List of hypothetical Solar System objects

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/list-of-hypothetical-solar-system-objects

1. What does it mean when scientists talk about a hidden planet in our solar system?
2. Why did astronomers discover Neptune before they could see it?

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 does it mean when scientists talk about a hidden planet in our solar system?It means they think there might be a planet that we haven’t seen yet, but its gravity is tugging on other planets and making their orbits a little strange.
2. Why did astronomers discover Neptune before they could see it?They noticed that Uranus was not moving exactly where it should, so they used math to guess where a new planet was, and then found it.

Trans-Neptunian Object (TNO): Any minor planet or dwarf planet whose orbit lies beyond that of Neptune, including objects in the Kuiper Belt and beyond.
Orbital Perturbation: A deviation in the predicted orbit of a celestial body caused by the gravitational influence of other celestial bodies.
Astrometry: The branch of astronomy concerned with the precise measurement of the positions and movements of stars and other celestial bodies.