Magnetism: Defending our Planet, Defining the Cosmos
Highly Recommended  If you choose only one video to supplement a lesson on Earth's magnetic field, we suggest this one, produced by Rice University, Houston Museum of Natural Science, and the Evans & Sutherland Digital Theater. In 24 minutes, it explores the importance of our magnetosphere, how it deflects ionizing radiation from the solar wind, and tells about the Magnetospheric Multiscale Mission launched in 2015 to observe conditions that allow charged particles to penetrate Earth's magnetic shield.
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PBS: Is Earth's Magnetic Field Reversing?
You probably know that Earth's geomagnetic pole reverses itself -- 183 times in the last 84 million years, to be exact. But WHY does Earth experience this reversal of polarity? It's been about 700,000 years since the last reversal, so does this mean Earth is about due for another? Well.....possibly. And possibly not. PBS Digital Studios host Matt O'Dowd explores the topic in this 14-minute video. Appropriate for high school and introductory college-level.
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Science Channel: Why Earth's Magnetic Shield Matters
This 4-minute video compares Earth and Mars in terms of magnetic field (Earth has a strong one, Mars doesn't). Both planets are in the "Goldilocks Zone" of habitability. So what happened? Why does Earth have a magnetosphere and what happened to Mars? Without our magnetic field to deflect ionizing radiation and protect our atmosphere, Earth would probably be devoid of life. The video explains how the two planets developed with such stark differences and why magnetic fields are important in sustaining life.
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PBS Space Time: Could We Terraform Mars?
Get ready to be entertained and informed in this 15-minute video featuring Australian astrophysicist Matt O'Dowd, who explores the possibility of terraforming Mars. He discusses ideas ranging from building a new atmosphere on Mars (unlikely prospect) to placing several city-sized domed structures on the surface (more realistic). Either way, the video will spark lively classroom discussions about how we should allocate resources to make Mars potentially habitable. Teachers: Great way to teach about atmosphere and magnetic field along with trade-off issues that scientists face in real projects. "Does the potential gain offset the titanic expense?"
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Veritasium: Spinning Sphere of Molten Sodium
Will it ever be possible to predict future changes to the Earth's magnetic field? Veritasium takes a trip to the University of Maryland Dynamo Lab to look at an experiment to figure out just that question. Physicist Derek Muller interviews Dr. Dan Lathrop about his "spinning sphere of molten sodium", a model designed to mimic the turbulent convection resulting from interactions in Earth's solid inner core and liquid outer core. The model has a 1-meter solid core with a liquid sodium outer core (sodium is a good conductor). Muller does his usual great job of providing context in explaining how Earth's outer core can be compared to an electromagnet, acting to sustain a magnetic field. Will this model work to help us predict magnetic field events on Earth? We don't know yet. But it's a great springboard for a class discussion on the importance of models in science.
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