Dance of Saturn’s Auroras. The first set of images by Hubble shows an active aurora dancing around Saturn’s north pole on April 5. Next follows a quiet time from late April to mid-May. The aurora flares up again from May 20.
If I had my way there would always be a space probe orbiting every planet in the solar system. You just can’t beat the box seat views. NASA just released new photos and a movie of Saturn’s auroras taken in tandem by the Hubble Space Telescope and Cassini orbiter.
The Hubble took in wide views from Earth orbit of the ringed world’s north polar auroras in ultraviolet light while the orbiter photographed the show up close in ultraviolet, infrared and visible light last April and May. During that time the sun was very active, sending gusts of solar wind in Saturn’s direction. As you watch the video you can see that Saturn’s auroras are as changeable as Earth’s as they respond to bursts in the solar wind.
The Cassini and Hubble photos are taken at wavelengths not visible with the human eye and are shown in false color. If you could see them for real, Saturn’s auroras would look like curtains with red at the bottom and purple at top. Earth’s are green and red due to the emission of light from oxygen and nitrogen molecules in the upper atmosphere. Hydrogen dominates the ringed planet’s atmosphere; when energized by gusty solar winds, the atoms release light of different colors.
“The movie also shows one persistent bright patch of the aurora rotating in lockstep with the orbital position of Saturn’s moon Mimas. While previous images had shown an intermittent auroral bright spot magnetically linked to the moon Enceladus, the new movie suggests another Saturn moon can influence the light show as well,” according to the NASA press release.
A question that remains to be answered is why the upper atmospheres of the gas giant planets Jupiter and Saturn are warmer than expected considering how far they are from the sun. The new images are helping scientists understand how and where auroras play a role in raising the heat.