We’ve all recognise that big bright thing that is periodically seen in the sky. It’s called the Sun, but how much do we know about it?
1 It’s very big
The average radius of the Sun is 695,508 km (109.2 x that of the Earth) of which 20-25% is the core.
If a hollow Sun was filled up with spherical Earths then around 960,000 would fit inside. On the other hand if these Earths were squished inside with no wasted space then around 1,300,000 would fit inside. The Sun’s surface area is 11,990 times that of the Earth’s.
2 Eventually, the Sun will consume the Earth
When all the hydrogen has been burned, the Sun will continue for about 130 million more years, burning helium, during which time it will expand to the point that it will engulf Mercury and Venus and the Earth. At this stage it will have become a red giant.
3 The Sun will one day be about the size of Earth
After its red giant phase, the Sun will collapse, retaining its enormous mass, but containing the approximate volume of our planet. When this happens, it will be called a white dwarf.
4 The Sun contains 99.86% of the mass in the Solar System
The mass of the Sun is approximately 330,000 times greater than that of Earth. It is almost three-quarters hydrogen, whilst most of the remaining mass is helium.
5 The Sun is an almost perfect sphere
There is only a 10 kilometre difference in its polar diameter compared to its equatorial diameter. Considering the vast expanse of the Sun, this means it is the closest thing to a perfect sphere that has been observed in nature.
6 Light from the Sun takes eight minutes to reach Earth
With a mean average distance of 150 million kilometres from Earth and with light travelling at 300,000 kilometres per second, dividing one by the other gives us an approximate time of 500 seconds, or eight minutes and 20 seconds. Although this energy reaches Earth in a few minutes, it will already have taken millions of years to travel from the Sun’s core to its surface.
7 The Sun travels at 220 kilometres per second
The Sun is 24,000-26,000 light years from the galactic centre and it takes the Sun 225-250 million years to complete an orbit of the centre of the Milky Way.
8 The distance from the Sun to Earth changes throughout the year
Because the Earth travels on an elliptical orbit around the Sun, the distance between the two bodies varies from 147 to 152 million kilometres. The distance between the Earth and the Sun is called an Astronomical Unit (AU).
9 The temperature inside the Sun can reach 15 million degrees Celsius
At the Sun’s core, energy is generated by nuclear fusion, as Hydrogen converts to Helium. Because hot objects generally expand, the Sun would explode like a giant bomb if it weren’t for its enormous gravitational force.