Mars Landform Identification Teacher Page Activity developed by Dr. Peter Mouginis-Mark.
	Purpose To identify landforms on the surface of Mars using Viking Orbiter spacecraft photographs.

Photographs taken from orbit give us closer looks at the surface of Mars. The fun part is knowing what you're looking at and that's what this activity is all about.

Students will need to know the following vocabulary of landforms on Mars:

• impact crater - roughly circular hole created when something struck the surface. The floor of the crater is below the surrounding landscape. You may see a raised rim or deposits of debris ringing the crater.
• volcano - a mountain formed by lava and/or erupted materials. A volcanic crater is a depression at the summit of a volcano. In contrast to craters made by impact, volcanic craters are above the surrounding plain.
• river valley - winding channel carved by water; may have multiple branches that make a pattern resembling a branching tree.
• river bed - may be wider than a river valley with a flatter floor; may contain streamlined islands.
• dry lake bed - irregularly shaped depressions.
• polygonal ground - surface patterns (wedges of polygonal shapes) generally attributed to the alternate freezing and thawing of soil layers containing water or ice. The size of the polygons is believed to be directly related to the thickness of the soil layer (i.e., thicker soils produce larger polygons). The implication for Mars: presence of liquid water at some time in the past.
• lava flow - a break out of magma from underground onto the surface.
• sand dune - a hill or ridge of wind-deposited sand.
• fractures - straight grooves or lines on the surface where rock has been broken.
• wind streaks - dark wind streaks associated with craters (as in Photo #6) have been interpreted previously as deposits of saltated relatively coarse-grained particles, but it seems the most widely accepted idea is that they are wind erosion features. The dark streaks have been interpreted as erosional zones - surfaces that have had fine-grained particles stripped away. The difference in brightness is probably due to a difference in the weathering state of the particles. Generally, fine-grained materials are lighter-colored because they are weathered more rapidly than the larger particles. Alternatively, dark streaks have been interpreted as mantles of dark-colored, silt- and clay-sized particles deflated from the adjacent crater floor. Deflation is defined as the sorting out, lifting, and removal of loose, dry, fine-grained material by wind action. The orientations of the streaks indicate the direction of the wind at the time they formed; so that differences in orientation may be due to local topographic influences on wind direction or to changes in wind regimes.

Additional on-line resources for Mars images and Mars mission information:

About Mars from the Mars Team Online.

Center for Mars Exploration at NASA Ames's Research Center.

Mars Exploration Program at the Jet Propulsion Laboratory.

Mars Global Surveyor MOC Images from Malin Space Science Systems.

Determining the age of surfaces on Mars from Malin Space Science Systems.

The Mars Millennium Project education initiative.

This Activity

This activity uses seven photographs taken by Viking Orbiter cameras to show nine different features on the surface of the Mars (defined above.) Students identify which features are present in each photograph. A "Mars Landform Identification" student chart is provided to record answers.

Preparation

Print out copies of the Mars photographs for this activity.
Make copies of the blank "Mars Landform Identification" student chart.
Print out copies of the answer chart.

In Class

This activity can be used as a group or individual culminating experience for students who have been studying Mars. The vocabulary words can be given as a separate assignment before the landform identification.

Wrap-Up

Compare student charts with the answer chart and discuss any discrepancies. Were some landforms easier to identify than others? Did shadows (sun angle) help make some features easier to see? Which landforms would you like to stand on?

Extensions

Use the latitude & longitude coordinates on each photo to locate the areas on a map or globe of Mars.
Research and discuss Mars missions past, present, and future.

Go to Mars Landforms Student Chart.

Go to Mars Landforms Answer Chart and labeled photographs.