What's happening to this cloud? Ice crystals in a distant cirrus cloud are acting like little floating prisms. Known informally as a fire rainbow for its flame-like appearance, a circumhorizon arc appears parallel to the horizon. For a circumhorizontal arc to be visible, the Sun must be at least 58 degrees high in a sky where cirrus clouds present below -- in this case cirrus fibratus. The numerous, flat, hexagonal ice-crystals that compose the cirrus cloud must be aligned horizontally to properly refract sunlight in a collectively similar manner. Therefore, circumhorizontal arcs are somewhat unusual to see. The featured fire rainbow was photographed in 2021 near North Fork Mountain in West Virginia, USA. Sky Surprise: What picture did APOD feature on your birthday? (after 1995)
HD image: LINK 🛸
Copyright: Christa Harbig 🔭
Project Website: LINK 🚀
👨🚀 How many people are in space right now? 👩🚀
12
| Name | Craft |
|---|---|
| Oleg Kononenko | ISS |
| Nikolai Chub | ISS |
| Tracy Caldwell Dyson | ISS |
| Matthew Dominick | ISS |
| Michael Barratt | ISS |
| Jeanette Epps | ISS |
| Alexander Grebenkin | ISS |
| Butch Wilmore | ISS |
| Sunita Williams | ISS |
| Li Guangsu | Tiangong |
| Li Cong | Tiangong |
| Ye Guangfu | Tiangong |
