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...

The Exploratorium in San Francisco has offered up this rather fun and interesting activity which gives interested parties the information to build their own scale model of the solar system. Visitors can start by filling...

This pair of web pages, authored and curated by David P. Stern, describes early calculations of the Earth-Moon distance by Greek astronomers. Using lunar and solar eclipses, the astronomers Aristarchus and Hipparchus...

Created by David P. Stern, this set of three web pages provides a calculation of paths, times, and distances for a flight to Mars and back. The author uses a Hohmann transfer ellipse between two circular orbits. This is...

Stars live for a very long time compared to human lifetimes. Your great, great grandparents saw the same stars as you will see tonight (if it's clear). Our lifetimes are measured in years. Star lifetimes are measured in...