aurora borealis

aurora borealis

CEFR: C1-C2 /au-ro-ra bo-re-alis/ [no ipa available]

Definition: A natural electrical phenomenon characterized by the appearance of streamers of reddish or greenish light in the sky, especially near the northern or southern magnetic pole.

Example Sentences:
The Hubble Space Telescope has spotted auroras near the poles of both Saturn and Jupiter.