Our Universe - 2 Class 3 Worksheet SST

Q1: Multiple-Choice Questions (MCQs)

(i) What is the path that Earth takes around the Sun called?
(a) Route
(b) Orbit
(c) Journey
(d) Loop
Ans: (b) Orbit

An orbit is the path that a planet takes around its star, like Earth's path around the Sun.

(ii) Which celestial body is the closest to Earth?
(a) Mars
(b) Venus
(c) Jupiter
(d) Mercury
Ans: (d) Mercury

Mercury is the closest planet to the Sun and therefore closest to Earth.

(iii) What is a shooting star also known as?
(a) Meteor
(b) Asteroid
(c) Comet
(d) Satellite
Ans: (a) Meteor

A shooting star is a meteoroid that burns up in Earth's atmosphere, creating a streak of light.

Q2: Fill in the Blanks

(i) The Sun is a __________ that provides light and warmth to Earth.
Ans: star

The Sun is a huge ball of hot, glowing gases and is classified as a star.

(ii) The Moon __________ around the Earth.
Ans: orbits

The Moon moves around the Earth in a path called an orbit due to the Earth's gravitational pull.

(iii) The __________ is the huge system of stars, planets, and other objects we see in the night sky.
Ans: universe

The universe encompasses all the galaxies, stars, planets, and other cosmic bodies.

(iv) The four inner planets of our Solar System are Mercury, Venus, __________, and Mars.
Ans: Earth

Earth is one of the four inner planets located closer to the Sun.

(v) The Milky Way is the name of our __________.
Ans: galaxy

The Milky Way is the spiral galaxy in which our Solar System resides.

Q3: Planet Facts Fun

Instructions: Write a fun fact about each planet below. You can make it silly or creative!

Planets:

• Mercury: ____________________________
• Venus: ____________________________
• Earth: ____________________________
• Mars: ____________________________
• Jupiter: ____________________________
• Saturn: ____________________________
• Uranus: ____________________________
• Neptune: ____________________________

Ans: 

Q4: Answer the following questions

(i) What is the Big Bang theory, and why is it considered the most accepted explanation for the origin of the universe?
Ans: The Big Bang theory suggests that the universe started as a small, hot, and dense point about 13.8 billion years ago and has been expanding ever since. It is widely accepted because it explains the cosmic background radiation, the presence of light elements, and the structure of galaxies.

(ii) Describe the significance of the Milky Way galaxy in the context of our Solar System.
Ans: The Milky Way galaxy is the home of our Solar System, including Earth and the Sun. It is a vast collection of stars, planets, and other objects, providing the environment where our Solar System exists.

(iii) Explain why Earth is referred to as an "ocean planet" and what makes it unique in the Solar System.
Ans: Earth is called an "ocean planet" because oceans cover about 71% of its surface. This large amount of water allows Earth to support life, making it the only planet known to have ecosystems and liquid water.

(iv) What role do satellites play in the Solar System, and can you provide an example of a natural satellite?
Ans: Satellites are objects that orbit planets, playing a key role in planetary motion and scientific research. A well-known natural satellite is the Moon, which affects Earth's tides and provides valuable scientific information.