People on the Internet appear to believe that the Sun has changed color over the last few decades. In a thread of some very confused Twitter users, people claimed to believe that the Sun used to be yellow, and is now white.
"I’m just telling a person in their 20s that the sun used to be yellow when I was a child and he’s laughing," one Twitter user wrote. "The last time he saw a yellow sun was on Teletubbies. Here’s the sun right now. White and a weird shape. How’s it looking where you are?"
The idea is not a new one, and has been the subject of conspiracy theories for years.
"The Sun used to be yellow. Okay? The Sun is no longer yellow. It’s white now," author and filmmaker Jay Weidner, who linked it to elites spraying chemtrails to block out the sun like Mr Burns, reportedly said in 2017. "And I’m old enough to tell you, it used to be yellow. And anybody my age will tell you that the Sun definitely was yellow."
So what color is the Sun really? Well, if you view the it from above the atmosphere, it appears white, as former NASA astronaut Scott Kelly will now confirm.
This is because the Sun emits light containing all wavelengths, including all colors on the visible spectrum, meaning that we perceive it as white. When the Sun hits our atmosphere, light in the blue spectrum is scattered more efficiently than red light. With less blue light hitting the old eyeballs, you will perceive the Sun as tinted slightly yellow. The more atmosphere the light has to travel through – say at sunrise and sunset – the more blue light gets scattered, making the sun appear yellower or red.
Conversely, when the Sun is directly above you it will appear whiter, as the blue light has less atmosphere to scatter through in order to reach your eyes.
The belief that the Sun was yellower when you were a kid could be down to nostalgia, a tendency to remember a beautiful sunset rather than a regular day, or – as one Twitter user suggested – because pollution was higher when you were young.
To really confuse things for fun, however, pedants could call our Sun green.
"So, the sun actually emits energy at all wavelengths from radio to gamma ray. But," NASA explained ahead of the 2017 eclipse, "it emits most of its energy around 500 nm, which is close to blue-green light. So one might say that the sun is blue-green!"
However, as the Sun emits all wavelengths and not just blue-green, when that spectrum hits our eyeballs we still see it as white.
But it hasn't got any less yellow.