Our Solar System
The solar system is thought to have originated from the interstellar collapsation of a huge cloud (nebula) of gas and dust. This collapse might have been caused by the explosion of a Supernova, or the shock waves of a spiral galaxy. Recent observations have discovered planetary like forming systems in other regions of the universe.
It is thought that a huge cloud of gas and dust was disturbed by the shock waves of a supernova, causing it to collapse under its own gravity; the cloud fragments began to compress and as the compression progressed, the fragments began to rotate, forming a flatten disk with a bulged center core; the central portion of this cloud accumulated most of the cloud´s mass and began to heat up.
The Primordial Solar Nebula
When the heat reached the temperature of 10 million degrees Kelvin, it began to fuse hydrogen into helium and as the cloud collapsed further, some regions began to condense into what is thought to be the planets and moons of a solar system. The protostar, which is the center core, and the flattened disk continued spinning in the same direction much like the Sun and the planets orbiting around it.
Astronomers call this rotating cloud of gas and dust the primordial solar nebula. The nebular hypothesis, which was first proposed by Kant and Laplace back in the 18th century, provides a complete explanation for some of the features of the solar system, for instance, the general sense of rotation and the planet´s orbits matching the plane of the ecliptic.
Star Forming Regions
New Planetary Systems
In recent years, astronomers have discovered with the aid of powerful telescopes evidence that other planetary systems could be forming around its own star from the collapsing of enormous clouds of gas and dust like our own solar system. The nebular hypothesis has been supported by recent observations that resemble planetary systems in the process of formation. It has been observed that new planetary systems might be forming in the Orion, Eagle, and Lagoon nebulas.