In a groundbreaking discovery, scientists have detected a high-speed jet stream in Jupiter's equatorial atmosphere using the James Webb Space Telescope, a joint mission by NASA, the European Space Agency, and the Canadian Space Agency.
The jet stream was observed on July 27, 2022, and was found to have winds reaching speeds of up to 515 kilometers per hour—about twice the speed of a Category 5 hurricane on Earth. This discovery provides valuable insights into the turbulent layers of Jupiter's atmosphere and their interactions.
The jet stream is located 40 kilometers above Jupiter's cloud tops and is relatively narrow, measuring approximately 4,800 kilometers in width. This is quite surprising given the immense size of the planet. "What we have always seen as blurred hazes in Jupiter's atmosphere now appear as crisp features that we can track along with the planet's fast rotation," said lead author Ricardo Hueso of the University of the Basque Country in Bilbao, Spain.
Before the Webb telescope's observations, scientists had only been able to characterize winds in Jupiter's troposphere, the layer just below the stratosphere, using ground-based telescopes and NASA's Hubble Space Telescope. However, these previous observations did not reveal much detail in the haze above Jupiter's clouds. With Webb's advanced infrared instruments, scientists were able to capture detailed images across a broad spectrum of light, allowing them to discern and track faint details in the planet's equatorial hazes for the first time.
The discovery has far-reaching implications for our understanding of Jupiter's atmospheric dynamics and the weather patterns of fast-rotating giant planets. "If the strength of this new jet is connected to this oscillating stratospheric pattern, we might expect the jet to vary considerably over the next two to four years," explained co-author Leigh Fletcher of the University of Leicester in the United Kingdom.
Jupiter’s fly like a jet stream high above the whole scene ♪
— NASA Webb Telescope (@NASAWebb) October 19, 2023
Webb has discovered a 3000-mi (4800-km) wide jet stream over Jupiter’s equator, above the main cloud decks. More on Webb's unique ability to track interactions in Jupiter's layered atmosphere: https://t.co/028rfjUkiN pic.twitter.com/2Xd5mKJI2c
This discovery is part of Webb's Early Release Science program, aimed at demonstrating the telescope's full potential and exploring its capabilities. As scientists continue to analyze the data, they look forward to testing theories and making further discoveries about Jupiter's complex atmosphere in the years to come.