Subsolar point in the context of "Tropic of Capricorn"

The March equinox or northward equinox is the equinox on the Earth when the subsolar point appears to leave the Southern Hemisphere and cross the celestial equator, heading northward as seen from Earth. The March equinox is known as the vernal equinox (or spring equinox) in the Northern Hemisphere and as the autumnal equinox (or fall equinox) in the Southern Hemisphere.

On the Gregorian calendar at 0° longitude, the northward equinox usually occurs on March 20. However, it can occur as early as March 19 (which happened most recently in 1796, and will happen next in 2044), and it can occur as late as March 21 (which happened most recently in 2007, and will happen next in 2102). For a common year the computed time slippage is about 5 hours 49 minutes later than the previous year, and for a leap year about 18 hours 11 minutes earlier than the previous year. Balancing the increases of the common years against the losses of the leap years keeps the calendar date of the March equinox from drifting more than one day from March 20 each year.

23°26′12.5″N 0°0′0″W / 23.436806°N -0.00000°E / 23.436806; -0.00000 (Prime Meridian)

The Tropic of Cancer, also known as the Northern Tropic, is the Earth's northernmost circle of latitude where the Sun can be seen directly overhead. This occurs on the June solstice, when the Northern Hemisphere is tilted toward the Sun to its maximum extent. It also reaches 90 degrees below the horizon at solar midnight on the December solstice. Using a continuously updated formula, the circle is currently 23°26′09.3″ (or 23.43592°) north of the Equator.

Pisces is a constellation of the zodiac. Its vast bulk — and main asterism viewed in most European cultures per Greco-Roman antiquity as a distant pair of fishes connected by one cord each that join at an apex — are in the Northern celestial hemisphere. Its traditional astrological symbol is (♓︎). Its name is Latin for "fishes". It is between Aquarius, of similar size, to the southwest and Aries, which is smaller, to the east. The ecliptic and the celestial equator intersect within this constellation and in Virgo. The Sun passes directly overhead of the equator, on average, at approximately this point in the sky, at the March equinox.

The right ascension/declination 00 is located within the boundaries of Pisces.

Lāhainā Noon, also known as a zero shadow day, is a semi-annual tropical solar phenomenon when the Sun culminates at the zenith at solar noon, passing directly overhead. As a result, the sun's rays will fall exactly vertical relative to an object on the ground and cast no observable shadow. When this occurs at a given location, the location is Earth's subsolar point. A zero shadow day occurs twice a year for locations in the tropics (between the Tropic of Cancer at approximate latitude 23.4° N and the Tropic of Capricorn at approximately 23.4° S) when the Sun's declination becomes equal to the latitude of the location, so that the date varies by location. The term "Lāhainā Noon" was initiated by the Bishop Museum in Hawaii.