Celestial Equator and Vernal Equinox

When does the Sun cross the celestial equator going northward?

Choose the correct answer:

a. Autumnal equinox

b. Vernal equinox

c. Summer solstice

d. Winter solstice

Answer:

The Sun crosses the celestial equator going northward at the point called the vernal equinox.

The vernal equinox occurs around March 21st each year and marks the beginning of spring in the northern hemisphere. On this day, the duration of daylight and darkness is approximately equal all over the world.

During the vernal equinox, the Sun is on the celestial equator, leading to approximately equal day and night all over the Earth. This event signifies the start of spring in the Northern Hemisphere.

At the vernal equinox, the Sun rises at the North Pole and sets at the South Pole, resulting in 6 months of sunlight followed by 6 months of darkness at each pole. On Earth's equator, the Sun will be directly overhead, or at the zenith, during the vernal equinox.