The Earth in the Solar System

Q39. What is a whitish broad band, like a white glowing path that we see across the sky on a clear starry night?

Ans. It is a cluster of millions of stars. This band is the Milky Way galaxy. Our solar system is a part of this galaxy.

Q40. Write a short note on asteroids.

Ans. There are numerous tiny bodies which also move around the sun. These bodies are called asteroids. They are found between the orbits of Mars and Jupiter.

Q41. Name all the planets according to their distance from the sun.

Ans. There are eight planets in our solar system. In order of their distance from the sun, they are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.

Q42. What is meant by the ‘Solar System’?

Ans. The sun, eight planets, satellites and some other celestial bodies known as asteroids and meteoroids form the solar system. We often call it a solar family, with the sun as its Head.

Q43. What are stars?

Ans. Some celestial bodies are very big and hot. They are made up of gases. They have their own heat and light, which they emit in large amounts. These celestial bodies are called stars. The sun is a star.

Q44. Why do we see only one side of the moon always?

Ans. The moon moves around the earth in about 27 days. It takes exactly the same time to complete one spin. As a result, only one side of the moon is visible to us on the earth.

Q45. How does a planet differ from a star?

Ans. Difference between a planet and a star

Q46. Why the Earth is called a unique planet?

Ans. Conditions favourable to support life are probably found only on the earth. The earth is neither too hot nor too cold. It has water and air, which are very essential for our survival. The air has life-supporting gases like oxygen. Because of these reasons, the earth is a unique planet in the solar system.

Q47. Despite being our nearest star, the tremendous heat of the sun is not felt so much. Why?

Ans. The sun is the ultimate source of heat and light for the solar system. But that tremendous heat is not felt so much by us because despite being our nearest star, it is far away from us. The sun is about 150 million km away from the earth.

Q48. Write a short note on Sun.

Ans. The sun is in the centre of the solar system. It is huge and made up of extremely hot gases. It provides the pulling force that binds the solar system. The sun is the ultimate source of heat and light for the solar system.

Q49. How do meteoroids burn up?

Ans. Sometimes these meteoroids come near the earth and tend to drop upon it. During this process due to friction with the air they get heated up and burn. It causes a flash of light. Sometimes, a meteor without being completely burnt, falls on the earth and creates a hollow.

Q50. Write about Human-made Satellite?

Ans. A Human-made Satellite is an artificial body. It is designed by scientists to gather information about the universe or for communication. It is carried by a rocket and placed in the orbit around the earth. Some of the Indian satellites in space are INSAT, IRS, EDUSAT, etc.

Q51. Write in brief about all eight planets of solar system.

Ans. Mercury - One orbit around sun - 88 days

One spin on axis - 59 days

Venus - One orbit around sun - 255 days

One spin on axis - 243 days

Earth - One orbit around sun - 365 days

One spin on axis - 1 day

Number of moons – 1

Mars - One orbit around sun - 687 days

One spin on axis - 1 day

Number of moons – 02

Jupiter - One orbit around sun - 11 years, 11 months about 12 years

One spin on axis - 9 hours, 56 minutes

Number of moons – 16

Saturn - One orbit around sun - 29 years, 5 months

One spin on axis - 10 hours 40 minutes

Number of moons - about 18

Uranus - One orbit around sun - 84 years

One spin around axis - 17 hours 14 minutes

Number of moons - about 17

Neptune - One orbit around sun - 164 years

One spin on axis-16 hours 7 minutes

Number of moons - 8