The earth's diameter is 12,756.3 km and its revolution period is 1 year. You probably knew the last fact, but most likely not the first. The Web site Absolutely Astronomy can provide this and a large amount of other facts about planets, moons, stars, constellations, messier objects, nebulas, and galaxies. Visitors can browse via the pull-down menus or search by a particular question. The basic...

"The Schoolyard Solar System was developed to demonstrate the solar system to scale; to show the relationship between units of thousands, millions, and billions; and to accomplish these goals with student involvement that will re-enforce the lessons." Students and educators can find images of the Sun and the nine planets in our solar system. The website presents bulk, orbital, and observational...

Space scientists postulate that the planets of our solar system arose from solar nebulae approximately 4.6 billion years ago. This July, NASA's Jet Propulsion Lab launched a new mission, Genesis, to investigate the transition from solar nebulae to planets by collecting and analyzing the isotopic composition of solar particles. You can learn more about the Genesis mission at its official Website....

Solvarviews.com is a private Web site maintained by scientist Calvin J. Hamilton, whose goal is to make high quality photographs of the planets and satellites available to the public on the Web. The Lesson Plans and Activities page of the site provides more than a dozen classroom activities with titles such as Comets, Convection, Impact Craters, Meteoroids and Space Debris, Eclipses, Life in the...