At-Home STEM Activity: How Planets Orbit Around the Sun
Why do planets orbit around the sun? In this blog post, learn about two different models of the solar system: heliocentric and geocentric. Learn what model is accepted and proved today and demonstrate how the planets revolve around the sun using a fun and simply activity you can do at home!
Heliocentric and Geocentric Models of the Solar System
Geocentric model vs. heliocentric model of the solar system
Ancient models of the universe date back to the first civilizations in Babylonia and Egypt. By third century BC, it was widely believed that the Earth was flat and the center of the universe and all other planets and the sun orbited around the Earth. The stars were also believed to orbit and revolve around the Earth once a day. With the philosophy of Pythagoras in 530–440 BC, the believed shape of Earth changed from a flat disc to a sphere. The Greeks reasoned if the Moon is a sphere, then the Earth must be a sphere as well.
Though the geocentric model was widely believed at the time, by the time if the Renaissance in the 16th century, mathematician and astronomer Nicolaus Copernicus had theorized that instead of the Earth being at the Center of the universe, it was the Sun that sat at the center and the Earth revolved around the sun along with all of the other planets in the solar system. By the time of the 17th century, the heliocentric model was adopted.
The Science Behind How Planets Orbit Around the Sun
image credit: NASA
In our solar system, the giant gas planets, Jupiter, Saturn, Uranus, and Neptune, spin more rapidly on their axes than the inner planets do and possess most of the system's angular momentum. The sun itself rotates slowly, only once a month. The planets all revolve around the sun in the same direction and in virtually the same plane. In addition, they all rotate in the same general direction, with the exceptions of Venus and Uranus. These differences are believed to stem from collisions that occurred late in the planets' formation. All of the planets in our solar system orbit around the Sun because of the Sun’s strong gravitational pull. The Sun pulls the planets in the solar system, including the Earth, towards it and allows the planets to remain in orbit.
Activity
Demonstrate how the planets revolve around the sun using this activity below!
Materials:
Image Credit: Gift of Curiosity
Orange or yellow play dough (to make the sun)
A blue ball or blue and green play dough (to represent or make the Earth)
A pie tin (to create the orbit)
Roll the ball of orange or yellow dough and squish it down in the center of the pie tin so it sticks to the bottom.
place your Earth ball in the pie tin and use your wrists to move the pie tin in a circular motion so the ball rolls around the outside of the pan.
Take it Further!
Try out this National Geographic Kids resource and explore out-of-this-world facts, photos, books, and games about all things planets and space!
