Jupiter's Great Red Spot is a mammoth storm—so big it could fit Earth right inside it. It's been raging for at least 350 years, since its discovery in 1664.
The storm is big, but it also changes over time—having shrunk substantially since Pioneer flew by in the early 1970s. As it shrinks, its winds pick up, swirling its chemicals faster and faster.
Researchers have long wondered how deep the storm goes, and now they have a pretty good idea. Data from the Juno spacecraft has found it most likely extends 300 ± 100km, but could reach up to 500km.
That's deep, but not as deep as the surround jet streams, which stretch up to 3000km into Jupiter's heart.
But what makes the Great Red Spot ... red?
The answer lies in the chemicals swirling inside it. Ammonia and acetylene break down under the Sun's radiation, turning into molecules that absorb blue light but reflect the red. The end result is a sort of crème brûlée, with a burnt top layer and plainer white clouds underneath.
Featured Image: Voyager 1 image of the Great Red Spot, reprocessed by Bjorn Jonsson | Credit: NASA/B. Jonsson
Sources and further reading:
NASA’s Juno: Science Results Offer First 3D View of Jupiter Atmosphere at NASA
Jupiter’s Great Red Spot: A Swirling Mystery at NASA
NASA’s Juno Spacecraft Spots Jupiter’s Great Red Spot at NASA