Solar System
• The solar system is the family of the sun, planets revolving around it, the satellites of the planets and the asteroids or meteoroids and comets etc.
• There are eight planets in the solar system.
• Starting from the sun there are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
• All the planets revolve around the sun in their orbits.
• Meteorite analysis shows that the age of solar system is about 4530 million years.
• The sun is not the largest star of the Milky Way; rather it is an average sized star.
• It is not at the centre of the galaxy but shifted towards a side.
• The diameter of the sun is 1, 392, 140 km and its mass is 2 * 1027 tonnes.
• The outermost layer of the sun is called photosphere, has an average temperature of 5570 0C.
• The photosphere rotates at a rate of 25.38 days per turn.
• At the centre of the sun hydrogen is undergoing nuclear fusion reaction which provides energy for the heat and light so sun.
• The planets of the solar system as well as the moons get light and sometimes heat from the sun.
• The four inner planets of the solar system are called terrestrial plants because of their rocky nature.
• The outer planets are called gaseous planets because they don’t have solid surface and are composed of gases.