The Geometry in Space Project

Sponsored by the Indiana Space Grants Consortium and Ball State University

 

Finding a place to land

 

 

 

Viewing the planet before landing

 

As you approach the planet, you turn on your holographic virtual globe of Mars by clicking the image below.

 

 

The terrain of Mars differs from place to place, just like Earth. If you were landing on Earth, a mountain top might not be the best place to choose.  On the other hand, the middle of the Pacific Ocean or Montana might be even worse!  You would prefer to find a location that is somewhat typical, and yet near to different interesting features.  Such a “Middletown” location would be flat but near interesting geological features such as glacial flows, river basins, and potential intelligent life.  Just as E.T. was looking for such a place on Earth, you are looking for a similar place on Mars.  The following activities will introduce you to the surface of Mars.

 

 

Viewing the features --- Mars Explorer for the Armchair Astronaut

 

Visit the PDS Mars Explorer for the Armchair Astronaut by clicking on the image below. 

Using this map, you may select nearly any location on the planet for exploration.  To begin, click on the blue dot labeled Olympus Mons in the upper left-hand corner of the map. 

 

 

An image something like that shown below will appear.  If you don’t like the image obtained , use the Back button of the browser to return to the map.  You may then click on a different location to obtain a different image. 

 

 

Below the image itself, there are a number of buttons for panning (moving around), zooming (moving closer or farther away), and other actions that change the image one way or another. 













 

Below these controls are the image statistics.  The most interesting of the image statistics is resolution.  Resolution represents the size of each pixel, or picture element, in pixels per degree, kilometers per pixel, and miles per pixel.  For instance, in the image shown above the resolution is 64 pixels per degree, which is equivalent to 0.93 kilometers per pixel and 0.58 miles per pixel.  

 

Zoom in on the image.  After each zoom, note the image resolution in kilometers per pixel.  What happens to the resolution as you zoom in?   Why?  What is the finest resolution that you can obtain using the zoom feature?

 

Spend a few minutes exploring Mars using the clickable map.  Which four sites to you find most interesting?  Why?

 

Viewing the features --- Mars Global Surveyor Data Maps

 

Another outstanding resource is the Mars Global Surveyor Data Maps.  When the map is loaded, click on the grid rectangle containing the following objects.

 

 

Next, select MOLA Elevation Data.  An image like that shown below will appear.  Run the mouse over the image and notice the elevation data that appears at the bottom of the screen.  What is the highest elevation you can find?  The lowest?

 

 

Click on the Create New Cross Section box at the bottom of the screen and drag a line segment across the volcano as shown above.  A graph like that shown below will appear.  How high is the volcano?  Create additional cross section graphs for the other volcanoes in the image.  Which volcano is tallest?

 

 

 

Using the Back key, return to the previous page and select Geology.  You will obtain an image similar to that shown below.  Move the mouse over the image.  As you move from one color to another, the geologic features of each region are displayed below the image.  What are the volcanoes make of?  The areas between the volcanoes?

 

 

 

 

Prior to virtual globes, most people used flat maps to navigate.  Of course, the world is not flat, so every flat map is not totally accurate.  Even so, flat maps are easy to fold and are always on line.  For example, here is a flat version of the entire surface of Mars, where blues are low elevations and reds are high elevations.

 

 

 

Questions

  1. Give the approximate latitude and longitude of the red dot at the right.  What feature could it possibly represent?
  2. What does the blue region look like in the rotating globe view?
  3. Locate two other features of Mars that can be found on both the flat map and the globe.  Give their approximate latitude and longitude locations.
  4. On the flat map, some features look larger than they should.  Locate an example of one such feature.  Why does this happen?  At which locations is this occurrence most extreme? 
  5. What do the red strips at the top and bottom of the flat map tell us about Mars?  How does this compare to Earth’s poles? 

 

Candidate Mars Surveyor 2001 Landing Sites

 

NASA has explored a number of potential landing sites.   Explore at least four of these sites.  Be sure to try out the Lo-Res VRML versions.

 

  1. What are three advantages and disadvantages of each of these sites? 
  2. Rank the sites as potential landing sites from best to worst.
  3. What additional information do you need to know about these sites?  For example, how could thermal or mineral data affect your decision? 
  4. How do the features surrounding your landing site compare in scale to similar features on Earth?  For example, the Volcano World entrance point linked below compares Mt. Everest, Olympus Mons, and Mauna Kea, the largest volcanic mountain on Earth.

 

 

Possible follow-up activities for novice students

 

  1. Photograph your class in front of your school building.
    1. Knowing your height, use the photograph to estimate the length of various features:  e.g., the height of the building, the areas of the windows, the length of the sidewalk. 
    2. Measure the actual features, e.g., the length of the sidewalk, and compare your results with your estimate.  Why do they differ?
  2. Create a fake rock field and photograph it from various perspectives and distances.  Possibly include objects of known length and area, such as a ruler or washcloth. 
    1. Use the photographs to estimate the size (or relative size) of the various features:  e.g., height of a mound, area of a rock face, area of a rock’s footprint.
    2. For pairs of objects of different size, how is it possible that the larger might look smaller? 
  3. Choose an interesting location on Mars using the clickable map. 
    1. Estimate the length/height/area, using the resolution data. 
    2. Is it possible that the actual measurements are different?  Why?  By how much?  How could we become more confident of our measurements?

 

Possible follow-up activities for advanced students

 

  1. Locate postcards from vacation destinations: e.g., the Grand Canyon, Niagara Falls, the Washington Monument 
    1. Using resources (such as the postcard back, or a web site) determine the actual length of the feature shown
    2. Determine the scaling factor between the photograph and actual object.  Use this information to estimate the measure of area and volume features included in the photographs
  2. Assist the middle grades in creating a fake rock field.
    1. Identify perspectives that provide a true perspective of the relative heights of the objects.
    2. Identify perspectives for which a larger object appears to be smaller.
    3. For a fixed zoom camera, photograph the same object from varying distances.  How does the distance between the camera and the object vary in relation to the scaling between the photographed image and the actual object length?
  1.  Choose an interesting location on Mars using the clickable map.
    1. In each case, estimate the length/height/area, using the resolution. 
    2. Is it possible that the measurements are different?  Why?  By how much?  How could we become more confident of our measurements?
    3. How do the length/area of these features compare to similar features on Earth? 
  2. Find photos of several mountains/cliffs/volcanic mounds on Mars. 
    1. Using this representative sample, estimate the range of heights/areas/depths that appear.
    2. Compare this range to the range of heights/areas/depths on Earth.  Are Mars measures generally larger, or are the outliers more extreme?