The Sun, the Moon, the planets, and the stars all rise in the east and set in the west. And that's because Earth spins -- toward the east. For a moment, let us ignore Earth's orbit around the …

The Sun (and, of course, the rest of our solar system) is located near the Orion arm, between two major arms (Perseus and Sagittarius). The diameter of the Milky Way is about 100,000 light …

(This may be easier to see if you set up two balls (using a light as the Sun) and make a model of the situation; place yourself on the Moon ball and you'll see what the Earth then looks like at …

How does this happen? Long ago, people believed many weird things about the Sun and how it traveled across the sky. The ancient Greeks believed that the Sun rode across the sky in a …

The Sun does not "burn", like we think of logs in a fire or paper burning. The Sun glows because it is a very big ball of gas, and a process called nuclear fusion is taking place in its core. Nuclear …

Mercury is only about one-third the size of the Earth. It is smaller than any other planet. Mercury is very close to the Sun and has no substantial atmosphere. These factors contribute to the fact …

The lamp represents the Sun while the orange represents the Moon and the volunteer represents the Earth. Only the volunteer can see the intended results of this demonstration, so each …

An asteroid is a bit of rock. It can be thought of as what was "left over" after the Sun and all the planets were formed. Most of the asteroids in our solar system can be found orbiting the Sun …

Note that this method of determining distances is based on observation (the shift in the spectrum) and on a theory (Hubble's Law). If the theory is not correct, the distances determined in this …

The Milky Way is over 100,000 light-years wide. It is called a spiral galaxy because it has long arms which spin around like a giant pinwheel. Our Sun is a star in one of the arms. When you …