This NASA Image of the Day is the first image of the Earth and moon in a single photograph. The image was captured 7.25 million miles from Earth by Voyager 1 in 1977. More information about the photograph and a link to...

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,...

This collection of astronomy lesson plans and experiments from across the internet was developed by Reach Out, a center linking University of Michigan and community mentors with children and teens. Topics covered include...

An algebra-based overview of elementary and pre-telescope astronomy. Topics covered include sundials, seasons, calendars, precession, shape and rotation of Earth, Greek astronomy, the path to heliocentric theory and...

Created by author Nick Strobel, "Astronomy Notes" is an educational resource for introductory astronomy classes for undergraduates. This section describes: the celestial sphere, coordinate systems, the motion of the...