Picture: Material is shattered in high-velocity impacts of meteoroids on Saturn's rings. The elongated bright streaks (marked by arrows) are formed by spreading debris ejected above the ring plane. Image Credit: NASA/JPL-Caltech/Space Science Institute/Cornell
Scientists observed small, bright clouds of material spreading out over Saturn's rings. The elongated clouds are seen in images from the CASSINI (NASA/ESA) mission to Saturn and they consist of debris ejected when meteoroids strike the rings.
The article by Tiscareno et al., with contributions by J. Schmidt from the University of Oulu, appears this week in the Journal Science on Friday 26th April.
Meteoroids, for instance visible as bright meteors in earths atmosphere, exist all over the Solar System and it has long been anticipated that they constantly erode Saturn's rings. The rings are made of water ice particles that are partly pulverized when struck by an impact of several tens of km/s. The erosion rate of the rings, and also their pollution with external material provided by the meteoroids, is of ultimate importance for the ongoing controversial scientific debate on the age of Saturn's ring system and how it has been created.
These debris clouds, providing direct evidence for the meteoritic ring erosion, were observed now for the first time. This was possible in images taken at a very special geometry, when in 2009 the sun was illuminating the Saturn system edge on, which happens only every 15 years. In this geometry the rings remain relatively dark, while the debris still stands out in full sunshine above the ring plane, making the detection possible.
Last updated: 26.4.2013