Astronomers first measured winds in Jupiter̵
Thibault Cavalié, lead author of the article published in Astronomy and Astrophysics and planetary scientist from the Laboratoire d’Astrophysique de Bordeaux in France noted that the jets were found beneath Jupiter’s polar auroras and are the “ lower tail of the supersonic jets seen 900 km (560 miles) above, ” and that the currents are an enormous anticyclone with a diameter of 3 to 4 earth diameters and a vertical extent of 900 km. This is unique in the solar system. Cavalié also noted in a statement from the European Southern Observatory that the jet streams are a “unique meteorological beast.”
Unlike Jupiter’s top layer, with the famous red and white bands of the gas giant, the Great Red Spot, and the auroras, the jets were much more difficult to measure and study. Scientists were finally able to capture this reading thanks to a famous comet and Chile’s powerful telescope.
The comet – Shoemaker-Levy 9 – collided with Jupiter in 1994, and its impact left unique hydrogen cyanide molecules in the planet’s atmosphere. These molecules have allowed Cavalié and his colleagues. The team used 42 of ALMA’s 66 high-precision antennas to detect the molecules and measure their frequency changes in their radiation emissions as they fan around, which is to say they measured the Doppler shift.
By focusing on this measurement, “we were able to derive the speed of the wind as you could infer the speed of a passing train by the change in the frequency of the train whistle,” says Vincent Hue, co- author of the study. and planetary scientist at the Southwest Research Institute in the earlier ESO statement.
The study revealed that the stratospheric winds under Jupiter’s auroras swept around at 895 miles per hour. Towards the planet’s equator, these same winds moved a little more slowly, at just 373 miles per hour (600 kilometers per hour). Scientists already knew about the fast winds on Jupiter’s upper layers and previously thought that if you went further into the planet, the wind would slow down. These new data turned that theory upside down and completely surprised Cavalié’s team.
What’s really exciting is that while Jupiter’s stratospheric winds are fast, they are far from the fastest in our solar system or even the rest of the planet. In Jupiter’s ionosphere, a layer of the atmosphere closer to the planet’s outside, there are supersonic winds that travel at a speed of 1-2 km per second (0.62-1.24 miles per second) or 3,600-7,200 kilometers per hour (2,240-4,475 miles per hour). However, Neptune holds the solar system’s record, with winds 25% faster than those measured under Jupiter’s aurora.