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.
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.
