This Eight Planets site briefly describes solar wind, a low density stream of charged particles emitted by the Sun. It also provides the basics on the sun's composition and additional sun links.

Empty space in outer space is not truly empty. Celestial objects fill the space not occupied by planets, stars, and such. This resource identifies these objects and further explains their existence.

A brief biography of American astronomer and science advocate Carl Sagan.

Celestial navigation is the art and science of finding one's geographic position by means of astronomical observations, particularly by measuring altitudes of celestial objects - sun, moon, planets or stars. This activity starts with a...

Figure out your age and your weight on all the planets in the solar system using the formulas given here. Then type them into the correct place, and let the computer check to see if you are correct.

A general introduction to Mars. Includes a glossary of terms and two images of Mars. Many interspersed links to more graphics and more detailed information about the planet Mars. Also includes a printable version and links to other...

An article explaining how the Greeks were able to use their science and mathematics to predict where astronomical objects such as the Planets could be found in the nighttime sky even though their underlying premise was that the earth did...

When we look at the night sky, we see stars and the nearby planets of our own solar system. Many of those stars are actually distant galaxies and glowing clouds of dust and gases called nebulae. The universe is an immense space with...

This site provides a free space simulation that lets you explore the universe in three dimensions. There is a forum for teachers and lesson plans that help enhance student use of the simulation. A program must be downloaded in order to...

This image, titled "Is There Anybody Home?" features six fuzzy pictures depicting six stars associated with known planets. The text under the image details various specifics about the picture and the planetary system associated with the...

See if you can identify the positions of the 9 planets in our solar system. Take an online quiz and get feedback on your answers.

Kids learn about astronomy, the study of outer space including the stars, planets, comets, black holes, and the Solar System. History and astronomers in this astronomy for teachers and kids section.

Everything in our universe has mass- from the smallest atom to the largest star. But the amount of mass has remained constant throughout existence even during the birth and death of stars, planets and you. How can the universe grow while...

While astronomers and philosophers have long mused on the possibility of other solar systems, the first planets confirmed to orbit a star other than our Sun weren't found until 1992. The reason it took so long is that it's really hard!...