Beyond Earth

 Book Work

A. Choose the correct answer.

1. (c)

2. (a)

3. (a)

4. (b)

5. (d)

6. (b)

7. (a)

8. (c)

B. Fill in the blanks.

1. galaxy

2. star, satellite

3. Venus

4. Neptune

5. meteors

C. State True or False. Also correct the false statements.

1. True

2. True

3. False, Jupiter is the biggest planet of the solar system.

4. True

5. True

Notebook Work 

D. Tick (√) the odd-one out giving reason.

1. Alpha centauri, others are constellations.

2. Elliptical galaxy, milky way is a spiral galaxy.

3. Saturn, others are terrestrial (or inner) planets.

4. Star, others are part of solar system.

5. Pluto, others are planets.

II. LOGIC BASED QUESTIONS

Short and Long Answer

1. No, the Moon does not receive more sunlight on a full Moon night than on any other day. The amount of sunlight the Moon receives depends on its position relative to the Sun, not the Earth.

2. Comets are made up of ice, dust, and rocky materials. They revolve around the Sun in a highly elongated orbit.

When a comet approaches the Sun, its ice melts due to the Sun’s heat. The melting ice, along with dust and other materials, sweeps into a long tail. As the comet comes closer to the Sun, solar winds exert pressure on the comet’s head and force part of it backward, pointing away from the Sun. That is why a comet’s tail always points away from the Sun.

3. The Pole Star, also known as Dhruv Tara, appears stationary in the sky because it is nearly aligned with the Earth’s axis of rotation. As the Earth rotates, the Pole Star does not change its position relative to the Earth, while other stars appear to move in the opposite direction.

4. Stars appear small because they are very far away from Earth.

5. Artificial satellites are used in

    • communication.

    • weather forecasting system.

    • GPS (Global Positioning System)

6. The planets Mercury, Venus, Earth and Mars, are called terrestrial because they have a compact, rocky surface like Earth. The terrestrial planets are the four innermost planets in the solar system.

7. (a) The full Moon is seen in the eastern part of the sky in the evening.

    (b) The crescent Moon is seen in the western part of the sky in the evening.

8. This is because the period of rotation of the Moon on its axis is equal to the period of its revolution round the Earth. So we only see the side that faces us and this side faces us all the time.

B—(indicates the position of the Sun.)

III. HIGHER ORDER THINKING SKILLS

1. Every planet is at a different distance from the Sun and has a fixed orbit in which it revolves around the Sun. The Sun’s gravitational force holds the planets in their places, and they do not collide with each other because their orbits do not intersect.

2. No, it is not correct to classify the Moon as a planet. The Moon is classified as a natural satellite, not a planet. A planet is a celestial body that orbits a star (like the Sun) and has cleared its orbital path of other debris. The Moon, however, orbits the Earth, which is a planet, and not the Sun directly. This relationship places it in the category of natural satellites rather than planets.

3. If a star is 100 light-years away from the Earth, the explosion will be visible to people on Earth after 100 years. The distance that light travels in one year is known as one light-year.

4. The Moon shines because it reflects light from the Sun, even though it doesn’t produce its own light.

5. B & C

6. It is a comet revolving around the Sun.

A very popular celestial body name is Halley’s comet

The tail of a comet always points away from the Sun and it becomes longer as the comet comes closer to the Sun.