Saturday, June 7, 2008

Formation and evolution of the Solar System

The formation and evolution of the Solar System began 4.6 billion years ago with the gravitational collapse of a small part of a giant molecular cloud. Most of the collapsing mass collected in the centre, forming the Sun, while the rest flattened into a protoplanetary disc out of which the planets,moons, asteroids and othersmall Solar System bodies formed.

This widely accepted model, known as the nebular hypothesis, was first developed in the 18th century by Emanuel Swedenborg, Immanuel Kant, and Pierre-Simon Laplace. Its subsequent development has interwoven a variety of scientific disciplines including astronomy, physics, geology, and planetary science. Since the dawn of the space age in the 1950s and the discovery of extrasolar planets in the 1990s, the models have been both challenged and refined to account for new observations.

The Solar System has evolved considerably since its initial formation. Many moons have formed from circling discs of gas and dust around their parent planets, while many other moons are believed to have been bodies captured by their planets or, as in the case of the Earth's Moon, to have resulted from . Collisions between bodies have occurred continually up to the present day and are central to the evolution of the system. The positions of the planets often shifted, and planets have switched places. This planetary migration is now believed to have been responsible for much of the Solar System's early evolution.

Just as the Solar System formed, so it will eventually disintegrate. In roughly 5 billion years, the Sun will cool and expand outward to many times its current diameter (becoming a red giant) before casting off its outer layers as a planetary nebula and leaving behind a stellar corpse known as a white dwarf. The planets will follow the Sun's course; in the far distant future, the gravity of passing stars will gradually whittle away at the Sun's retinue of planets. Some will be destroyed, others ejected into interstellar space. Ultimately, over the course of trillions of years, the Sun will likely be left alone with no other bodies in orbit.

I was bored because I don't have anything to do at home!! haha!!

Thanks I hoped you enjoyed this literature!!!


{girl}forallstatus said...

no new post? it's been a week