© NASA/JPL
When the storm was first discovered in 2015, it stretched over 3,100 miles in length, but now, it's shrunk significantly, measuring a mere 2,300 miles long. This goes against computer models of its development, meaning that our current understanding of how storms move on Neptune is woefully flawed.
Storms of this nature have been observed on Neptune regularly since the 1980s, when the Voyager 2 probe gave us a close look at the planet for the first time. Back then, a large storm on Neptune's surface was spotted, and scientists drew similarities to the large circular storm that rages on the much larger planet Jupiter.
Over time, as further photographs of Neptune were taken, it was proven that the planet's storms hardly last as long as those on Jupiter - while the so-called Giant Red Spot has been swirling on the gas giant for two centuries, it seems that only a few years are necessary for storms on Neptune to dissipate.
According to Michael H. Wong, a planetary scientist at UC Berkeley:
"It looks like we're capturing the demise of this dark vortex, and it's different from what well-known studies led us to expect... that anticyclones under Neptune's wind shear would probably drift toward the equator. We thought that once the vortex got too close to the equator, it would break up and perhaps create a spectacular outburst of cloud activity... No facilities other than Hubble and Voyager have observed these vortices. For now, only Hubble can provide the data we need to understand how common or rare these fascinating neptunian weather systems may be."The biggest problem to understanding the life cycle of storms on Neptune has been the fact that, until recently, powerful telescopes only took snapshots of the distant planet very rarely. It's only since the Hubble telescope began regularly photographing all planets in the solar system that we gained enough data to be able to track storms on Neptune.
Not much is known about what this dying storm is actually like, but scientists expect that it's probably dredging up a lot of materials from deep within the planet's surface. One key element of this mix is probably the chemical compound hydrogen sulfide, which is known for smelling a lot like rotten eggs.
As such, it's probably for the best that this storm is fading away, as if we ever actually invent the "smelloscope" from Futurama, we don't want this clogging up the solar system.
In the meantime, the scheduled launch of the James Webb Telescope next year may be able to give us a better look at Neptune and what's happening to form and kill off these enormous storms. Considering the fact that our predictions about Neptune's weather were so off-base, it'll be interesting to see what else we'll be able to learn by simply taking a closer look at the beautiful blue planet.
Science-speak for "is wrong" - "we do not understand".