This article discusses the importance of water in supporting and sustaining life and focuses on why water, and solely in its liquid form, is so essential. The focus here is on the potential presence of water on Mars. Some of the physical and chemical properties of water are summarized, and their uniqueness is presented as the reason planetary scientists are on the lookout for water on Mars and elsewhere ... Full description.

Researchers have identified approximately 140 individual impact craters on Earth. These craters probably represent only about 25 percent of those to be found. Assuming an equal rate of impact around the globe, many more craters remain to be discovered, particularly in remote land regions of our planet and in the oceans. This activity uses satellite images of several craters on the earth to study impact ... Full description.

This library features teacher-tested, standards-based engineering content for K-12 teachers to use in science and math classrooms. Engineering lessons connect real-world experiences with curricular content already taught in K-12 classrooms. The collection is searchable by keyword, grade level, or educational standard, and can be browsed by subject area, curricular unit, lessons or activities. Full description.

Users can read about the discovery of ice on Earth's moon, which occurs in the form of ice crystals accumulated near the lunar poles. The discussion covers the use of the neutron spectrometer as a tool for detecting water by sensing the hydrogen it contains, some ideas on the origin of the ice, and the fact that water has been found elsewhere in the solar system (on Europa, Jupiter's fourth-largest ... Full description.

This article describes the ongoing research on the possible presence of water on Jupiter's moon Europa. It includes satellite images of Europa, scientific illustrations, and extensive text. It also discusses similar research being done on Lake Vostok in Antarctica. It also offers a variety of related links. Full description.

In this activity, students download NASA Hubble Space Telescope (HST) images of the Martian polar ice caps in summer and winter. Using image processing techniques, students measure and compare various images of the changing Martian and Earth polar ice caps. By completing this activity, they will understand that the sizes of the polar ice caps on Earth and Mars depend on the lengths of the seasons. ... Full description.

Surf Your Watershed is a service to help you locate, use, and share environmental information about your state and watershed. There are four components to the site. Clickable maps, zipcode look-ups and plance name searches provide access to local watershed information. A searchable database offers information on the Adopt a Watershed campaign, a project that challenges citizens and organizations to ... Full description.