The sun is a big ball of gas, and it is responsible for giving us the light and heat we need to survive.
Learn about the complex layers of the sun, where that energy and light originates, and the powerfully hot temperatures within our favorite star.
How Hot Is the Sun?
Have you ever wondered how hot is ‘really hot?’ What is the hottest thing you can imagine? Is it a day you spent at the beach or a hike you took on a really hot day in the summer? Is it your house on the hottest day of the year when the air conditioner isn’t working?In each of these situations you probably experienced temperatures around 90;F to 100;F (32;C to 38;C). This is nothing compared to the hottest temperature ever recorded on the surface of the earth. It was 134;F (56.
7;C) and was measured on July 10, 1913, in Death Valley, California.Now consider our sun, the star at the center of our solar system that provides us with all of this earthly heat. The sun is hotter than you can imagine and its temperature varies depending on the layer.
The surface of the sun is unbelievably hot, but you won’t believe how hot it gets in the core, or the center, of the sun!
What Is the Sun?
You see and feel the effects of the sun every day as it heats and lights the earth, but do you ever think about what it is? The sun is a star, and it’s not a very special star in the grand scheme of the universe. A star is a ball of glowing gas. Stars in the universe vary in terms of size and age. Our sun is a middle-aged star of average size.
It may not be special compared to other stars, but without it, life on Earth would not be possible. It radiates heat and light toward the earth and allows plants to grow and animals to thrive. Earth’s atmosphere and magnetic field protect us from most of the damage that the radiation from the sun can cause, but still lets in enough energy to keep us going.
The Layers and Temperature of the Sun
While the sun is a big ball of gas, it does have some complexity in its structure. The sun is made up of several layers, starting with the core and working out to the corona, the outermost layer.The core is the center of the sun and is responsible for producing the star’s light and heat. The core is a fusion engine, fusing atoms of hydrogen to produce helium and a tremendous amount of energy.
The temperature in the core is around 28,000,000;F (15,700,00;C).The radiative zone extends about 70 percent of the way out from the core. Energy produced in the core radiates outward to the edge of the sun through this zone. Temperatures here range from 12,000,000;F to 4,000,000;F (7,000,000;C to 2,000,000;C).From the radiative zone, energy travels into the convective zone. Just as water boils in a pot on the stove, in this zone energy is transferred by gases moving in convection cycles. The temperature here is a mere 4,000,000;F (2,000,000;C).
A thin layer after the outer edge of the convective zone is called the photosphere. This is the part of the sun we can see from the earth and which appears yellow to us. The temperature of the photosphere is around 10,300;F (5,700;C).
With the proper telescope, you can see the boiling convective zone through the thin photosphere. The small dots are convective cycles called granules. Also visible on the photosphere are sunspots. There are dark spots caused by magnetic activity in the convective zone.The chromosphere is the coolest layer of the sun at 7,500;F (4,100;C), where it is closest to the photosphere.
As it approaches the outermost layer of the sun, it gets hotter. The chromosphere is a pinkish-red color and is punctured by hot jets of gas.The outermost layer of the sun is a thin and wispy layer of gas called the corona. It extends, in some places, several millions of miles outward into the space around the sun.
The corona is very hot at 1,800,000;F (1,000,000;C). Particles from the corona can escape the gravity of the sun and blow towards the earth in what we call solar wind. We also see huge loops of gas shooting out of the corona. These are called solar prominences, and they originate in the photosphere.
Fun Facts About the Sun
The sun is huge.
From our perspective, it is the largest celestial body we can see in the sky, even though it is 93,000,000 miles away from us. The volume of the sun is large enough to hold more than 1,000,000 Earths. The gravitational pull of this massive ball of gas is what keeps all of the planets in orbit around it.Solar flares are huge eruptions of solar wind. They can be large enough to see from Earth and are made up of charged particles that disrupt our technologies. They are capable of disrupting satellites, radio transmissions, and even power grids on the surface of the earth.
The magnetic field surrounding the earth protects us from most of the particles carried by solar wind. If you have ever seen the northern lights, or aurora borealis, then you have seen these particles interacting with Earth’s magnetic field.
The sun is the star at the heart of our solar system. It is extremely hot because of the nuclear fusion reaction that occurs in its core. Outside of the core, the radiative and convective zones transfer that energy outward. The thinner layers of the chromosphere and photosphere are much cooler and are punctuated by phenomena like sunspots and granules.
The outer layer of the sun, the corona, is extremely hot and extends outward for millions of miles. The solar wind blowing out of the corona passes through the earth’s magnetic field, sometimes interrupting our communications and creating the northern lights.