New scientific analysis of Cassini data reveals seas of Saturn’s moon Titan

Using data from multiple experiments bistatic radara research team led by Cornell University was able to separately analyze and evaluate Composition and roughness of Titan’s sea surfacewhich previous analyses of monostatic radar data failed to achieve. This will help pave the way for future combined surveys. nature of the seas of Titan using data from Cassini.

Valerio Poggialia research fellow at Cornell University, is the lead author of “Surface properties of Titan’s seas revealed by Cassini’s bistatic radar experiments(translated into Spanish), which was published in Natural communications.

Analysis of Titan’s surface by the Cassini spacecraft using bistatic radar

Experiment with Bistatic radar involves directing a radio beam from a spacecraft to a target. (in this case Titan), where is reflected back to the receiving antenna on EarthThis surface reflection is polarized, meaning it provides information collected from two independent viewpoints, unlike monostatic radar data where the reflected signal is returned to the spacecraft.

“The main difference– said Poggiali.is that bistatic information represents a more complete set of data and is sensitive to both the composition of the reflecting surface and its roughness.“.

The current work uses four bistatic radar observationscollected by Cassini during four flybys in 2014 (May 17, June 18, October 24, and November 14, 2016). Each observed reflections from the surface as the spacecraft approached its closest point to Titan (entry) and again as it moved away (exit). The team analyzed the emission observationsTitan’s Three Great Polar Seas: Kraken Mare, Ligeia Mare and Punga Mare.

Their analysis revealed differences in the composition of the surface layers of hydrocarbon seasdepending on latitude and location (such as near rivers and estuaries). In particular, the southernmost part of Kraken Mare has the highest permittivity, a measure of a material’s ability to reflect a radio signal. For example, Earth’s water is highly reflective.With permittivity about 80; Titan’s ethane and methane seas are about 1.7 in size..

The researchers also found that During the flights, all three seas were generally calmwith surface waves no more than 3.3 mm. A slightly higher level of roughness (up to 5.2 mm) is noted near coastal areas, estuaries and inter-basin straits, which may be a sign of tidal currents.

“We also have indications that the rivers that feed the seas are made up of pure methane.– said Poggiali.until they flow into open liquid seas, richer in ethane, like on Earth, when freshwater rivers flow and mix with the salt water of the oceans.“.

“This fits very well with Titan’s weather patterns.“said co-author and professor of astronomy Philip Nicholson“who predict that the “rain” falling from their skies will likely consist of almost pure methane, but with traces of ethane and other hydrocarbons.“.

Poggiali said additional work is already underway on the data Cassini has collected over 13 years of exploration of Titan.There is a wealth of data that still awaits full analysis that should lead to new discoveries.“, said. “This is just the first step.“.

Representatives from the University of Bologna, the Paris Observatory, NASA’s Jet Propulsion Laboratory (JPL), the California Institute of Technology and the Massachusetts Institute of Technology are also participating in this work.

Link

Poggiali V. et al. Surface properties of Titan’s seas revealed by Cassini’s bistatic radar experiments, Nature Communications (2024). DOI: 10.1038/s41467-024-49837-2