The folks managing the Juno spacecraft believe the huge wave structures seen below are atmospheric gravity waves.
You know the ripples caused when you throw a rock into a pond? It’s the same principle at play here but in the atmosphere. Here are a couple of fantastic examples of what atmospheric gravity waves look like on Earth.
It’s not a new discovery on Jupiter, but Juno’s JunoCam did count “more distinct wave trains than any other spacecraft mission since Voyager,” says Glenn Orton, a Juno scientist working at NASA’s JPL. “The trains, which consist of as few as two waves and as many as several dozen, can have a distance between crests as small as about 40 miles (65 kilometers) and as large as about 760 miles (1,200 kilometers).”
The Juno team even managed to estimate the height of one of the waves at 6 miles by looking at the shadow of one of the wave structures.
As for how they form on Jupiter? Scientists are going to keep studying these to find the exact reason, but the average atmospheric gravity wave forms when the air flow is disturbed. Updrafts, vortices, or any feature that can throw a wrench in the usual air flow could be the culprit.
Orton did say the waves form in a variety of conditions.
“The waves can appear close to other Jovian atmospheric features, near vortices or along flow lines, and others exhibit no relationship with anything nearby,” said Orton. “Some wave trains appear as if they are converging, and others appear to be overlapping, possibly at two different atmospheric levels. In one case, wave fronts appear to be radiating outward from the center of a cyclone.”
Juno’s trek around Jupiter is entering its third year. In four days (October 29), the spacecraft will dive towards the gas giant for its 16th science flyby. Instruments will study Jupiter’s aurora and poke through the cloud cover to expand our knowledge of the solar system’s biggest world.
Juno’s time around Jupiter won’t last forever, but it still has a few more years left. Back in June, NASA gave the thumbs-up to extend Juno’s science operations until July 2021. That was partly due to a change in the spacecraft’s orbit when it reached Jupiter. Instead of the planned 14-day orbit, Juno takes a longer 53-day orbit due to concerns over the spacecraft’s fuel system.
Juno still gathers the same science; it just takes a little longer. The spacecraft’s final day will be a fiery one as it enters Jupiter’s atmosphere.