239 South Main St.
57 Central Plaza Landmark
A 24 foot tall azimuth dial in a complex sculpture comprising a light projection gnomon within a 36 foot diameter base with numerous additional shadow-casting structures. The "Asteroid Landed Softly" sundial sculpture was created in 1993 by architect Kazuo Matsubayashi. The sculpture symbolizes the concepts of space and time: space as a large boulder (asteroid) sitting on a square pedestal; and, time as an azimuth sundial that shows the path of the sun through the day and seasons.
The gap between the vertical pedestals projects a shaft of light indicating the azimuth angle of the sun. The change in azimuth of the sun is interpreted as "seasonal or unequal time." This is not the usual usage of seasonal and unequal hours that divide any day into 12 equal periods that vary in duration through the year. The azimuth angle is displayed relative to two circles of posts. A sloping analemma tablet and noon marks for the summer solstice show specifics on the yearly orbit of the sun.
The azimuth vs. time relationships incorporated into this sundial are not hours by any usual sundial or astronomical conventions. The relationships displayed by this dial vary greatly through the day and the seasons. At the summer solstice, the sunrise-to-sunset day duration is 14:56 hours but the south-centered 90? azimuth window of this sundial sculpture functions for only 2:16 hours. At the winter solstice, the day duration is only 9:59 hours but the azimuth window functions for 6:36 hours, much longer than in summer. The change of azimuth with time is strongly dependent on the altitude of the sun which is related to the solar declination and longitude.
For a detailed analysis, pictures and tables of data, see K. Fisher's website: http://fisherka.csolutionshosting.net/astronote/observed/ALSSundial/ALSPage.html
Owner: The Redevelopment Agency of Salt Lake City (Gallivan Center)
"Asteroid Landed Softly"
Designer: Kazuo Matsubayashi
Builder: Pace Architects - major contribuition from Utah Power & Light