Sun is at the centre of our Solar System and the heart of our Solar system. It is a nearly perfect sphere of hot plasma. Its gravity holds the solar system together, keeping everything from the biggest planets to the smallest particles of debris in its orbit. It accounts for about 99.86% of the total mass of the Solar System.

Mass: 1.9884×1030^30 kg

Radius: 696,342 km

Density: 1.408 g/cm^3

Escape Velocity: 617.7 km/sec

Gravity: 274 m/s^2 (28 x Earth)

Distance from Earth: 151.65 million km (8.3 light minutes)

The sun fuses 600 million tons of Hydrogen into Helium every second (Yes, you read that right! 600 million tons a second) converting 4 million tons of matter into energy every second by a simple equation, E=mc^2. This energy takes thousands of years to get out of core. Let’s understand in a detailed way how energy takes thousands of years to get out of the core of the sun.

Hydrogen is fused into Helium and mass is converted into energy in that process. Since this process takes place in core and core is a very dense part of the sun (really dense!). Photon (energy) which is created in the fusion process gets bounced off infinite times within the dense plasma in its core before it reaches to the surface of the sun. When the light reaches the surface it takes just 8.3 minutes to reach the Earth. So, technically we all are receiving the sunlight which was made inside the core of our sun 100,000s of years ago. During the fusion process one more elementary particle is created which does not interact with any matter and gets out of the core at light speed – Neutrino. It is sometimes referred as “Ghost particle” as it passes through all the matter known to us and never interacts with anything. Billions of neutrinos passed through your body every second which were created at the heart of the Sun.

Sun is mainly composed of Hydrogen – 73% and Helium – 24%, rest of the matter is composed of oxygen, carbon, iron, neon nitrogen, sulphur, silicon & magnesium. Hydrogen is the fuel which goes through the nuclear fusion process to create helium and energy is released in the process. 

The sun takes around 225 million years to revolve around the centre of our galaxy. Not only the planets revolve around the Sun, the sun also revolves around the galaxy and its orbital period is 225 million light years. Last time when the sun was at its current position dinosaurs just started to walk on earth.

Bonus Fact : The amount of energy hit the earth from the sun in an hour is more than what we use in a year.