Two Moons for Planet Earth?
A new theory suggests that, after 80 million years of co-existing, a slow collision between our current Moon and a smaller, second Moon occurred. Is this how the mountains on the far side of the Moon formed?
Articles to Share with Students
- Earth had Two Moons, New Model Suggests
- E Pluribis Lunum: Did Earth Once Have Two Moons?
- Earth May Once Have Had Two Moons
- NPR AUDIO: Early Earth May Have Been Orbited By Two Moons
- The Moon – NASA Lunar and Planetary Science
- Moon – New York Times Science Topics
- GRAIL Mission - NASA
- Astrogeology Science Center – The Moon [USGS]
Questions for Classroom Discussion
- How did the Moon form?
- What is the physical evidence that has led scientists to believe there was a second Moon?
- Define how the collision took place and the aftermath.
- How could scientists prove this new idea?
- What is the significance of this idea of there once being a second Moon?
Compiled August 8, 2011, by L.A. Guertin