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NASA captures 360 degree views of dancing lights of Saturn
11 February 2014
‘Glamorous’ images of the dancing lights around Saturn have been captured in greater detail than ever before, thanks to two NASA spacecraft.
Lancaster University researchers are part of the international team analysing the new films captured by NASA's Cassini spacecraft (orbiting around Saturn) and Hubble Space Telescope (orbiting around Earth), which together provide a spectacular 360-degree view of Saturn’s auroras.
While NASA's Hubble Space Telescope was able to observe the northern auroras in ultraviolet wavelengths, NASA's Cassini spacecraft got close-up views of the north and south in infrared, visible-light and ultraviolet wavelengths.
Marcia Burton, a Cassini fields and particles scientist at NASA's Jet Propulsion Laboratory, Pasadena, California said: "The auroras at Saturn are some of the planet's most glamorous features – and there was no escaping NASA's paparazzi-like attention.”
The images ( http://www.nasa.gov/jpl/cassini/saturn-aurora-20140211/), taken in April and May of 2013, provide the best view yet of the intriguing light displays and help shed light on an unsolved mystery.
Sarah Badman, a Cassini Visual and Infrared Mapping Spectrometer team associate at Lancaster University, said: "Scientists have wondered why the high atmospheres of Saturn and other gas giants are heated far beyond what might normally be expected given their distance from the sun.
“We know there must be other energy interactions going on to cause this heating, but we can’t yet say for sure what they are. From the Earth, we can only see part of the picture, but by looking at these amazing new movies from the vantage points of both Cassini and the Hubble Space Telescope, we can see exactly where the aurora is heating Saturn’s atmosphere and for how long. Being able to track the aurora all around Saturn’s poles is vital if we are to discover how its atmosphere is heated.”
The University of Leicester’s Jonathan Nichols, who led the work on the Hubble images, said: "Saturn's auroras can be fickle – you may see fireworks, you may see nothing. In 2013, we were treated to a veritable smorgasbord of dancing aurora, from steadily shining rings to super-fast bursts of light shooting across the pole."
The visible light data has also helped scientists figure out the colours of Saturn's auroras. While the curtain-like auroras we see on Earth are green at the bottom and red at the top, Cassini's imaging cameras have shown similar curtain-like auroras on Saturn that are red at the bottom and purple at the top.
Ulyana Dyudina, an imaging team associate at the California Institute of Technology, Pasadena, California, said: "While we expected to see some red in Saturn's aurora because hydrogen emits some red light when it gets excited, we also knew there could be color variations depending on the energies of the charged particles bombarding the atmosphere and the density of the atmosphere. We were thrilled to learn about this colorful display that no one had seen before."
Saturn's northern ultraviolet aurora taken by the Hubble Space Telescope. J.D. Nichols, University of Leicester, NASA, ESA.