How many times does the sun hit the zenith at the Tropic of Capricorn?

The sun reaches the zenith at the Tropic of Capricorn twice each year, which occurs during the solstices. Specifically, the sun is directly overhead at the Tropic of Capricorn around the December solstice, usually on December 21st or 22nd, marking the southernmost point of the sun's apparent path in the sky. The second occurrence happens around the March equinox, where the sun is no longer overhead but aligns closely in terms of overall sunlight distribution at varying latitudes.

The concept of zenith refers to the point in the sky directly overhead; for locations in the tropics, this happens at least once or more during the year as the earth orbits the sun and the tilt of its axis changes the sun’s position relative to observers at different latitudes. In contrast, locations beyond the Tropics experience zenith only once per year or not at all, reflecting differences in solar position based on latitude. Thus, the answer indicating twice a year accurately reflects this solar phenomenon specifically at the Tropic of Capricorn.