2014 programme

Sat 14:30-15:00
New York

The Fossil of Saturn's Great Storm of 2010/2011

Trevor Barry

Astronomy Society of NSW, Broken Hill Observatory, Australia

The Great Storm started as a small white spot Dec 8th 2010, By mid January 2011 the storm had dredged up so much material that it totally encircled the planet. Professionals captured data with Cassini and ground based telescopes such as NASA’s IRTF and ESO’s VLT, the latter at thermal wavelengths. A dark vortex formed in the turbulence back from the head of the storm. Amateurs also tracked the evolution of the storm including the dark vortex.

By October 2011 the storm was dissipating, the vortex was shrinking and most thought that would be the end of it. Through 2012, amateurs tracked a dark spot at the latitude of the Great Storm. Following solar conjunction in Dec 2012, a dark spot was again recovered by amateurs, and followed right through 2013.

The amateur data through 2012 was analysed in amateur spreadsheets and drift charts. When Kunio Sayanagi (Cassini ISS) merged this amateur data with his Cassini ISS data and drift chart, it became apparent that this dark spot was in fact the surviving fossil of the original dark vortex, formed by the Great Storm, the longest lived continually tracked feature of its type ever at Saturn. Another outstanding example of what Pro/Am collaborations can achieve.