If you own a laptop, please bring it to class. You will submit your answers into the dropbox on Cobra using the answer sheet (Word, RTF).
You can find links to complete this lab in the procedure below or here.
Pre-Lab Assignment: In class, we've talked about Earth, covering things like its interior structure, atmosphere, and its magnetic field. This video lab goes into more detail on the last of those three, taking a look at what the magnetic field does for Earth, what would happen to Earth if it did not have a magnetic field, and what interesting phenomena are occurring with Earth's magnetic field.
Answer the following questions before coming to lab:
1) How does Earth's magnetic field protect us from the solar wind?
2) What is an aurora and how is it produced?
3) What do you think Earth would be like if the magnetic field disappeared?
Introduction: The magnetic field of Earth is much more useful than as a method for finding the cardinal directions. In fact, if it weren't for the magnetic field of Earth, life as we know it would not be able to survive. In this lab, you'll learn about a model which attempts to explain the origin of Earth's magnetic field, see what the magnetic field does to protect us, and find out what changes are occurring in the magnetic field that will have important consequences for future generations.
Procedure: Watch the NOVA special, titled "Magnetic Storm," during the lab period. Visit the specified websites for the remaining questions. Your answers to video labs should be typed and in complete sentences. You may use the answer sheet (Word, RTF)
1A. What are conditions like at the center of Earth?
1B. Where on the surface of Earth can you find conditions similar to those at
the center of Earth?
2A. How is the strength of the magnetic field changing?
2B. How long do scientists expect this trend to continue?
3. Why would we be in trouble if we didn't have our magnetic field?
4. How are the northern and southern lights produced?
5. Describe two ways in which space probes measure the magnetic field of a distant planet.
6. What did Mars Global Surveyor discover about Mars's magnetic field today and in the past?
7A. What was Mars like over 4 billion years ago?
7B. What happened to the global environment since then?
7C. Why do some astronomers think this happened? (Note: The impact events
tell us about what Mars was like before the environmental changes; they were not
responsible for the changes.)
8. What evidence do astronomers have that the magnetic field of Earth has been changing over the last several thousand years?
9A. Explain the dynamo model for how Earth's magnetic field is generated.
9B. What could make the dynamo shut down?
10A. How are the rocks formed more than 780,000 years ago different
magnetically than the rocks of today?
10B. On average, how often do these
magnetic upheavals occur?
11. How did astronomers find evidence of magnetic anomalies over the last 300 years?
12A. What could be the effect on our descendents if there is a magnetic
reversal?
12B. Is it likely that our civilization will be destroyed by this event?
Internet Questions: We know that solar activity combined with Earth's magnetic field will create aurorae here on Earth. However, most aurorae are seen only near Earth's poles.
Go to the website: spaceweather.com and read through the "Aurora Watch" section of the "What's up in space" post. If there is no "Aurora Watch" section, there is nothing interesting to report. If that is the case, just write "No activity." for Question 13.
13. Can we expect to see any aurorae here in Illinois any time soon? Explain your answer.
Although the video that you've watched supports the idea that Earth is heading for a magnetic reversal, there are other opinions. Here is an article that came out just after the video was produced: nbcnews.com/id/3693932/ns/technology_and_science-science/
14A. What is their alternate explanation for the current rapid decline of
the magnetic field?
14B. What are some of the consequences of their proposed model?
15. What do you think is the most likely of the two proposed scenarios (the one from the video or the one from Question 14)? Why?
16. What do you think life will be like on Earth when its magnetic field reaches its minimum field strength? How will life then be different than it is now?