Cassini, a satellite orbiting Saturn, first picked up radio outbursts on Dec. 5, 2010 from a lightning storm. Shortly after, astronomers saw a bright white spot through their telescopes on Saturn's northern hemisphere. Days later, it grew into a megastorm. Almost 2 years later, this same storm is alive and well, but we are just now getting a better view thanks to the change of seasons. One calendar year for Saturn is the equivalent of 30 Earth years. So the change of Saturnian seasons does not happen as often as you would think.
NASA explained that Cassini has been able to photograph storms before on Saturn's north pole, but only in infrared wavelengths because the north pole was in darkness up to this point. But, now that Saturn's seasons have changed, the sun has moved over the planet's north pole, allowing us to see these stunning pictures.
This storm, which occurred during the start of Saturn's most recent spring season, eventually grew so large, it now stretches around the entire planet. While scientists don't exactly know what causes these storms to form, they do think it is related to the change of seasons, since that is when they most often form.
Normally, Saturn is hazy and calm, but occasionally will get storms, but ones of this size and magnitude are quite rare. Since 1876, astronomers have observed only five other "megastorms" as they are referred to.
"This is a one-of-a-kind storm," said Andrew Ingersoll, a self-described planetary weatherman at the California Institute of Technology.
Scientists have long studied weather on other planets. One of the solar system's most famous landmarks is Jupiter's Great Red Spot, which looks and behaves like a hurricane, except that is much larger (more than twice the size of Earth), and lasts much longer (this one is estimated to be between 182-347 years old). Landers and rovers to Thanks to the new Mars rover, which has an elaborate weather station on board, we are able to see frequent dust storms and study them more intensely than ever before.
Since Saturn lacks any solid surface like land or ice, storms are able to rotate rapidly creating some incredibly fast winds. In fact, Saturn has some of the fastest wind speeds in the solar system, blowing at over 1,100 miles an hour (Neptune is first in that category and Jupiter is third). At the higher latitudes close to the poles, the winds often shift a direction, which is what creates the spiraling motion in the storms, and also produces the powerful shears that help drive the wind bands around the planet.
At its peak, the storm produced 10 lightning strikes per second. Scientists said the electrical activity emitted by the bursts were 10,000 times stronger than lightning on Earth. Not only are the strikes frequent, but the amount of electrical activity emitted by these flashes are thousands of times more intense than ones on Earth.