Page 91 - ACTIVE SCIENCE 4 TOC

• Dwarf planets are those planets which do not fall in the category of planets but
revolve around the sun.

• The natural satellite of the earth is the moon.
• Stars are small twinkling objects in the sky which can be seen during night.

Glossary
• Solar system : It consists of the sun, the eight planets and their respective
moons.
• Stars : Small twinkling objects in the sky which can be seen only at
night.
• Equator : An imaginary line passing through the centre of earth.
• Dwarf planet : An object which revolves around the sun but is not large
enough to be called a planet.
• Craters : The large pits on the surface of a planet formed when a
meteor or an asteroid collides with it.
• Satellite : An object which revolves around the planet on a fixed
path.
• Artificial Satellites : Man-made satellites.

Practice Time

A. Tick the correct option.
1. Uranus is a _____________.

a. satellite b. planet

c. star d. dwarf planet
2. _____________ is also called blue planet.

a. Earth b. Sun
c. Venus d. Saturn

3. _____________ is the second largest planet after Jupiter.
a. Saturn b. earth

c. Sun d. Neptune

4. _____________ is the coldest planet.
a. Uranus b. Neptune

c. Earth d. Star

B. Fill in the blanks.

1. The planets revolve around the sun in fixed _____________.
2. The temperature of the surface of the sun is about _____________ degree Celsius.

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