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.

This tutorial explains some of the techniques developed by astronomers to determine the distances of objects we see in the sky. Links to additional information are embedded in the text.

This site presents graphic plots of solar wind and magnetic field data from the Advanced Composition Explorer (ACE) spacecraft.

This site presents information about the Advanced Composition Explorer (ACE) spacecraft and its mission, science goals, history, and background. The mission summary includes a brief description of the energetic particles from the sun and from interstellar and galactic sources that are the objectives of the ACE mission. Links to additional information are also supplied.

This is the homepage of the American Geological Institute (AGI). Visitors can access information about geoscience education, public policy, environmental geoscience, careers in geoscience, publications, news articles, and events. Materials presented here include databases, curriculum materials, legislation and appropriations information, and an image bank.

This lithograph provides a full-disk view of Earth photographed by Apollo 17 astronauts, Dec. 7, 1972. The accompanying text describes the view seen in the photograph and the circumstances in which it was taken. Suggestions for activities in which the photograph can be used are also provided.

These views of asteroids were imaged at close range by the Galileo and Near Earth Asteroid Rendezvous (NEAR) spacecraft. They are presented at the same scale, and images of Mars' moons, Phobos and Deimos, and Ida's moon Dactyl are also shown. The accompanying text provides a description of the images, some historical facts and statistical data, along with significant dates in asteroid exploration.

This training module was designed to help the user identify and grasp basic concepts associated with space travel and deep space missions. Separate sections deal with topics such as the physical environment of space (solar system, gravity, orbital mechanics), flight projects (mission concepts, system requirements, design, onboard systems and instruments), and flight operations (launch, cruise, encounter). Links to related topics are embedded in the text.

Wilson Alwyn Bentley (1865-1931), famous for his photomicrographs of snow crystals, prepared sets of glass lantern slides of dew, frost and ice crystals. He obtained thousands of photomicrographs of individual ice crystals over the course of his lifetime. Images in this collection are scanned from glass lantern slides. Most snow crystals found in nature will fit into one of these seven main categories: plates, stellar crystals, columns, needles, spatial dendrites, capped columns, and irregular forms. Because there are many variations within these categories which are not separately identified by the International Snow Classification the Bentley project uses the Magono and Lee (1966) snow crystal classification scheme. Each crystal is classified and searchable according to this scheme.

This collection of images, movies, and animations from NASA's Solar and Heliospheric Observatory (SOHO) features a large selection of images of the sun and of solar phenomena. Although most of the imagery is of the sun, a few images of comets and planets as they transit the solar disk are available.

This activity has students create a Cartesian diver, which will act in some ways like a submarine. Students will adjust the amount of air and water in an inverted test tube (the "diver") so that it at first barely floats in a water-filled bottle. Then, they will squeeze the closed bottle to create higher water pressure, causing the diver to sink. Releasing the bottle allows the diver to float again. Written instructions, a list of materials, and illustrations are included.

This site, originally published as part of NASA's History Series, presents a detailed history of the Apollo program. The story begins in the 1950s with early efforts to beat the Soviet Union into space, carries through the Kennedy administration, with its famous challenge to land a man on the moon and return him safely to Earth by the end of the 1960s, and culminates with the landing of Apollo 11 on the Moon in July 1969. The site features text, pictures, references, and several appendices containing more detailed information.

This resource offers access to a variety of materials, including general information about COOL, a photo gallery, press releases, talks and papers, and research projects. There are links to archived and real-time ocean data (sea surface temperature, surface currents and waves, autonomous glider data), and an "underwater weather forecast".

This poster shows images of comets Hale-Bopp and Shoemaker-Levy 9. The accompanying text describes possible source regions for comets in our solar system, the behavior of comets as they approach the Sun, their possible role in the evolution of Earth, and significant dates in the study of comets.

You can use this calculator to create your own metaphor for geologic time. The history of the could be the the distance from your home to school - you can figure out where dinosaurs would be on the trip. Or the history of time could be the length of a class - and you could figure how much of the class you have to sit through before intelligence appears.

At this site, users can access and compare data from a large selection of spacecraft, instruments, and ground-based facilities. Most data is related to studies of solar wind, other particle emissions, and Earth's magnetic field.

This site explains how core samples are taken from the ocean floor. Topics include how research cruises are planned, who makes up the crew of a research vessel, and what a cruise track is. Links to additional information are embedded in the text.

Sand covers only about 20 percent of the Earth's deserts. Nearly 50 percent of desert surfaces are gravel plains where removal of fine-grained material by the wind has exposed loose gravel and occasional cobbles. This web page, produced by the U.S. Geological Survey, features text and photographs that describe desert landforms, soils, plants, and the role of water in the formation of desert landscapes.

Desertification, the degradation of formerly productive land into desert, is a complex process. It involves multiple causes, and it proceeds at varying rates in different climates. This web page, produced by the U.S. Geological Survey, features text and photographs that explain what desertification is, how human activities may contribute to it, how satellite imagery is used for monitoring vulnerable areas, and how its effects may be mitigated by improved agricultural and land management practices.

