The SUN

“I don’t think the human race will survive the next thousand years, unless we spread into space. There are too many accidents that can befall life on a single planet. But I’m an optimist. We will reach out to the stars.” — Stephen Hawking, theoretical physicist and cosmologist.

The SUN

 

                      Sun is the only star and most important feature in our solar system. Large and violent eruptions are occurring on the Sun due to surface and coronal activities like., sunspots, coronal mass ejections (CMEs), solar X-ray flares, faculae, prominences and coronal holes. The Sun is with diameter of about 1,392,000 km (about 109 times that of Earth) and mass about 2 × 1030 kg (330,000 times that of Earth). The other important characteristics are the following : (1) Sun is about 99.86% of the total mass of our solar system, (2) Chemically, about 75% of the solar mass consists of hydrogen, while the rest is mostly helium, (3) Less than 2% consists of heavier elements, including carbon, nitrogen, oxygen, neon, magnesium, silicon and iron and (4) The mean distance of the Sun from the Earth is approximately 149.6 × 106 km (known as 1 Astronomical Unit (1 AU) and it is a unit of length in Astrophysics).