On January 19, the Webb Space Telescope peered deep into Uranus’ chaotic world for 17 hours, observing how faint light from molecules above Uranus’ clouds met its unusual magnetic field. The resulting data helped scientists map Uranus’s upper atmosphere in unprecedented detail and revealed new insights into how fascinating auroras form.

An international research team used Webb’s Near Infrared Spectrometer (NIRSpec) instrument to map the temperature and density of ions found about 3,000 miles (5,000 kilometers) above Uranus’ cloud tops. The survey results are published Geophysical Research Letters reveals how the planet’s eccentric magnetic field affects its auroras, providing new insights into how energy behaves in the upper layers of ice giants.

“This is the first time we have been able to see Uranus’s upper atmosphere in three dimensions,” Paola Tiranti, a PhD student at Northumbria University in the UK and lead author of the study, said in the paper. statement. “Using Webb’s sensitivity, we can track how energy moves upward through the planet’s atmosphere, and even see the effects of polarized magnetic fields.”

huge weirdo

Uranus has a rather unusual magnetic field. The planet’s axis of rotation is tilted more than 90 degrees, causing the planet to rotate sideways. The magnetic axis is also significantly tilted, nearly 60 degrees away from the rotation axis. That sideways magnetic field gives Uranus a more variable magnetosphere, meaning the auroras traverse the surface in a more complex way, according to the authors. NASA.

Recent Webb observations detected two bright auroral bands near Uranus’s magnetic poles, as well as a significant decrease in ion density and emission in the region between the bands. This may be due to how magnetic field lines guide charged particles through Uranus’ atmosphere.

it was the hubble space telescope First aurora discovered on Uranus Since then, scientists have been trying to understand how the planet’s strange magnetosphere affects aurora displays.

“Uranus’ magnetosphere is one of the strangest in the solar system,” Tiranti said. “Webb showed us how deep that effect reaches into the atmosphere.”

cold world

NASA’s Voyager 2 spacecraft performed its first flyby of Uranus on January 24, 1986. The mission revealed a pale blue world that was very cold compared to its neighboring planets. At that time, the temperature of Uranus’ upper atmosphere was below -353 degrees Fahrenheit (-214 degrees Celsius).

Webb’s recent data also confirmed that Uranus’ upper atmosphere is still cooling. Based on data collected by Voyager 2’s flyby, researchers found that Uranus’ upper atmosphere is undergoing a long-term cooling trend, becoming cooler over time. The researchers measured temperatures about 302 Fahrenheit (150 Celsius) lower than those recorded in previous attempts.

“By revealing Uranus’s vertical structure in such detail, Webb is helping us understand the ice giant’s energy balance,” Tiranti said. “This is an important step toward characterizing giant planets outside our solar system.”