During which event is the sun directly overhead at the Tropic of Cancer?

During which event is the sun directly overhead at the Tropic of Cancer?

• A. June solstice
• B. December solstice
• C. Vernal equinox
• D. Autumnal equinox

Answer: (A)

During the June solstice. At this time the Sun’s declination reaches +23.5°, so the subsolar point—the point on Earth where the Sun is directly overhead at solar noon—aligns with the Tropic of Cancer (about 23.5°N). That means everywhere along that latitude receives vertical sunlight at noon on this day. The other events don’t place the Sun directly overhead at that latitude: the December solstice has the Sun over the Tropic of Capricorn (23.5°S), and the equinoxes place the Sun over the equator (0° latitude), not at 23.5°N.

During the June solstice. At this time the Sun’s declination reaches +23.5°, so the subsolar point—the point on Earth where the Sun is directly overhead at solar noon—aligns with the Tropic of Cancer (about 23.5°N). That means everywhere along that latitude receives vertical sunlight at noon on this day.

The other events don’t place the Sun directly overhead at that latitude: the December solstice has the Sun over the Tropic of Capricorn (23.5°S), and the equinoxes place the Sun over the equator (0° latitude), not at 23.5°N.