Facts About the Solar System for Class 3 Science
- We live on the planet Earth, the part of the solar system that comprises the Sun and other planets.
- The solar system is a part of a more extensive planetary system called the Milky Way Galaxy.
- There are numerous planetary systems in the galaxy. The assemblage of many such galaxies is called the universe.
- Some planets are made of solid mass, while others are giant spheres of gases and ice.
- Besides the planets, the solar system also contains many celestial objects such as asteroids, meteors, comets, etc.
Earth, Sun and Moon
What Will Happen to Earth if the Sun Disappears Suddenly From Space?
- If the Sun disappears suddenly from space, it will lead to complete darkness on Earth.
- Sunlight is necessary to maintain an optimum temperature on Earth for the continuity of life, which would not be possible without the Sun.
Despite Being the Most Significant Object in the Solar System, the Sun Cannot Control Earth’s Tides As the Moon Does. Why?
- Yes, the Sun is the biggest, has the strongest gravitational force, and controls the orbits of every object in the solar system.
- But the distance between Sun and Earth varies considerably compared to the Moon. The gravitational force varies with the distance between two celestial bodies.
- Since Moon is closer to the Earth, its gravity plays a significant role in the formation of tides and waves on Earth.
The Four Inner Planets of the Solar System Are Solids and Smaller in Size. Why?
- The inner planets are closer to the Sun.
- The materials which can survive in the extreme heat produced by Sun combine to form the inner planets, and most of them are metals and rocks.
- This aggregation of metals and rocks makes the inner planet smaller and rocky.
Why Are There Fewer or No Moons for the Inner Planets?
- The inner planets are smaller and denser than all the planets in the solar system.
- Thus they do not have enough gravitational force to attract any celestial body or a Moon. Hence they have significantly less or no moon.
Why Is Mars Called the ‘Red Planet’?
- The soil on mars is very rich in rust due to the presence of iron in the soil.
- This large amount of rust in the soil gives it its characteristic red colour.
Why Does Uranus Rotate Sideways?
Uranus is the only planet that rotates sideways. It is possible due to the impact of the collision between Uranus and an Earth-like celestial body in space.
The Planets Are in a Ball Shape. Explain Why.
- Planets are spherical due to gravity.
- Gravity attracts objects equally from all directions.
- Due to this uniform aggregation of mass, planets got their spherical shape.
Explain Why the Asteroids Are Not Spherical Like the Planets.
- Asteroids are smaller (a few inches to a few kilometres in diameter) irregular objects that revolve around the Sun.
- They do not have a liquid core like planets and lack gravity.
- Due to the lack of gravity, they cannot pull material from the surroundings uniformly and hence do not attain a spherical shape.
What Is a Meteor Shower? Explain Why Meteors Rarely Reach the Earth’s Surface.
- The meteor shower is a celestial phenomenon characterised by the appearance of many meteors together in the sky, originating from one point in the sky.
- Meteors are of small size and get burned up completely while crossing the Earth's atmosphere.
- Only huge-sized meteors can sustain through the atmospheric heat and reach the surface of the Earth, which is rare.