The Solar System and its basic definition

The Solar System



The solar system was the only planetary system known existing until 1995, when astronomers discovered a planet with a mass comparable to Jupiter, orbiting around the star 51 Pegasi, like the sun later, astronomers detected two planets, masses larger than Jupiter, revolving around the star trails: 70 Virginis and 47 Ursae Maioris. In 1999, two teams of astronomers working independently announced the discovery of the first multi-planet system than ours, they were three gas planets orbiting the star? Psilon Andromedae. In January 2000 announced the discovery of two extrasolar planetary systems. The planetary system like our solar system discovered so far is formed by at least two planets revolving around the star 55 Cancri. In June 2002 announced the discovery of the second of these planets, which is located at a distance from its star similar to that between Jupiter and the Sun Its orbit is somewhat elliptical, also similar to that of Jupiter. Since 1995 it discovered the first planet outside our Solar System, have been detected more than two hundred of these planets. See Extrasolar Planets.

Current theories connect the formation of the Solar System with the formation of the Sun occurred about 4,700 million years. The fragmentation and gravitational collapse of an interstellar cloud of gas and dust, triggered perhaps by nearby supernova explosions may have led to the formation of a primordial solar nebula. The sun would then formed in the central region, more dense. The temperature is so high near the sun that even silicates, relatively dense, have difficulty forming there. This phenomenon may explain the presence near the Sun of a planet like Mercury, which has a small silicate envelope and a dense iron core more than usual. (It helps to steam iron powder and clump near the central region of a solar nebula that for lighter silicates.) At large distances from the center of the solar nebula, the gases condense into solids such as those found today in the outer part of Jupiter.

Full article about the solar system