태양이 천구의 적도를 통과하여 낮과 밤의 길이가 거의 같아지는 시기.
The time or date twice each year when the sun crosses the celestial equator and day and night are of approximately equal length.
예문:
"The spring equinox usually falls on March 20th or 21st in the Northern Hemisphere."
"Daylight hours begin to decrease steadily after the autumnal equinox."
황도와 천구의 적도가 만나는 두 지점 중 하나.
Either of the two points on the celestial sphere where the ecliptic intersects the celestial equator.
예문:
"The vernal equinox is used as the starting point for the celestial coordinate system."
"Astronomers track the movement of the equinox due to the Earth's axial precession."