Scientists have compiled 41 observations of the Sun’s occult for Saturn’s rings from the Cassini mission.
Scientists have compiled 41 observations of the Sun’s occult for Saturn’s rings from the Cassini mission. The compilation will inform future investigations into the particle size distribution and composition of Saturn’s rings, important factors for understanding their formation and evolution.
“For nearly two decades, NASA’s Cassini spacecraft has shared the wonders of Saturn and its family of icy moons and characteristic rings, but the origin of the system is still unknown. belt system,” said Dr. Stephanie Jarmak, a researcher in the SwRI Space Science Division program. “Evidence indicates that the rings are relatively young and may have formed from the destruction of an icy moon or a comet. However, to support any origin theory, we need have a good idea of the size of the particles that make up the rings.”
Cassini’s Ultraviolet Imaging Spectrometer (UVIS) is sensitive to some of the smallest ring particles, particularly to the observations it makes at ultraviolet wavelengths.
To determine the size of the ring particles, UVIS observed them when the instrument was pointed at Sun, looking through rings in what is known as the solar occult. The ring particles partially blocked the light’s path, providing a direct measurement of optical depth, an important parameter for determining the size and composition of ring particles.
“Given the wavelength of light coming from the Sun, these observations give we “UVIS can detect dust particles at the smallest micrometer level, helping us understand the origin, colloidal activity and destruction of ring particles in the system,” says Jarmak.
The compilation also delves into variations in optical depth of occult observations, which can help determine particle size and composition. In an occult, light emitted from a background source, such as the Sun, is absorbed and scattered by particles in the light’s path. The amount of light blocked by the ring particles provides a direct measurement of the optical depth of the ring.
Including optical depth is important to understand the structure of the rings. The study measured optical depth as a function of observational geometry, which refers to the viewing angles of the ring system for the Cassini spacecraft. As the light passing through the rings changed at different angles, scientists were able to form a picture of the ring’s structure.
“The belt system around the giant planets also provides testbeds for investigating fundamental physical properties and processes in the universe. solar system in general,” said Jarmak. These particles are thought to be the result of objects colliding and forming in a disk and forming larger particles. Understanding how they form these ring systems can help us understand how planets form. ”
