New Images Of Pluto From 7,750 Miles

[A Theist]

[Anomalocaris]

The relative absence of craters on Pluto is extremely remarkable. It would be interesting to learn what long lasting sources of energy is allowing so small a world to be continuously paving over the craters on its surface so long after its formation.

[pocaracas]

Maybe the non-co-planar orbit with the rest of the solar system provides some relative lack of rocks flying by?

[Anomalocaris]

The main repository of potential impact bodies in the region of Pluto would be the Keiper belt. Keiper belt is very thick. The average inclination of orbits of objects in it is probably around 10 degrees. So the inclination of pluto's orbit won't take it out of danger zone.

So pluto's lack of craters likely didn't result from scarcity of impacts. Much more likely is Pluto was resurfaced quite recently.

Also, Pluto has an atmosphere. Pluto's Gravity is too weak to hold on to a primordial atmosphere over the life of solar system. So the presence of atmosphere might suggest Pluto remains volcanically active and continues to out gas from its interior.

[ignoramus]

Please explain "resurfaced" Chuck! I'm getting interested...

[Anomalocaris]

Please explain "resurfaced" Chuck! I'm getting interested...

Pluto has large percentage of water content.   The bedrock under its surface is made mostly of water ice.    At pluto's surface temperature water ice is very strong and stiff, stronger than most types of rocks on earth, and as strong and stiff as granite.  So in prevailing temperatures surface of Pluto behaves as if it was made from light but very strong rock, like granite, capable of supporting large verticle relief indefinitely, in other words allow impact craters to survive for as long as the age of solar system. 

 If the interior of Pluto remains warm, then there is probably an water or ice/slush mantle under pluto's solid crust.   If the interior is warm enough, then the solid ice crust could be relatively thin.   In this case, liquid water may periodically break through to the surface.   When warm water from deep mantle erupts onto a cold ice surface, it's called cryovolcano.    Much of the erupted water would instantly freeze, and then come back onto pluto's surface in a manner analogous to volcanic ash.   If the volume of eruption is large enough, not all the warm water may have time to freeze before it starts to flow like hot lava on the ice surface.   Either way, cryovolcano said would bury existing topolographies like craters.  This is what likely resurfaced Pluto, and erased most craters.

[orogenicman]

Another thing to consider is that Pluto has an atmosphere that freezes out during the Plutonian winter, and sublimates during the Plutonian summer. That can cause erosion which can erase craters and other features.

[Anomalocaris]

Would there be strong erosion if the gases of the atmosphere never undergo a liquid phase between summer and winter?    Erosive agent probably has to be able to transport away the eroded material and expose Fresh material for erosion to continue for the the agent to become persistently effective.   

There doesn't seem to be any runoff channels in the pictures seen so far?

Although the flat parts between hilly regions might be depositional surfaces.

[Jackalope]

Another thing to consider is that Pluto has an atmosphere that freezes out during the Plutonian winter, and sublimates during the Plutonian summer.  That can cause erosion which can erase craters and other features.

I don't recall where, but I remember reading a week or so that this phenomenon is questionable after some observations from New Horizons.

[SteelCurtain]

Poor Pluto: