Saturday, January 1, 2022

3388 - PLUTO - ice sheets explored?

  -  3388  -  PLUTO  -  ice sheets explored? -  Scientists have unravelled a fascinating new insight into how the landscape of the dwarf-planet Pluto has formed.   The most striking feature on Pluto's surface, “Sputnik Planitia” is an impact crater, consisting of a bright plain, slightly larger than France, and filled with nitrogen ice.


---------------------  3388  -  PLUTO  -  ice sheets explored?

-  These ice forms, polygonal in shape, are formed by the sublimation of ice.  This is a phenomenon where the solid ice is able to turn into gas without going through a liquid state.  This sublimation of the nitrogen ice powers convection in the ice layer of Sputnik Planitia by cooling down its surface.

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-  Pluto is still geologically active despite being far away from the Sun and having limited internal energy sources. This included at Sputnik Planitia, where the surface conditions allow the gaseous nitrogen in its atmosphere to coexist with solid nitrogen.

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-  The surface of the ice exhibits remarkable polygonal features formed by thermal convection in the nitrogen ice, constantly organizing and renewing the surface of the ice. 

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-  The research team conducted a series of numerical simulations that showed the cooling from sublimation is able to power convection in a way that is consistent with numerous data coming from New Horizons including the size of polygons, amplitude of topography and surface velocities.

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-  It is also consistent with the timescale at which climate models predict sublimation of Sputnik Planitia, beginning around 2,000,000 years ago. It showed that the dynamics of this nitrogen ice layer echo those found on Earth's oceans, being driven by the climate.

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-  Such climate-powered dynamics of a solid layer could also occur at the surface of other planetary bodies, such as Triton (one of Neptune's moons), or Eris and Makemake (from Kuiper's Belt).

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-  December 31, 2021       PLUTO  -  ice sheets explored?               3388                                                                                                                                               

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