Honolulu residents can witness a shadowless moment Tuesday at 12:37 p.m.

The phenomenon, known as Lahaina Noon, occurs when the sun is directly overhead, said Kathleen Robertson, librarian at University of Hawai'i Institute for Astronomy.

Lahaina Noon happens twice a year at slightly different places and times throughout the state.

There will be no shadows from things like poles at that time, Robertson said.

The event was named through a contest sponsored by the Bishop Museum in 1990, said Mike Shanahan, director of museum education and exhibits. "Lahaina," the old version of the name, means "cruel sun" in Hawaiian.