Earth and the Solar system

The Big Bang explosion was somassive that an enormous cloud of gases and dust known as Nebula was generated.

The nebula had a spinning motion and its own gravity.

What happened to the dust in the nebula?

The dust particles were attracted to each other to form a bigger and denser matter.

The particles collided at high speed and generated heat. Glowing bodies were born which we call as Stars.

Considering that the Big Bang happened 15 BILLION years ago, can you take a wild guess on the age of OUR STAR, THE SUN??

It is 4.6 billion years old. (which is young!!!)

Thus the Solar System was born!!!!

Akash Ganga , the Milky Way

There are eight planets in all. In order of distance from the Sun, they are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. In 2006, the International Astronomical Union (IAU) reclassified Pluto as a dwarf planet. Apart from this, the other celestial bodies are Satellites, Comets, Asteroids and Meteors

The Solar familyThe Solar family

The Sun is the star of our Solar System.

It is a massive ball of heat that supplies energy to the whole Solar System. It is more than 100x the size of the Earth.

Due to its size, it has a huge amount of gravity which holds the planets in their orbits

It is about 150 million km away from Earth. Therefore the light from the Sun takes around 8 minutes to reach us.

The Sun

The Inner planetsThe Inner planets

Why do you think Earth is an unique planet?

The Earth is a unique planet because it is the only planet in the solar system which supports all forms of life – plants, animals and human beings. It is the only planet which has a life giving source called water. Our planet has all the essential gases, a moderate temperature and an atmosphere which makes life possible on this planet.

The Moon is the only satellite of the Earth.

Its diameter is about one quarter of the Earth’s.

The Moon has no light of its own.

The Moon appears in the sky in different shapes. These are known as the phases of the Moon.

The Moon’s gravity is about one-sixth that of Earth’s.

Due to the absence of an atmosphere, The Moon has extreme temperatures.

The Moon

The outer PlanetsThe Outer Planets

Asteroid Belt in the Solar SystemAsteroid Belt in the Solar System

Meteors Are made of dust particles in

the Solar system. Appear in the sky as the

shooting stars or falling stars. Are observed during the

night. The atmospheric pressure

heats up the meteor and this is why it has a shining and a long glowing tail.Asteroids Are small heavenly bodies

which orbit around Sun; Also called Planetoids. Lie between the orbit of Mars

and Jupiter and thus separate the Inner planets from the Outer planets.

Are made up of rocks, ice and metal.

Meteors

Asteroids

Comets

Are small celestial bodies made up of ice crystals, dust and rock particles.

When they are close to Sun they appear with a long shining tail.

Have long orbit periods which range from hundreds to thousands of years , for example the Hailey’s comet which is seen after every 76 years!!

Comets

Inner Planets• Close to Sun and are

positioned before the Asteroids

• Small in size• Solid planets made of

rocks• Heavier than outer

planets as they are made of rocks

• Move faster as they are smaller in size

Outer Planets• Far away from Sun

and are positioned after the Asteroids

• These are giant planets

• Gaseous planets• Lighter as they are

made of gases• Move slowly as they

are bigger in size

Differences between:-

Differences between Stars and Planets.

Differences between Planets and Satellites.