Tropic of Capricorn
Explanation
The position of the Sun relative to the Earth changes throughout the year due to the Earth's revolution around the Sun and its constant axial tilt of 23.5°. This results in the apparent movement of the Sun between the Tropic of Cancer and the Tropic of Capricorn, determining which latitude receives vertical (direct) solar rays.
Analysis of Solar Position on 22nd December
- Winter Solstice: On 22nd December, the Earth is positioned such that the South Pole is inclined towards the Sun, while the North Pole is tilted away.
- Vertical Rays: On this date, the Sun's rays fall vertically overhead at the Tropic of Capricorn (23.5° S).
- Implications: This marks the longest day in the Southern Hemisphere (Summer Solstice for the Southern Hemisphere) and the shortest day in the Northern Hemisphere (Winter Solstice for the Northern Hemisphere).
- Comparison with other latitudes:
- Equator: Receives direct rays on the Equinoxes (March 21 and September 23).
- Tropic of Cancer: Receives direct rays on the Summer Solstice (June 21).
- Arctic Circle: Does not receive vertical rays; on December 22, it experiences 24 hours of darkness or twilight as it is tilted away from the Sun.
Key Takeaway: On 22nd December, the Sun reaches its southernmost point of vertical incidence, shining directly over the Tropic of Capricorn.