Nicolaus Copernicus developed the theory of Earth's orbit around the sun demonstrated in this science simulation.

A discussion and statement of an equation for orbital speed. An interactive JavaScript form allows the user to investigate the relationship between orbital height and orbital speed. A very good opportunity to practice and receive...

[Free Registration/Login Required] An interactive animation demonstrating the Earth's tilted axis and how that causes the seasons. Also included on the site is a short quiz on the topic.

The BBC provides a general overview of the planet Earth. Content includes statistical information, a focus on the four seasons, moon information, and more.

Experience a science simulation illustrating the Copernican theory of Earth's orbit around the sun.

The Swiss Propulsion Laboratory is a non-profit organization whose primary goal is the development of means of lifting civilian payloads into low-earth orbit at reasonable prices.

Why do some regions experience full-time heat while others are reckoning with frigid temperatures and snow? And why are the seasons reversed in the two hemispheres? Rebecca Kaplan explains how the shape of the Earth's orbit around the...

A video and a short multiple-choice quiz on how the Earth's tilt on its axis, its rotation, and its orbit around the Sun give us a 24-hour day, a 365-day year, and our seasons.

Move the sun, earth, moon, and space station to see how it affects their gravitational forces and orbital paths. Visualize the sizes and distances between different heavenly bodies, and turn off gravity to see what would happen without it.

Experience a simulation of ballistic trajectories in relationship to Earth's orbit. Java 1.5 or more recent is required.

Facts about the Earth including its orbit, its atmosphere, and its landforms. Includes a discussion question on seasons, with facts about them, and the answer. A linked page covers similar material in a "Level 2" version, and has a...

Help Sarah Jane and her team put the solar system's planets back in order. Following the activity, read more about the sun, the Earth, and its moon, and then take a quick quiz to check for understanding.

[Free Registration/Login may be required to access all resource tools.] Orbital motion and why it occurs, and the orbits of the Earth around the sun and the moon around the Earth.

[Free Registration/Login may be required to access all resource tools.] Looks at the size and shape of planet orbits.

[Free Registration/Login may be required to access all resource tools.] Examines the eight planets of our solar system and their orbits and rotation.

[Free Registration/Login may be required to access all resource tools.] Examines the eight planets of our solar system, their orbits, and rotation.

[Free Registration/Login may be required to access all resource tools.] How objects in the solar system orbit around each other.

[Free Registration/Login may be required to access all resource tools.] How objects in the solar system orbit around each other.

A slideshow exploring Earth's rotation and revolution around the sun. Learn that because of Earth's axis tilt we experience the seasons!

Picture of the Earth with an astronaut flying around in orbit.

This resource provides information about Earth and space. In addition, there is a quiz provided.

Nutation is a small cyclical motion superimposed upon the steady 26,000-year precession of the Earth's axis of rotation. It is mainly caused by the gravitational effect of the 18.6-year rotation period of the Moon's orbit. The main...

Eight hands-on lessons module in which students explore the characteristics of planet Earth, its moons, the sun, the solar system, planets, and the difference between science fact and science fiction.

A university-level course that looks at the structure of the solar system, the sun, the planets, and other bodies in space. Includes course readings, assignments, and study notes.