Even though the Cassini spacecraft burned up in Saturn’s atmosphere a few years ago, researchers are still unraveling its record data. Now, scientists at the Southwest Research Institute have compiled 41 solar occultation observations of Saturn’s rings from the Cassini mission (that is, when the rings face our star).
“For nearly two decades, NASA’s Cassini spacecraft shared the wonders of Saturn and its family of icy moons and characteristic rings, but we still don’t definitively know the origins of the ring system,” explains Stephanie Jarmak, a researcher in the Science Division. Space from SwRI (Southwest Research Institute).
From these observations, scientists can infer the size of the particles that make up the rings, the density of the rings, and the features within these spectacular structures. During an occultation, light from the background source (in this case the Sun) is scattered or absorbed by the ring particles, and the amount of light is a direct measure of optical depth. The amount of light blocked tells scientists the optical depth of the particles. These data provided clues about the size and composition of the particles.
Will this give us information about how the rings formed?
Are Saturn’s rings young, relative to the rest of the solar system? How old are they exactly? Did they form through the destruction of an icy satellite or a comet? Will they disappear one day?
“Evidence indicates that the rings are relatively young and could have formed from the destruction of an icy satellite or comet. However, to support any theory of origin, we need to have a good idea of the size of the particles that make up the rings.” rings,” continues Jarmak.
By looking at sunlight passing through the rings at various angles, researchers can also learn more about the overall structure of the ring system. Any information about Saturn’s rings could also teach researchers about the physical properties of our solar system.
“These particles are thought to be the result of colliding objects forming into a disk and accumulating larger particles,” Jarmak said. “By understanding how they form, these ring systems could help us understand how planets form as well.”
Specifically, Cassini’s Ultraviolet Imaging Spectrograph (UVIS) was exceptionally sensitive to some of the smaller ring particles, particularly with observations it made in the extreme ultraviolet wavelength.
“Given the wavelength of light coming from the Sun, these observations gave us an idea of the smallest particle sizes with Saturn’s rings,” Jarmak said. ” UVIS can detect dust particles at the micron level, which helps us understand the origin, collision activity and destruction of ring particles within the system.”
Referencia: S.G. Jarmak, T.M. Becker, J.E. Colwell, R.G. Jerousek, L.W. Esposito,
Solar occultation observations of Saturn’s rings with Cassini UVIS, Icarus, Volume 388, 2022, 115237, ISSN 0019-1035,