This page is part of NASA's website "From Stargazers to Starships". It discusses the evolution of scientific thought concerning the nature of the solar system, beginning with the earth-centered solar system advocated by Hipparchus and Ptolemy. Ptolemy's idea that the sun and planets moved around the Earth persisted for nearly a thousand years until Copernicus and Galileo, using his newly-invented telescope, began to understand that the Earth and its companion planets all orbited in around the sun. The site features text, pictures, a scientific illustration showing retrograde motion, and links to other relevant sites.

This online collaborative project is part of the Center for Improved Engineering and Science Education (CIESE) program, which has developed internet activities for the elementary, middle, and high school level student. Based on data collected by their household members and their classmates, students determine the average amount of water used by one person in a day. They compare this to the average amount of water used per person per day in other parts of the world. The project provides instructions, information, reference materials, online help, and a teacher area for help and ideas.

This lithograph depicts a view of Earth taken from Apollo 10 during its journey to the Moon in May 1969. False-color satellite images showing chlorophyll concentration, sea surface temperature, topography, and ozone concentration are also featured. The images are accompanied by a brief description, some statistical facts, and a list of important dates in the history of Earth exploration.

Visitors can use sea surface temperature data to build animations that show seasonal and yearly fluctuations, and compare them to data from other selected months and years. The animations can be constructed in map or globe formats and may be viewed on the website or downloaded.

This site provides a brief description of the Dustbowl in the American Great Plains during the 1930s and relates its effects to what is occurring presently in the Sahel of North Africa. In this dry savannah environment, human activity coupled with prolonged drought are causing desertification. The site features text, satellite imagery, and links to other related materials.

EarthComm (Earth System Science in the Community) is an Earth science curriculum designed for use by all students in U.S. high schools. This website contains resources for teachers, students, and parents, as well as information on the goals and learning approaches EarthComm uses. In addition to the general resources offered, state-based resources are also available.

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.

This online magazine features articles on astronomy and environmental issues. Users can access sky charts for viewing celestial objects, weather reports for viewing conditions, or sign up for email lists to stay informed of upcoming celestial events.

This page consists of two maps of the world, showing how earthquakes define the boundaries of tectonic plates. Volcanoes are also distributed at plate boundaries (the "Ring of Fire" in the Pacific) and at oceanic ridges. It is part of the U.S. Geological Survey's Cascades Volcano Observatory website, which features written material, images, maps, and links to related topics.

This section of the Windows to the Universe website provides information and images about Earth's magnetic field (the magnetosphere), including detailed information about the aurora borealis, magnets, and solar wind. Windows to the Universe is a user-friendly learning system pertaining to the Earth and Space sciences. The objective of this project is to develop an innovative and engaging website that includes a rich array of documents, including images, movies, animations, and data sets that explore the Earth and Space sciences and the historical and cultural ties between science, exploration and the human experience. Links at the top of each page allow users to navigate between beginner, intermediate and advanced levels.

Materials presented here describe how new data from surveys, satellite imagery, and buoys have led to a revised view of the nature of the coastal upwelling that occurs seasonally off the coast of California. Includes references and links to related sites.

This webpage is part of NASA's Classroom of the Future program. It provides background information about how ocean temperatures, currents, and atmospheric conditions combine to produce an El Nino event. The site features text, scientific illustrations, a glossary, and links to other Classroom of the Future pages.

This site, part of NASA's Classroom of the Future program, describes how oceanic temperatures, currents, and atmospheric pressure patterns vary and, under certain conditions, produce an ENSO (El Nino Southern Oscillation) event. It features text, scientific illustrations, a glossary, teacher pages, and a list of references.

Users can select a variety of materials on El Nino/La Nina. Materials presented here include bibliographies, news articles, technical and research information, movies, animations, and cartoons.

This tutorial introduces students to the concepts of electromagnetic waves, wavelength, and the electromagnetic spectrum. Diagrams and written descriptions explain how wavelength is measured and explore the traditional divisions of the spectrum: radio, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.

This site offers informative sections on air and climate, land, water, ecosystems, energy, food, and environment and society. A teachers section provides online resources for the classroom, including background information, scientific research and data, lesson plans, labs, and activities. A student section provides homework help and a Weird and Wonderful page with strange creatures of the universe.

Gases have various observable properties, such as pressure (p), temperature (T), mass (m), and volume (V). Careful scientific observation has determined that these variables are related to one another, and the values of these properties determine the state of the gas. Users can read an explanation of the three laws (Boyle's Law, Charles' Law, and Gay-Lussac's Law) that describe the properties of gases and observe how gases behave under changing conditions.

As part of this activity, students learn about geologic processes on Earth in order to interpret surface features recently seen on Europa by NASA's Galileo spacecraft. Materials presented here include a vocabulary list, geology jigsaw puzzle, review questions, and links to related sites.

Visitors can see online versions of some exhibits from the Exploratorium. These exhibits involve optical illusions of color, space and perception. Spanish, French, and Italian translations are available.

This museum exhibit allows visitors to examine how medical imagery has changed the way we look at our bodies. Exhibits include modern medical imaging, art and artifacts, and historic medical illustrations and models.

Visitors can explore the scientific principles behind popular sports such as baseball, skateboarding, surfing, and bicycling.