Theia (hypothetical planet)

High school (ages 12+)
Space & Astronomy

Name:

Date:

Step 1 · Read the article

Open the article and read it at the level above. Then answer the questions below in your own words.

https://smallwhale.org/articles/theia-hypothetical-planet

Write what each word means, using the article.

Do not copy the article. Write two things you learned, the way you would explain them to a friend.

Answers below are taken from the article’s stored facts, so they match what the student read.

1. How big is Theia (hypothetical planet)?Theia
2. What is Theia (hypothetical planet) known for?Delivery of volatile compounds via impact
3. What is the estimated formation epoch?Early Solar System, ~4.5 billion years ago
4. What is the proposed formation location?Earth's L4 or L5 Lagrange points (or migrated from Outer Solar System)

Protoplanet: A celestial body that is in the process of becoming a planet through accretion.
Giant-impact hypothesis: The leading scientific theory for the formation of the Moon via a collision with a Mars-sized body.
Lagrange points: Gravitationally stable points in a two-body system where a third body can maintain a stable orbit.
Accretion: The process by which dust and gas particles clump together to form larger bodies.