Images of Pluto

Sorry, couldn't resist (see also Pinku-Sensei, with music added).  Seriously, New Horizons is now sending images like these (click each to enlarge) of a planet which until now was nothing but a blurry dot to us:

Those are mountains, more than two miles high, probably made of ice (discussion here).  In Pluto's extreme cold and low gravity, ice is rigid enough to form such features.

This overview picture was taken just before the closest approach, showing the variety of the terrain:

The relative lack of cratering suggests ongoing geological activity (cratering happens continuously on all planets and moons; if we don't see craters, that means that geology or weather is erasing them as fast as they form).  This was unexpected.  Geological activity on the moons of Jupiter and Saturn is driven by heat caused by tidal forces exerted by the gravity of the nearby giant planet, but Pluto has no such giant planet nearby, no source of tidal forces except its own five moons.

This is Charon, Pluto's largest and closest-in moon:

It too shows a surprising variety of terrain and paucity of craters (discussion here).

And these aren't even the real high-resolution images yet.  New Horizons collected so much data that it will take about 16 months to transmit everything back here.  Updates will continue to be posted on the mission page.

This machine is working perfectly at hundreds of degrees below zero, after nine and a half years of travel, sending us mountains of information about a place thirteen thousand times further away than our Moon -- showing what we as a species can accomplish when we put our minds to it.

If only Galileo, Copernicus, Aristarchus could have lived to see this!

Pluto is named after the Roman god of the underworld, while Charon in Greek mythology was the ferryman who carried the souls of the dead across the river Styx to Hades.  Now that a wealth of newly-discovered surface features on both worlds need naming, we're giving them similarly dark and underworld names from mythology and literature (found via Progressive Erupts).  In the very unlikely event that Pluto is ever colonized, some people will have "Cthulhu" as part of their address.