The Sun is composed of a number of different compounds and elements which exist at different temperatures and therefore emit radiation with different wavelengths (this is explained in more depth below the video).
All of the light we see with our eyes is electromagnetic radiation that falls within the “visible spectrum”, meaning that the photons, or light particles, have a wavelength between 400 and 700 nanometers (a nanometer is 1 billionth of a meter).
The range of wavelengths within the sun in 250-2500 nanometers. This video shows you all of the the other forms of radiation that our eyes can’t see.
Since all photons travel at the speed of light (roughly 30million m/s or 670,616,629mph), a photon with a longer wavelength must have a shorter frequency (how many waves pass a point in a given time).
For example, imagine you have two waves traveling past a line you have drawn: one wave that has a wavelength of one meter and another that has a wavelength of two meters. If they travel at the same speed, two of the one-meter waves will pass your line in the time it takes one full two-meter wave to pass it, so we say the shorter one has twice the frequency. In fact, multiplying the wavelength and frequency of any photon will give you the speed of light.
Frequency and temperature are directly proportional so different materials release photons with different frequencies, depending on how hot the material is. Here’s a great chart that shows the relationships between wavelength, frequency and temperature. Click to see full size.
For more information, visit the project’s page on NASA’s website by clicking the image below.