This movie shows Venus and Earth as they rotate. The images are superimposed on each other so that differences in rotation speed and tilt of axes can be seen. Links to documents describing the physical properties and characteristics of the two planets are provided. Full description.

This biographical index provides short descriptions of the lives and achievements of prominent astronomers, physicists, mathematicians, and other persons who have made contributions to astronomy. Links to related persons and topics are embedded in the text. Full description.

This movie brings attention to humanity's fascination with the Sun, and how it has been viewed by various civilizations in the past. A link is provided to a document that describes the Sun's physical characteristics and properties. Full description.

This movie shows a total eclipse of the Sun which occurred in 1994. It is accompanied by a link to a written description of the Sun's physical characteristics. Full description.

This animation depicts the formation of the solar system from a solar nebula, a great swirling cloud of gas and dust. It is accompanied by a link to a written description explaining the solar system's formation in greater detail. Full description.

This animation showing Neptune as it rotates was imaged by the spacecraft Voyager. A link is provided to a written document that describes the physical characteristics and appearance of the planet. Full description.

Students who wish to ask a question about the TOPEX/Poseidon satellite or mission may submit their name, email address, and a question by using this online form. Full description.

Visitors to this site will learn about NASA's manned and unmanned explorations of the Moon and Mars. Topics include the history of the Apollo program, robotic missions to Mars, and future visions for space exploration. The document "Vision for Space Eploration," which describes a timeline and major realignment of NASA's resources and efforts for manned and unmanned missions to the Moon and elsewhere, ... Full description.

The homepage of the Visitor Center at Goddard Space Flight Center provides access to a variety of information about the history, missions, and upcoming events at the center. Users can find information on public exhibits, educational resources, and programs on space and Earth science and technology. Full description.

In this activity, the teacher will construct a "comet" from ingredients that closely resemble the substances which make up a real comet. A list of ingredients, materials, and instructions are provided. Students can watch the comet as it melts, releasing jets of carbon dioxide and becoming pitted with craters in much the same way as a real one. Full description.