Have you ever thought about what color the sun really is? If you were to draw the sun, you’d probably reach for a yellow crayon, right? Maybe orange if you’re drawing a sunset. But did you know that in Japan, kids often choose red? It’s interesting because none of these colors are the sun’s true color.
On Earth, the sun appears yellow or sometimes orangish-red. This happens because our atmosphere scatters the blue and violet light from the sun, leaving the yellowish light for us to see. But if you were to look at the sun from space, it would actually look white!
When you see pictures of the sun in movies or on TV, they often show it as orange. This is done to make it look more familiar to us, but it’s not the sun’s true color. These images are made using a mix of red, green, and blue light to create the colors we see.
Think about when you heat metal in a fire. It starts glowing red, then white, and if it gets really hot, it might even look blue. This happens because the metal is emitting energy as electromagnetic radiation. This radiation changes color based on the temperature.
Everything emits some form of radiation. Humans, for example, emit infrared radiation because our bodies are relatively cool compared to stars.
The sun’s surface is about 5800 Kelvin, which is very hot! Because of this temperature, the sun emits light that falls mostly in the visible range, which is the light we can see. This is why we have evolved to see this range of light.
Stars come in different colors based on their temperatures. Cooler stars look red, while the hottest stars appear blue. If you look up at the night sky, you might spot Sirius, the brightest star, which shines with a blue hue.
Astronomers have studied the light from stars in over 200,000 galaxies to find the average color of the universe. They call this color “cosmic latte,” which is a light beige color.
In 2012, astronomers also figured out the color of our galaxy, the Milky Way. They described it beautifully in a haiku:
Look at new spring snow
See the River of Heaven
An hour after dawn
So next time you think about the sun or look up at the stars, remember there’s more to their colors than meets the eye. Stay curious and keep exploring!
Gather different colored filters (red, blue, yellow, etc.) and a flashlight. Shine the flashlight through each filter and observe how the light changes. Discuss with your classmates why the sun appears different colors from Earth and space, and how this experiment relates to atmospheric scattering.
Draw two pictures of the sun: one as you see it from Earth and another as it would appear from space. Use colored pencils or crayons to illustrate the differences. Share your drawings with the class and explain why you chose those colors based on what you’ve learned about the sun’s true color.
Research different stars and their temperatures. Create a chart that matches star colors with their temperatures (e.g., red for cooler stars, blue for hotter stars). Present your findings to the class and discuss how temperature affects the color of stars, including our sun.
Inspired by the haiku about the Milky Way, write your own haiku about the sun. Focus on its color, temperature, and the way it appears from Earth and space. Share your haiku with the class and discuss the scientific concepts you included in your poem.
Research the concept of “cosmic latte” and how astronomers determined the average color of the universe. Create a presentation or poster that explains this concept and how it relates to the colors of stars and galaxies. Present your work to the class and discuss the significance of this discovery.
Here’s a sanitized version of the transcript, removing any informal language and maintaining a professional tone:
—
[MUSIC][MUSIC] If I were to ask you to illustrate the sun, which crayon would you select? Most individuals would likely choose yellow, or perhaps orange if depicting a sunset. However, in Japan, children typically opt for red. It is safe to say that no one would select the actual color of the sun.
It is true that on Earth, the blue and violet wavelengths in sunlight are scattered by the atmosphere, causing the sun to appear slightly yellow or even orangish-red. However, from above Earth’s atmosphere, the sun appears essentially white.
When we see images of the sun from outer space in films, television shows, and even photographs from astronomers, it is often tinted orange to appear more familiar to us. However, this display cannot accurately represent the true color of the sun. The images being presented to you are mixtures of red, green, and blue light, with varying intensities that create the sensation of any visible wavelength or combination of wavelengths. This color is essentially a representation of these colors.
When metal is heated in a fire, it begins to glow, first red-hot, then white, and at its highest temperature, even blue, as it emits thermal energy in the form of electromagnetic radiation. This emitted blackbody radiation consists of a mix of wavelengths that depend on the temperature.
When objects reach extremely high temperatures, they can emit radiation in the ultraviolet range. Humans are emitting radiation at this moment, but it is in the infrared range because of our relatively lower temperature.
The sun has a surface temperature of approximately 5800 Kelvin, and the radiation it emits is concentrated in the visible range, which is why it is termed the visible range; it corresponds to what we have evolved to perceive.
Across the universe, stars of varying temperatures emit different mixtures of light. Cooler stars appear red, while the hottest stars appear blue. If one knows where to look, colored stars can be observed, such as the blue of Sirius, the brightest star in the night sky.
By analyzing the light emitted by that star and countless others across more than 200,000 galaxies, astronomers have determined the average color of the universe, which they refer to as cosmic latte.
As for our own galaxy, the Milky Way, astronomers also identified its color in 2012 and captured it in a haiku:
Look at new spring snow
See the River of Heaven
An hour after dawn
Stay curious.
—
This version maintains the informative nature of the original transcript while ensuring a more formal tone.
Sun – The star at the center of our solar system that provides light and heat to the planets orbiting it. – The sun is essential for life on Earth because it provides the energy needed for plants to grow.
Color – The characteristic of light as seen by the human eye, determined by its wavelength. – The color of a star can tell astronomers a lot about its temperature and age.
Light – Electromagnetic radiation that is visible to the human eye and is responsible for the sense of sight. – Light from the sun takes about 8 minutes to reach Earth.
Stars – Massive, luminous spheres of plasma held together by gravity, often visible in the night sky. – Stars are born in nebulae, which are large clouds of gas and dust in space.
Temperature – A measure of the average kinetic energy of the particles in a substance, indicating how hot or cold it is. – The temperature of the sun’s core is extremely high, reaching millions of degrees Celsius.
Radiation – The emission of energy as electromagnetic waves or as moving subatomic particles. – The Earth receives solar radiation from the sun, which warms the planet’s surface.
Universe – All existing matter and space considered as a whole; the cosmos. – The universe is vast and contains billions of galaxies, each with millions of stars.
Galaxies – Large systems of stars, gas, dust, and dark matter bound together by gravity. – Our solar system is located in the Milky Way, which is one of the many galaxies in the universe.
Atmosphere – The layer of gases surrounding a planet or celestial body. – Earth’s atmosphere protects us from harmful solar radiation and helps regulate the planet’s temperature.
Infrared – A type of electromagnetic radiation with wavelengths longer than visible light but shorter than radio waves. – Infrared telescopes can detect heat emitted by objects in space, allowing astronomers to study celestial bodies that are not visible in regular light.
