Pi Day celebrations kick off with a "pi in the sky"

Pi Day skywriting by AirSign aircrafts in Austin.

Pi Day celebrations have already begun to take place around the United States.

Sky gazers in Austin, Texas, may have noticed something interesting happening with skywriting airplanes on Thursday -- namely, a "pi in the sky."

To celebrate Pi Day and honor the great mathematical constant of 3.141592 etc., AirSign aircrafts took to the skies to attempt to spell out the infinite pi sequence across 100 miles of sky in Austin.

The skywriting was part of a public art project put on by AirSign and California artist ISHKY to applaud the "universal language of pi and the limitless potential it represents," an AirSign spokesperson told CNET. The hundreds of numbers written across the afternoon sky were done by five synchronized AirSign aircrafts flying at 10,000 feet using dot-matrix technology.

The numbers -- each measuring a quarter-mile in height -- were written out in a spiral that eventually became several miles wide. "Pi In The Sky explores the boundaries of scale, public space, impermanence, and the relationship between Earth and the physical universe," AirSign said in a statement.

Pi Day, March 14 (3/14), was commemorated as an official holiday by Congress in 2009. The idea was to draw attention to improving math and science education in the US. Celebrations have often included eating pies, reciting as much of the pi number sequence as possible, and talking about the significance of the mystifying number.

This article originally appeared on CNET.

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    Dara Kerr, a freelance journalist based in the Bay Area, is fascinated by robots, supercomputers and Internet memes. When not writing about technology and modernity, she likes to travel to far-off countries.