How Do Objects Move In The Solar System?
Objects in our Solar System:
•Planets are large objects that travel around the sun. Most planets in our solar system have at least one moon (a type of satellite). An orbit is the path on which a planet travels around the sun. Even though people aren’t able to feel it—Earth travels through space at almost 30 kilometers (19 miles) per second. This is almost 100 times as fast as planes travel. The planets orbit the sun in the shape of an ellipse. An ellipse is like an egg shape.
•Asteroids (Fr. astéroide) are small and rocky. Most of them are scattered between the orbit paths of Mars and Jupiter. Some scientists think that asteroids are pieces of planets that never formed. Asteroids can be as large as 620 miles wide, or as small as a grain of sand! There are over 5000 objects in our solar system--and most of them are asteroids.
•Comets (Fr. comète) are small balls of dust and ice that orbit the Earth. A comet’s orbit is a long oval-shaped path. When a comet travels through its orbit and gets close to the sun, some of the ice on the comet’s surface melts into water vapor and leaves a long, glowing tail.
الرئيسية 
