noun
zodiacal light
Astronomical term for the faint, roughly triangular glow visible in the night sky, caused by sunlight scattered by interplanetary dust along the ecliptic.
黄道光は、春の夕方の西空や秋の明け方の東空で観測しやすい。
Zodiacal light is easiest to observe in the western sky on spring evenings or in the eastern sky on autumn mornings.
From 黄道 (こうどう, ecliptic) + 光 (こう, light). The term directly describes the phenomenon's appearance along the ecliptic.