Images continue to come back to Earth as NASA's New Horizons probe heads deeper into space. The latest include some details of the dwarf planet's surprisingly complex topography.

Pluto isn't large enough to have retained significant heat from its formation or to carry enough radioactive materials to generate its own heat. Charon, its only large moon, isn't capable of generating tidal friction in Pluto's interior, either. So the expectation was that anything interesting that had happened with Pluto's geology had done so in the distant past.

That expectation has been completely shattered by the images obtained by New Horizons. Huge plains, jagged mountains, and evidence of recent activity all speak to an extremely active world. Now, as more detailed pictures become available, we're getting an up-close look at the results of some of that activity. This week's picture dump includes a twilight view of some of Pluto's mountains, which shows just how steep and rugged they are. Details of another picture show exit glaciers that wouldn't look out of place on Greenland—except the ice here is probably frozen nitrogen.

As a bonus, we'll throw in a picture of Charon, which shows that it's a very different world, one with its own distinctive geological features.