--Astronomy for kids (online resources about solar system, photos from space, mythology about constellations, and more...)
-Harvard/Smithsonian Center for Astrophysics
-Mars: Is there evidence of life?
-NASA for Educators
-NASA: solar system
-National Air and Space Museum
(online exhibit of the universe, planets and technology)
-Nine planets? Or Eight?
-NOVA Space videos, simulations, and more