Noon sun not directly overhead everywhere
POSTED: Tuesday, May 11, 2010
Many people think that the sun passes directly overhead at noon every day, but this is not true. In fact, much of the world never experiences the sun at the zenith. This phenomenon only happens in locations that fall within the Tropic of Capricorn and the Tropic of Cancer. Since Hawaii is within the tropics, we experience the zenith passage of the sun twice a year.
The first zenith passage of the sun occurs in May, and the second in July. The particular day depends on your exact latitude. In Honolulu the sun transits through the zenith on May 26 at 12:28 p.m. Farther south, in Hilo, the zenith sun occurs on May 18 at 12:16 p.m. The more northerly Lihue will experience the zenith passage on May 31 at 12:35 p.m.
The term "Lahaina Noon" is sometimes used within Hawaii to refer to the zenith passage of the sun, but this is a modern phrase chosen as part of a contest held by Bishop Museum in the early 1990s. A more authentic Hawaiian term for this phenomena is kau ka la i ka lolo, which roughly translates to "the sun rests on the brains." It was believed that the moment in which the sun passed over the zenith causing a person's shadow to disappear was a time of great personal power. At this moment the person's mana would collect inside, and the person would be aligned with the forces of the universe.
Constellation: Southern Cross
One of the great things about living in Hawaii is that every spring we can see the Southern Cross in the evening sky. Officially known as Crux, this beautiful constellation cannot be seen at higher latitudes in the Northern Hemisphere. To see the Southern Cross in Hawaii, you will need a clear view of the southern horizon. At the beginning of May, this kite-shaped group of stars rises completely above the horizon by 8:30 p.m. and is fully visible until just after midnight. By the end of the month, it rises and sets about two hours earlier.
Because it is so easy to identify in the Southern Hemisphere, the Southern Cross is featured on the flags of several countries, including New Zealand and Samoa. It is important in celestial navigation because the upright stars of the cross point the way due south.
Venus continues to blaze in the western sky after sunset throughout May. Mars is visible high in the western sky throughout the evening, in between the stars of Gemini and Leo. After you have found Mars, draw an imaginary line to Regulus, the bright star marking the point of Leo's backward question mark, then continue on until you see the planet Saturn.
As we move into the summer months, take advantage of the dry weather to star-hop your way around the night sky.