Beaming with pride, cosmic wonder is pleased to introduce Aurora Cometalis. According to Marina Galand of Imperial College London, lead author of research published this week in Nature Astronomy., Comet 67P has auroras. Galand’s paper explaining how 67P turns jets of water into Aurora Cometalis is nothing short of remarkable. Seems Aurora Borealis has European Space Agency Rosetta Mission to thank posthumously for expanding the Borealis family tree.
While orbiting Comet 67P between 2014-2016, Rosetta captured images of odd light emissions. Astronomers scratched heads over peculiar ultraviolet light glow invisible to the human eye. 67P doesn’t have a magnetic field, glaring absence of observable green, red, purple or pinkish undulating waves never screamed “wake up people, these invisible ultraviolet bursts are auroras!”.
Galand’s team persevered. Years of combining data from Rosetta’s sensors coupled with computer models plotting interactions between solar wind and comet atmosphere concluded – auroras are real even when invisible to the human eye.
In a nutshell, naturally occurring electric fields in a comet’s atmosphere can grab electrons tossing them inward to collide with spewing water molecules. Exuberant atoms empowered by sudden molecular disruption dance with wild abandon to the tune of ultraviolet auroras.
If you could stand on Comet 67P and see UV light, Aurora Cometalis would appear as bands of diffused, uneven light punctuated by brighter bands when jets of water march across the field of view. Best of all, you’d be surrounded by light – Aurora Cometalis descend all the way down to the surface. So cool! There’s no reason why other comets can’t have auroras. Galand’s research is based on Comet 67P because Rosetta just happened to be in the neighborhood. Welcome to the cosmos Aurora Cometalis.