Page 81 - Science class 4

4. Mars : It is red in colour. It takes 687 days to orbit the sun. It has
two Moons.

5. Jupiter : It is the largest planet in the solar system. It takes 12 years
to orbit the sun. Jupiter has 16 moons. It can be easily seen

with the naked eyes.
6. Saturn : It is characterised by rings. It takes 29½ years to orbit the

sun. It has more than 18 moons, more than any other
planet in the solar system. It can be seen with the naked

eyes.
7. Uranus : It takes 84 years to orbit the sun. It has 15 moons. It can be

seen with the naked eyes.
8. Neptune : It takes 165 years to orbit the sun. It has 8 moons.

ARTIFICIAL SATELLITES
The satellites launched by man, that Scientific Updation

revolve round the Earth and collect data Pluto is not the planet now.
and information about various things, are

called artificial satellites. Sputnik–I was
the first artificial satellite launched by man.
It was launched by Russia on October 4,

1957. Now, there are hundreds of artificial
satellites in the sky launched by different

countries.
These artificial satellites are used for

various purposes such as weather
forecasting, education, communication and

transmission of the television programmes. Satellites
,
India also launched many artificial satellites namely Aryabhatta Rohini ,
Insat–IB Insat–IC PSLVs, , (Polar Satellite Launch Vehicles) and GSLVs
(Geo–Synchronus Satellite Launch Vehicles).

Rockets are used to carry satellites

and other things into space.

The first man who landed on the
moon was Neil Armstrong, an

American. Rakesh Sharma was the
first Indian to go to space.
Neil Armstrong Rakesh Sharma

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