Although nanoparticles may be ubiquitous throughout Saturn’s rings, they have not been studied with the thoroughness of their larger siblings. These smallest of particles, ranging from clusters of a few molecules to aerosols with radii of 10 nanometers, are smaller than the wavelength of a UV photon and are not detectable using remote observations. During Cassini’s final, spectacular months, three of Cassin’s in situ instruments made the first measurements of nanoparticles in the region between Saturn and its inner ring. Cassini’s Ion and Neutral Mass Spectrometer (INMS) measured material in three different altitude bands and discovered that nanoparticles are flowing from the rings into Saturn at a thousand times the predicted rate and are comprised primarily of methane and hydrocarbons, not water. The particles enter in a tight stream along the equatorial plane with a varying flux that provides clues to the transport mechanisms that deliver the molecules and particles to Saturn.
 
About the Speaker:

Mark Perry, a planetary scientist at the Johns Hopkins Applied Physics Laboratory, uses data from in situ mass spectrometry and remote observations such as RF occultations to study the internal structure of rocky planets, the magnetospheres of outer planets, the plumes of icy moons such as Enceladus, the topography of asteroids, and now the interactions between the rings of Saturn and its atmosphere. Before returning to research, Dr. Perry spent fifteen years involved with live-cycle engineering and managing many missions, from deep-space missions such as the MESSENGER mission to Mercury and the New Horizons mission to Pluto, to technology-demonstration missions, the International Space Station, and astrophysics missions such as the Far Ultraviolet Spectroscopic Explorer.