Karnataka Board Class 8 Science Chapter 23 Earth and Beyond
KSEEB Class 8 Science Chapter 23 Textual Questions & Answers
I. Four alternatives are given to each of the following incomplete statement/ questions. Choose the right answer.
The constellation that helps to locate north star is.
The second biggest planet of the solar system has.
(a) lowest density
(b) density equal to water
(c) highest density
(d) density equal to earth.
(a) lowest density
The poles of this planet faces the sun for longer periods of time than any other planet.
Polar ice caps of the planet mars are due to.
(a) Solidified water
(b) solidified carbon dioxide
(c) volcanoes erupted near the poles
(d) cover of dust particles that reflect
(b) solidified carbon dioxide
Heatwaves are trapped to the maximum extent in the planet.
II. Fill in the blanks with suitable words:
Radio signals are emitted by the planet ………….
The color of the planet Mars is ………….
Winter season constellation is ………….
Asteroids are mainly found between the orbits of ………..
Mars and Jupiter
Ultraviolet rays from the sun can be filtered by the earth’s atmospheric layer called …………
Ozone layer present in the upper regions of the Stratosphere.
III. Match the following:
IV. Answer the following:
Which planet is called morning star or evening star?
Which planet was removed from the list of 9 planets in 2006?
Express the following in km.
- 10 light minutes
- 10 light days
- 10 Light year
- light minutes
10 × 60 × 300000 = 180000000 km = 180 million km
- 10 light days
10 × 24 × 60 × 60 × 300000 = 259300000000 km = 259200 million km
- 10 light years
10 × 365 × 24 × 60 × 60 × 300000 = 94608000000000 = 94608000 million km
Name the following:
- Most fascinating planet with a set of ring systems as viewed from a telescope.
- Nearest planet to earth.
- Nearest planet to the sun
- Biggest planet of the solar system
How are satellites different from planets?
- planets are natural celestial objects
- planets revolve round the sun
- planets are big in size Satellites:
- Satellites may be natural or artificial objects.
- Satellites revolve round the planets.
- Satellites are smaller in size than planets.
Which satellite has active volcanoes?
In a satellite of Jupiter has active volcanoes.
Give a reason for the following.
- A person in England can recognize the pole star easily than a person in Bangalore: Pole star appears to be stationary above the Earth’s North Pole since England lies in the Northern side Northern hemisphere a person in England can recognize pole star than a person in Bangalore.
- Mercury in difficult to observe: It is very difficult to observe mercury because it is very close to the sun and most the time it is hidden by the glare of the sun. However, it can be seen just before sunrise and just after sunset.
- A day on Venus is longer than its year: The period of rotation of Venus is 243 days and the period of revolution is 224 days. Since the period of rotation is longer than a period of revolution, a day on Venus is longer than its year.
- The greenhouse effect is prominent on Venus: Venus is composed mostly of carbon dioxide. There are several layers of clouds many kilometers thick composed of sulfuric acid. This dense atmosphere of carbon-dioxide blocks the long-wavelength infrared radiation and heat is trapped inside, hence the greenhouse effect is prominent on Venus.
V. State true or false:
Saturn has the highest density.
Venus can be seen overhead in the night sky.
Aries (Mesha) is zodiacal constellations.
Mars contains oxygen in its atmosphere.
Moon has no atmosphere.
Titan is the satellite of Jupiter.
KSEEB Class 8 Science Chapter 23 Additional Questions & Answers
Define the following terms
- celestial objects
- celestial sphere
- celestial objects: The objects in the sky are called celestial objects.
- celestial sphere: The imaginary sphere centered around us is called the celestial sphere.
- horizon: The imaginary circle along which the sky appears to meet the ground is called the horizon.
Write the differences between the geocentric model and the heliocentric model.
- Geocentric model:
- Earth is considered the center of the universe.
- all other celestial objects move around the earth.
- This model scientifically not accepted.
- It was not possible to explain many events like solar eclipses and the variation in the path of planets.
- Heliocentric model:
- Sun is at the center of the observable universe.
- All other celestial objects including the earth move around the sun.
- Kepler and Galileo provided scientific evidence.
- Possible to explain the events like solar eclipses and gravitational laws helped in better undering of Heliocentric model.
Explain our solar system?
Our solar system comprises of the following:
- The sun which is the center of the solar system.
- Eight planets are mercury, Venus, Earth, mars, Jupiter, saturnuranus and Neptune,
- The Asteroid belt between the orbits of mars and Jupiter
- Satellites of the planets, which are also Called the moons of the planets.
- Comets such as Halley.
- Artificial Satellites and space crafts,
What is meant by light year?
The light year is the distance traveled by light in one year, traveling at the speed of 3,00,00 Km/S through Vacuum.
What is meant by period of rotation
The time taken by a planet or a satellite to rotate once around its own axis is called period of rotation.
What is meant by period of revolution.
The Time taken by a member of solar system to go around the sum once is called period of revolution.
What factors made us to think about the existence of some form of life in mars?
Some places in mars hove moderate range of temperature, It has Oxygen, nitrogen and water It has Frozen Carbon dioxide near the poles factors that mode us to think about the existence of some Formic of life on mars.
What are asteroids?
Thousands of irregular Shaped lumps of rocks that orbit the sun are called asteroids,
Name Some of the largest asteroids.
Ceres, pallas, Juno and Vesta are the some largest asteroids.
What are Meteoroids?
Meteoroids are the Chunks of matter which may originate from asteroid belt that may enter the earth’s atmosphere and burn due to neat generated by Friction.
What are meters?
The meteoroids which bum completely are called meteors and also called as Shooting stars or Falling Stars
What are Meteorites?
The Bigger meteorites Sometimes Survive the Journey and hit the earth Surface resulting Craters and vent on the earth’s crust they are called as meteorites.
Which is the biggest planet of the solar system.
Jupiter is the biggest planet of the solar system.
Name the Galilean Satellites.
Io, Europa, Ganymede, and Callisto are the Four satellites identified by Galileo.
What are comets?
Comets are considered as the guests of the solar system made up of silicates and frozen gases, and dust which have a very long orbital period and appear rarely
Name the Second biggest planet of the solar system.
Saturn’s The second biggest planet of the solar system, Its special feature is permanent ring system.
What are constellations?
The region around recognizable pattern of a group of stars is called Constellation.
What are Zodiacal constellation?
The 12 Constellation which is located in the Zodiacal belt is called Zodiacal constellation.
What is meant by the zodiac belt?
The movement of the sun, the planets, and the moon appear to Follow a path From east, to west This apparent path is called zodiac belt.
Name the zodiacal constellations
- Aries (Mesha)
- Tautds (Vrishabha)
- Gemini (Mithuna)
- Cancer (Karka)
- Virgo (Kanya)
- Libra (tula)
- Scorpius (vrischika)
- Sagittarius (Dhanu)
- Capri cornus (Makara)
- Aquarius (Kumbha)
- Pisces (Meera)
Stars appear small even they arc very large, Give reason.
Stars appear very Small because they are far away from the earth.
Saturn Can plot on water Give reason.
The specific gravity of Saturn is (0,13) less than that of water hence it can Float on water
Why do comets develop tails as they approach the sun?
Comets are silicates and matter made up of frozen gases. As they approach the sun, their frozen gases gradually vaporize. The energetic particles produced by the sun push the gases away leading to the formation of tail.