Environment Canada illustrates our everyday impact on the environment through "An Environmental Citizen... Who Me?" at
www.ns.ec.gc.ca/udo/who.html

As a starting point for information on the solar system from the National Aeronautics and Space Administration:
www.nasa.gov/topics/solarsystem/index.html

National Space Sciences Data Center (NSSDC) planetary home page
nssdc.gsfc.nasa.gov/planetary/planetary_home.html

Photos of planets and moons from many missions (Apollo, Mariner, Voyager, Galileo, and more)
http://nssdc.gsfc.nasa.gov/photo_gallery/

For the "Astronomy Picture of the Day," with a discussion of the feature shown and links to related information:
http://antwrp.gsfc.nasa.gov/apod/astropix.html

A related site features the "Earth Science Picture of the Day":
epod.usra.edu

A wide selection of earth images and animations is accessible at
visibleearth.nasa.gov

An online geology/paleontology museum offers information on the history of life and geology, at the University of California at Berkeley Museum of Paleontology site:
www.ucmp.berkeley.edu

The Vertebrate Paleontology Lab at the University of California at Davis hosts an online 3D fossil museum at which you can manipulate the fossil images
3dmuseum.org/

and for 3D views of geology in the national parks, see
3dparks.wr.usgs.gov/

The Population Reference Bureau provides a variety of population information:
www.prb.org

Additional world population information: United Nations Population Information Network (POPIN)
www.un.org/popin/

Frequently Requested Population Tables (U.S. Census),includes demographic information
www.census.gov/stat_abstract/pop.html

General resource/population/environmental information: World Resources Institute home page
www.wri.org

Excellent satellite images of a variety of environmental developments are available as "Earthshots" presented by the U.S. Geological Survey:
edcwww.cr.usgs.gov/earthshots/slow/tableofcontentstext

NASA's Earthobservatory site features "Images of the Day" taken from space (some of which appear in this text!)
earthobservatory.nasa.gov/Newsroom/NewImages/images_index.php3

"Ask-A-Geologist" e-mail service: U.S. Geological Survey staff and others answer geologic questions
walrus.wr.usgs.gov/ask-a-geologist/

The USGS also maintains links to resources for K-12 educationat "The Learning Web":
www.usgs.gov/education/

The Smithsonian Institution's National Museum of Natural History has been going online with its geology exhibits
www.mnh.si.edu/earth