Cassini glimpses the dark eye of Saturn's south polar storm
The Cassini spacecraft has captured a stunningly detailed view of the "dark eye" of Saturn's vast south polar vortex, a feature so large that it could comfortably swallow planet Earth. The vista is a composite shot comprised of two separate images captured in July 2008 from a distance of roughly 392,000 km (243,578 miles) from the gas giant.
The image is roughly 10 times more detailed than any previous image of the vortex, with a resolution of around 2 km (1.2 miles) per pixel. Earlier attempts to capture the eye of the polar vortex revealed a center apparently filled with transparent air and blurry cloud-like features.
In the new image, fresh features resolve themselves in the 8,000-km (4,971-mile)-wide storm. Convection clouds swirl within the dark expanse, formed as warmer gas rises from within the eye, subsequently cooling to form clouds nearer the surface. To the top left of the image, a sub-vortex can be seen forming from interior clouds.
Saturn's storms do not operate like their cousins back on our home planet. Earth-bound storms draw on a liquid ocean for power, but there is no such ocean at the base of Saturn's storms. One theory holds that the colossal, permanent vortexes that mark Saturn's polar regions are driven by many smaller short-lived storms.
The small storms drift toward the poles over time, diverting air that is instrumental in forming the vortexes. Astronomers believe that by observing the polar vortexes prevailing on distant exoplanets, that they may be able to extrapolate a gas giant's overall storm intensity.
NASA is currently exploring the potential of using a series of "windbots" that could be used to explore the astmophere of Jupiter and Saturn. The probes would rely on a form of in-situ resource harvesting to maintain power and propulsion systems while riding the storms of a gas giant.
As Cassini enters the final stage of its mission, which will take the spacecraft into a polar orbit passing between the surface and the rings of Saturn, we will undoubtedly be treated to more breathtaking views of the impressive vortexes.