First Observation of an Ultraviolet Aurora at a Comet

(University of Bern, September 21, 2020)

Thanks to the analysis of data from the European Space Agency's Rosetta mission, an international consortium involving the University of Bern recently discovered an ultraviolet aurora at a comet – in this case, comet 67P/Churyumov-Gerasimenko, or Chury for short – for the first time. This was an exciting discovery because although UV emissions had already been previously observed at Chury, it was wrongly assumed at that time that these emissions were caused by particles of sunlight, known as photons, as opposed to solar wind electrons. Furthermore, according to University of Bern Professor and co-author of the study Martin Rubin, beyond the aesthetic value of the observation of cometary aurora phenomena, the "UV observations from Earth could one day also provide information about the solar wind at these comets."