Earth's Magnetic Shield

Students learn how Earth's churning liquid iron outer core generates a magnetic field, how that field forms a magnetosphere that turns aside the solar wind and traps the Van Allen belts, and why the Moon and Mars, which lost their global fields, are so different from Earth.

Grades 5-8About 15 minutes of narrated flight, plus discussion stops8 stops

The full guide, with the 40-minute plan, discussion key points, exit ticket, activities, transcript and PDF, comes with a teacher license. Already licensed? Use Open the full guide.

What students will see and do

Students visit Earth five times (the core, compasses and animal navigation, the magnetosphere, the Van Allen belts, the wandering magnetic pole), plus the Sun, the Moon and Mars. Aetherion pauses at the Sun (the long-term effect of a steady solar wind), the Moon (rocks as recorders of an ancient magnetic field) and Mars (whether a magnetic field is necessary for life).

Learning objectives

• Explain how moving liquid iron in Earth's outer core produces a magnetic field.
• Describe how the magnetosphere deflects the solar wind and creates auroras and the Van Allen belts.
• Identify evidence that the magnetic north pole moves and that the field has reversed in the past.
• Compare Earth with the Moon and Mars to explain how losing a magnetic field can affect a planet's atmosphere.

NGSS connections

Stops on this journey

1. A Magnet Deep Inside
2. Compasses and Animal Navigators
3. The Wind from the Sun (discussion stop)
4. The Magnetosphere
5. The Van Allen Belts
6. The Wandering North Pole
7. The Moon's Lost Magnet (discussion stop)
8. Mars Lost Its Shield (discussion stop)

Vocabulary

• magnetic field
• outer core
• geodynamo
• magnetosphere
• solar wind
• Van Allen belts
• magnetic pole
• aurora