Students in this lesson will be introduced to the concept of tides and tidal forces. By viewing a related applet which visualizes the relationship between the Earth, moon and tides, students will gain an understanding of why the Earth experiences tides. In the process they are asked to observe and explain how the relative positions of Earth, the moon, and the sun are responsible for the moon phases, ... Full description.

This site provides a discussion of the downward movement, or infiltration, of water from the surface into soil or porous rock. Graphics illustrate the processes affecting infiltration, including precipitation, soil characteristics and saturation, land cover, slope, and evapotranspiration. Links to additional sources of information are also provided. Full description.

NeMO studies the dynamic interactions between submarine volcanic activity and seafloor hotsprings at an observatory called Axial Seamount. The research activities at NeMO provide an extraordinary educational opportunity, both from the daily reports from expeditions at sea and from creative learning materials based on NeMO results. The site features curriculum materials designed for high school and ... Full description.

This booklet provides a brief introduction to the concept of plate tectonics and complements the visual and written information in This Dynamic Planet, a map published in 1994 by the U.S. Geological Survey (USGS) and the Smithsonian Institution. The booklet highlights some of the people and discoveries that advanced the development of the theory and traces its progress since its proposal. Although ... Full description.

This information is designed to belie the misconception that the capacity of air to hold water vapor is temperature dependent and that air can become saturated with water vapor. The temperature of a cloud droplet or ice crystal will be nearly the same as that of the air, so people imagine that somehow the air was to blame. But, if the other gases of the air were removed, leaving everything else the ... Full description.

This site provides an overview of the Earth's atmospheric greenhouse effect by briefly exploring the atmospheres of nearby planets and discussing the greenhouse gases of our atmosphere, such as, water vapor, carbon dioxide, methane, ozone, and nitrous oxide. Students will learn that the heat-trapping ability of a greenhouse is influenced by a number of factors, including the transparency of the greenhouse ... Full description.

This site gives students an opportunity to explore storm clouds and climate change through the use of National Aeronautic and Space Administration (NASA) climate research data obtained through satellite imaging. The challenge is to investigate actual scientific research data on clouds and storms, and make the resulting observations and interpretations available to NASA research scientists for review. ... Full description.

These science bulletins from the American Museum of Natural History feature news on space science, astronomy, and astrophysics topics with in-depth feature stories about cutting-edge developments, weekly images from observatories around the world and in space, and and 'Astro Viz', a visualization of astronomical or astrophysical phenomena. Each story features a link to an educators' guide and links ... Full description.

This activity explores the potential for climate variability and change to trigger more frequent occurrences of El Nino, and the impacts that could result. Designed to teach through scientific inquiry, the activity seeks to stimulate thought about the long-term impacts of a warmer planet. Through their participation in this activity, students will access information at remote sites using telecommunications, ... Full description.

The materials presented here highlight the fact that Earth's supply of water is finite and is constantly recycled. We depend on water for drinking, washing, recreation, agriculture and industry. It controls the world's weather and sustains the natural systems above and below the earth's surface. Users can examine an illustration that shows the role played by groundwater in the hydrologic cycle and ... Full description.