Cosmic Rays
Cosmic rays are high-energy radiation, mainly originating outside the Solar System. Upon impact with the Earth's atmosphere, cosmic rays can produce showers of secondary particles that sometimes reach the surface. Composed primarily of high-energy protons and atomic nuclei, they are of mysterious origin. Data from the Fermi Space Telescope (2013) have been interpreted as evidence that a significant fraction of primary cosmic rays originate from the supernova explosions of stars. Active galactic nuclei probably also produce cosmic rays.
Earth's Magnetic Field
Earth's magnetic field, also known as the geomagnetic field, is the magnetic field that extends from the Earth's interior out into space, where it meets the solar wind, a stream of charged particles emanating from the Sun. Its magnitude at the Earth's surface ranges from 25 to 65 microteslas (0.25 to 0.65 gauss). Roughly speaking it is the field of a magnetic dipole currently tilted at an angle of about 10 degrees with respect to Earth's rotational axis, as if there were a bar magnet placed at that angle at the center of the Earth. The North geomagnetic pole, located near Greenland in the northern hemisphere, is actually the south pole of the Earth's magnetic field, and the South geomagnetic pole is the north pole. Unlike a bar magnet, Earth's magnetic field changes over time because it is generated by a geodynamo (in Earth's case, the motion of molten iron alloys in its outer core).
Pre-Media
Discuss the following with a partner/group, or as a class.
- What massive geological and atmospheric changes are currently in process?
- Which changes to our earth do we have control over? What should be done?
Media
Exercise
Watch the remainder of the video from 20:20. As you listen, take notes as if you are in an academic lecture classroom, writing down information you believe will be important for the class.
Post-Media
Discuss the following with a partner/group, or as a class.
- How many STEM fields were discussed throughout the entirety of the video?
- Which STEM discipline interests you most?
- How does the STEM discipline that interests you most interrelate to STEM fields discussed in the media?