On Monday, NASA and the European Space Agency released a fascinating image of auroras on the most misunderstood planet of all time, Uranus. Auroras, like the Northern Lights here on planet Earth, are caused by collisions between electrically charged particles released from the sun.
However, it turns out that auroras aren’t a uniquely terrestrial phenomenon. The auroras on Jupiter and Saturn have been well-documented, but up until now, not much was known about the auroras of Uranus.
Settlers on Uranus would get a magnificent view too. Scientists used the Hubble Space Telescope took a look at Uranus’ auroras, which are caused by streams of charged particles coming from a variety of locations, from solar winds to the planet’s upper atmosphere.
The auroras get caught in powerful magnetic fields which are then channeled into the upper atmosphere, where their interactions with gases like oxygen or nitrogen set off spectacular bursts of light.
Over several years from 2012 and 2014, a team led by an astronomer from The Paris Observatory in France took a second look at Uranus’ auroras using the ultraviolet capabilities of the Space Telescope Imaging Spectrograph (STIS) installed on Hubble.
Much like Earth’s stunning auroras, the results they achieved were simply incredible. However, it wasn’t just the sheer beauty of the auroras that made them remarkable – it was what the scientists could deduce from their existence.
It turns out that by observing the auroras, astronomers could deduce the existence of Uranus’ magnetic poles. When they first attempted it back in the ’80s, scientists had a real problem figuring that one out, because they couldn’t make head nor tail of the featureless planet.
As NASA explained on their website:
They tracked the interplanetary shocks caused by two powerful bursts of solar wind traveling from the sun to Uranus, then used Hubble to capture their effect on Uranus’ auroras — and found themselves observing the most intense auroras ever seen on the planet.
By watching the auroras over time, they collected the first direct evidence that these powerful shimmering regions rotate with the planet. They also re-discovered Uranus’ long-lost magnetic poles, which were lost shortly after their discovery by Voyager 2 in 1986 due to uncertainties in measurements and the featureless planet surface.
It looks like astronomy has come a long way since the 1980s, and features of our closest planets that were once utterly misunderstood have now finally been figured out. Who knew Uranus had so many secrets hidden away beneath its icy surface?