We’ve seen the famous picture of Earth as taken from the moon There are two slightly less famous versions; they’re both lunar pictures of the Earth, but they’re both pictures taken from ultraviolet cameras.
On the left we have a straightforward picture of the Earth in the sunlight. It was taken by the Far UV Camera, placed on the moon by the Apollo XVI mission. The bright side of the world is lit up by sunlight, and the faint bands that stretch around the globe are auroral light generated by charged particles from the sun hitting Earth’s atmosphere.
The image on the right is called a geocorona. This is the ultraviolet light from the sun reflecting off the neutral hydrogen atoms in Earth’s atmosphere, and as you can see, it’s blindingly bright. It’s been seen a hundred thousand kilometers from the Earth.
Read more about the Far UV Camera at the Lunar and Planetary Institute and the geocorona at the Southwest Research Institute.
Image: G. Carruthers (NRL) et al., Far UV Camera, Apollo 16, NASA
