This unit introduces students to some general concepts of astronomy. Topics include geocentric versus heliocentric theories of the solar system and how they explain the sun's movements, sidereal days versus solar days,...

This collection of animations introduces students to planetary motions, gravitational effects, and the scale of astronomical distances. Students can view visualizations of Earth's changing seasons, circumpolar motion,...

How does the sun determine the Earth's seasons? This is the question that the National Geographic Education site seeks to answer with a lively 35-minute activity designed for students between the ages of seven and eleven...

How does a meteorologist or other such individual predict seasonal weather? That question forms the basis for this special report from the National Science Foundation. The interactive report starts by offering an...

This applet simulates what happens inside a house when the temperature and dew point change outside. The user of this applet has control over the outdoor values of the two thermometers (one for temperature and one for...