Learn how to tell time by the sun with this cool science fair project idea that tracks how the accuracy of a sundial changes over time.

This science fair project idea researches the different layers of the atmosphere and creates a visual representation of the atmospheric layers.

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!

The apparent movement of the sun has been used to keep time since the bronze age. In this science fair project, kids plot solar time against mean solar time.

This science fair project idea recreates the movement of planetary bodies in order to learn why they sometimes appear to move backwards.

What is a barycenter? Kids learn how gravity and mass influence the orbit of binary systems like planets and moons or stars and planets in this cool experiment.

How does water pressure change with depth? Kids learn how pressure works underwater with this cool and easy demo.

Science fair project that determines how UV radiation emitted by the sun varies depending on the time of day, using a handheld UV detector

Compare air temperature with the infrared temperature from a reflecting surface at different times of the day, in shade and in sunlight.

The objective of this science project is to determine the relationship between carbon dioxide gas and the temperature of the atmosphere.

This science fair project idea investigates whether rocks containing geodes can be determined from the outside.

Here's a simple science activity that will help your child better understand how wells bring us water.

Do heavier objects fall faster than lighter ones? Students learn the answer by watching the effect gravity in a vacuum has on a coin and a feather.

How do organic materials become soil? This science experiment measures what materials biodegrade.

Learn about the greenhouse effect- and get great science fair experiment ideas. Read more.

The Galileo inclined plane physics experiment was one of the first ways scientists calculated acceleration due to gravity. Do it yourself in this project!

This science fair project idea explores what it takes to create a biosphere, or a self-sustaining ecosystem.

Science fair project which compares the rate of temperature change and the maximum temperature as a result of the angle of light radiation.

In this experiment you explore how tectonic plates move to create land and expand bodies of water.

Develop a new system for predicting geographic changes. Demonstrate the nature of geographic change. Make logical predictions.

In this cool science experiment, learn about magnetism and poles, and test magnet strength to find out if two magnets are twice as strong as one.

In this experiment, students find out what happens when a less-dense fluid interacts with a denser one, replicating the effect of cooler solid rock on magma.

Explore the craters, maria, and highlands on the surface of the Moon! In this fun science project you'll create a 3-D model of the moon using paper mache.

In this experiment, you'll make a seafloor spreading model to learn more about how plate tectonics work and create mid-ocean ridges.

Check out this free high school science fair project to explore the physics of the Coriolis effect with a homemade Foucault Pendulum.

The objective of this free science fair project is to examine the way in which the phases of the moon affect circadian patterns in mammals.

In this experiment you will use plastic and magnets to test your local soil composition.

Consult astronomers for opinions and advice. Devise a mathematical argument regarding the probability of other planets supporting extra-terrestrial life.

The project investigates how water and movement affects erosion.

Explore this fun science fair project idea to investigate different microclimates in and around your home and their effects on the plant and animal life.