The Sun is extremely hot, with a surface temperature of around 5,500 degrees Celsius (9,932 degrees Fahrenheit). However, the core temperature reaches an astounding 15 million degrees Celsius (27 million degrees Fahrenheit). The Sun’s high temperature is due to the nuclear fusion reactions happening in its core, where hydrogen atoms combine to form helium and release a massive amount of energy. This energy is what powers the Sun and provides heat and light to our planet. Despite its scorching temperature, the Sun’s heat is not directly felt on Earth due to the vast distance between us and the Sun.
The sun that warms our planet and supports life on Earth is a large sphere of gas. These gases are predominantly hydrogen and helium, but the sun also contains small amounts of other elements such as oxygen, carbon, nitrogen, magnesium, and iron.
In its core, the sun undergoes a process called “nuclear fusion” where millions of tons of hydrogen are converted into helium, releasing immense amounts of energy. It is this fusion process that generates the heat and light rays that eventually reach Earth.
Have you ever experienced extremely high temperatures during the summer where you live? Temperatures exceeding 100°F are common in many regions of the United States during this season.
Imagine how much hotter it would be if Earth were closer to the sun. Fortunately, Earth is positioned 93 million miles away from the sun, allowing us to live comfortably throughout the year.
When asked about the hottest thing on Earth, many people think of lava, the molten rock that occasionally flows from volcanoes.
Indeed, lava is extremely hot, reaching temperatures of 2,200°F or more. However, even lava cannot compare to the sun’s temperature!
At the sun’s surface, known as the “photosphere,” the temperature reaches an astonishing 10,000°F! This is approximately five times hotter than the hottest lava on Earth. However, the photosphere is not the hottest region of the sun.
The sun’s temperature increases as you move away from the photosphere, whether towards the core or the outermost atmospheric layer of the sun.
This outermost atmospheric layer is called the “corona.” The corona appears as a bright halo of light during a total solar eclipse.
The farthest point of the corona from the sun can reach temperatures as high as 3,600,000°F. Yes, you read that correctly – 3.6 million degrees Fahrenheit. Surprisingly, the corona is not the hottest part of the sun either.
To discover the hottest part of the sun, you would need to travel all the way to its core. In the core, the process of nuclear fusion generates temperatures of approximately 27,000,000°F. A temperature of 27 million degrees Fahrenheit is more than 12,000 times hotter than the hottest lava on Earth!
If the core is the hottest part of the sun, what is the coolest? Occasionally, dark and cool areas of magnetic disturbances appear on the photosphere.
These areas are known as “sunspots.” Sunspots tend to be cooler than their surroundings and typically reach temperatures of “only” 6,700°F.
Try It Out
Wow! Today’s Wonder of the Day really raised the temperature, didn’t it? Well, we encourage you to turn up the heat even more as you engage in one or more of the following activities with a friend or family member:
Fun with Temperature
To determine how hot different liquids are, you can conduct an enjoyable experiment using a thermometer. In this experiment, you will need a variety of liquids at different temperatures. It would be helpful to have an adult assist you, especially if you plan to heat water using the stove or microwave. Gather samples of various liquids, including room temperature tap water, refrigerated milk, the coldest tap water available, the hottest shower water, water microwaved for different durations (e.g. 10, 20, 30, or more seconds), and boiling water. Create a list of these items and make a guess about their temperatures. Then, use a thermometer to measure their exact temperatures. Evaluate the accuracy of your guesses. Identify the coldest and hottest liquids. Compare the temperature of the hottest liquid to the heat at the core of the sun.
Protecting Yourself from the Sun
Now that you have an understanding of the sun’s temperature, it is important to know how to shield your body from its harmful rays. Additionally, you should be aware of what to do if you get sunburned. When spending time in the sun, it is advisable to wear sunglasses and apply sunscreen. This is particularly crucial for prolonged sun exposure, such as a day at the beach. Apply sunscreen generously and reapply every two hours. If you are sweating excessively or engaging in physical activity, you may need to apply sunscreen more frequently. Sunscreens are available in various types, and the bottle should indicate a Sun Protection Factor (SPF) number. Opt for a sunscreen with an SPF of at least 15. The higher the SPF, the greater the sun protection. If you are prone to sunburn, consider additional protective measures such as wearing long-sleeved shirts, hats, and sunglasses to minimize sun exposure. If you do get sunburned, there is not much you can do to expedite the healing process. Focus on alleviating symptoms and allowing your skin time to heal. Keep your sunburned skin cool by using damp towels or taking cool baths. Moisturize the affected areas with creams containing aloe. Specialty lotions for sunburns are available at most drugstores. If you experience severe sunburn, consult a doctor. Signs of severe sunburn include multiple blisters, as well as headaches and nausea. If you have only a few blisters, medical attention may not be necessary, but avoid breaking them as it can delay healing and increase the risk of infection.
Life on Mercury and Venus
Curious about life on planets closer to the sun? Earth is habitable due to its distance from the sun, but what about Mercury and Venus? Conduct your own research online to explore the weather conditions on these planets compared to Earth. How extreme are the temperatures? Could humans survive there? Share your discoveries with friends and family.