About the Formation of the Solar System

The formation of the solar system is a topic of great controversy. While some experts claim it was divine formation, others look to science for their answers. The most common explanation is that the planets themselves were formed form the cloud of gas and dust resulting from the sun's formation. This method is the most widely accepted and is called accretion.

History

Accretion states that the history of the solar system began after the formation of the sun. This idea of thought says the planets started from dust grains in orbit around the sun (the central protostar). It then states that because of direct contact in space, the grains began to turn into clumps and then collided to form larger bodies now known as planets. This is said to have taken a few million years.

Time Frame

It is predicted the formation of the solar system literally took millions of years. In addition, scientists believe that the planets quit growing after 3 to 10 million years of formation because the sun's solar winds cleared away all excess gas and dust in the protoplanetary disc. Thus, the planets could collect no more dust or gas for growth (according to the accretion theory).

Identification

There are currently eight recognized planets within the Milky Way solar system. They are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. While Pluto was once considered a planet, it is no longer recognized as holding planet status.

Features

It is thought the inner portion of the solar system was too hot for molecules to condense. Thus, rocky bodies were formed and included Mercury, Venus, Earth and Mars. These four planets are considered the terrestrial planets and are quite rare in the entire universe.
Jupiter, Saturn, Uranus and Neptune are considered the gas giant planets and formed further out from the sun (beyond the frost line). These planets were thought to have been able to grow larger than the terrestrial planets because the ices that formed them were more abundant.
While finding other planets outside of the Milky Way is challenging, there have been numerous new planet candidates reported over the past ten years. Some of the planets are circling sun-like stars and may offer a great deal of insight to scientists still looking for the answer to how the solar system was formed or created.

Misconceptions

There are many theories and misconceptions regarding the formation of the solar system. For example, the time scale of when it's thought Uranus and Neptune were formed is often debated. While some say they were formed after Jupiter and Saturn, it seems they may have been formed closer to the sun and later migrated outward. It is known during the planetesimal era the motion was not always inward toward the sun. In addition, many scientists do not even believe in the accretion theory and follow other theories of planet formation.