Thursday, March 15, 2018

Stories for Odin: what the NASA analyst saw in storms at Jupiter's north pole

These are stories I make up for Odin as he falls asleep. Usually he asks for specific features. Tonight I was given free reign.

Tonight's story is about the planet Jupiter. First the real part, then the made-up part.

Do you remember which planet is Jupiter? It is the fifth one out from the sun. Sometimes Jupiter is called a "failed star" because it's like our sun but much smaller. This means it can't light up. However, it is much, much larger than our planet, and we think made up mostly of gases. As it rotates, the atmosphere forms bands that move in opposite directions. This creates swirls at the boundaries.

Our government agency NASA, the National Aeronautics and Space Administration, sent a satellite to look closely at Jupiter. It is called Juno. The probe orbits Jupiter in an unusual way, axially - north to south. This means we get our first good looks at Jupiter's poles, and they are very weird - swirls piled on top of each other. It's like all the mixing was shoved together.



Do you know what "dissipate" means? Remember when you wake up and have breakfast, then all you want to do is run around and jump and play? This is energy inside you that wants to "dissipate" -- to go from where it is to where it wants to be. Sometimes when this happens in gases or liquids, structures form. These structure make it easier to dissipate energy, and are called "dissipative structures." 

Odin here is the made-up part. 

During an axial orbit, mission control takes many pictures in sequence. One of the analysts saw something odd in them, but she couldn't identify what. She looked many times, but the part of her brain sensing a pattern wasn't talking clearly to the rest of itself. She used a tool; she overlaid the images to make an animation. The result puzzled her so she took it to a colleague who studies Jovian weather. Her colleague spotted the funny thing immediately: the directions of wind around the pole were obvious but the polar swirls weren't moving with them. That is, the storms seemed to be moving on their own, or more likely in response to unseen forces. They took the result to the broader team.

That team argued about the meaning, with arguments falling into three camps. First, that the storms showed signs of self-determination in movement. Second, that this was seeing what we wanted to see, and that simpler explanations were available. Third, that we didn't understand this observation, but that self-determination wasn't extraordinary.

There was no answer to be had. They decided to have some fun. Juno carried a backup set of communication devices. On the next orbit, they transmitted into the polar storms everything they imagined could interest sentience (Odin, this means a creature that can think): music, words, math. Then they waited for the next flyby.

They found Jupiter's polar storms arranged differently. A trident and a tuning fork. Another trident, rotated 90 degrees. Then a crescent. Even weirder, the analyst's overlays suggested that the storms were completely still.

Images coming from the next flyby stunned our NASA team: nothing had changed except the arrival of another storm, which had apparently disintegrated into the others. It formed what everyone took to be the shape of our number "2."

(Odin has been bored into sleep at this point, but the analysts work out the Jovian response to be "E = mc^2")