SwRI scientists determined that charged particles coming from the edge of Jupiter’s massive magnetosphere triggered these auroral emissions.
“We think these newly discovered faint ultraviolet features originate millions of miles away from Jupiter, near the Jovian magnetosphere’s boundary with the solar wind,” said Dr. Vincent Hue, lead author of a paper accepted by the Journal of Geophysical Research: Space Physics. “The solar wind is a supersonic stream of charged particles emitted by the Sun. When they reach Jupiter, they interact with its magnetosphere in a way that is still not well understood.”
Both Jupiter and Earth have magnetic fields that provide protection from the solar wind. The stronger the magnetic field, the larger the magnetosphere. Jupiter’s magnetic field is 20,000 times stronger than Earth’s and creates a magnetosphere so large it begins to deflect the solar wind 2–4 million miles before it reaches Jupiter.
“Despite decades of observations from Earth combined with numerous in-situ spacecraft measurements, scientists still do not fully understand the role the solar wind plays in moderating Jupiter’s auroral emissions,” said SwRI’s Dr. Thomas Greathouse, a co-author on this study. “Jupiter’s magnetospheric dynamics, the motion of charged particles within its magnetosphere, is largely controlled by Jupiter’s 10-hour rotation, the fastest in the solar system. The solar wind’s role is still debated.”
