On Earth, the northern lights are caused by charged particles flung out by our sun, which interact with our upper atmosphere and emit visible light. It creates a stunning effect which has been observed to take place on other planets too; Jupiter and some of its moons are notable examples. However, we have never known these northern lights to appear on comets until this astonishing discovery from the Rosetta mission.
"The glow surrounding 67P/C-G is one of a kind"Marina Galand, Imperial College London
Comet 67P was photographed in 2014 and thought to have something called a dayglow, meaning that photons of light from the sun interacted with a layer of gas around the comet called the coma. But this was found to be incorrect, "The glow surrounding 67P/C-G is one of a kind," said Marina Galand, lecturer at Imperial College London and lead author of the study.
In fact, the process occurring on the comet was its very own aurora, where electrons from the sun’s solar wind split oxygen away from molecules and excite individual atoms. So, the process occurring on 67P is analogous to the northern lights on Earth! An ultraviolet aurora is produced on the comet’s surface, invisible to the naked eye but captured by some of the Rosetta spacecraft’s many sensors.
With the aid of some magic glasses, the effect would be completely breathtaking
Although not in the visible spectrum, if we could stand on the comet and view this with the aid of some magic glasses the effect would be completely breathtaking. That's if you could get over the lack of habitable conditions on the comet’s surface!
Scientists can now explore the light emissions from 67P, examining how it changes over time to learn more about the mysterious solar winds emitted by our Sun. Future discoveries from this special phenomena could be groundbreaking. There are many unanswered questions regarding the “weather” in space around stars and how solar winds propagate, which could be answered by further study of 67P and other comets like it.
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