Caption: "In 2009 January and March, astronomers using NASA's Hubble Space Telescope (HST) took advantage of a rare opportunity to record Saturn when its rings were edge-on, resulting in a unique movie featuring the nearly symmetrical light show at both of the giant planet's poles. It takes Saturn 29.4571 years to orbit the Sun, with the opportunity to image both of its poles occurring only twice during that time. The light shows, called aurorae, are produced when electrically charged particles race along the planet's magnetic field and into the upper atmosphere where they excite atmospheric gases, causing them to glow. Saturn's aurorae resemble the same phenomena that take place near the Earth's polar regions." (Slightly edited.)
The quantified oblateness is defined by the formula
where a is equatorial radius and b is polar radius.
Loosely speaking, quantified oblateness is the fractional squashing.