Jupiter is a storm planet, but also a mystery planet. How can the expanse of a gas giant swirling with cyclones be a desert?
Expect anything from a planet known (or notorious) for things like the Big Red Spot and the weird, stormy pentagon that could pass to form a UFO. Jupiter’s “hot spots” (first seen by NASA’s Galileo spacecraft) were an enigma that has remained in the dark so far. Now his Juno probe has got another look. Earlier it was considered to be local deserts. What Juno retorted suggests that these focal points, which deceptively glow in the infrared network, may not be as different from the rest of Jupiter – at least the part of Jupiter where they exist. That whole region of the planet is a cosmic desert.
Turns out Galileo messed up without even knowing it. Because he dived into one of the foci in the northern equatorial region of Jupiter and discovered how dry and windy it is, astronomers on Earth have automatically assumed that each focal point is its own localized desert. They go much deeper and further than that, if you ask Juno co-investigator Tristan Guillot.
“We see that there is little ammonia in the whole area and we realize that the hotspots may just be clearing up in the clouds,” Guillot told SYFY WIRE. “The storms we see in the JunoCam images had to carry both ammonia and water deep into the ground, not just where the hotspots are, but all around these latitudes.”
Juno discovered that the hotspots have to do with cracks in Jupiter’s dense clouds, which could allow the probe to peek into the depths of Jovian’s atmosphere, where it is hotter and drier than anywhere else. Another thing Juno saw was that these desert storms triggered a phenomenon known as shallow lightning. In order to create lightning, there must be a liquid in the atmosphere that will increase the particles and transfer the charge. Shallow lightning is so strange because it can appear at atmospheric levels that are too cold to keep water in a liquid state. That’s where the ammonia comes from. If you mix water and ammonia, you can keep the water in the liquid so that the lightning can ignite even at such a deep freeze.
It just gets weirder from here. Juno’s microwave instrument can no longer see water and ammonia when they join forces. And not only that, but they also produce alien hailstones, not so scientifically called mushrooms. Huge storms caused by water condensation much deeper in the atmosphere lead to the formation of mushrooms. Shallow lightning literally illuminates where these storms form, something that could ultimately help in understanding how heat moves within the planet. If humans could really live on Jupiter, shallow lightning would be a terrible sign of oncoming boletus.
“Mushballs reveal that Jupiter’s atmosphere is completely different than expected,” Guillot said. “Instead of being convectively unstable and homogeneously mixed, we now imagine a deep atmosphere on average stable, with an increase in the abundance of ammonia and water as you go deeper.”
When the mushrooms become heavy enough, they fall out through the atmosphere and leave behind an area almost free of ammonia and water. They have to melt and evaporate in order for ammonia and water to become gas again and therefore, once again visible Juno. Giljo sees the behavior of ammonia and water in storms analogous to the slow addition of milk to water without mixing liquids. The milk will sink to the bottom of the glass just as water and ammonia sink through Jupiter’s atmosphere during a storm. The difference is that, unlike glass, Jupiter does not have a bottom – or surface that we know of. How deep ammonia and water can sink is something that will need further investigation. Hypothetically, it could sink to the end. Nobody knows.
What the Juno team needs to do now is understand how effective mushroom formation really is and how to apply it to Juno data. The probe has already allowed the Juno team to realize how much water is hidden deep in Jupiter’s atmosphere. For a more accurate assessment, they will need to understand how water penetrates to the depths of other regions. Juno could demystify this as he gradually moves toward the North Pole of Jupiter, which is believed to have significantly different properties that could tell Guillot and his colleagues even more about the bizarre time of Jovie.
“Our research has broad implications,” he said. “All the planets in our solar system, as well as exoplanets, have an atmosphere that is very light. The same process could occur when elements condense in these atmospheres. Understanding what is happening on Jupiter will be crucial in applying our models to interpret exoplanetary spectra that will soon be measured by the James Webb Space Telescope. “