Mysterious Dark Vortex Found On Neptune Fires Up Long-Term Research

This week, NASA astronomers have publicly confirmed the sighting of a dark vortex found on the surface of Neptune.

NASA’s Hubble Space Telescope captured new images from Neptune on May 16, and has only recently confirmed the dark vortex found in the planet’s atmosphere.

The HubbleSite news center put out a press release Thursday about the find and noted that the features described were had already been seen “during the Voyager 2 flyby of Neptune in 1989 and by the Hubble Space Telescope in 1994, (but) this vortex is the first one observed on (the planet) in the twenty-first century.”

The press release states that a research astronomer leading the team that analyzed the data, Mike Wong of the University of California at Berkeley, explained the find in detail via CBAT (Central Bureau for Astronomical Telegrams) on May 17.

The first new dark spot on Neptune detected of the 21st century
The release explains that in July of last year, a combination of amateurs and astronomers at the W. M. Keck Observatory in Hawaii, spotted white clouds on the planet’s surface thinking they could be following a dark unseen vortex, much like clouds that surround mountaintops.

It would not be until September that the Outer Planet Atmospheres Legacy program (OPAL) which is taking the remainder of Hubble’s operation “to obtain long time baseline observations of the outer planets in order to understand their atmospheric dynamics and evolution as gas giants” — as described on the MAST archive, found the dark vortex, as the Hubble is the only telescope with the resolution to see them.

The OPAL project thus confirmed that what they were seeing was a long-lived feature, and they were able to target it to create a high-quality map.

Close up shot of clouds surrounding dark spot.
The CBAT system which collects the reported discoveries is considered a “clearing house” non-profit operation, and it assigned the discovery to Mike Wong for follow-up. Wong explained the dark vortices in the press release.

“Neptune’s dark vortices are high-pressure systems and are usually accompanied by bright ‘companion clouds,’ which are also now visible on the distant planet. The bright clouds form when the flow of ambient air is perturbed and diverted upward over the dark vortex, causing gases to likely freeze into methane ice crystals. Dark vortices coast through the atmosphere like huge, lens-shaped gaseous mountains. And the companion clouds are similar to so-called orographic clouds that appear as pancake-shaped features lingering over mountains on Earth.”

Similar to the process leading to how they were found — where they built up the collaboration of observations to focus on the vortices — the official release also refers to a “UC Berkeley doctoral student named Joshua Tollefson, who was recently awarded a prestigious NASA Earth and Space Science Fellowship to study Neptune’s atmosphere.” Tollefson will be studying the dark vortex to learn about its drift, how it originated, how vortices interact, and how vortices dissipate.

This means they will now have the opportunity to see the full evolution of a vortex over time.

As the Great Dark Spot (GDS89) was first found by Voyager 2, everything that has been discovered about it resulted from that year.

The new storm found is said to be the size of the United States, and it is, so far, the third one seen since 1989.

A satellite is also scheduled to orbit Jupiter to get a closer look at the Great Red Spot on its surface on July 4.

Similar research on the Great Red Spot found that it was a raging storm lasting from 100 to over 300 years, in comparison to the dark vortex found on Neptune, which has been observed to have a much shorter lifespan.

[Image (resized and cropped) by NASA / Jet Propulsion Lab/Public Domain 1.0]