Jupiter Was Once a Sauna Planet With Vast Oceans—What Happened?

Friday, 03 November 2017 - 10:46AM
Solar System
Friday, 03 November 2017 - 10:46AM
Jupiter Was Once a Sauna Planet With Vast Oceans—What Happened?
Image Credit: NASA/JPL-Caltech/SwRI/MSSS/Gabriel Fiset

We all know Jupiter as the biggest, brightest, gassiest planet in the solar system, but the planetary giant wasn't always as it appears today. 

Larger than all the other planets in our neighborhood combined, Jupiter is often considered a failed star (or "brown dwarf," as they're known), as it contains a lot of the same elemental building blocks as the sun (such as hydrogen and helium), but just didn't quite grow large enough to burst forth in a blast of light to become a genuine star.

According to a new unpublished study, though, Jupiter wasn't always the giant gaseous ball that we know and love. Back in the early days of the planet, Jupiter wasn't that much bigger than Earth, and had a fairly stable surface; a far cry from the light and fluffy planet that exists today.

So what happened?

It's possible that Jupiter steamed itself into a new, larger, less dense form.

As part of a simulation of planetary formation, the study started by examining what might produce a so-called "hot Jupiter" planet that has a large, gaseous mass and a lot of heat. If the simulation is accurate, these planets would start as big chunks of ice and rock, the same as worlds like our own, and wouldn't be much bigger than planet Earth either.

As time goes on, though, planets like Jupiter would begin heating up faster and faster - with no air in the planet's atmosphere, the ice on the planet would melt, leading to a sauna-like vapor cloud that would surround the entire planet.

As water vapor is an excellent greenhouse gas, this cloud would in turn heat the planet further, which would cause more water from the surface to be released into the growing steamy atmosphere.

This cycle would continue on and on, as the planet heats up further and further, and as more and more steam enters the atmosphere, slowly thickening to the point that, despite still being vapor, it's a thick, densely packed "supercritical fluid" that swirls around the entire planet, floating above the surface.

Eventually, the pressure gets so great, and the planet expands so far, that there's no distinguishable line between the planet's atmosphere and its surface - the gas that surrounds Jupiter is now, to all intents and purposes, its own planetary surface.

Then, over time, the planet picks up debris and material from its local star, as the expanding size of the hot Jupiter allows it to throw its weight around a bit more and attract more dust as it passes by.

The simulation was initially run by John Chambers, a researcher at the Carnegie Institution of Washington in Washington, D.C.

Said Chambers of his experiment:

Opening quote
"I calculated the structure of atmospheres in this case, and worked out when conditions are right for rapid inflow of gas to form a giant planet... I'm still working through the implications of this, but the next step is to feed this result into more general models for planet formation. The idea is to compare the outcome of these models with the observed population of extrasolar planets to pin down other unknown factors in planet formation."
Closing quote

If Chambers' model is accurate, he may have identified the process by which a large, glowing hot Jupiter planet forms.

If this is the case, then it turns out that Jupiter once wasn't much different to our own home world - except, of course, that it had such phenomenal heat and energy at its core that it couldn't help but burst forth into a bright gaseous ball of swirling, storming vapor.

This feels like a nice reminder that, as with the moon, Mars, and other large bodies within our solar system, local environments are in a constant state of flux.

Who knows what the Earth will look like in millennia to come?

One thing's certain - our home planet will probably be completely unrecognizable.

Solar System
Jupiter Was Once a Sauna Planet With Vast Oceans, Study Suggests