Themis (hypothetical moon)

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/themis-hypothetical-moon

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. Who discovered Themis (hypothetical moon)?1905
2. What is the proposed discoverer?William Pickering
3. What is the parent planet?Saturn
4. What was Themis?Themis was a moon that astronomer William Pickering said he found around Saturn in 1905, but later scientists could not see it again.
5. Why did scientists not find Themis again?Later observations couldn't confirm it, and scientists think it might have been a mistake in early photographic plates, like a defect or a light leak.

Spurious Detection: An observation that appears to be a discovery but is actually caused by errors or artifacts in the measurement process.
Reproducibility: The ability of an experiment or observation to be repeated by different researchers with similar results.
Gravitational Resonance: A phenomenon where two orbiting bodies exert a regular, periodic gravitational influence on each other.