Have you ever wondered why the Sun looks yellow or orange in the sky, but white in pictures taken from space? The answer has to do with how light interacts with the Earth’s atmosphere.
The Sun is a star that emits light of all colors, from red to violet. This light is called white light, because when you mix all the colors together, you get white. However, when the Sun’s light reaches the Earth, it encounters the air molecules that make up the atmosphere. These molecules scatter some of the light in different directions, depending on the wavelength of the light.
The blue light, which has a shorter wavelength, gets scattered more than the red light, which has a longer wavelength. This means that more blue light reaches our eyes from all directions, making the sky appear blue. On the other hand, the red light, which gets scattered less, travels in a straight line from the Sun to our eyes, making the Sun appear red or orange.
However, this effect is only noticeable when the Sun is low in the sky, such as during sunrise or sunset. When the Sun is high in the sky, it appears yellow, because some of the blue light still reaches our eyes directly from the Sun, along with the red light. The yellow color is a result of mixing red and blue light.
But if you were to see the Sun from space, where there is no atmosphere, you would see it as it really is: white. The Sun’s light would not be scattered by any air molecules, and you would see all the colors of the spectrum at once. The Sun would look like a bright white disk, surrounded by the blackness of space.
The Sun is not the only star that appears white, but has a different color in the sky. Other stars also have different colors, depending on their temperature and composition. For example, Betelgeuse is a red giant star that looks orange in the sky, but is actually red. Sirius is a white dwarf star that looks blue in the sky, but is actually white. And Polaris is a yellow supergiant star that looks white in the sky, but is actually yellow.
The next time you look at the Sun or the stars, remember that they are not what they seem. They are white, but the atmosphere makes them look different. And that is a fascinating science fact.