(In reference to this post.)
BECAUSE I’M GOING TO TELL YOU ALL ABOUT IT NOW, OF COURSE.
This is an optical image of Saturn, visible to the naked eye. Look at this badass, spinning calmly on while millions of chunks of ice rocket around it.
Now this is an ultraviolet image of Saturn. The universe liked it so much that it not only put a giant ring around the planet’s middle, it also decided to ring the poles.
Unlike Jupiter, the auroras aren’t created by volcanic moons spewing charged articles into the atmosphere. In fact, Saturn’s auroras are much more like Earth’s—they’re caused by solar wind, which crashes charged particles into the outer atmosphere. The planet’s magnetic field guides these particles to the poles, where their interactions create a swirling, colourful glow, at high-altitudes of over a thousand kilometres above the cloud tops.
However, Saturn’s auroras can only be seen in ultraviolet light—so they’re invisible to the human eye until equipment sensitive to ultraviolet radiation captures images of them. The images we’ve captured show the evolution of ripples and patterns independent of the planet’s rotation, as well as both regularities and variations of local brightening. This indicates that Saturn’s auroras are basically a giant tug-of-war between the planet’s magnetic field and the solar wind.
And now an extra bit of eye-candy:
This image shows Saturn’s north pole, but it’s a composite image of two different wavelenths—it was captured by both Cassini’s visual and infrared mapping spectrometer. The blue shows the aurora, capturing high-altitude emissions from atmospheric molecules that are excited by the solar wind’s charged particles, while the red shows escaping heat generated in the Saturn’s warm interior.
Space weather is GLORIOUS.
(Image Credit: NASA)