where appropriate.

Step 1: Large Scale Features

  1. Which is older, the plains or the cratered terrain found mostly in the southern hemisphere? How can you tell?

  2. What are the names and approximate coordinates of the two most obvious volcanic regions?

  3. What evidence do you see for large impacts on Mars? Give names and coordinates.

  4. What probably caused the huge plains regions primarily found in the northern hemisphere?

  5. Is there any easily identifiable correlation between the albedo features and any particular kind of terrain (e.g. are cratered regions characteristically lighter or darker than plains regions, etc.)?

  6. Do you see any evidence on the map for large scale erosion by wind or water? Where, and by wind, water, or both? (Hint: look at 25 S, 245 W)

  7. Using a ruler and the scaling information accompanying the map, estimate the sizes and range in altitude of each of the following features:

    Table 1 - Sizes of Prominent Martian Surface Features

      Coordinates       Elevation  
    Feature Lat. Long. Scale

    NOTE: For comparison, the Grand Canyon is about 150 km long, 6 to 28 km wide, and at most 2 km deep while the peak of Mt. Everest is about 8.8 km above sea level.

  8. Compare the appearance, relative height and relation to nearby regions of the Viking 1 (22.5 N, 48 W) and Viking 2 (48 N, 226 W) landing sites from their appearance on the map.

Step 2: Analysis of Surface Features in Mariner 9 Photographs

  1. Volcanic Features (MTVS 4142-93, 4184-84,4298-47, IPL 1699/125324)
    From the evidence, deduce how the Martian volcanoes and the surrounding plains were formed.

    1. Although these volcanoes are relatively "fresh" looking, what evidence do you see for the proposition that, in reality, these volcanoes are quite old?

    2. From your previous measurements of Olympus Mons and Ascraeus Mons, we can see that the Martian volcanoes are huge and very broad by comparison to their earthly counterparts (remember, they're on a planet half the size of Earth!). What might be the reason Mars' volcanoes are so large?

    3. With regard to the map, what can be said about the general elevation of the plains areas surrounding the volcanoes? What might cause this?

    4. What might be the significance of multiple calderas on some of the summits?

  2. Valles Marineris (MTVS 4187-45, 4191-45, 4144-87, IPL 1628/210149)
    Consider the processes which may have led to the formation of Valles Marineris.

    1. Describe two processes which may have formed the Valles Marineris. This is your first guess. The following questions will help you decide which is most likely.

    2. The first photo shows a close-up of the section of chaotic terrain at the western end of Valles Marineris. The other photos show sections of the canyon system itself. Discuss the changes in altitude of the feature from Noctis Labyrinthus on the west to Chryse Planitia on the north-east.

    3. Given your observations in the previous question, what might have caused the chaotic terrain?

    4. What evidence do you see for aeolian or fluvial erosion in the canyon itself?

    5. What can be said about the age of this feature relative to the surrounding plains and how did you reach this conclusion? Remember to consider the scale as you compare the map to the Mariner 9 photograph.

    6. Estimate how far the crater chains extend. Were the chains more likely to have formed from a fragmented meteor or from outgassing along an underground fault?

    7. Briefly discuss what may have originally formed Valles Marineris and what subsequent changes have probably taken place to give it its present appearance.

  3. Polar Layered Terrain (MTVS 4213-21, 4247-7)
    Consider what is responsible for the layered terrain surrounding the poles of Mars.

    1. From inspection of the map, describe the appearance of the south polar region in relation to the surrounding area.

    2. Thinking in terms of the seasonal changes Mars undergoes, what do you think might have caused the layered terrain?

  4. Cratered Terrain (MTVS 4212-66, 4287-24, IPL 1651/154245, 7350/165312)
    Consider the history of the cratered regions.

    1. MTVS 4287-24 shows a section of relatively unmodified cratered terrain. Using the coordinates given on the photo, identify some of the features in this image (including the "doublet" craters referenced in the caption) on the map. Assuming the diameter given for the large crater, estimate the diameters of the doublet craters. From this and the apparent size of these craters on the map, what would you estimate the size of the smallest craters on the map to be? Show your work!

    2. Locate the positions of the two IPL images on the map. Where are these features located relative to the plains and cratered regions?

    3. In IPL 7350/165312, what would you guess to be the relative ages of the fretted and the cratered terrain? Why? What do you think caused the fretted terrain?

    4. In IPL 1651/154245, there are again fretted terrain and craters. What appears to be the relative ages of the features in this photograph? Is this consistent with what you found above? If not, why might they be different?

  5. Channels (MTVS 4294-12, 4294-16, 4294-20)
    Consider the evolutionary history of this feature.

    1. There are a number of channels (not canals!) or channel-like features on Mars. The three photos here show a section of one such channel and fit together in a mosaic form as described in the caption. Find the location of this feature on the map and describe its location relative to other features.

    2. Given its location, what might have formed this feature?

    3. Describe the appearance of this feature. What evidence can you see for fluvial erosion? In your estimation, could this feature have been formed by wind or lava flows? Explain.


Write a brief ( page) summary of what you have learned about the large scale surface features of Mars from the investigation of Mariner 9 images. Discuss the relative importance of plate tectonics, volcanism and erosion processes on the Martain surface.