Although the Sun is the largest object in the Solar System, it is considered an average-sized star when compared to other stars in the Milky Way galaxy.
Located 149.6 million kilometers away from Earth, the Sun is composed of a flowing plasma intertwined with electromagnetic fields, with a surface temperature reaching up to 5,505 degrees Celsius. Most of the life on Earth has been able to exist and thrive for billions of years thanks to the Sun.
How Big is the Sun?
The Sun is nearly a perfect sphere. Its equatorial diameter and polar diameter differ by only 10 kilometers. The average radius of the Sun is 696,000 kilometers, and its diameter is about 1.392 million kilometers. According to NASA, you could fit 109 Earths side by side across the surface of the Sun.
According to solar energy scientist C. Alex Young at NASA, if the Sun were hollow, it would take about one million Earths to fill it. In contrast, if the Earth were hollow, it would only take about 50 Moons to fill it.
The total mass of the Sun is 1.989 x 1030 kg, which is about 333,000 times the mass of Earth. In terms of size, if the Sun were the size of a basketball, Earth would be as small as the tip of a matchstick.
Size comparison of Earth and the Moon next to the Sun. (Photo: Mehmet Ergün)
Despite being at the center and the largest celestial body in the Solar System, the Sun is just an average-sized star among the hundreds of billions of stars in the Milky Way. For instance, Betelgeuse, a red supergiant star, is approximately 700 times larger and shines over 14,000 times brighter than the Sun.
“We have found stars with diameters over 100 times that of the Sun. These stars are truly massive,” NASA stated on its SpacePlace website. However, there are also stars that are only about 1/10 the size of the Sun.
According to NASA experts, the size of the Sun could be much larger than previously published figures, as humans have yet to measure this star precisely.
Researcher Ernie Wright from NASA told Space that measuring the Sun is not as simple as one might think; it is not just about placing a ruler on satellite images and coming up with numbers. Even using the transit of Mercury and Venus to measure may not yield the desired results.
The Sun and Earth
The Sun is classified as a G-type main-sequence star, or G dwarf star, more commonly referred to as a yellow dwarf. In reality, the Sun—like other G-type stars—appears white but looks yellow in Earth’s atmosphere.
Sizes of the planets in the Solar System.
Stars tend to grow larger as they “age.” According to NASA, in about 5 billion years, scientists believe that the Sun will begin to exhaust the hydrogen in its core and will gradually transform into a red giant star, expanding its orbit further than it is now.
By running simulations on computers, scientists discovered that instead of fading and gradually disappearing as previously thought, the Sun will become a beautiful planetary nebula that can be clearly seen for millions of light-years after its death.
Even though Earth may still exist after the Sun’s demise, life on the planet will have perished long before that. As the Sun ages, it will become increasingly brighter, and in about two billion years, the Sun could become hot enough to boil Earth’s oceans.
If humans are still around at that time, they will have to consider migrating to another planet, such as Mars, which will become warmer due to the Sun’s expansion.
