The Dark Vortex on Neptune changes direction in a never-before-seen event

Jupiter may be the most famous hurricane in the solar system, but that doesn’t mean it gets all the fun – and Neptune has been introduced to scientists by Doozy.

However, the tendency of the storm over a large part of the ice is not uncommon, but this is the first time it has returned to the polar region after migrating to the equator.

Astronomers are not yet sure how, or why, it could have changed, but finding it can give us more information about Neptune’s atmospheric dynamics.

Neptune is actually very difficult compared to other planets in the solar system. The average distance between the earth and the sun is 30 times out of the sun, which makes it difficult to make too much detail. So it wasn’t until 1989, when Voyager 2 made its flyby, discovering two storms on Neptune.

Since then, Hubble – the only tool capable of doing so – has been observing and tracking four more hurricanes called dark spots for a darker color than the surrounding atmosphere.

In general, their behavior is very similar: they appear at mid-latitudes, they hang for about two years as they migrate to the equator, and then disintegrate. Then, four to six years later, another show.

This storm, however, has been the fourth exception observed by Hubble named NDS-2017.

“This was a really exciting act to watch and then all of a sudden it just stops and swings back,” said Michael Wang, a planetary scientist at the University of California, Berkeley. “That was amazing.”

As per the name, NDS-201 name was first discovered in 2018. By that time, it had evolved over many years, measuring around 11,000 kilometers (6,800 miles).

When Hubble re-observed it in January 2020, it was behaving as expected, shifting from north mid-latitude to the equator south.

During migration, the Coriolis effect was expected to weaken the hurricane by keeping it stable at mid-latitudes, while the hurricanes gradually disappeared until they reached the equator. Then, according to the simulations and previous observations, NDS-201 should fade into oblivion.

But those January observations revealed something awkward – a little tiny dark smudge like a miniature version of a big storm. NDS-2017, at the time, was about 7,400 kilometers (4,600 miles). Dark Spot Jr., nicknamed, crossed about 6,275 kilometers (3,900 miles).

Then, in August of this year, when Hubble took another look at the NDS-201 look (it’s a very busy telescope and can’t see Neptune all the time), the storm was heading north again. Dark Spot Jnr. went.

Spot label(NASA, ESA, STSCI, MH Wong / UC Berkeley, and LA Smovowski and PM Fry / University of Wisconsin-Madison)

“We’re excited about these observations because this little dark piece is probably part of the dark dark spot disruption process,” Wong said.

“This is a process that has never been observed. We’ve seen some other dark spots go away, and they’re gone, but despite the predictions in computer simulations, we’ve never seen anything disruptive.”

It is impossible to know exactly what happened, but the appearance of Dark Spot Jr. and his subsequent disappearance may be the key. For one thing, it was closer to the side of the NDS-2017 that was closer to the equator. According to simulations, if anything disrupts a Neptune hurricane, it happens right there.

The fact that the dark spot shows Jr. when it can also be a clue.

“When I first saw the small spot, I thought the big one was getting messy. I don’t think the second one is forming a whirlpool, because the small one is farther towards the equator. No. Prove that the two are related. It remains a complete mystery, “Wong said.

“It was also in January that the Dark Whirlpool stopped moving and started moving north again. Maybe that piece was enough to stop it from moving towards the equator.”

We don’t know much about Neptune’s black spots yet. They are much more empty of clouds in the middle than the storms of Saturn and Jupiter. The clouds we can find are fluffy white clouds that appear around the edges, probably as a result of the cooling of the gases in the methane ice crystals as they rise above the lower it.

On that score, NDS-201 has yet to reveal another secret: its fluffy white companion clouds disappeared when the hurricane changed direction.

Researchers say this could reveal more information about how Neptune hurricanes evolved. Meanwhile, they are taking a closer look at the available data to see if they can find any more information on Dark Spot Jr., a small storm or its bits, a little longer.

While Hubble is now turning its glare to Neptune as part of the Outer Planet Atmospheric Legacy program, scientists will be really interested to see what NDS-2017 does.

The team’s research was presented at the American Geophysical Union’s 2020 Fall Meeting.