The Sun (or Sol), is the star at the centre of our solar system and is responsible for the Earth’s climate and weather. The Sun is an almost perfect sphere with a difference of just 10km in diameter between the poles and the equator. The average radius of the Sun is 695,508 km (109.2 x that of the Earth) of which 20–25% is the core.
Size of the Sun
Facts about the Sun
- The Sun is all the colours mixed together, this appears white to our eyes.
- The Sun is composed of hydrogen (70%) and Helium (28%).
- The Sun is a main-sequence G2V star (or Yellow Dwarf).
- The Sun is 109 times wider than the Earth and 330,000 times as massive.
- The Sun’s surface area is 11,990 times that of the Earth’s.
- The distance between the Earth and the Sun is an Astronomical Unit (AU)
- One million Earths could fit inside the Sun.
A hollow Sun would fit around 960,000 spherical Earths. If 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.
- 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.
- The Sun is an almost perfect sphere.
There is a 10 kilometre difference between the Sun’s polar and equatorial diameter. This means it is the closest thing to a perfect sphere that has been observed in nature.
- The Sun will consume the Earth.
When the Sun has burned all its Hydrogen, it will continue to burn helium for 130 million more years. During this time it will expand to the point that it will engulf Mercury, Venus, and the Earth. At this stage it will have become a red giant
- The Sun will one day be about the size of Earth.
After its red giant phase, the Sun will collapse. It will keep its enormous mass with the approximate volume of our planet. When this happens, it will have become a white dwarf.
- The temperature inside the Sun can reach 15 million degrees Celsius.
Energy is generated at the Sun’s core, by nuclear fusion, as Hydrogen converts to Helium. Hot objects expand, the Sun would explode if it weren’t for its enormous gravitational force. The temperature on the surface of the Sun is closer to 5,600 degrees Celsius.
- Light from the Sun takes eight minutes to reach Earth.
The Sun is an average distance of 150 million kilometres from Light travels 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.
- The Sun travels at 220 kilometres per second.
The Sun is 24,000-26,000 light years from the galactic centre. It takes the Sun 225-250 million years to complete an orbit of the centre of the Milky Way.
- The distance from the Sun to Earth changes throughout the year.
This is 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 Sun is middle-aged.
At around 4.6 billion years old, the Sun has already burned off about half of its store of Hydrogen. It has enough left to continue to burn Hydrogen for approximately 5 billion years. The Sun is currently a type of star known as a Yellow Dwarf.
- The Sun has a very strong magnetic field.
Magnetic energy released by the Sun during magnetic storms causes solar flares. We see these as sunspots. In sunspots, the magnetic lines twist and they spin, much like a tornado would on Earth.
- The Sun generates solar wind.
The wind is a stream of charged particles. This travels at approximately 450 kilometres per second through the solar system. Solar wind occurs when the magnetic field of the Sun extends into space.
|Name||Distance from Sun||Length of Year||Classification|
|Mercury||57,909,227 km||88 Earth days||Planet|
|Venus||108,209,475 km||225 Earth days||Planet|
|Earth||149,598,262 km||365.24 days||Planet|
|Mars||227,943,824 km||1.9 Earth years||Planet|
|Ceres||413,700,000 km||4.6 Earth years||Dwarf Planet|
|Jupiter||778,340,821 km||11.9 Earth years||Planet|
|Saturn||1,426,666,422 km||29.5 Earth years||Planet|
|Uranus||2,870,658,186 km||84.0 Earth years||Planet|
|Neptune||4,498,396,441 km||164.8 Earth years||Planet|
|Pluto||5,874,000,000 km||248.0 Earth years||Dwarf Planet|
|Haumea||6,452,000,000 km||283.3 Earth years||Dwarf Planet|
|Makemake||6,850,000,000 km||309.9 Earth years||Dwarf Planet|
|Eris||10,120,000,000 km||560.9 Earth years||Dwarf Planet|
Further reading solarsystem.nasa.gov/solar-system/sun/overview/