The dark storm on Neptune abruptly changed direction and began to drift away from near-certain death, confusing astronomers.
NASA’s Hubble Space Telescope first spotted the 2018 vortex. A year later, a storm began hovering south toward Neptune’s equator, following the path of several storms before it. Usually these dark spots on Neptune live for several years before they either disappear or disappear. However, the storm mysteriously stopped moving south and made a sharp turn, hovering back north. At the same time, astronomers spotted another, smaller dark spot on the planet.
They theorize that this minor “cousin” storm may be part of an original vortex that broke off and receded.
Related: Birth of storm “Big Dark Spot” on Neptune seen for the first time (photo)
“We are excited about these observations because this smaller dark fragment is potentially part of the process of breaking the dark spot,” said Michael H. Wong of the University of California, Berkeley. NASA statement. “This is a process that has never been noticed. We’ve seen some other dark spots fade and disappear, but we’ve never seen anything disturbed, even though it’s predicted in computer simulations.”
Although Hubble has followed similar storms on Neptune in the last 30 years, astronomers have never seen such unpredictable atmospheric behavior.
The current storm, which is 4,600 miles wide (larger than the Atlantic Ocean), is the fourth darkest spot Hubble has tracked since 1993. These storms are high-pressure systems that rotate clockwise due to planetary rotation (unlike hurricanes on Earth). , which are low pressure systems that rotate counterclockwise).
Typically, as storms sail toward Neptune’s equator, the Coriolis effect that usually keeps them stable begins to weaken and the storm disintegrates. Yet, unlike past recorded storms and computer simulations showing storms following a more or less flat path to the equator, this latest vortex has not migrated into this “killing zone”.
“It was really exciting to see this one act like it was supposed to act, and then all of a sudden it just stopped and came back,” Wong said in the same NASA statement. “That was surprising.”
It was also surprising to notice a smaller storm that potentially broke off from a larger vortex. Astronomers informally call a minor storm a “dark spot younger.” This “jr.” it is still quite large, stretching 6,276 km. Although researchers cannot prove that the smaller storm separated from the larger one, Wong said it is possible that the spillage of that fragment was enough to stop the continuation of the larger storm toward the equator.
This latest giant storm on Neptune has been best studied so far on the planet. For example, when Hubble first noticed a storm in 2018, the telescope saw bright companion clouds around the vortex. Those clouds are gone now, they disappeared when the storm stopped coming south. It is possible that the lack of these clouds could reveal some secrets about how dark spots develop.
There are still many mysteries surrounding storms on Neptune, but NASA’s Outer Planet Atmospheres Legacy (OPAL) program is on standby to unravel those mysteries. But for now, astronomers will be watching out for this mysterious dark spot on Neptune.
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