MARS ROCKS!

Introduction

In this WebQuest, students do some Internet research on the planet Mars. They learn about space missions to Mars and about what planetary science can tell us about Mars geology. They learn about the composition of Mars meteorites and why scientists think that meteorites provide evidence that life once existed on Mars. They discover the possibility that liquid water once existed on Mars, and learn why that possibility is significant. Finally, they answer some questions about Mars rocks, based on their Internet research.

Top

Task

Students will try to answer the set of questions as they explore the Internet sites given. Each web site has some of the answers to the questions, but several of the questions require information from two or more of the web sites. Students should be about to compile information to answer the questions as they read through each web site. Although several of the web sites give detailed information about the geological composition of meteorites from Mars, students are not expected to become experts in Mars geology. Rather, they should be able to gain a general understanding of how meteorites from Mars show evidence of the geology of the planet. From their Internet research, students should also be able to make a reasonable conclusion as to whether life once existed on Mars.

Objectives

• Research meteorites from Mars and identify the type of rock each is composed of.
• Describe the evidence that indicates that these meteorites came from Mars.
• Discuss the evidence that shows that liquid water once existed on Mars.
• Identify the evidence that shows that life once existed on Mars.

Top

Resources

Students will use the Internet links given to find out all about Mars rocks. They will learn why scientists have identified Mars as the origin of certain meteorites, and what those meteorites can tell us about the planet Mars. They will also explore what we have learned about Mars from past and present spaceflights and find out what future missions to Mars hope to accomplish. Finally, they will decide for themselves if there is enough evidence to show that life once existed on Mars.

Top

Time

1 class period for research and answering the set of questions.

Top

Process

As students progress through the list of web sites, you may help them to focus on what they need to know to answer the questions given. Several of the web sites have links to other web sites with relevant information. If time allows, you may want to allow students to explore this subject further. However, many of the sites eventually link back to those listed on the student pages.

Top

Evaluation

You may assign 10 points to each of the 10 questions for a total of 100 possible points. The answers to the questions are given below. You may rate the answer to each questions by the following scale: Excellent – 9-10 points; Very Good – 7-8 points; Good – 5-6 points; Satisfactory – 3-4 points; Poor – 1-2 points; and Unsatisfactory – 0 points.

Questions about Mars Rocks!

1. meteoroid impacts on Mars surface ejected them into space; they landed on Earth millions of years later
2. igneous rocks
3. SNC refers to the locations in which the first three meteorites believed to have come from Mars were found: Shergotty, India; Nakhla, Egypt; and Chassigny, France. All are achondrites as well. The 18 Mars meteorites found so far can be classified as one of five different types, including the snc types.
4. The gases trapped inside Mars meteorites match those measured by the 1970s Viking mission in Mars' atmosphere.
5. They tell us that Mars had volcanism (igneous rocks): that there was at least some liquid water on Mars (Mars rocks show weathering from water); that volcanism continued for quite a long time on Mars (some meteorites are as old as 3.6 million years ago, while some are just 1.3 billion years old).
6. Mars Surveyor 2003 Lander/Rover will be launched on May 22, 2003.
7. All of the Mars meteorites are igneous rocks, which do not usually contain sediments, soils, or fossils. Also, we don't know exactly where on Mars the meteorites came from. We need to collect rocks on Mars to compare them to the meteorites and to see if there are also sedimentary and metamorphic rocks as well as igneous.
8. The Mars meteorites have minerals in them which are highly soluble in hot water and which are crystallized in the rocks. The crust of Mars is red, which scientists agree is due to iron oxide; iron oxide forms in reaction with water. Photographs of Mars show layers of sediments in canyons and gullies; sedimentation occurs on Earth only from deposition under water.
9. They have found magnetite crystals in Mars meteorites; the shape of the crystals matches similar crystals formed only by living things on Earth. They have found gases trapped in the meteorites that match the gases of Mars atmosphere. They have found microscopic fossils of what may be bacteria in some of the meteorites.
10. Student answers may vary. Accept all answers that are supported by facts from students' Internet research.

Top

Conclusion

Using information gathered from the Internet, students should be able to answer the questions given about Mars rocks. From their research, students should be able to draw some conclusions about the possibility that life once existed on Mars. Have students discuss the importance of finding magnetite crystals in Mars meteorites. Also have students discuss how the presence of liquid water on Mars influences whether life as we know it could exist on that planet.

Top