What is happening to Jupiter's Great Red Spot?

It is shrinking, and quickly enough to watch across a career. In the late 1800s it spanned around 40,000 kilometres and could have swallowed three Earths; it is now about 14,000, and it has changed shape from a long oval to something close to circular. It has also been getting taller as it narrows, which is roughly what you would expect of a storm being squeezed.

Nobody knows whether it is dying. It has been under continuous observation since 1830, with plausible sightings back to the 1660s, and a storm that has run for centuries is not obviously due to stop - but there is no accepted model that predicts either its longevity or its current contraction. It may be settling into a smaller stable state, or it may be in its last century.

What keeps it alive at all is the absence of everything that kills storms here. There is no land surface to create drag and no ocean to exhaust; it sits wedged between two jet streams running in opposite directions, which keeps it spinning, and it absorbs smaller storms that drift into it. Losing it would be an odd kind of loss - the most recognisable feature of the largest planet, gone within the period of human observation that noticed it.