Purple Suns

Posted by Kelly Whitt Jun 29, 2008

Sometimes, during lunar eclipses, the moon can turn color. While orange is traditional, purplish to all-black can result when particles, such as volcanic ash, are present in the atmosphere.

California is experiencing an amazing amount of wildfires at the moment, especially in the northern half of the state. The smoky air at times blocks out the sun, and at other times it turns the sun a violet hue.

The tiny smoke particles are scattering red light, the longest wavelengths, and letting through blue/purple light, the shortest wavelengths.

This phenomenon of turning the sun and moon colors due to particles in the atmosphere is not unique to Earth. Mars has unusual sunsets from the dust scattered in its atmosphere around times of dust storms. Salmon sunsets, blue suns: the Red Planet can provide a rainbow of colors.