NCERT 5th class (CBSE) Science: Earth, Sun and Moon

Question: Describe the lunar eclipse.

Answer: Lunar eclipse:

1. When the earth comes between the sun and the moon it blocks the sunlight from reaching the moon and creates a shadow. This is called a lunar eclipse.
2. The earth’s shadow has two parts:
   (i) Umbra – Where the earth totally blocks the sunlight.
   (ii) Penumbra – Where the earth blocks a part of the sunlight.
3. Lunar eclipse is either partial or total. During a partial lunar eclipse, a part of moon can be seen and during a total lunar eclipse the moon cannot be seen at all.

Question: How does the solar eclipse happen?

Answer: Solar eclipse

1. When the moon comes between the earth and the sun, it bends some part of the sun. This is called a solar eclipse.
2. The moon’s shadow has 2 parts:-
   (i)Umbra – The region on earth where umbra falls will have a total solar eclipsse.
   (ii)Penumbra – The region where penumbra partial solar eclipse.
3. Solar eclipse may be partial or total.. During a partial solar eclipse, a part of sun can be seen and during a total eclipse the sun cannot be seen at all.

Question: Give the full form of:

1. IAU – International Astronomical Union
2. ISRO – Indian Research Organisation

Question: What are artificial satellites? Describe their uses.

Answer: Artificial satellites are man-made objects taht orbit the earth.

1. Communication satellites – They send signals for T.V and radio programmes and telephone calls.
2. Navigation satellites – Help ships and aircraft find their way.
3. Astronomy satellites – Carry telescopes into spaces.
4. Weather satellites – Help in weather forecasting.