Online in 2009, the Aquarius instrument will measure sea surface salinity. Site provides background information about salinity, salinity lesson plans, and salinity data and tools. Activities include relating salt to...

This portal provides links to a variety of information on the United States Geological Survey (USGS). There is a brief overview of the USGS mission and vision, links to news articles and press releases, and a link to...

This resource covers general features of asteroids; the asteroid belt; Kirkwood gaps; the spacecraft Galileo flying by the asteroid Gaspra; the asteroid Ida and its moon Dactyl; the spin of the asteroid Toutatis; and...

This site provides useful interactive tools for teaching astronomy and space science. It includes an Earth and Moon viewer where users can set the time and a variety of points to view the Earth and Moon. Orbits in...

This is an archive of questions and answers about Mars. It is divided into Beginner, Intermediate, and Advanced categories and covers such topics as the possibility of life on Mars, Martian atmosphere and geography, and...