#ANCIENT GLYPHS ON SATURNS MOONS SERIES#

We applied this new chronology to the inner Saturnian satellites to compute more accurate model surface ages of their most densely cratered surfaces.'įrom this, they computed new ages for Saturn's regular satellites, which were approximately 110 to 300 million years older than previous estimates obtained by Wong and colleagues. We computed model surface ages for said satellites for various crater diameters from age isochrons similar to those that exist for the moon and Mars in the inner solar system. 'In this work, we obtained a more accurate crater chronology onto the icy regular satellites that can be applied to the whole history of the solar system. This composite image, taken by the NASA/ESA Hubble Space Telescope on 6 June 2018, shows the ringed planet Saturn with six of its 62 known moons. This prevented them from obtaining accurate ages of satellites with low crater densities (like Enceladus), and the ages derived showed significant variation based on the two different sizes of TNOs. Unfortunately, these and other previous simulations suffered from poor resolutions for the last 3.5 billion years because of a limited number of planetesimals in their simulations. These were combined to derive surface ages for the most heavily cratered satellites of Jupiter, Saturn, and Uranus, ranging from 3.8 to 4.4. They then used predictive Monte Carlo simulations to determine the expected crater densities, assuming two different size-frequency distributions of TNOs encountering the giant planets and their satellites. In a previous study, Wong and her colleagues conducted a timeline simulation of the outer solar system starting from the onset of giant planet migration, which they set at 4.5 billion years ago. The first step in this process was to model cratering rates in the outer solar system, where the migration of the giant planets led to periods of bombardment by displaced TNOs and other objects. Their paper, 'Saturn's ancient regular satellites,' appeared in the journal Icarus.īy dating impact craters on the surface, some general constraints can be established for how long these moons have been around. Kirchoff of the Southwest Research Institute (SwRI). Werner, the deputy director of the Center for Planetary Habitability (PHAB) at the University of Oslo, and lead research scientist Michelle R. She was joined by Ramon Brasser, an associate professor at the ELSI and the Origins Research Institute at the Research Center for Astronomy and Earth Sciences (ORI-RCAES), Stephanie C. The research was led by Emily Wai Wong, a researcher with the Earth-Life Science Institute (ELSI) at the Tokyo Institute of Technology. These results could have significant implications for our understanding of the formation and tidal evolution of moons in the outer solar system. This established age limits of 4.1 and 4.4 billion years for all five, with the two innermost moons appearing more youthful than the outer three. This allowed them to construct a chronology of impacts for Saturn's most heavily cratered regular satellites-Mimas, Enceladus, Tethys, Dione, and Rhea.

#ANCIENT GLYPHS ON SATURNS MOONS SERIES#

To address these questions, an international team of astronomers created a series of high-resolution simulations coupled with improved estimates of trans-Neptunian object (TNO) populations. “This is a clue to some process that is happening in the whole Saturn system, and probably elsewhere as well.In addition, there are unresolved questions about the age of these satellites, with some suspecting that they formed more recently (like Saturn's rings, which are a few hundred million years old). “This is a possible explanation for the feature on Rhea, but we still have work to do to figure out why it occurs on other moons,” says Hendrix. Even though Cassini did use hydrazine as fuel for its thrusters, those thrusters were never fired near Rhea, so the researchers are confident that it didn’t come from the spacecraft. It could also float over from the thick atmosphere of the neighbouring moon Titan. Hydrazine, on the other hand, could be made in reactions between chemicals that we know exist on the icy moon.

While either could be a match for Cassini’s observations, it is hard to come up with a way for chlorine to be produced on Rhea’s surface, Hendrix says. She and her colleagues observed how light bounced off several compounds in laboratory experiments, and found two that seemed to match what Cassini saw on Rhea: hydrazine and chlorine. Read more: The weird and wonderful inner moons of Saturn revealed by Cassini

Ancient glyphs on saturns moons