At noon on September 21, the Sun is directly overhead at a latitude of
23.5 s. Latitude
To determine the latitude at which the Sun is directly overhead at noon on September 21, we need to consider the tilt of the Earth's axis and its position in its orbit around the Sun.
On September 21, the Earth is experiencing an equinox, which means the tilt of the Earth's axis is neither towards nor away from the Sun. The equinoxes occur twice a year, around March 20 and September 22, when day and night are of equal length.
During the equinoxes, the Sun is directly overhead at noon on the Equator (0° latitude). This means that at noon on September 21, the Sun is directly overhead at a latitude of 0° (the Equator).
To determine at which latitude the Sun is directly overhead at noon on September 21, we need to consider the tilt of the Earth's axis and how it affects the position of the Sun throughout the year.
On September 21, the Earth is transitioning from summer to autumn in the Northern Hemisphere, and from winter to spring in the Southern Hemisphere. This date corresponds to the autumnal equinox in the Northern Hemisphere and the vernal equinox in the Southern Hemisphere.
During an equinox, the Earth's axis is not tilted toward or away from the Sun. As a result, the Sun is directly overhead at the Equator (0° latitude) on these dates.
So, at noon on September 21, the Sun is directly overhead at 0° latitude (the Equator).