Solar System: A General Introduction
The solar system is a system of planets (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune) meteors, asteroids, comets, and satellites that orbit the sun. The center of our solar system is the sun. All planets present in the solar system revolution the sun and also rotate at their axis. Planets have not their own source of light.
– Mercury, Venus, Earth, and Mars are known as the inner planets of the solar system. All these planets are small in size but carry high density compared with the other 4 planets.
– Jupiter, Saturn, Uranus, and Neptune are the outer planets of the solar system. There is an asteroid belt that exists between Mars and Jupiter. All these planets are big in size but the density of one of these planets is low as compared with inner planets.
| Planet | Size |
| Jupiter | 43,441mi (69,911km) radius |
| Saturn | 36,184mi (58,232km) radius |
| Uranus | 15,759mi (25,362km) radius |
| Neptune | 15,299mi (24,622km) radius |
| Earth | 3,959mi (6,371km) radius |
| Venus | 3,760mi (6,052km) radius |
| Mars | 2,106mi (3,390km) radius |
| Mercury | 1,516mi (2,440km) radius |
| Planet | Average Distance from the sun (In million km) | Revolution time |
| Neptune | 4472 | 165 years |
| Uranus | 2854 | 84 years |
| Saturn | 1419 | 29 years |
| Jupiter | 773 | 12 years |
| Mars | 227 | 687 Days |
| Earth | 150 | 365 Days |
| Venus | 107 | 225 Days |
| Mercury | 58 | 88 Days |
Some facts about our Solar System
– In solar system sun is the main source of energy for all the planets.
– Most of the planets follow the west to east (Anti clockwise) orbital path for the rotation but in the case of Venus and Uranus they both follow the opposite
– orbital path east to west (Clock wise) for there revolution to the sun.
– Venus is the closest planet to the earth. The size of Venus is approximately similar to the earth that why it is also known as the twin of earth.
– According to Nasa previous studies Saturn has 53 natural satellites, Jupiter more than 60.
– Ganymede is the biggest natural satellite of the solar system.
– Titan is the brightest natural satellite of the solar system and the biggest of Saturn planet.
– There are only two planets which has no natural satellites, mercury and venus.
– Venus is the brightest planet of the solar system also known as morning star.
– Mars has two natural satellites named Phobos and demos. Mars is also known as the red planet of the solar system. The second nearest star from the earth is Proxima Centauri. Proxima Centauri is the low mass star which is located 4.244 light-years (distance cover by the light in one year) away from the sun in the southern constellation of the Centaurus.
Origin of the Universe
There are different theory exists at present which describes the origin of the universe but the most relevant theory regarding the origin of the universe is the Big bang theory introduced by Georges Lemaitre. A proper explanation of the theory was presented by Robert Wegner in 1967.
According to the big bang theory, the universe began approximately 13.7 billion years ago with a huge explosion in a heavy dense, and very high-temperature matter which was existed in the center of the universe at that time.
In 1920 Edwin Hubble proves that the universe is still expanding. He showed the evidences of increasing distance between the galaxies.
Some theories which help for understanding the Origin of the Solar System Earth
1. Gaseous Hypothesis,
2. Nebular Hypothesis,
3. Planetesimal Hypothesis,
4. Tidal Hypothesis,
5. Binary star hypothesis,
6. Supernova Hypothesis,
7. Inter Stellar Dust hypothesis,
8. Elextro Magnetic Hypothesis,
9. Electro Magnetic hypothesis,
10. Rotational and tidal hypothesis,
11. Big-band Theory.
