If you’re lucky, you may have seen one during your time on Earth. A glory is a shimmering optical phenomenon that forms when water droplets scatter light. It’s ethereal, like a rainbow halo that shifts from red on the outside to blue on the inside.
European Space Agency astronaut Alexander Gerst saw one, which he calls a pilot’s glory, from on board the International Space Station. He shared his surprise at the sighting in a Twitter message on Tuesday.
“A ‘glory’ is a rare optical phenomenon that is mostly seen by pilots and mountain climbers looking down at mists or clouds,” says the ESA. They are sometimes called pilot’s halos or “the glory of the pilot.” To see one from space is very unusual.
Airplane passengers sometimes see glories while flying, usually while spotting the plane’s shadow at the center. The ISS doesn’t throw a shadow into the center of the glory seen by Gerst due to its high orbital altitude above Earth.
NASA’s Terra satellite captured a cross-section of a glory in June. The space agency traces one of the earliest scientific reports of a glory to a 1730s French expedition to the equator.
While we’ve known about glories for a long time, witnessing one from space is an extra special experience and we’re fortunate Gerst managed to capture a photo of it.