To understand how sediments can help reveal a planet's geologic history, students compare sand samples from different locations.
This activity introduces students to one of the main geologic reasons why the mouth of Ares Vallis is such a desirable landing site. By examining sand samples from different locations, students realize that sediments can provide information about where they originated and how they were deposited. By looking at the abundance of various minerals and the condition of the grains, students formulate a reasonable history for each sand sample. They then locate Ares Vallis on a map and speculate about what Pathfinder might find in the sediments there.
- Sand grains contain clues about their origin and history.
- A sand sample reflects the geology of its water-shed or region.
- One of Pathfinder's mission objectives is to gather evidence that will enable scientists to better understand the composition of the Martian crust and the planetŐs early geologic history.
- Ares Vallis was selected as the landing site because it satisfies the geologic and engineering criteria for the mission.
- The Thermal Emission Spectrometer on the Mars Global Surveyor and the APXS mounted on the micro-rover will enable scientists to determine the abundance of major chemical elements in the rocks and soil near the lander.
- Observe differences between various sand samples and among individual sand grains.
- Interpret the clues contained in a sample of sand.
- Estimate the size of the area Pathfinder will be able to sample from within the landing ellipse.
- Explain the appeal of Ares Vallis as a landing site in terms of its geological potential.
- Sand rises to the surface from the ground below it. Ask: What is sand? Where does it come from?
- Each rock (and all sand) is made from one kind of material.Ask: Is a rock (or sand) made from one or many different materials? How do you know?
- Rocks and sand grains have always had the shape we see today.Ask: How did this rock get this shape?
- The material that covers the surface of Mars is all the same.Ask: Is the land on Earth all covered by the same material?
- Sand from several locations, magnet, tape, magnifying glass, marker, Image set.
- Provide students background in interpreting sand grains.
- Gather sand samples from a variety of locations.
1-2 class periods