After nearly six years of travel, Juno is gearing up for the real mission – studying Jupiter. While we’re all grilling and shooting off fireworks, NASA mission controllers will be anxiously awaiting word from Juno that it successfully entered the correct elliptical orbit around Jupiter.
On June 24th, Juno crossed the bow shock just outside of Jupiter’s magnetosphere. It was 5.56 million miles away from the gas giant when the Waves instrument gathered the data below. The Jet Propulsion Laboratory took the data and created a recording of the exact moment Juno hit the bow shock.
Did You Know: The Waves instrument resembles a pair of rabbit-ear antennas used way back before the days of Netflix. Except it’s much larger than your parents’ set. It measures about 13 feet from tip to tip. One ‘ear’ detects the electric portion of radio and plasma waves, while the other looks for the magnetic part. The magnetic antenna is home to a coil of wire wrapped 10,000 times around a nearly 6-inch long core.
Think of this bow shock like a sonic boom created in Earth’s atmosphere by a supersonic aircraft. We are hearing the region of space where incredibly fast solar wind is heated and slowed when slamming into Jupiter’s magnetosphere.
“The bow shock is analogous to a sonic boom,” said William Kurth of the University of Iowa in Iowa City, lead co-investigator for the Waves investigation. “The solar wind blows past all the planets at a speed of about a million miles per hour, and where it hits an obstacle, there’s all this turbulence.”
JPL explains what we see in the video after Juno crosses the bow shock:
The vertical bar to the right of the chart indicates the color coding of wave amplitude, in decibels (dB) above the background level detected by the Waves instrument. Each step of 10 decibels marks a tenfold increase in wave power.
A day later (June 25) and 500,000 miles closer, the spacecraft officially entered Jupiter’s magnetosphere. Give it a listen.
The science gathering part of Juno’s mission has officially begun. Scientists were a bit surprised at how complex the structure of this boundary was.
“This unusual boundary structure will itself be the subject of scientific investigation,” said Barry Mauk, who is the instrument lead for the Jupiter Energetic-Particle Detector Instrument (JEDI).
Ok, the sounds are cool – but when will we start seeing the epic images NASA is known for? Yesterday, mission controllers transmitted the commands that will place Juno into orbit around Jupiter on July 4th. Any instrument that isn’t designed to get the spacecraft into orbit is shutdown. That includes JunoCam (the spacecraft’s camera).
Two days after successful orbital entry, Juno’s instruments will be switched back on. According to Juno’s mission team, we will see the first up-close images of Jupiter from Juno in late August or early September.
And what we will see will be breathtaking. From polar auroras from a never-before-seen perspective, to intricate details of Jupiter’s orange and white clouds. We’ll even get a new image of Jupiter’s famous Great Red Spot before JunoCam succumbs to the planet’s intense magnetic field.
Yep, JunoCam’s days are already numbered. Juno’s mission team expects the camera to last until Orbit 8, out of 33 planned orbits. I’m crossing my fingers that JunoCam can squeeze out a couple of extra orbits.