Berlin: Researchers, using the NASA/ESA Hubble Space Telescope, recently took advantage of a rare opportunity to record Saturn’s aurorae, resulting in a unique movie featuring both of the giant planet’s poles.
Saturn is only in this position every 15 years and this favorable orientation has allowed a sustained study of Saturn’s almost symmetric northern and southern lights.
An enormous and grand ringed planet, Saturn is certainly one of the most intriguing bodies orbiting the Sun. Hubble has now taken a fresh look at the fluttering aurorae that light up both of Saturn’s poles.
It takes Saturn almost thirty years to orbit the Sun, with the opportunity to image both of its poles occurring only twice in that period.
Hubble has been snapping pictures of the planet at different angles since the beginning of the mission in 1990, but 2009 brought a unique chance for Hubble to image Saturn with the rings edge-on and both poles in view.
At the same time, Saturn was approaching its equinox so both poles were equally illuminated by the Sun’s rays.
These recent observations go well beyond just a still image and have allowed researchers to monitor the behavior of both Saturn’s poles in the same shot over a sustained period of time.
The movie they created from the data, collected over several days during January and March 2009, has aided astronomers studying both Saturn’s northern and southern aurorae.
Given the rarity of such an event, this new footage will likely be the last and best equinox movie that Hubble captures of our planetary neighbor.
At first glance, the light show of Saturn’s aurorae appears symmetric at the two poles.
However, analyzing the new data in greater detail, astronomers have discovered some subtle differences between the northern and southern aurorae, which reveal important information about Saturn’s magnetic field.
The northern auroral oval is slightly smaller and more intense than the southern one, implying that Saturn’s magnetic field is not equally distributed across the planet; it is slightly uneven and stronger in the north than the south.
As a result, the electrically charged particles in the north are accelerated to higher energies as they are fired toward the atmosphere than those in the south.