This site allows users to browse through a library of JPEG images of the various space missions. The images are grouped under several categories: Human Exploration, the Apollo Program, Robotic Exploration, and General images (launches, landings, satellites). Full description.

This portal provides an extensive set of links to information on solar and lunar eclipses, planetary transits, solar system data, moon phases, and related resources. Information on recent and upcoming eclipses and other celestial events is also included. Full description.

This educational brief provides an overview of the concepts of radioactivity, basic particle physics, and the use of radioactive decay as a mechanism to date our galaxy. Full description.

This document provides an overview of the TOPEX/Poseidon spacecraft and mission. Topics include a description of the satellite and its instruments, the cooperative effort of the joint U. S. - French mission, and how TOPEX/Poseidon performs its measurements. Illustrations of the spacecraft and a link to additional information are also provided. Full description.

This illustration of Earth's sea surface temperature was obtained from two weeks of infrared observations by the Advanced Very High Resolution Radiometer (AVHRR), an instrument on board NOAA-7, during July 1984. Temperatures are color coded with red being warmest and decreasing through oranges, yellows, greens, and blues. The caption provides a brief description of the features seen in the image. Full description.

This educational brief provides an overview of the layers of the atmosphere, the effects of the solar wind upon them, and how these effects are mitigated by Earth's magnetic field. It also describes OMNIWeb, an internet-based data retrieval interface for obtaining datasets on solar energetic particles. Full description.

This educational brief explains the idea that nuclear fusion is thought to be the mechanism by which virtually all of the elements around us are created. Topics include the proton-proton cycle, the carbon-nitrogen-oxygen cycle, and endothermic reactions in supernova explosions. There is also a discussion of the Advanced Composition Explorer (ACE), a spacecraft intended to study the origin and evolution ... Full description.

This educational brief provides an overview of the types of solar activity and their potential effects on Earth, along with brief descriptions of some spacecraft and instruments that are used to study solar acvtivity. Links to a glossary and to additional information are included. Full description.

This educational brief describes the structure of Earth's magnetosphere, how it interacts with energetic particles emitted by the sun, and how it protects Earth from the effects of these particles. Short descriptions of NASA missions to study the magnetosphere, solar wind, and other particle emissions are included. Full description.

This educational brief provides an overview of solar activity, including a description of Earth's magnetosphere and of various solar phenomena such as the solar wind, Coronal Mass Ejections (CMEs), sunspots, solar flares, and others. A list of links to additional material is also provided. Full description.