Is it a square or a circle? See if you can trick your friends with this zany science project!

What causes the seasons to change? Kids find out by modeling the earth's tilt using a globe, flashlight and graph paper in this cool science fair project idea.

Demonstrate how you can make your own compass using a magnetized needle. It also allows you to compare magnetic north and geographic north.

What causes dilated pupils? Young scientists will find out by applying what they already know about changes in pupil size and making models of the pupil.

In this free science fair project, build a star clock and learn how to tell time on a clear night by observing the big dipper!

How do icicles form and what do they look like? Do this free science fair project and watch the formation of icicles occur right before your eyes.

Saturn is the ringed planet in our solar system, a gas giant with rings made of ice and dust. Let's make a cool scale model with an old CD and some glitter!

This science fair project idea experiments with spinning color wheels and optical illusions.

Prove that the Earth is not flat. The objective of this science fair project is to measure the angle of the sun and calculate the circumference of the Earth.

Tree rings can tell the age of the tree but also information about the world. This science experiment uses tree stumps to discover new facts.

This is a quick, easy science fair project that conveys the idea of density to preschool and early elementary children.

In this project, all you need is a protractor to learn how to use the altitude of Polaris to find latitude on Earth. Polaris is also known as the North Star.

Learn about the layers of the Earth and make a model! Create a earth layer book, cake, or clay diagram.

What is persistence of vision? With this hands-on science fair project idea, students will demonstrate this cool and dramatic phenomenon in their own classroom.

How does a compass work? What's a magnetic field? Kids will build their own compass at home to find the answers in this great science fair project idea.

In this simple circular motion experiment, you'll observe tangential velocity and learn about how acceleration and centripetal force affect an object.

In this fun science fair project, make two different scale models of our solar system using Astronomical Units and planets' relative size!

This simple heat transfer experiment is a great introduction to the concepts of heat transfer and conduction.

Have you ever noticed the way a dropped stone makes a fun pattern in a pond or lake? What's the science behind these splashy occurrences?

Are you ready to be a detective for science? Then get out your magnifying glass and start studying fingerprints!

Learn about the role of Earth's rotation on the Coriolis Effect and hurricanes in this science project. Model the Coriolis Effect on a hurricane's direction.

Use chemical analysis to identify a variety of mystery powders that look the same but actually have very different properties.

Is it possible to trick the forces of nature that make your bubbles round to create a square bubble?

How does distance affect the spreading of light? Kids see diffraction and the inverse square law of light in action with this great science fair project idea.