NATURAL SATELLITES, ASTEROIDS, COMETS AND METEORIODS

A.     NATURAL SATELLITES

1. Natural satellites are the natural objects which orbit around planet.
2. The Moon is the Earth's only natural satellite.
3. All the planets in the Solar System have natural satellites except Mercury and Venus.

NATURAL SATELLITES 

B.     ASTEROIDS

1. Besides the nine planets there is also an asteroid belt.
2. The asteroid belt lies between the orbits of Mars and Jupiter.
3. Asteroids are small pieces of rocks mixed with metals orbitibf round the Sun.
4. Asteroids vary in size. Some can be as small as dust particles while some can be a few hundred kilometres in diameter.

C.    COMETS

1. Comets are small pieces of ice and dust that orbit around the Sun, but their paths are not like those of the planets.
2. Most comets spend much of their time out of the Solar System, beyond Pluto. However, they can enter new orbits that bering them into the Solar System where they become visible from Earth.
3. The most famous comet is called Halleys's comet which returns to the centre of the Solar System every seventy six years.
4. Every comet has a head and a long tail. The small solid part at the centre of the head is called the nucleus.

 

Halley's Comet

D.    COMETS

1. Meteoroids are small pieces of rock or metal floating in outer space.
2. Meteoroids float near to the Earth, they may be drawn into the Earth's atmosphere due to gravity.
3. Meteoroids which enter the Earth's atmosphere are called meteors.
4. Most meteors will burn up when they enter the Earth's atmosphere due to friction.
5. Thus, streaks of ligth can be seen in the sky at nigth in the dark. They leave behind fierl tails and are called shooting stars.
6. Meteors which do not burn completely and reach the Earth's surface are called meteorites.
7. Meteorites which fall to the gravity will make huge craters.

 HUGE CRATES BY METORITES