The solar system is simply the Sun and its 8 planets revolving around it in an elliptical path. In this tutorial we will get answers of questions like -What is a planet?,What is a natural satellite?, What are the essential conditions required for sustaining life on a planet? and many other such questions related to our solar system and it's planets.
The Sun:-
- It’s size is thirteen times the Earth.
- It’s diameter is 1.4 million kilometres.
- The sun is about 150 million kilometres away from the earth.
- The composition of the Sun:- Hydrogen71% , Helium26.5% and remaining 2.5% consists various metals and elements, including neon, iron, oxygen and carbon.
- The sun continuously gets energy from the fusion of hydrogen to helium releasing huge amount of energy and vice-versa.
- The planet revolve around it at an about the speed of 70000 km per hr.
- It takes around 8 minutes and 20 seconds to reach the sunlight from the sun to the earth at an speed of light that is 300000 KM/seconds.
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| Solar System |
1. Terrestrial Planets(Inner Planets):-
- The four inner planets which is near to sun (mercury, Venus, Earth and Mars)are terrestrial planets.
- These planets are also called as rocky planets or solid planets.
- These are made up of the denser materials like metals, minerals and rocks.
- They contain few or no satellites.
- They have a thin layer of atmosphere.
2. Jovian Planets (Outer Planets):-
- The four outer planets (Jupiter, Saturn, Uranus and Neptune) are called as Jovian planets.
- They are made up of gases mainly Hydrogen and Helium.
- Some planets have rings around it.
- They have large numbers of natural satellites.
1. Mercury:-
- It is the closest planet to the sun.
- It does not have any protective blanket like ozone on earth to prevent it from harmful radiations.
- Many building blocks of life carbon dioxide, nitrogen, Hydrogen and oxygen.
2. Venus:-
- This planet is nearest planet to the earth and also known as the earth’s twin.
- Venus is known as the Evening Star as well as Morning star.
- Venus is the hottest planet of the Solar system due to a thick blanket of methane which prevents the reflection of incoming radiations of the Sun due to which it is also called as Veiled Planet.
3. The Earth:-
- Earth is the largest planet of the inner planets.
- It takes around 23 hours 56 minutes and 4.09 seconds to rotate on its own axis., while it takes about 365 days 5 hours and 48 minutes to revolve around the Sun.
- It is the only of the solar system that has the ability to sustain life due to presence of water, oxygen, nitrogen etc.
- The is tilted on its axis and makes 66.5°.
4. Mars:-
- Mars is known as Red Planet due to presence of iron rich red soil and pinkish atmosphere of it.
- Phoebes and Demos are only two satellites of Mars.
5. Jupiter:-
The Moon:-
- This the largest planet of solar system.
- Also the largest satellite of solar system is the Jupiter’s satellite Ganymede.
- The average temperature of Jupiter is very low (-148 degree Celsius.
- It is the fifth planet from the sun and average distance from the sun is 772.8 million kilometres.
- It is the 2nd largest planet of the solar system.
- Saturn has bright concentric rings, It is made up of ice and dust particles.
- It’s largest satellite is Titan.
- It was discovered by Sir William Hersiel.
- Uranus and Venus are the only planets which rotates from east to west on its axis. which is opposite to other.
- It is seventh planet from the Sun and it is also the third largest planet of the solar system.
- It appears greenish in colour since it has methane gas in present in its atmosphere.
- It is also called as “Planet on its Side”.
- It is the fourth largest planet of the solar system and 47 times bigger than the Earth.
- Neptune and Uranus is known as twins because of similarities.
- It has 8 natural satellites.
- Pluto is not considered as Planets from 24th August 2004 as declared by IAU(International Astronomical Union).
- Earlier Pluto was discovered by Clyde Tombaugh in 1930.
- Now Pluto is an asteroid and numbered as 134340.
- It is newly identified planet of solar system.
- But it is not yet proved and officially declared by IAU.
The Moon:-
- The moon is the only satellite of the earth, it takes 27 days, 7 hours and 43 minutes to rotate on its axis(This is also known as sideral month and moon’s period.
- The moon’s period of revolution with reference to the sun is about 29 days, 12 hours, 44 minutes and 2.8 seconds. This period is called a synodic month.
- The bright part of the moon is full of mountains whereas the dark spots are low lying plains.
- Liebuity mountain is the highest mountain of the moon that is 10600 meter high.
- The light of the moon takes 1.3 seconds to reach the Earth.
- Moon is known as fossil planet and it’s study is known as Selenology.
- The gravitational force on the surface of the moon is 1/6 the gravitational force on the Earth.
- The minimum distance between the moon and Earth is 3,64,000(perigee) and maximum distance is 4,06,000 km(apogee).
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