Page 80 - Science class 4

metals and gases. They are Mercury,

Venus, Earth, Mars, Jupiter, Saturn,
Earth
Earth
Earth
Uranus and Neptune. All the planets in
Mars
Mars
Venus
Venus Mars
Venus
the solar system revolve round the sun in
Sun
Sun their own orbits but in the same direction.
Sun
Mercury
Mercury
Mercury
Jupiter The path that a planet takes to revolve
Jupiter
Jupiter
round the sun is called an orbit. Besides
Saturn
Saturn
Saturn
Neptune these stars and planets there are many
Neptune
Neptune
Uranus
Uranus other heavenly bodies called satellites .
Uranus
Satellites move around the planets. They do not possess light of their own.
They reflect the light from the sun. The Moon is the natural satellite of the
Earth. The Moon takes 27 days to orbit the Earth. The satellites of planets are
called moons.
Keeping Update
The first woman who went round the Earth in a spacecraft was a Russian

woman, Valentina Tereshkova.

Now let us learn more about the planets
1. Mercury : It is the closest planet to the sun. It is the hottest planet of
all. It takes 88 days to orbit the sun. It has no moons. We

can see it with the naked eyes.

2. Venus : It takes 225 days to orbit the sun. It is the brightest of all
planets. It has no moons. It is also known as the morning
star.

Saturn
Jupiter
Jupiter
Saturn
Venus
Venus Jupiter Saturn
Venus
3. Earth : The Earth is the only planet that supports life. It takes
365¼ days to orbit the sun. It has only one satellite, that is
the Moon.

Discover 81 Science/4
81
81