First observation of a polar cyclone on Uranus

2023-05-23 18:00:59

NASA scientists used microwave observations to detect the first polar cyclone on Uranus, seen here as a light-colored dot to the right of center in each image of the planet. – NASA/JPL-CALTECH/VLA

MADRID, 23 May. (EUROPA PRESS) –

For the first time, NASA scientists have strong evidence of a polar cyclone on Uranus. By examining radio waves emitted by the ice giant, They detected the phenomenon at its north pole.

The findings confirm a broad truth about all planets with substantial atmospheres in our solar system: whether the planets are composed primarily of rock or gas, their atmospheres show signs of a swirling vortex at the poles.

Scientists have long known that Uranus’ south pole has an eddy feature. Images of the methane cloud tops from NASA’s Voyager 2 showed winds at the polar center spinning faster than at the rest of the pole. Voyager’s infrared measurements did not observe temperature changes, but the new findings, published in Geophysical Research Lettersif they do it.

Using huge radio antennas from the Very Large Array in New Mexico, they looked below the ice giant’s clouds and determined that the air circulating at the north pole appears to be warmer and drier, the hallmark of a strong cyclone. Collected in 2015, 2021 and 2022, observations went deeper than ever into Uranus’s atmosphere.

“These observations tell us a lot more about the history of Uranus. It’s a much more dynamic world than you think,” he said. it’s a statement lead author Alex Akins of NASA’s Jet Propulsion Laboratory in southern California. “It’s not just a simple blue ball of gas. There’s a lot going on under the hood.”

Uranus is showing off more these days, thanks to the position of the planet in orbit. It’s a long journey around the solar system for this outer planet, taking 84 years to complete one full turn, and for the past several decades the poles have not pointed towards Earth. Since about 2015, scientists have had a better view and been able to look deeper into the polar atmosphere.

The Uranus cyclone, compact in shape with warm, dry air at its core, is very similar to those detected by NASA’s Cassini at Saturn. With the new findings, cyclones (spinning in the same direction as your planet spins) or anticyclones (spinning in the opposite direction) have now been identified at the poles of all the planets in our solar system except Mercury, that has no substantial atmosphere.

But unlike hurricanes on Earth, cyclones on Uranus and Saturn don’t form over water (neither planet has liquid water) and they don’t drift; They are locked at the poles. Researchers will be watching closely how this newly discovered Uranus cyclone evolves in the coming years.

“Does the warm core we observe represent the same high-velocity circulation seen by Voyager?” Akins asked. “Or are there stacked cyclones in Uranus’ atmosphere? The fact that we’re still discovering such simple things about how Uranus’ atmosphere works really excites me to find out more about this mysterious planet.”