FYFD

Tag: Saturn

  • Slipping Along Enceladus

    Slipping Along Enceladus

    Home to a sub-surface ocean, Saturn‘s moon Enceladus is a fascinating candidate for life in our solar system. As it orbits Saturn, plumes periodically shoot out long surface features known as tiger stripes that sit near the icy moon’s southern pole. A recent study, based on numerical simulation, suggests a geophysical mechanism that could account for the plumes.

    The team suggests that, like the San Andreas Fault, the tiger stripes are a fault subject to strike-slip motion. In this type of fault, the ice on either side meets along a vertical face and the two sides will slide past one another in opposite directions. As Enceladus orbits, its proximity to Saturn causes tidal compression across the fault that modulates how much slip motion occurs. In their model, the authors found that strike-slip motion would intermittently open gaps in the fault that would allow water from the subsurface ocean to create plumes at intervals consistent with those observed. (Image credit: top – NASA/JPL-Caltech/Space Science Institute, illustration – A. Berne et al.; research credit: A. Berne et al.; via Gizmodo)

    Illustration of the strike-slip mechanism over the course of Enceladus's tides. The two sides of the "tiger stripe" fault move in opposite directions. How much they move depends on the amount of tidal compression caused by Enceladus's orbit around Saturn. At times, motion along the fault pulls apart narrow sections of the ice, allowing a plume to spray out.
    Illustration of the strike-slip mechanism over the course of Enceladus’s tides. The two sides of the “tiger stripe” fault move in opposite directions. How much they move depends on the amount of tidal compression caused by Enceladus’s orbit around Saturn. At times, motion along the fault pulls apart narrow sections of the ice, allowing a plume to spray out.
  • Probing Saturn’s Interior

    Probing Saturn’s Interior

    Saturn’s rings are one of the most iconic sights in our solar system, and scientists are using them to learn more about the planet they surround. Until recently, scientists believed that gas giants like Saturn and Jupiter have dense, rocky cores buried beneath their gassy atmospheres. But a new study of Saturn’s rings suggests that Saturn’s core is far larger and more fluid than assumed.

    When the interior of Saturn wobbles, it causes gravitational shifts that affect the material making up its rings. By studying disturbances in the ring system — a technique known as ring seismology — researchers can deduce what motions took place inside the planet to cause the changes in the rings.

    Using data from the Cassini spacecraft, the authors determined that Saturn’s core likely spreads to nearly 60% of its radius, and, rather than being dense and rocky, the core is a relatively fluid mixture of ice, rock, and metallic fluids. The core diffuses gradually into the gaseous atmosphere, and it’s stably stratified against convection, so its wobbles are quite small for the planet’s size. (Image credit: rings – NASA; illustration – Caltech/R. Hurt; research credit: C. Mankovich and J. Fuller; via Gizmodo)

    Illustration of Saturn's interior showing a large, wobbly core composed of a mixture of ice, rock and metallic fluid.
  • Farewell, Cassini!

    Farewell, Cassini!

  • Titan’s Bubbly Islands

    Titan’s Bubbly Islands

    Titan, Saturn’s largest moon, is a fascinating world with remarkable similarities to our own. It is the only other world we know of with stable bodies of liquid at its surface. Unlike Earth, frigid Titan’s lakes and seas are filled with methane and ethane. Radar data from the Cassini mission has shown oddly changing shorelines on Titan, above, with islands that seem to magically appear and disappear over time.

    Researchers at NASA’s Jet Propulsion Laboratory now think these islands may, in fact, be bubbles. As Titan’s lakes cool, they’re better able to absorb nitrogen gas, but when temperatures warm up, that gas comes out of solution and floats to the surface, much like the bubbles of carbon dioxide in a soda. If this hypothesis holds up, there are some interesting implications for Titan’s atmosphere. Here on Earth, bubbles popping in the ocean are a major source of aerosol particles. It’s possible migrating rafts of bubbles could behave similarly on Titan. (Photo credit: NASA/JPL-Caltech/ASI/Cornell; submitted by jpshoer)

    I’m excited to announce I will be visiting JPL later this month (March 30th), where I have the honor of giving a Women’s History Month talk. If there are any JPLers who are FYFD fans, I hope to see you there. Be sure to RSVP to the ACW luncheon by the March 24th deadline.

  • Saturnian Clouds

    Saturnian Clouds

    It may look like an oil slick, but the photo above actually shows the clouds of Saturn. The false-color composite image reveals the gas giant in infrared, at wavelengths longer than those visible to the human eye. NASA uses this infrared photography to identify different chemical compositions in Saturn’s atmosphere based on how they reflect sunlight. You can see an example of how they construct these images here. This detail shot appears to show cloud bands of different compositions mixing. You can see hints of shear instabilities forming along the edges  where the light and dark bands meet. (Image credit: NASA; via Gizmodo)

  • Fluids Round-up – 7 December 2013

    Fluids Round-up – 7 December 2013

    Fluids round-up time! I missed out last weekend because of the holidays, so this is a long list of links. There’s a lot of really great stuff here, including some neat fluidsy geophysics and astronomy.

    (Photo credit: E. Whittaker)

  • Featured Video Play Icon

    Saturn’s Great White Spot

    We’ve touched a couple times on Saturnian storms, but this NASA video gives a great overview of the Great White Spot, a storm that appeared in late 2010. Gauging the fluid dynamics of gas giants like Saturn and Jupiter is difficult, in large part because we can see only the outermost portion of the atmosphere. Numerous theories and models have been suggested to explain features and dynamics that we observe, but much of the overall behavior remains a subject of debate among planetary scientists. (Video credit: NASA Goddard)

  • Saturn’s Polar Vortex

    Saturn’s Polar Vortex

    Nothing quite compares to the beauty of fluid dynamics on astronomical scales. What you see here are raw photographs of recent storms at Saturn’s north pole. The recent change in Saturnian seasons has afforded Cassini a sunlit view of the northern pole, which had previously lain in darkness. A roiling vortex filled with clouds being twisted and sheared was revealed near the center of its famed polar hexagon. (Photo credit: NASA/JPL-Caltech/Space Science Institute; submitted by J. Shoer)

  • Portrait of Gas Giants

    [original media no longer available]

    Here raw footage from NASA’s Cassini and Voyager missions has been combined in a stunning portrait of Saturn and Jupiter. Watch as tiny moons create gravity waves in the rings of Saturn and observe the complicated relative motion between the cloud bands on Jupiter and the swirls and vortices that result. Fluid dynamics are truly everywhere. (Video credit: Sander van den Berg; submitted by Daniel B)

  • Saturn’s Storm Stretches All the Way Around

    Saturn’s Storm Stretches All the Way Around

    This picture captured by Cassini in February shows a storm on Saturn stretching all the way around the planet. Unlike Earth and Jupiter, which have numerous storms virtually all the time, Saturn tends to store energy in its atmosphere for decades and then release it all at once in mega-storms like this one. #