What is an equinox?

What is an equinox?

• A. The longest day of the year
• B. The shortest day of the year
• C. The sun is at its highest point in the sky at noon
• D. Each of the two times of the year when days and nights are of equal length

Answer: (D)

An equinox is when day and night are roughly the same length because Earth’s axis is tilted relative to its orbit around the Sun, and there are moments when the Sun appears to cross the celestial equator. On these days, the Sun rises nearly due east and sets nearly due west, giving about 12 hours of daylight and 12 hours of darkness. This happens twice a year: once in spring (vernal equinox) and once in autumn (autumnal equinox). The longest and shortest days occur near the solstices, when the Sun is at its highest or lowest noon position and daylight is not equal to night. The statement about the Sun being at its highest point at noon refers to a daily position, not to equal day and night.

An equinox is when day and night are roughly the same length because Earth’s axis is tilted relative to its orbit around the Sun, and there are moments when the Sun appears to cross the celestial equator. On these days, the Sun rises nearly due east and sets nearly due west, giving about 12 hours of daylight and 12 hours of darkness. This happens twice a year: once in spring (vernal equinox) and once in autumn (autumnal equinox).

The longest and shortest days occur near the solstices, when the Sun is at its highest or lowest noon position and daylight is not equal to night. The statement about the Sun being at its highest point at noon refers to a daily position, not to equal day and night.