The Work of a Goddess
The Greek goddess Theia was the daughter of Earth (Gaia) and sky (Uranus). Theia gave birth to Selene, the goddess of the Moon. So Theia plays a big role in the Moon’s birth story.
Why It Matters
- The Moon has been around for about 4.5 billion years.
- The Moon is not an active planetary body, so there is some evidence of how it formed.
- There are currently three hypotheses (hypothesis is the correct term) for how the Moon formed:
- Capture Hypothesis: Earth’s gravity captured a passing asteroid
- Co-formation Hypothesis: Earth and Moon formed at the same time
- Giant Impact Hypotheses: A Mars-sized body collided with Earth and the Moon formed from the orbiting debris.
With the links below, learn more about the formation of the Moon. Then answer the following questions.
- VSauce, Why is There a Moon? (Video; watch from 0:40 to 3:10 only) http://www.youtube.com/watch?v=YBi6gUbsz-E
- Space.com, How Was the Moon Formed? (article): http://www.space.com/19275-moon-formation.html
- What is the evidence against the capture hypothesis?
- What is the evidence against the co-formation hypothesis?
- What is the evidence in favor of the giant impact hypothesis?
- How did the small planet of Theia cause the Moon to form?
- Why are Earth’s seasons evidence for this hypothesis for how the Moon formed?