Earth's green sun - 26th June 2023

The question of the sun's true colour has divided physicists but most agree our sun's a green star that appears white. Children drawing the sun might depict a yellow blob with rays around it.

At noon, the sun looks white, but in the evening it appears dark orange or even crimson. These colour changes are mainly caused by the atmosphere and how humans perceive an extremely hot object's temperature. NASA scientist W Dean Pesnell stated, "Essentially, it's a green star that looks white because it's too bright, and it can also appear yellow, orange or red because of how our atmosphere works."

93 million miles away, our sun shoots radiation across the solar system. When this hits Earth, molecules in our atmosphere redirect the stronger blue and violet wavelengths, therefore making the sky appear blue. The atmosphere allows the weaker orange and red wavelengths to pass through to our eyes giving us gorgeous sunrise and sunset colours.

Our sun contains more green light photons, the quantum particles which produce light, than any other colour. However, the strength and heat of the sun overloads our retina causing them to see white.

Not everyone agrees, like astrophysicist Ethan Siegel. He pointed out that even if the sun has mostly these photons, the light the earth receives appears white, therefore that should be the sun's colour.

Siegel pointed to a simple experiment to prove his point. Take a piece of white paper and shine a red light on it, red appears on the paper. Put the paper in the sunlight, and it won't look green but white.

Alongside scientific debate, there are cultural and linguistic issues to consider. Some languages like Vietnamese don't have a word to differentiate between blue and green. Japan depicts the sun as blood red on its flag. In your language, what colour is the sun?