Nav: Home

Close Cassini flybys of Saturn's ring moons

March 28, 2019

The properties of five small moons located close to Saturn's rings have been illuminated, thanks to data from the Cassini spacecraft's final orbits. These small inner moons have unusual morphologies, and their optical properties are determined by two competing processes - an understanding of which helps explain any difference in color between the moons and their adjacent ring, the authors say. While Saturn has more than 60 confirmed moons, Saturn's main ring system is associated with a unique set of small moons that are either embedded within it or interact with the rings to alter their shape and composition. Among questions about interactions between the ring system and these inner moons, whether the rings formed from the break-up of an inner moon, or, by contrast, whether the consolidation of existing ring material formed the moons remains unclear. Whether any volatiles other than water ice exist on these moons has also been a question. Between December 2016 and April 2017, the Cassini spacecraft performed six close flybys of the moons Pan, Daphnis, Atlas, Pandora, and Epimetheus, collecting collect data on these moons' morphology, structure, particle environment, and composition. The analysis involved several instruments onboard Cassini. From these flybys and the data captured, Bonnie Buratti and colleagues report that no volatiles other than water ice exist on the ring moons. The moons' geology was shaped by a complex history, including groove formation caused by tidal stresses. Finally, depending on the position of the moon with respect to the rings, with Pan being reddest, and Epimetheus being bluest, the optical properties of the moons are determined by two competing process, the authors say: contamination by a red chromophore from the main rings and ice particles or water vapor from the E-ring. The authors say the low densities of the small moons as measured here support a multi-stage moon formation scenario involving accretion of ring material.

American Association for the Advancement of Science

Related Moon Articles:

More Earth-like than moon-like
Mars' mantle may be more complicated than previously thought. In a new study published today in the Nature-affiliated journal Scientific Reports, researchers at LSU document geochemical changes over time in the lava flows of Elysium, a major martian volcanic province.
Older than the moon
Geochemist Matt Jackson finds that only the hottest, most buoyant mantle plumes draw from a primordial reservoir deep in the Earth.
New theory explains how the moon got there
Earth's Moon is an unusual object in our solar system, and now there's a new theory to explain how it got where it is, which puts some twists on the current 'giant impact' theory.
New model explains the moon's weird orbit
A new research paper suggests that the impact that formed the moon also sent the Earth spinning much faster, and at a much steeper tilt, than it does today.
How this Martian moon became the 'Death Star'
For the first time, physicists at LLNL have demonstrated how an asteroid or comet impact could have created Stickney crater without destroying Phobos completely.
More Moon News and Moon Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Do animals grieve? Do they have language or consciousness? For a long time, scientists resisted the urge to look for human qualities in animals. This hour, TED speakers explore how that is changing. Guests include biological anthropologist Barbara King, dolphin researcher Denise Herzing, primatologist Frans de Waal, and ecologist Carl Safina.
Now Playing: Science for the People

#534 Bacteria are Coming for Your OJ
What makes breakfast, breakfast? Well, according to every movie and TV show we've ever seen, a big glass of orange juice is basically required. But our morning grapefruit might be in danger. Why? Citrus greening, a bacteria carried by a bug, has infected 90% of the citrus groves in Florida. It's coming for your OJ. We'll talk with University of Maryland plant virologist Anne Simon about ways to stop the citrus killer, and with science writer and journalist Maryn McKenna about why throwing antibiotics at the problem is probably not the solution. Related links: A Review of the Citrus Greening...