sort by best latest
It is just a gigantic storm. Spots form on Jupiter all of the time, this one just happens to be the largest. It has decreased in size over the past decade, however.
You can help the HubPages community highlight top quality content by ranking this answer up or down.
Mattforte has provided the answer, but just as a cheeky extra I'll add that the spot is big enough to fit three earths into its boundaries.
As mattforte says its a giant storm system that has existed for centuries, it's so huge you could fit 3 Earths inside it.
Copyright © 2017 HubPages Inc. and respective owners. Other product and company names shown may be trademarks of their respective owners. HubPages® is a registered Service Mark of HubPages, Inc. HubPages and Hubbers (authors) may earn revenue on this page based on affiliate relationships and advertisements with partners including Amazon, Google, and others.
Copyright © 2017 HubPages Inc. and respective owners.