10 Fun facts about the Sun – size, composition, distance, layers, etc.

Sun is a star located at the center of the Solar System. It is around the Sun that planets, asteroids, and other small astronomical bodies of the Solar System orbit. The following are some interesting facts about the Sun. Let’s read.

10 Fun facts about the Sun

Size of the Sun

The Sun has a diameter of about 1.4 million kilometers (865,000 miles). The Sun is so big that 1.3 million Earths would fit inside it. Also, the mass of the Sun is more than 330,000 times the mass of the Earth.

Diameter of Sun = 1.4 million kilometers (865,000 miles)
Diameter of Earth = 12,742 kilometers (7,918 miles)

Mass of Sun = 1,988,500 × 10^24 kg
Mass of Earth = 5.972 × 10^24 kg

An image of the Sun

Distance from the Earth

The Sun is at a distance of about 150 million kilometers (93 million miles) from Earth. This distance is also termed as 1 Astronomical unit or 1 AU.

An image showing Sun, Earth, and Moon

Composition of the Sun

Sun is mainly composed of Hydrogen and Helium. There is also a small amount of Oxygen, Carbon, Iron, and other elements.

Our Sun is neither a very big nor a very small star

Among the billions and billions of stars in the Universe, Sun is neither a very big nor a very small star. It is an average-sized star.

Rotation and Revolution

The Sun rotates around its axis as well as moves around the Milky Way’s galactic center. At the equator, the Sun completes one rotation around its axis in 25 Earth days. At the poles, it completes one rotation in 36 Earth days. It takes Sun 230 million Earth years to complete one revolution around the galactic center.


The Sun’s rotational axis has a tilt of 7.25 degrees from perpendicular to the Earth’s orbital plane.

Layers of the Sun

There are basically two regions of the Sun – inner and outer. The inner region has three layers – the core, the radiative zone, and the convection zone. The outer region has four layers – the photosphere, the chromosphere, the transition region, and the corona. The core is the hottest part of the Sun where the temperature reaches 15 million °C (27 million °F). As we move away from the core in the inner region, the temperature drops.

In the photosphere, the temperature is around 5,500 °C (10,000 °F ). As we move up in the outer region, the temperature increases. In the Sun’s corona, the temperature can reach 2 million °C (3.5 million °F).

Time left for the Sun

The Sun was formed about 4.5 billion years ago. It is estimated that the Sun will produce energy through fusion for another 5 billion years. After 5 billion years, the Sun will become a white dwarf. A white dwarf is a star in which no further nuclear fusion takes place.

Before becoming a white dwarf, the Sun will expand into a Red dwarf and will engulf nearby planets.

Closest stars from the Sun

The closest three stars to the Sun are the three stars of the Alpha Centauri star system (Alpha Centauri A, Alpha Centauri B, and Alpha Centauri C). Alpha Centauri C also known as Proxima Centauri is the closest star to the Sun. It is about 4.25 lightyears away from the Sun.

Aurora/Polar lights

Aurora/polar lights

When the stream of charged particles released from the Sun’s corona reaches Earth, it is directed to the poles by the Earth’s magnetic field. These particles on contacting the Earth’s ionosphere produce Auroras.

Sun’s mass

Sun comprises over 99.8 percent of the total mass in the Solar System.

Basic facts about the Sun

Diameter1.4 million kilometers (865,000 miles)
Mass1,988,500 × 10^24 kg
TypeYellow dwarf
Major Planets8
Ageabout 4.5 billion years
Distance from Earth150 million kilometers (93 million miles)
Compositionmainly Hydrogen and Helium

Most asked questions

How old is the Sun?

4.5 billion years old

What is Sun made of?

mainly Hydrogen and Helium

Does the Sun move?

Yes, the Sun revolves around the Milky Way’s galactic center.

What is the closest star to the Sun?

Proxima Centauri

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