This classic image of Earth was taken by the Apollo 17 astronauts as they traveled to the moon. (Image Credit: NASA)

On Dec. 7, 1972, the crew of the Apollo 17 spacecraft snapped a photograph that forever changed the way people see Earth. "The Blue Marble," as the picture is known, was the first image to show an entire face of the world in stunning true color. The photograph sparked a renewed desire to learn more about our home planet.

In the decades since, our understanding of Earth has evolved. Once viewed as separate and largely independent of each other, the planet's main components – air, land, water and life – are now seen as a system of interconnected and constantly interacting parts.

To ensure that future scientists possess the perspective necessary to better understand Earth and tackle complex environmental problems, the Earth System Science Education Alliance (ESSEA) is training geoscience teachers in the systems approach to Earth science. ESSEA offers a series of online Earth system science courses, each geared toward teachers within the K-12 range.

ESSEA participants earn undergraduate or graduate credit while learning to teach Earth system science using inquiry-based classroom methods. The semester-long courses are offered through a network of educational institutions across the country. Almost 40 institutions are engaged in ESSEA by offering the courses, providing resources to the network, and helping to develop new modules for the courses.

Learning modules used in the courses are available to anyone through the ESSEA Web site. Each module starts with a scenario (text and images) that sets the stage for investigation of an Earth science topic. Sample investigations are provided for varying grade levels, as are links to related resources and a listing of national science education standards addressed by the module.

"The uniqueness of the ESSEA Web site is that even before enrolling in the courses, teachers can avail themselves of the modules and put them to immediate classroom use," said the Institute of Global Environment and Strategies' Bob Myers, principal investigator for ESSEA. "The modules allow students to take a critical look at potential threats to Earth's health and to grow in the critical thinking skills needed to become environmentally literate citizens."

With NASA funding, the K-4 course and modules have been revised to include topics and resources related to the International Polar Year, a coordinated effort by the international science and education communities to learn more about the polar regions and how they impact the rest of the world.

ESSEA courses and modules emphasize that Earth is a system of interconnected parts. (Image Credit: Institute for Global Environmental Strategies)

In each of the K-4 modules – "Air," "Land," "Living Things" and "Water" – a list of essential questions guide teachers and students as they explore a different part of the Earth system from both a general and polar perspective. Sample investigations range from building edible models of the Arctic to constructing polar terrariums.

ESSEA also offers a course specifically targeting informal educators. A recent survey of informal Earth science venues showed that the typical museum or science center has only one staff person with an Earth science-related degree, and about 30 percent have none.

"Science centers, museums, aquaria, zoos and the like are excellent educational resources for promoting inquiry-based learning experiences in Earth system science," said Carlyn Buckler, an education associate at the Paleontological Research Institution and Museum of the Earth in Ithaca, N.Y. Buckler is helping to develop ESSEA modules for informal educators.

"By providing this professional development and introducing informal venues to the ESSEA program, we hope not only to improve the quality of informal Earth system science education throughout the U.S., but also bring informal organizations into the fold of bringing quality professional development via ESSEA to their local formal educators," Buckler added.

ESSEA is an initiative of the Institute for Global Environmental Strategies, funded by the National Science Foundation. The NSF-supported program builds and expands on the original ESSEA program funded by NASA and administered by IGES from 2000 to 2005.

Course offerings, modules and additional information are available here.