Fact about The Sun(1-5)

 1. The Sun is the Solar System

We live on planets, so we think that our planet is an equal member of the solar system. But it is not true.

The reality is that the mass of the Sun alone is 99.8% of the mass of our Solar System. Most of the remaining 0.2% comes from Jupiter.

Then you think that when our earth is not even 1% of our solar system, then it is too far to imagine the existence of earth in the universe.


2. The Sun is mostly hydrogen and helium.

If you look at the different elements of the Sun by separating them, you will find that 74% of its mass is from hydrogen and 24% from helium.

The remaining 2% consists of iron, nickel, oxygen and other elements. In other words, the solar system is mostly made of hydrogen.


3. The sun is very bright.

We know of some amazingly large and bright stars like Eta Carina and Betelgeuse. But they are far away. Our own Sun is also a relatively bright star.

If you take the 50 closest stars within 17 light years of Earth, the Sun will be the 4th brightest star in absolute terms.


4. The Sun is huge, but small.

The diameter of the Sun is 109 times the size of the Earth. You can fit 1.3 million Earths inside the Sun, and at the same time cover the Sun's surface by flattening 11,990 Earths.

These figures seem very big to hear but there are bigger stars than this. For example, the largest star that we know of if placed inside the Solar System would almost reach Saturn.


5. Sun is of middle age.

Astronomers believe that the Sun (and the planets) formed from a solar nebula about 4.59 billion years ago. The Sun is still in its main sequence stage, and is slowly using up its hydrogen fuel.

But in about 5 billion years from now, the Sun will enter the red giant phase, in which the Sun will consume the inner planets—including (probably) Earth.


6. The Sun has layers.

The Sun looks like a burning ball of fire, but it actually has an internal structure as well. The layer we can see is called the photosphere, which heats up to a temperature of about 6000 degrees Kelvin.

Below this is the convection zone, where heat travels slowly from the inner part of the Sun to the outer surface. This zone starts at 70% of the Sun's radius.

Radiative zone comes under the Convection zone. In this zone heat travels only through radiation. The core of the Sun extends to a distance of 0.2 solar radii from the Sun.

This is where the temperature reaches 13.6 million degrees Kelvin, and the hydrogen molecules fuse with helium.


7. The sun is slowly heating up.

It seems that the sun has remained unchanged forever, but it is not true. The sun is heating up really slowly. It is getting 10% brighter every billion years.

In fact, within just one billion years to come, the Sun's heat will increase so much that liquid water will no longer exist on Earth's surface.

Due to which life on earth will end forever. It will take 7 billion years for the Sun to reach its Red Giant Phase.


8. Different parts of the Sun rotate at different speeds.

Unlike the planets, the Sun is a very large ball of hydrogen gas. Due to this, different parts of the Sun rotate at different speeds.

The regions near the equator take 25 days to complete one rotation, while the regions near the poles may take up to 36 days.


9. The outer atmosphere is hotter than the surface.

The surface of the Sun reaches a temperature of 6,000 Kelvin. But it is much less than the atmosphere of the Sun.

Actually there is an atmosphere above the surface of the Sun, which is called Chromosphere, where the temperature reaches about 100,000 Kelvin. But this is also nothing.

There is another region called Corona where the temperature reaches 1 million Kelvin.


10. Now the spacecraft are observing the Sun.

The most famous spacecraft sent to observe the Sun is the Solar and Heliospheric Observatory built by NASA and ESA, and it was launched in December 1995.

It has been observing the Sun continuously since then, and sending back countless images.

Another recent mission of NASA is the STEREO spacecraft. In fact, these two spacecraft were launched in October 2006.


These twin spacecraft were designed to observe the same activity on the Sun from two different points of view, to give a 3D perspective on the Sun's movements and help astronomers better predict the weather.