Page 254 - New Medley 4 Semester 2 PDF (Merged)

AT ONE GO

m The sun, planets and their moons make up the solar system.
m The Earth has three layers–the crust, the mantle and the core.
m The spinning of the Earth on its axis is called rotation. This causes day and night.

m The movement of the Earth around the sun in a fixed orbit is called revolution.
m The tilted axis and the revolution of Earth around the sun cause different seasons.

REMEMBER THESE TERMS

Moon : A heavenly body that revolves around a planet

Universe : The whole of space including the Earth, the planets and the stars
Telescope : An instrument that makes far away objects appear larger and nearer

Equator : An imaginary line around the Earth which is equidistant from both the poles

Check Your Study

A. Tick () the correct answers.

1. The closest star to our planet is

(a) Sun (b) Moon

(c) Mars (d) Neptune

2. The number of planets in our solar system is

(a) 8 (b) 9

(c) 10 (d) countless

3. The source of all form of energy on the Earth is
(a) water (b) green plants

(c) sun (d) core of the Earth

4. The total number of stars in the night sky is

(a) 4 billion (b) 6 billion

(c) 10 billion (d) uncountable

5. The galaxy to which our solar system belongs is the
(a) Milky Way (b) Ursa Major

(c) Ursa Minor (d) Orion

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