Where Moons Come From

Students learn the three main ways moons form (giant impacts, capture, and growth in a disk around a young planet) and how scientists read a moon's orbit, size and makeup as evidence for its birth story.

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

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What students will see and do

Students start at Earth, visit the Moon twice (the giant impact and the evidence in Apollo rocks), fly to Mars (Phobos and Deimos), Jupiter twice (disk-born moons and captured outer moons), Neptune (Triton) and Pluto (Charon). Aetherion pauses for discussion at the first Moon stop (judging the giant impact evidence), the first Jupiter stop (rock-to-ice pattern), Neptune (why Triton was captured) and Pluto (the Pluto-Charon balance point).

Learning objectives

• Describe the three main ways moons can form: giant impact, capture, and growth in a disk.
• Identify orbital fingerprints of each process, such as backward or tilted orbits for captured moons.
• Explain the evidence that Earth's Moon formed from a giant impact.
• Use evidence to predict how a newly discovered moon most likely formed.

NGSS connections

Stops on this journey

1. Three Ways to Make a Moon
2. A Collision Makes the Moon (discussion stop)
3. Evidence in Moon Rocks
4. Two Tiny Moons, Two Possible Stories
5. A Miniature Solar System (discussion stop)
6. Captured Moons of Jupiter
7. Triton Goes Backward (discussion stop)
8. Pluto and Charon (discussion stop)

Vocabulary

• giant impact hypothesis
• capture
• circumplanetary disk
• retrograde orbit
• Kuiper Belt
• barycenter
• Apollo samples