NASA’s Juno spacecraft has finally entered Jupiter’s magnetosphere — the area surrounding the planet that encompasses its large and insanely strong magnetic field. Three days away from inserting itself into Jupiter’s orbit, Juno has “crossed the boundary into Jupiter’s home turf,” said Juno principal investigator Scott Bolton in a news release. ”We’re closing in fast on the planet itself and already gaining valuable data.”
That data, actually, includes some recorded waves of the spacecraft’s crossing of the “bow shock” — analogous to a sonic boom — right outside the magnetosphere. NASA covered those measurements into a volume and pitch that correlates with the waves’ amplitude and frequency — yielding audio that makes the crossing sound like a nightmarish cry from hell. It’s pretty spectacular.
A planet’s magnetic field is basically the first and only line of defense against solar winds that blow out into space at over a million miles per hour. Jupiter’s magnetic field is 20,000 times stronger than Earth’s — pretty much the largest structure in the solar system. And that also means it’s a threat to Juno. When solar winds hit this particular magnetosphere, particles can become hyper-charged and trapped within the field itself, making the magnetosphere a radioactively violent place for electronic equipment.
Luckily, NASA’s engineers have turned Juno into something of an “armored tank” that should stand a really good chance of barreling through the magnetosphere without much harm.
Of course, Juno isn’t out of the woods just yet. It needs to make it safely into Jupiter’s orbit — a task that presents its own set of obstacles. We’ll find out in just a few days whether a mission that launched five years ago has a bright future, or ends with an explosive bang.