Hills cloud

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/hills-cloud

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. What is the related astronomical concepts?Inner Oort Cloud, Oort Cloud, Kuiper Belt, scattered disc objects, long-period comets
2. How far is the Hills Cloud from the Sun?Its outer edge is about 20,000 to 30,000 astronomical units (AU) from the Sun, while its inner edge is estimated to be between 250 and 1,500 AU.
3. Why do scientists think the Hills Cloud exists?Computer models that explain the many long‑period comets we see and the movements of the outer solar system suggest a hidden disk of comets inside the Oort Cloud.

Planetesimal Scattering: The process by which gravitational interactions with massive bodies alter the orbits of smaller celestial objects.
Protoplanetary Disc: A rotating disc of dense gas and dust surrounding a newly formed star, from which planets eventually form.
Tidal Forces: Gravitational forces exerted by a celestial body that vary across the body of another celestial body, causing stretching or compression.