In December 2010, Saturn was quickly overrun by a storm several times the size of Earth. For months the atmospheric outburst raged, growing and traveling so quickly that it soon managed to wrap itself around the entire northern hemisphere. To date, it is the most massive storm we've ever observed on the ringed planet. Now, NASA scientists are saying the storm was even more powerful than previously believed — and that things got very, very hot.
Shortly after the Saturnian storm erupted in late 2010, NASA scientists used infrared imaging equipment onboard the Agency's Cassini spacecraft to identify two "beacons" within the tempest, where temperatures were elevated above normal by around 20 degrees Kelvin. This temperature differential, explains planetary scientist Brigette Hesman, is regarded as "reasonable" for your typical Saturnian storm.
In the months that followed, however, a series of strange events began to unfold. Hesman explains in the video featured below:
As time progressed, we started to see even larger temperature changes. By May 2011, the two beacons had merged into one, and we saw a temperature change of over 80 Kelvin [roughly 150 degrees Fahrenheit] from the quiet conditions [observed] before the storm.
That's a positively massive temperature differential, no matter how you slice it.
"This temperature spike is so extreme it's almost unbelievable," explains Hesman, "especially in this part of Saturn's atmosphere, which typically is very stable."
"That would be like going from the depths of winter in Fairbanks, Alaska to the height of summer in the Mohave Desert, all in one storm system. Can you imagine what that would feel like sitting on your deck?"
At the same time that temperatures within the storm were flying off the handle, researchers at NASA's Goddard Space Flight Center were detecting an unprecedented spike in ethylene. According to NASA, the odorless, colorless gas is typically barely detectable on Saturn; in fact, according to Hesman, ethylene concentrations during the storm reached concentrations 100 times greater than scientists had previously believed possible for the ringed planet.
What really stands out about these observations — apart from the unprecedented nature of the findings themselves — is that we were able to make them in the first place. Planetary scientists predict that this type of storm pops up on Saturn around once every thirty Earth-years. This storm actually came around a few years earlier than expected, but the point is this: the last time a storm like this cropped up, we had no spacecraft in place to watch it unfold. What's more, with Cassini scheduled to plunge into Saturn in just five years, and no spacecraft scheduled to take its place, there are currently no plans to have another spacecraft whipping around the Saturnian system when the next planet-wide storm unfolds.
Cassini is a champion, and consistently delivers not just beautiful images of some of the most photogenic astronomical bodies in our solar system, but damn good science. We owe it to ourselves to keep spacecraft like Cassini — and more of them — out there exploring our solar neighborhood.
The spikes in temperature and ethylene concentrations are described in a paper to be published in the November 20 issue of the Astrophysical Journal.