(July 16, 2015 at 8:41 am)ignoramus Wrote: 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.
