Star Cities: Globular Clusters

Students explore globular clusters, dense balls of hundreds of thousands of stars that are more than 10 billion years old and orbit in the Milky Way's halo, and learn how astronomers use them to date the galaxy, plus the story of the 1974 Arecibo message aimed at M13.

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 fly above the Milky Way, then to M13, back to Earth, and on to Omega Centauri, 47 Tucanae, M22, the Sun, and a final view of the Milky Way. Aetherion pauses three times: at Earth (designing a picture message like the Arecibo message), at Omega Centauri (what mixed star ages suggest about its origin), and at the Sun (why heavy elements matter for rocky planets).

Learning objectives

• Describe what a globular cluster is and where globular clusters are found around the Milky Way.
• Explain how astronomers estimate a cluster's age from which stars are still shining normally.
• Compare the age and makeup of globular cluster stars with those of the Sun.
• Identify what the 1974 Arecibo message contained and why it will take about 25,000 years to arrive.

NGSS connections

Stops on this journey

1. A Swarm Around the Galaxy
2. The Great Cluster in Hercules
3. A Message to M Thirteen (discussion stop)
4. Omega Centauri, the Giant (discussion stop)
5. Forty Seven Tucanae
6. M Twenty Two, a Close Neighbor
7. Your Sun Is Young (discussion stop)
8. Clues to the Age of Everything

Vocabulary

• globular cluster
• halo
• light-year
• heavy elements
• pulsar
• dwarf galaxy
• Arecibo message