Hubble Space Telescope Captures Auroras on Uranus

The Uranus aurora photos were captured by the Hubble Space Telescope, marking the

first time the icy blue planet’s light show has been seen by an observatory near Earth. Until now, the only views of auroras on Uranus were from the NASA Voyager probe that zipped by the planet in 1986. Hubble recorded auroras on the day side of Uranus only twice, both times in 2011, while the planet was 2.5 billion miles (4 billion kilometers) from Earth. Auroras are created by the interplay between the magnetic field of a planet and charged particles from the sun’s solar wind. The magnetosphere funnels the particles down to the planet’s upper atmosphere, where interactions between the atmosphere and solar particles cause a visible glow. On Earth, auroras occur at the north and south magnetic poles, so the light displays are known as the northern or southern lights. The last glimpse of Uranus auroras came from NASA’s Voyager 2 spacecraft when it flew by the planet more than 25 years ago. As said planetary scientist Fran Bagenal of the University of Colorado in Boulder, Colo. the Voyager 2 flyby showed that Uranus was a “strange beast,”. To snap the views, astronomers tracked a series of major solar eruptions in mid-September 2011 and calculated the time it would take them to reach Uranus. The charged particles from the solar storm passed Jupiter in about two weeks, but it wasn’t until mid-November that they arrived at Uranus, researchers said. By then, the scientists had reserved time on the Hubble Space Telescope to gaze at Uranus and hope for auroras. Earth’s northern lights can last for hours and dazzle skywatchers with colorful displays, but the Auroras on Uranus lasted only a few minutes. Even then, the events were just faint glowing dots above the planet’s atmosphere. Hubble spotted the light shows at locations that corresponded to the northern magnetic pole of Uranus, researchers said, which would make them the Uranian northern lights.