The solar system and the eight planets – Erakina

The gravitationally bound system of the sun, planets, and heavenly bodies revolving around its axis is known as the solar system. In order, the names of planets from their distance from the sun are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. The solar system also contains comets, asteroids, stars, moon, satellites, and dwarf planets too.

How has our solar system evolved and formed?

The formation of the sun and the planets began approx 4.5 billion years ago when gravity pulled the cloud of gas and dust called the solar nebula to form the solar system. Before the solar system existed, large concentrations of interstellar gas and dust particles created a molecular cloud named the sun in the center of the planets. The small grains or parts that condensed in the solar nebula joined and formed a large solid material in the form of planetesimals. In those planetesimals, some are still alive today in the form of asteroids and comets and many of them were thrown out to far places and greater distances by close gravitational encounters with other large and giant planets. Rocky debris is represented as asteroids.

Similar to the sun, moon formation took place by orbiting the giant gas planets. 

The formation of the solar system includes contraction, accretion disk, protostar, condensation, protoplanets, and fragmentation.

When the gas, dust, and rock debris were floating around the universe, the solar system was complex and messy. But planet formation appears to have happened relatively at a fast pace. The clumping of small parts of gases and dust particles began. After the ignition and release of fire from the sun, Its heat evaporated and all the nearby ice. The gas and dust particles got cleared with the strong solar wind. This event is called late heavy bombardment which resulted in small bodies becoming members and part of the solar system.

Planets of the solar system

• Mercury- It is the smallest planet in the solar system and closer to the Sun. It takes 88 days to complete the orbital period. It is slightly larger than earth’s moon. Mercury has no moon.

• Venus- It is the second planet of the solar system. Venus has no moon of its own.

• Earth-  It is known as the homeland of living organisms. It is the only planet that has three components to survive- air, water, and land. Earth has one moon. It takes 225 days to complete its orbital period.

• Mars- It is dusty, and a cold planet. It takes 687 days to complete its orbital cycle. Mars has two moons. It is also known as the red planet.

• Jupiter- It is the largest planet in the solar system. It takes 12 years to complete its orbital period. Jupiter has sixty-three moons.

• Saturn-  It is a giant planet with rings around it. It takes around 29 years to complete its orbital period. Saturn has fifty-nine moons.

• Uranus- It is the seventh planet of the solar system. It takes 84 years to complete its orbital cycle. Uranus has twenty-seven moons.

• Neptune- It is the eighth planet of the solar system. It takes 165 years to complete its cycle. It is very dark and full of gases Neptune has fourteen moons.

Facts about the solar system

• All the planets revolve around the sun anticlockwise in the same direction around its axis. This proves that the planetary system was formed in a unified process. 
• Satellites face the planet on the same side, similar to the moon because they are locked in resonance with the planet’s rotation.
• The orbits of the planet are circular with little inclination of the ecliptic.
• The Sun mass comprises 99.8% of the mass of the solar system.
• The Sun consists of non-volatile chemical elements which are inherited from the protosolar nebula.
• Migration and collisional processes throughout the solar system history and matter transport play an important role in the evolution of planets.

Conclusion

To understand the evolution and origin of the solar system, the theoretical and experimental studies of the recent decades have played a major role. The data provides and enlightens the evidence and facts that the formation of the planetary system was caused due to fragmentation(the process of breaking into fragments). These small fragments took the shape and evolved into a newborn star surrounded by dust and gases. By this different sizes of celestial bodies with the largest planet emerged.