What causes the strange green flash at sunset and sunrise on Earth?

Here’s something you might remember from your high school Earth science class: As sunlight—which appears to be pure white—passes through a glass prism, it is refracted, or bent. Different wavelengths of light bend by different amounts. In this way a prism can scatter a beam of white light into the rainbow spectrum.

Refractive color scattering can be seen in poor quality binoculars and telescopes. On such inexpensive instruments, the optics tend not to align properly, so sometimes you’ll see the full moon appear with an orange-yellow tinge to one side and a bluish tinge to the other.

Leave a Reply

Your email address will not be published. Required fields are marked *