### Overview

The "Pi in the Sky" math challenge gives students a chance to take part in recent discoveries and upcoming celestial events, all while using math and pi just like NASA scientists and engineers. In this problem from the set, students use the mathematical constant pi and data from NASA spacecraft to determine the percentage by which Jupiter's Great Red Spot shrank between 1979 and 2018.

### Background

Animation showing Hubble observations of Jupiter's Great Red Spot, 1992 through 2017. Image credit: Z. Levay (STScI)/R. Garner (NASA Goddard) | › Full image and caption

Jupiter’s Great Red Spot, a giant storm that has been fascinating observers since the early 19th century, is shrinking. The storm has been continuously observed since the 1830s, but measurements from spacecraft like Voyager, the Hubble Space Telescope and Juno indicate the storm is getting smaller. How much smaller? In Storm Spotter, students can determine the answer to that very question faced by scientists.

### Procedures

#### Storm Spotter

Jupiter’s well known Great Red Spot is shrinking and someday may disappear entirely. Continuously observed since the 1830s, this massive storm was once more than three times the diameter of Earth.

When the twin Voyager spacecraft flew by Jupiter in 1979, they sent back images of the Great Red Spot. At that time, the storm measured 24,700 km wide by 13,300 km tall. When scientists measured the storm again in 2018, using images from the Hubble Space Telescope, their estimates were 16,500 km wide by 11,400 km tall.

Given these measurements, how does the current width of the Great Red Spot compare to the diameter of Earth?

By what percent did the area of the Great Red Spot shrink from 1979 to 2018? The formula for the area of an ellipse is πab.

### Assessment

Image credit: NASA/JPL-Caltech/Kim Orr | + Expand image

### Extensions

#### Participate

Join the conversation and share your Pi Day Challenge answers with @NASAJPL_Edu on social media using the hashtag #NASAPiDayChallenge