2016
  • This is the final year of our project. The two planned papers are close to submission, and the final report was sent to FWF at the end of July. To date (end of July) there is still no new lightning activity on Saturn.
  • A nice article (written in German) about our project was published in the science section of the Austrian newspaper "Die Presse" at the end of May. Check out this link.
2015
  • 2015 was the second year in a row that no Saturn lightning could be detected by Cassini/RPWS. Apparently there were no thunderstorms present in Saturn's atmosphere, so currently there could be a convective inhibition phase as suggested by Li and Ingersoll (2015).
  • From an organisational point of view our project switched from the Space Research Institute of the Austrian Academy of Sciences to the Institute of Physics of the University of Graz. We are working on two joint publications about the four last equinox storms that occurred in the "storm alley" of the southern hemisphere before the Great White Spot.
2014
  • This year the 10th anniversary of the Saturn orbit insertion (SOI) of the Cassini spacecraft was celebrated. Since more than 10 years Cassini has provided us many important insights about the Saturn system including measurements of Saturn lightning which we study in this project. However, 2014 was the first years since SOI that no Saturn lightning could be detected by Cassini/RPWS as there were no thunderstorms present in Saturn's atmosphere. This behavior was expected by us as the occurrence of Saturn's thunderstorms seems to be seasonal, with less appearances in the years far from equinox.
  • Despite the lack of new lightning data for 2014, there is still plenty of "old" data for us to analyze from the previous years, including the incredible number of almost 30 million SEDs for the Great White Spot (GWS) event of 2010/2011. We also published a paper in the journal Annales Geophysicae about a possible relation between the GWS and the periodicity of Saturn kilometric radiation.
2013
  • After a year without lightning activity, on July 8, 2013 SEDs are back. Cassini RPWS has measured 14 episodes in the month of July 2013. That is, 3 episodes from July 8-10 and another 11 episodes from July 20-26. Then starting July 26, 2013, there was again SED inactivity for about 20 Saturn rotations. Then from August 5 to 20, 2013 SEDs were back again but short-lived. The long duration without lightning activity is puzzling. The storm is most likely the same storm that was first observed in January 2011, then somewhat later in 2012, and became active again in the months of July and August 2013. From images provided by various amateur astronomers, the spot at about 48° North is most likely the SED source. The spot seems to appear very close to the wind speed minimum around 50° North.
  • An article about the daytime lightning on Saturn was published in the journal Icarus 226 on August 21, 2013. A graphical abstract of this article is provided at the storm images page of this website. The figure shows the intense daytime lightning that was first detected while Cassini was observing the 2010-2011 giant lightning storm at ~35° North on the day side but in blue wavelengths only. The flash shown here is approximately 200 km in diameter when it exits the tops of the clouds. Lightning bolts originate in the clouds deeper down in Saturn's atmosphere where water droplets freeze, analogous to the location where lightning in Earth's atmosphere is created. Before the detection of daytime lightning, Cassini detected in 2009 lightning on the night side of Saturn in a broadband clear filter at ~35° South.
  • Some german-speaking newspapers featured this published article. For example, see Der Standard, Austrian Journal, Salzburger Nachrichten, and the Austrian Physical Society. There was a press release from our own institute and the Austrian Academy of Sciences, followed by a press release from the Austrian Press Agency.
2012
  • New FWF Project P 24325-N16, Lightning on planets with focus on Saturn, has started.
  • Compared to the previous years 2010-2011, only marginal Saturn lightning activity was monitored throughout 2012. Some weak SED activity was registered by Cassini RPWS in April and July 2012 which most likely originated from a convective cloud at 50° north latitude.
  • Through its Imaging Science Subsystem (ISS) instrument, Cassini has been found to have captured lightning flashes that have been observed for the first time (i) in the visible wavelengths and (ii) on Saturn's day side. These lightning flashes occurred within the huge storm that engulfed Saturn's northern hemisphere in 2011.
2011
  • An article about the giant thunderstorm in Saturn's northern hemisphere was published in the journal Nature 475 on 7 July 2011. A nice image of the giant storm also made it on the cover! It shows how the disturbance has wrapped around the whole planet, a distance of 300,000 km by February 2011. Corresponding press releases were published by the FWF (in German) as sponsoring agency, and by the JPL on the Cassini webpage. The story about Saturn's giant storm was subsequently published on several hundred webpages worldwide, as well as national and international newspapers brought it also in their printed issues. Images of the giant storm were chosen as "Astronomy Picture of the Day" several times in 2011 (19 Jan., 17 Mar., 8 July, 26 Dec.). The German magazine for amateur astronomers "Sterne und Weltraum" also put the Saturn storm on its cover in September 2011.
  • A publication about the search for radio emissions indicative of lightning on Saturn's enigmatic moon Titan was selected as Editor's highlight in Geophysical Research Letters. However, no evidence for Titan lightning was found.
2010
  • The year 2010 brought a 5 months long lightning storm lasting from February to July, located at a latitude of 35˚ south. It has been imaged by various amateur astronomers with their ground-based backyard telescopes. There is a video on Youtube about Saturn lightning with members of the Cassini imaging team, see here. However, that was not all and in early December 2010 a giant lightning storm developed in the northern hemisphere. All previous lightning storms detected by Cassini were located in the southern hemisphere. This switch in hemispheres probably reveals a seasonal influence. Within a few weeks the plume of the storm grew to a latitudinal size of 10,000 km! One image of this storm taken by the Cassini camera on December 24 can be seen at the image page of this website.
2009
  • The Cassini cameras have made their first detection of visible lightning in Saturn's atmosphere! Around Saturn's equinox, while the ring shine was a minimum, the cameras imaged illuminated cloud regions of a few hundred kilometers in size which are caused by the lightning flashes. At the same time RPWS has detected the SEDs.
  • The year 2009 has been a year with much lightning activity in Saturn's atmosphere that is monitored by the Cassini/RPWS (Radio and Plasma Wave Science) instrument via detection of the lightning radio signatures called SEDs (Saturn Electrostatic Discharges). In mid-January a lightning storm started and lasted for ~11 months making it the longest continuously observed lightning storm in the solar system. Like previous storms, this storm was again related to a prominent cloud feature in Saturn's "storm alley" located at a latitude of 35˚ south. A story about this longest lightning storm was released by the press office of the European Planetary Science Congress (EPSC) 2009 in Potsdam.
  • Thereupon the story got some attention and was featured by several on-line magazines, e.g. New Scientist, or Saturn Daily.
2008 and before
  • Previously, a press release about Saturn`s long-lived lightning storms was issued in 2008 on the Cassini webpage, and a one month long lightning storm from early 2006 also got some attention from the press (e.g. see story on Space Daily).
  • Radio emissions of terrestrial lightning bolts create pops and cracks which one can hear on AM radio during a thunderstorm. Similarly, the SEDs of Saturn can be converted into an audible signal and check out the following link to the RPWS webpage to hear the "sounds" of Saturn lightning.