The sun's colour, heated debate - 26th June 2023

Debate over the real hue of the sun's been a matter of extensive speculation among physicists. While there's no definitive answer, many experts lean towards the notion of our sun being a green star that appears white to us.

Children often depict the sun as a yellow circle with rays emanating from it. The high noon sun appears white to our eyes, but during the evening, it takes on a darker orange or crimson hue. These colour variations are primarily influenced by our atmosphere and how we perceive the intense heat of the sun.

According to NASA scientist W Dean Pesnell, "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."

Despite being located 93 million miles away, our sun emits radiation that reaches Earth. When this radiation interacts with molecules in our atmosphere, it scatters the stronger blue and violet wavelengths, creating the blue sky effect, whilst the weaker orange and red wavelengths are allowed to pass through, resulting in the stunning colours of sunrises and sunsets.

The abundance of green light photons in the sun contributes to its perceived greenness. Nevertheless, the intensity and heat of the sun overwhelm our retinas, causing us to see it as white. Astrophysicist Ethan Siegel challenges the notion of the sun's green colour, arguing that even if it emits mostly green light photons, the light we receive on Earth appears white, making white the sun's true colour.

In addition to scientific debates, cultural perspectives and linguistic nuances also come into play. Some languages don't distinguish between blue and green, such as in Vietnamese whilst Japan represents the sun as blood red on its flag. Thus, the perception of the sun's colour can vary depending on language and cultural influences.