Heliocentrism

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/heliocentrism

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 historical precursor?Ptolemaic geocentric model, dominant for over 1400 years
2. What is the key proponent of heliocentric model?Nicolaus Copernicus
3. Why did Copernicus propose heliocentrism?Copernicus suggested heliocentrism because the old Ptolemaic system was too complex and had many inaccuracies.
4. How did Galileo prove heliocentrism?Galileo used a telescope to see moons orbiting Jupiter and the phases of Venus, showing that not everything revolves around Earth.

Geocentricity: The astronomical model in which the Earth is assumed to be the center of the universe.
Heliocentricity: The astronomical model in which the Sun is assumed to be the center of the solar system.
Retrograde Motion: The apparent backward movement of planets in the sky as observed from Earth.
Epicycles: Circles whose centers move along a larger circle (deferent), used to explain planetary motion in geocentric models.