On July 4, 2016 – at 8:18 p.m. PDT (July 5 at 0318 UTC) – NASA’s solar-powered Juno spacecraft will begin moving into orbit around Jupiter. One of the mission goals is to understand Jupiter’s enormous magnetosphere, the magnetic environment surrounding the planet.
Juno crossed the boundary into Jupiter’s immense magnetic field on June 24, 2016. The craft’s Waves instrument recorded the encounter with the bow shock over the course of about two hours. Bow shock – analogous to a sonic boom on Earth – is where the supersonic solar wind is heated and slowed by Jupiter’s magnetosphere.
— NASA's Juno Mission (@NASAJuno) July 1, 2016
The next day, June 25, 2016, the Waves instrument witnessed the crossing of the magnetopause. In the video above, trapped continuum radiation refers to waves trapped in a low-density cavity in Jupiter’s magnetosphere.
Planets’ magnetic environments don’t exist in isolation. They’re the result of a collision between a planet’s intrinsic magnetic field and the supersonic solar wind. NASA said :
Jupiter’s magnetosphere – the volume carved out in the solar wind where the planet’s magnetic field dominates – extends up to nearly 2 million miles (3 million km). If it were visible in the night sky, Jupiter’s magnetosphere would appear to be about the same size as Earth’s full moon.
As Juno orbits Jupiter in the coming months and years, we’ll learn more!
Bottom line: NASA video discusses how the Juno mission, arriving at Jupiter on July 4, 2016, will explore the planet’s massive magnetosphere.
Eleanor Imster has helped write and edit EarthSky since 1995. She was an integral part of the award-winning EarthSky radio series almost since it began until it ended in 2013. Today, as Lead Editor at EarthSky.org, she helps present the science and nature stories and photos you enjoy. She also serves as one of the voices of EarthSky on social media platforms including Facebook, Twitter and G+. She and her husband live in Tennessee and have two grown sons.