The Quiz: These are noctilucent clouds. What does ‘noctilucent’ mean in Latin?
Noctilucent roughly means ‘night-shining,’ an apt name since the clouds are difficult to see during the day. They’re the highest clouds in our sky, about 50 miles up. Formed of icy dust, they can be seen long after the sun has set on Earth’s surface, but while the noctilucent clouds are still in sunlight. They occur only in summer, when that layer of the atmosphere is at its coldest.
The correct answer to this quiz is Night-shining.