A solar system is a group of celestial objects located in the Milky Way Galaxy. It is made up of eight planets, namely Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune, Their moons, dwarf planets, asteroids, meteoroids, and several other smaller celestial bodies. Astronomers believe that the solar system is around 4.5 billion years old.




The solar system is about 25000 light-years from the center of the Milky Way Galaxy. It is elliptical in shape and has the Sun at its center. The solar system is always in motion. All the planets and celestial bodies move around the Sun in elliptical paths.





 Sun:

The Sun is a huge, glowing star. It is the largest and the most important object in the solar system. The sun is composed of hydrogen, helium, and other heavier elements. It contains 99.8 percent of the solar system's mass and is the main source of light and heat on earth.




Planets:

A planet is a celestial body that orbits the Sun or any other star. The solar system consists of eight major planets. They are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
The first four planets are small and rocky, while the next four planets are giant gaseous planets.
The eight four also vary greatly in mass, temperature, and the rate of rotation.




Dwarf Planet:

In the year 2006, the International Astronomical Union adopted the term dwarf planet to classify a celestial body that like all other planets orbit the  Sun but has not cleared the neighborhood around its orbit. By this definition, Pluto was classified as a dwarf planet. Pluto has a number of icy objects that share its orbits. it was discovered in 1930 and its status as a planet had been debited from the very beginning. Its average distance from the sun is about 5,86,96,59,999km. 




Minor planets:

Minor planets are small objects found in the solar system whose orbits lie between the Sun and the asteroid belt. These objects are larger than meteoroids but smaller than planets and therefore are not considered planets.



Planetary motion:

Johannes Kepler, a German mathematician, proposed in the 17th century that the planets move around the Sun in ellipses and not in circles. Kepler also stated that a line joining a planet and the Sun sweeps out equal areas during equal intervals of time.




Other solar systems:

There exist many other solar systems like our own solar system. The first evidence of the presence of other solar systems was discovered in the mid-1990s. These solar systems can be detected by measuring the gravitational pull of the planets on the star they orbit. Though the gravitational pull is not very strong, it still can make the star wobble back and forth a little bit.  Astronomers measure this gravitational pull and use it to calculate the orbit and mass of the planet. Till now astronomers have been able to find around 70 other solar systems.



Planet names:

All planets except Earth have been named after Greek and Roman gods and goddesses.
-> Mercury was named Mercurius by the Romans after their god of trade. Mercurius was also a messenger of the gods known for his swift flights from place to place. The Romans named the planet Mercurius because the planet appears to move very swiftly.


-> Venus is named after the Roman goddess of love. The Romans considered the planet the brightest and most beautiful planet or star in the heavens.

-> Mars was named by the Romans after their god of war because of its blood-like red color.

-> The Romans and the Greeks named the biggest planet Jupiter after their most important deity, Zeus.

-> Saturn was named after the Greek god Cronos, the father of Zeus. Saturn is the Rom: name for Cronos.

 -> Uranus was named by Johann Bode in 1781. Uranus was the father of the Greek god Cronos.

-> Urbain Le Verrier suggested the name Neptune for the planet after the Greek god of the sea and earthquakes, Poseidon, Neptune is the Roman name for Poseidon,