The Rosetta mission of the European Space Agency and the National Aeronautics and Space Administration (Nasa) has discovered a comet which has its own "far-ultraviolet aurora".

The comet named 67P/Churyumov-Gerasimenko - Chury for short - is one of a kind as it is for the time that an ultraviolet aurora has been detected on a celestial object that is not a moon or planet.

According to the space agency: "It is the first time such electromagnetic emissions in the far-ultraviolet have been documented on a celestial object other than a planet or moon."

Launched in 2004, Rosetta is the space exploration's most travelled comet hunter. It orbited comet 67P/Churyumov-Gerasimenko (67P/C-G) from August 2014 "until its dramatic end-of-mission comet landing" in September 2016.

According to Nasa, the data reveal that 67P/C-G's emissions are auroral. The findings were published in the journal Nature Astronomy.

"Electrons streaming out in the solar wind - the stream of charged particles flowing out from the Sun - interact with the gas in the comet's coma, breaking apart water and other molecules. The resulting atoms give off a distinctive far-ultraviolet light. Invisible to the naked eye, far-ultraviolet has the shortest wavelengths of radiation in the ultraviolet spectrum," Nasa said.

The space agency further said that "exploring the emission of 67P/C-G will enable scientists to learn how the particles in the solar wind change over time, something that is crucial for understanding space weather throughout the solar system".

According to Nasa, the northern or southern lights, also called aurora, are "generated when electrically charged particles, speeding from the Sun hit the upper atmosphere to create colourful shimmers of green, white, and red". However, this is the case on Earth.

Elsewhere in the solar system, Jupiter and some of its moons, as well as other planets like Saturn, Uranus, Neptune, and even Mars - all have showcased their own version of northern lights. "But the phenomena had yet to be documented in comets," Nasa said.

Continued here:

In a first, scientists discover comet having own northern lights - India Today