Why is the Sun so hot?

Why Is The Sun Hot?

The Sun is the hottest place in the Solar System. The surface of the Sun is a mere 5,800 

Kelvin, but down at the core of the Sun, the temperatures reach 15 million Kelvin.

The Sun is just a big plasma ball of hydrogen, held together by the mutual gravity of all its mass. This enormous mass pulls inward, trying to compress the Sun down. It’s the same reason why the Earth and the rest of the planets are spheres. 

As the pull of gravity compresses the gas inside the Sun together, it increases the temperature and pressure in the core which results in small, sudden bursts of heat and energy, called nano-flares, responsible for hot temperature of the sun's tenuous atmosphere.

The process where protons are merged together into atoms of helium is called nuclear fusion. It can only happen in hot temperatures, and under incredible pressures. 

But the process of fusion gives off more energy than it uses. So once it gets going, each fusion reaction gives off gamma radiation. It’s the radiation pressure of this light created in the core of the Sun that actually stops it from compressing any more.
Gravity is trying to squeeze it together into a little ball, but this creates the right conditions for fusion and increases its temperature to a greater extent.

The Sun

The Sun

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.

Star Profile

Age: 4.6 Billion Years
Type: Yellow Dwarf (G2V)
Diameter: 1,392,684 km
Circumference at Equator: 4,370,005.6 km
Mass: 1,989,100,000,000,000,000,000 billion kg (333,060 x Earth)
Surface Temperature: 5500 °C

Size Of The Sun

Facts About The Sun

One million Earths could fit inside the Sun:
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 Suns surface area is 11,990 times that of the Earth’s.

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

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.

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 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.

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.

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.

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).

The Sun is middle-aged:
At around 4.5 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 another 5 billion years. The Sun is currently a type of star known as a Yellow Dwarf

The Sun has a very strong magnetic field:
Solar flares occur when magnetic energy is released by the Sun during magnetic storms, which we see as sunspots. In sunspots, the magnetic lines are twisted and they spin, much like a tornado would on Earth.

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.

The Sun generates solar wind:
This is a stream of charged particles, which travels through the Solar System at approximately 450 kilometres per second. Solar wind occurs where the magnetic field of the Sun extends into space instead of following its surface.

Satellites

Name  Distance from Sun  Type
Mercury  57,909,227 km (0.39 AU)          Planet
Venus  108,209,475 km (0.73 AU)         Planet

Earth  149,598,262 km (1 AU)          Planet

Mars  227,943,824 km (1.38 AU)         Planet

Ceres  413,700,000 km (2.77 AU)         Dwarf Planet
Jupiter  778,340,821 km (5.20 AU)         Planet

Saturn  1,426,666,422 km (9.58 AU)         Planet

Uranus  2,870,658,186 km (19.22 AU)         Planet

Neptune  4,498,396,441 km (30.10 AU)         Planet

Pluto  5,874,000,000 km (39.26 AU)         Dwarf Planet

Haumea  6,452,000,000 km (43.13 AU)         Dwarf Planet

Makemake 6,850,000,000 km (45.79 AU)         Dwarf Planet

Eris  10,120,000,000 km (68.01 AU)         Dwarf Planet

Facts On Solar Eclipse

Solar Eclipse

What Is A Solar Eclipse?

A solar eclipse in when the Moon passes in front of the Sun casting a shadow on the Earth (this is also known as an occultation). As the Sun’s distance from Earth is around 400 times the Moon’s distance and the Sun’s diameter is around 400 times the Moon’s diameter, the Sun and the Moon as seen from Earth appear to be approximately the same size. There are several sorts of eclipses; partial, annular and total.

Partial Solar Eclipse: Occurs when the Moon does not line up with the Sun exactly only partially obscuring it.

Annular Solar Eclipse:  When the Moon is further from the Earth and/or the Earth is closer to the Sun the Moon will appear smaller in comparison to the Sun so during an eclipse will not entirely cover it appearing as a bright ring surrounding the Moon.

Total Solar Eclipse: Occurs when the Moon completely obscures the Sun allowing the fainter solar corona to be visible.

Facts About Solar Eclipses

1.There are between 2 and 5 solar eclipses each year.

2.When the Moon completely obscures Sun so only the solar corona can be seen it is called a Totality

3.A total solar eclipse only happens once every 1 and a half years

4.The Moon moves across  the Sun at 2,250 km per hour

5.Only partial solar eclipses can be observed from the North and South Poles

6.The longest a total solar eclipse can last is 7 and a half minutes

7.The width of the path of totality is at most 269 km wide

8.Almost identical eclipses occur after 18 years and 11 days, this is known as the Saros Cycle