The Juno space probe detected new northern lights in Jupiter’s atmosphere, characterized in a ring shape and rapidly expanding. The discovery was pointed out by an ultraviolet spectrograph on board the spacecraft, developed by scientists from the scientific organization Southwest Research Institute (SwRI), United States. According to them, small charged particles originating from the Sun were responsible for the creation of the phenomenon, after contact with the gas giant’s magnetosphere.
“We believe that these recently discovered faint ultraviolet features originated millions of kilometers from Jupiter, near the boundary of the magnetosphere in contact with solar wind. The latter is a supersonic stream of charged particles emitted by the Sun. When they reach the planet, they interact with their magnetosphere in a way that is not yet well understood, “said study leader Vincent Hue, in a statement from SwRI.
“Despite decades of observations combined with numerous spacecraft measurements, scientists still don’t fully understand the role that the solar wind plays in moderating Jupiter’s auroral emissions. Its magnetosphere dynamics are controlled by the 10-hour rotation, the fastest in the Solar System, ”added Thomas Greathouse, involved in the research published in the Journal of Geophysical Research: Space Physics.
The rings, also called “ultraviolet emissions in circular expansion”, reached a propagation speed between 3.3 and 7.7 km / s. In this case, the largest aurora identified was about 2 thousand kilometers in diameter. Previous observations, through Juno and data from the Hubble space telescope, pointed out that most of them were generated strictly by internal processes.
However, “the location of the rings at high latitude [between 3 and 6 kilometers] indicates that the particles that cause the emissions come from the distant Jupiterian magnetosphere,” commented Bertrand Bonfond, an astrophysicist at the University of Lieja, Belgium. “In this region, solar wind plasma often interacts with Jupiter’s plasma in a way that is thought to form Kelvin-Helmholtz instabilities – phenomena that occur when there is a speed difference between two fluids,” said the statement from SwRI.
In this way, both processes are accepted to explain the creation of beams of particles in Jupiter’s magnetic field, responsible for the auroras. Thus, the researchers hope that with the extension of NASA’s mission until 2025, they will get more evidence to study the events.