NASA scientists have for the first time obtained strong evidence for the existence of a polar cyclone on Uranus. While studying the radio waves emitted by the ice giant, they discovered a phenomenon at the planet’s north pole. The findings confirm a broad truth about all planets with significant atmospheres in our solar system: Whether planets are predominantly rock or gas, their atmospheres are the signature of a swirling vortex at the poles.

Scientists have known for a long time that the south pole of Uranus has a vortex feature. NASA’s image of the Voyager 2 methane cloud tops showed that the wind at the pole center was spinning faster than the rest of the pole. Voyager’s infrared measurements did not observe temperature changes, but new findings published Geophysical Research Lettersobserved.

Using the massive antennae antennas of the Very Large Array in New Mexico, they looked under the ice giant’s clouds and determined that the air circulating over the north pole appeared hotter and drier — hallmarks of a violent cyclone. Observations collected in 2015, 2021 and 2022 penetrated Uranus’ atmosphere more deeply than ever before.

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

Today, Uranus is paying more attention due to its position in the planet’s orbit. This exoplanet has a long way to go around the solar system, it takes 84 years to make a full circle, and the poles have not been turned to Earth for the past few decades. Since around 2015, scientists have had better vision and have been able to peer deeper into the polar atmosphere.

materials for cyclone

A compact cyclone on Uranus with hot, dry air at its center is very similar to what NASA’s Cassini observed on Saturn. Thanks to the new discoveries, cyclones (rotating in the same direction as their planets) or anticyclones (rotating in the opposite direction) have been detected at the poles of every planet in our solar system, with the exception of Mercury, which has no significant atmosphere. .

But unlike hurricanes on Earth, cyclones on Uranus and Saturn do not form over water (both planets are not known to have liquid water) and do not drift; they are locked in poles. Researchers will closely follow how this newly discovered Uranus hurricane evolves in the coming years.

“Does the hot core we observe represent the high-speed circulation that Voyager saw?” Akin asked. “Are there cyclones in the atmosphere of Uranus? The fact that we’re still trying to figure out such simple things about how the atmosphere of Uranus works makes me want to learn more about this mysterious planet.”

The 2023 National Academy of Planetary Sciences and Astrobiology Decadal Survey prioritized Uranus studies. In preparation for such a mission, planetary scientists focus on strengthening their knowledge of the ice giant’s mysterious system.