The Sun is Actually White and Not Yellow, Ex-Astronaut Confirms

Responding to a tweet on the colour of the Sun, veteran astronaut Scott Kelly said that the Sun appears yellow in space due to refraction.


In common parlance, the colour of the Sun has always been shown to be yellow. This, however, is likely due to the Earth’s atmosphere and the properties of physics, which makes light appear different once it traverses wide distances. The incident has surfaced courtesy a post on the matter on Twitter, which stated that the colour of the Sun is actually not yellow, but appears so due to the interference of the Earth atmosphere with its light rays. Lending credence to this post, veteran NASA astronaut, Scott Kelly, has attested that the Sun does indeed appear yellow on Earth — but looks white when in space.

Why Does the Colour of the Sun Change?

Light, owing to the refraction of rays through various interfering bodies, can change in the way it appears — particularly when it travels across large distances. The Sun, for instance, sits at a distance of 150 million kilometres from Earth, which makes light interfere when reaching us — via the Earth atmosphere.

Due to this interference, the light coming from the Sun passes through the various gasses of the Earth atmosphere, which leads to the light being refracted through the atmosphere. Add to this is the volume of light that comes through, which is extremely high in volume for human eyes.

When the Sun is at its peak, the main light that is emitted is towards the blue end of the visible light spectrum — which can get scattered in the Earth atmosphere. It is this scattering that leads to light from it appearing yellow for humans on Earth. The setting Sun, on the other hand, shows us light that has already refracted into the red spectrum — which has lesser scattering of light.

It is this that leads to the Earth’s nearest star appearing the way it does for humans on Earth. As the veteran astronaut Kelly stated affirming the post, if you wish to really see the Sun without its light being refracted and altered due to the distance it traverses, a trip to space is what you would require.