Image credit: NASA/JPL
In Ancient Roman mythology, Jupiter claimed domain over the sky and the thunder. He cloaked himself in cloud to hide his mischief— but his wife, Juno, could see past it all. It’s no accident that NASA named a spacecraft after her (though they did give the craft a backronym in an attempt to cover their sentimental tracks), or that she has been zipping through space at almost 19 miles per second for the past five years, her sights set on Jupiter and it’s mysteries.
Juno snuck its way into Jupiter’s orbit on July 4th. At 11:18 PM Eastern Time the main engine started firing, slowing the spacecraft enough so it could fall into the planet’s orbit. At 11:53 PM, those engines were shut off. Almost four hundred million miles away, NASA received a three-second beep to reassure them that the spacecraft had made it into orbit in one piece. Juno project manager Rick Nybakken told the room: “We just did the hardest thing NASA’s ever done.”
When Juno was launched on August 5, 2011, NASA knew full well how hard it would be to get a closer look at Jupiter. In the lead up to the orbital insertion The New York Times compiled a doomsday list of all the things that could go wrong in Juno’s travels (think Gravity, but more disappointment, and less Sandra Bullock).
The planet is largely made up of hydrogen and helium, like the sun, and many suspect its core is a sea of metallic hydrogen. Aside from making Jupiter all the more badass, the metallic hydrogen core could account for the planets massive magnetic field. Fourteen times stronger than the Earth’s, the magnetic field traps charged particles and creates radiation belts capable of crushing hopes, dreams, and all eight-thousand-pounds of Juno.
And then there’s the debris: Jupiter’s gravitational field is known to draw dust and meteorites in, only to spit them out the other side in a slingshot-like manoeuvre. So all-in-all, the gas giant is a hard planet to study. But it’s worth it— it’s worth the $1.1 billion, it’s worth the five year mission, and it’s worth the stress, and here’s why.
Under Jupiter’s clouds are clues to the early formation of the solar system. Because Jupiter is so similar to the sun in composition, it probably formed pretty early on. The theory is that the solar system formed from a collapsing nebula, in other words a giant heap of gas and dust, and when the sun formed Jupiter laid claim to the leftovers and formed out of the scraps of the sun.
What the Juno spacecraft is asking, now that Jupiter is all grown up, is how the formation really went down. It’s one of many missing pieces to the puzzle of how the heck we humans got here—finding out how Jupiter came to be Jupiter will help us figure why we’re here (physically, not spiritually) (I suggest yoga or a Beyoncé concert for that).
NASA wants to find out how much water there is in the atmosphere, the composition of the lower atmosphere, the structure of the magnetic and gravitational fields, whether the planet has a core, and what that core could be—since we don’t really know what’s going on underneath Jupiter’s thick and colorful cloud cover. It could be entirely gaseous, or have that totally-heavy-metal hydrogen core, or the core could be rocky. Finding that out means finding out how the fifth planet from the sun got its leg up in the universe.
From here on out, Juno will be cartwheeling around, having a great old time, giving each of its instruments time to gather data from the planet below. Juno travels at skyrocketing speeds, uses the power equivalent to a household blender, and is, on record, the farthest travelling solar-powered spacecraft we’ve sent out into the abyss. It’ll orbit Jupiter 37 times, soaking in as much as it can of the massive planet: the hundred-year-strong Great Red Spot, the rich clouds, and the auroras lighting up the sky at its poles.
Now that Juno is relatively snug in Jupiter’s orbit, the plan is to send as much data as possible back to NASA headquarters so we can fill in the missing spaces in our space history— it’s hoped that Juno will send home answers before it crashes into Jupiter and burns up in the atmosphere in February of 2018. Like the Jupiter and Juno in Ancient Roman mythology, their relationship is a complicated one: it’s a little bit romantic, and a whole lot insightful.