Using Europe’s ALMA telescope, researchers measured wind speeds three times faster than the strongest tornado winds on Earth.
(CN) — Better not let Toto out in this one. A first-of-its kind study of the largest planet in the solar system documented head-spinningly fast winds, three times faster than Earth’s most intense tornadoes.
Recording speeds of up to a whopping 900 miles per hour near the planet’s poles, scientists from the United States and the European Southern Observatory used dozens of powerful telescope antennas to directly measure the winds in Jupiter’s middle atmosphere for the first time.
The team described recordings taken by the internationally operated telescope ALMA, or Atacama Large Millimeter/submillimeter Array, in a study published Thursday in the journal Astronomy & Astrophysics.
Using 42 of ALMA’s 66 high-precision antennas, scientists analyzed atmospheric particles on Jupiter, which allowed them to track tiny changes in radio frequency caused by winds. That allowed them to extrapolate how quickly the winds were moving.
“By measuring this shift, we were able to deduce the speed of the winds much like one could deduce the speed of a passing train by the change in the frequency of the train whistle,” said study co-author Vincent Hue, a planetary scientist at the Southwest Research Institute in San Antonio, Texas.
For the ability to measure Jupiter’s top wind speeds, the scientists can thank a 1994 collision with a comet.
In a dramatic fashion, the comet, which scientists call Shoemaker-Levy 9, hit Jupiter, producing new molecules that still persist today in Jupiter’s stratosphere, swept around in the planet’s mighty winds.
Scientists studying Jupiter’s winds might use cloud-tracking techniques, looking at the swirling clouds that give Jupiter its signature red-and-white bands. But there are no clouds in Jupiter’s stratosphere, ruling out that option.
Instead, it was the particles produced by the comet collision — in particular, the molecule hydrogen cyanide — that helped scientists track stratosphere speeds by way of Jupiter’s “jets,” narrow bands of wind not unlike Earth’s own jet streams.
Astronomer Thibault Cavalié, of the Laboratoire d’Astrophysique de Bordeaux in France, led the research.
“The most spectacular result is the presence of strong jets, with speeds of up to 400 meters per second, which are located under the aurorae near the poles,” says Cavalié. Four hundred meters is around 1,312 feet per second, or more than 900 miles per hour.
The jets seem to act like a giant vortex, researchers said, some 550 miles high — and there’s nothing else like it in our neighboring planetary system.
“A vortex of this size would be a unique meteorological beast in our Solar System,” Cavalié said.
In addition to being orders of magnitude faster than Earth’s fastest winds, the speeds are more than twice the maximum observed in Jupiter’s Great Red Spot, a massive storm on the planet. The storm’s center winds are relatively calm, but around the edges, speeds can reach more than 400 miles per hour.
Previous studies had suggested that winds in the stratosphere, now measured for the first time, would be slower — having decreased in velocity since traveling away from the Great Red Spot.
“The new ALMA data tell us the contrary,” Cavalié said in remarks released with the research, adding that gathering evidence of such strong winds near Jupiter’s poles was a “real surprise.”
Around the center of Jupiter, the winds were not as strong as their polar top speeds, but still clocked in around 372 miles per hour, the scientists discovered.
Researchers attributed the results to the power of the ALMA telescope. Perhaps surprisingly, it took only 30 minutes of telescope time to gather all of the data to directly measure Jupiter’s winds.
This kind of study of Jupiter’s stratosphere was “really unexpected just a few months back,” Cavalié said. The new findings, he said, “set the stage for similar yet more extensive measurements.”
Those kinds of data are expected to be collected by the European Space Agency’s JUpiter ICy moons Explorer, planned to launch into space next year.