Pi day, celebrated on March 14 (or 3/14 in the American date system), is a special day for mathematicians and scientists worldwide. Pi, denoted by the mathematical constant π, represents the ratio between a circle’s circumference and its diameter. The approximate value of Pi is 3.14, hence the name and date of the occasion.
NASA, the American space agency, relies on Pi in its daily work, and has published a list of how it uses the symbol. One significant use of Pi is in mapping unknown worlds. As spacecraft orbit other planets, they use rectangular fields of view cameras that capture images in bands on the planet’s surface. To calculate how many images are needed to map an entire planet, scientists use a formula that includes Pi.
Pi is also crucial in the search for distant planets. Powerful telescopes in space and on Earth track the light emitted by distant stars. When an exoplanet passes in front of a star, the telescope detects a dip in the amount of light emitted by the star. Scientists use the percentage figure and the formula for the area of a circle to derive the size of the planet that passed in front of the star.
Pi, a symbol that is celebrated and cherished by mathematicians, also plays a vital role in space exploration. From mapping unknown worlds to finding new planets, NASA uses the power of Pi to better understand the universe and our place in it. Happy Pi Day!