The solar system consists of the sun, the closest star to us, and the planets Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto, as well as numerous comets, asteroids, meteoroids, and the interplanetary medium. The nine planets, along with their satellites, revolve around the sun in certain orbits. The planets and the satellites are said to be the members of the solar family or the solar system.
It’s thought that the sun, the center-piece of the solar system, has been born five billion years back, emitting heat and light non-stop, and it is expected to do this for another five billion years. The sun is the richest repository of electromagnetic energy, in the form of heat and light. The sun contains 99.85 percent of all the matter in the solar system. The planets, which were condensed from the same disk of material that formed the sun, contain only 0.135 per cent of the mass of the solar system.
They all have compact, rugged surfaces like the Earth’s. Jupiter, Saturn, Uranus, and Neptune are known as the Jovian (Jupiter-like) planets on account of their colossal sizes.
By quantity, nearly all the solar system seems to be an empty void. But, this”vacuum of space” encompasses the interplanetary medium containing various forms of energy, dust, and gas. The flow of gas and charged particles called plasma, mostly protons and electrons, is called the solar wind. Its speed is about 250 miles (400 km ) per second in the neighborhood of the Earth’s orbit.
The entire solar system, together with the stars visible on a clear night, orbits the center of our home galaxy called the Milky Way, which is a spiral disk of 200 billion stars.