Saturn's
auroras dance in a new video that shows the ringed planet's northern
and southern lights shining in amazing, 360-degree detail.
Scientists combined observations from NASA's Cassini spacecraft with views from the Hubble Space Telescope to create the new video of auroras on Saturn unveiled today (Feb. 11). The video shows multiple views of Saturn's auroras as they appear in different wavelengths of light.
The Cassini probe, which is currently orbiting Saturn, and the Hubble
Space Telescope spotted Saturn's cosmic light shows in April and May
2013. By analyzing the data, scientists found that the aurora activity
was caused by the solar wind. When charged particles carried away from
the sun on the solar wind slam into Saturn's atmosphere, it can cause
the celestial lights to glow at the planet's poles.
"Saturn's auroras
can be fickle — you may see fireworks, you may see nothing," leader of
the work on the Hubble images Jonathan Nichols of the University of
Leicester in England, said in a statement. "In 2013, we were treated to a
veritable smorgasbord of dancing auroras, from steadily shining rings
to super-fast bursts of light shooting across the pole."
Saturn's northern and southern lights glow in red on the bottom and purple on top in visible light, according to Cassini photos.
Earth's auroras are green on the bottom and red on top. The difference
in color is due to variation in the dominant molecules of each planet's
atmospheres. Nitrogen and oxygen are prevalent in Earth's auroras, while
Saturn's are composed of hydrogen, NASA officials said.
The Cassini and Hubble telescope photos give
scientists a new look at how the sun affects the planet's auroras and
how the lights move, NASA officials said in a statement.
"Scientists have wondered why the high atmospheres of Saturn and
other gas giants are heated far beyond what might normally be expected
by their distance from the sun," Sarah Badman, a Cassini visual and
infrared mapping spectrometer team associate at Lancaster University,
England, said in a statement. "By looking at these long sequences of
images taken by different instruments, we can discover where the aurora
heats the atmosphere as the particles dive into it and how long the
cooking occurs."
By analyzing the new images, scientists have also found more evidence
that auroras can be created through new connections in magnetic field
lines. In one part of the new video, a bright part of the aurora moves
in time with the position of Saturn's moon Mimas, NASA officials said.
Earlier images have also shown that a bright aurora spot could be
associated with the moon Enceladus, NASA officials added.
"This is our best look yet at the rapidly changing patterns of
auroral emission," Wayne Pryor, a Cassini co-investigator at Central
Arizona College in Arizona, said in a statement. "Some bright spots come
and go from image to image. Other bright features persist and rotate
around the pole, but at a rate slower than Saturn's rotation."
Scientists are still combing through data collected during the 2013
auroras. A group of scientists are analyzing ground-based data gathered
at the Keck Observatory in Hawaii and NASA's Infrared Telescope Facility
to piece together an even more comprehensive view of the aurora events
on Saturn between April and May of 2013, NASA officials said.
"The auroras at Saturn are some of the planet's most glamorous
features – and there was no escaping NASA's paparazzi-like attention”,
said Marcia Burton, a Cassini fields and particles scientist at NASA's
Jet Propulsion Laboratory, Pasadena, Calif., who is helping to
coordinate these observations. "As we move into the part of the 11-year
solar cycle where the sun is sending out more blobs of plasma, we hope
to sort out the differences between the effects of solar activity and
the internal dynamics of the Saturn system."
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