During the last flyby over the surface of Jupiter, the cameras of the Juno probe recorded the birth of a powerful new storm at the south pole of the giant planet. This was reported by the press service of the NASA Jet Propulsion Laboratory (JPL).
"The size of the new vortex is small, but subsequent flights will show whether it will grow to the same size as its neighbors," commented Alessandro Mura, a member of Juno's scientific team and planetary scientist at the National Astrophysical Institute in Rome, Italy.
In addition to the famous Great Red Spot of Jupiter, dozens of other "eternal" hurricanes are raging in the atmosphere of the solar system's largest gas giant. A striking example of this is the "younger brother" of the Great Red Spot, the anticyclone NN-LRS-1, as well as the so-called "pearls", a set of seven giant vortices of bright white color, which are located in the southern hemisphere of the planet and were discovered back in 1986 …
Scientists now suspect that such vortices are responsible for heating Jupiter's atmosphere and transporting heat from its interior to the upper air layers. This makes the surface of the gas giant much hotter than theories predict. Therefore, the Juno probe, which arrived in the Jupiter system in July 2016, closely studies both the Great Red Spot and other vortices in the planet's atmosphere during each approach to its surface.
Planetary geometry
According to the press service of JPL, Moore and his colleagues made an unexpected discovery during one of the last such "rendezvous" of the probe with the giant planet, which took place in early November this year. This rapprochement was remarkable in that it marked a kind of new stage in Juno's life. During this event, the probe successfully "jumped" through the shadow of Jupiter, which protected it from death during subsequent flights due to the fact that it would be deprived of access to the light of the Sun for tens of hours.
During this maneuver, Juno accidentally witnessed an extremely unexpected event. Analyzing the images obtained by the probe's camera and the JIRAM device, scientists have discovered that a new, seventh giant hurricane has arisen at the southern pole of the giant planet.
The surprise of planetary scientists was due to the fact that the first pictures of Jupiter's poles, which Juno took after the first flights over the planet's surface, indicated that there is a kind of pentagon at its south pole, which is made up of six giant hurricanes. In this respect, Jupiter is unlike Saturn, whose north pole has a hexagonal "eternal" hurricane.
An infrared image of six cyclones near Jupiter's south pole. The new, smallest one is visible in the lower right part.
Like its Saturnian cousin, Jupiter's pentagonal hurricane turned out to be unusually stable - during the previous 21 Juno flyby, astronomers did not notice that there were any changes in its structure, and new hurricanes would appear in the polar regions of the planet. In November of this year, JIRAM measurements showed that this is not the case. The device recorded the birth of a new, seventh polar hurricane, the diameter of which is about a thousand kilometers, and the speed of the winds in it exceeds 360 kilometers per hour.
Already now, this vortex has "built" into the pentagon of other polar cyclones, turning it into a hexagon. Juno's subsequent approach to the planet's south pole, according to Mura, will help to understand whether this structure will persist and whether Jupiter will thus become a bit like Saturn.