noctilucent cloud

Questions

What does noctilucent cloud mean?

Clouds characterized by their electric-blue or silvery-white, wispy streaks, filaments, or ripples high in the twilight sky; Earth's highest clouds, glowing at the edge of space, serving as indicators of climate change, showing increased frequency and visibility linked to human activities like methane emissions and rocket launches; maintain unique formation in frigid summer mesosphere, from ice crystals on meteoric dust, providing scientists with high-altitude atmospheric window into changes in upper atmospheric water vapor and dynamics.

Where does noctilucent cloud come from?

The clouds were studied extensively by German astronomer Otto Jesse, who was the first to photograph them in 1887, and seems to have been the one to coin the term noctilucent cloud.

How to pronounce noctilucent cloud

1. Open the pronunciation page — Open the Speakur entry for “noctilucent cloud”.
2. Read the phonetic spelling — Read the IPA spelling () so you know which sounds to aim for.
3. Play the audio — Click Play to hear reference audio for “noctilucent cloud”.
4. Repeat and practice — Say “noctilucent cloud” aloud, matching stress and vowels until it feels natural.