Spirals, Ellipticals and Irregulars
Students learn to classify galaxies as spirals, ellipticals, lenticulars and irregulars and connect each shape to how gravity, gas and collisions shaped the galaxy's history.
Grades 5-8About 15 minutes of narrated flight, plus discussion stops7 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 fly from the Milky Way to the Whirlpool, Andromeda, Triangulum, the giant elliptical M87 and the two Magellanic Clouds while Aetherion explains what each shape reveals. The lesson pauses for discussion at the Whirlpool, M87 and the Small Magellanic Cloud.
Learning objectives
- Classify a galaxy image as spiral, barred spiral, elliptical, lenticular or irregular using visible features.
- Explain why spiral arms appear blue and pink while galaxy centers and ellipticals appear yellow.
- Describe how spiral arms work like a traffic jam (a density wave) rather than a solid structure.
- Explain how collisions and gravitational tugs can change a galaxy's shape over billions of years.
NGSS connections
| MS-ESS1-2 | Students use a model of gravity's role in holding galaxies together and reshaping them through tugs, mergers and stretching. |
|---|---|
| MS-ESS1-3 | Students compare scale properties of galaxies, including size, star count and distance, from the Magellanic Clouds to M87. |
Stops on this journey
- Sorting the Galaxies
- The Whirlpool's Arms (discussion stop)
- Andromeda, a Giant Spiral
- Triangulum, the Fluffy Spiral
- The Giant Elliptical M87 (discussion stop)
- The Large Magellanic Cloud
- The Small Magellanic Cloud (discussion stop)
Vocabulary
- spiral galaxy
- barred spiral
- elliptical galaxy
- lenticular galaxy
- irregular galaxy
- bulge
- globular cluster
- merger