NASA’s James Webb Space Telescope (JWST), a key piece of equipment for modern astronomical observation, is getting ready to start a ground-breaking investigation of the auroras that illuminate Saturn and Uranus’ northern skies. Under the direction of University of Leicester researchers, this project aims to investigate the mechanisms that underlie these captivating displays of cosmic light.
The $10 billion space telescope will be used by two different teams of University of Leicester astronomers to examine auroras above the gas giant Saturn and the icy ice giant Uranus. The goal is to provide a more thorough explanation of the mechanisms underlying the polar light displays across several planets.
Stargazers over Earth are familiar with auroras as the magnificent Northern and Southern Lights, which can be viewed when they appear at our planet’s poles.
When charged particles from the sun’s solar wind collide with the magnetosphere, which acts as a shield for Earth, spectacular light displays are produced. These particles leave Earth by streaming out behind it along magnetic field lines, but not before interacting with other particles in our atmosphere to produce dazzling light.
The sun can produce large amounts of star plasma during coronal mass ejections, which make auroras more noticeable and visible at lower latitudes over Earth.
The auroras of Uranus, an ice giant with an atmosphere composed of water, ammonia, and methane, are now largely unknown.
After thirty years of research, a research team from the University of Leicester School of Physics and Astronomy headed by a PhD student finally proved the existence of an infrared aurora surrounding Uranus last year.
The main concern now is how these gas giant planets are so much hotter than expected given that the temperature of all of them, including Uranus, is hundreds of degrees Kelvin/Celsius higher than what models would indicate if they were simply warmed by the sun. According to one idea, this is because of the energetic aurora, which produces and drives heat from the aurora towards the magnetic equator.
Starting in early 2025, the JWST will explore Uranus, taking pictures of the ice giant in a single day that lasts roughly 17 Earth hours. With this, the scientists should be able to map aurora emissions across the course of Uranus’ magnetic field’s full revolution. Additionally, the scientists hope to ascertain whether emissions originate from sources within the system, akin to how Jupiter produces its auroras, or whether they are formed when the Uranian magnetic field interacts with the solar wind, as occurs over Earth. Alternatively, it is possible that, similar to how Saturn’s auroras appear to be produced, Uranus’ auroras are produced by a combination of these events.
