A great swathe of Pluto that features a strange rippling terrain is perhaps the highlight of the latest image release from the New Horizons mission.
The Nasa probe, which flew by the dwarf planet in July, continues to downlink its data, and as it comes in, the scientists get to work on it.
The ripples stretch for many hundreds of km.
"It looks more like tree bark or dragon scales than geology," observed mission team member Bill McKinnon.
"This'll really take time to figure out; maybe it's some combination of internal tectonic forces and ice sublimation driven by Pluto's faint sunlight," the Washington University, St Louis, scientist said in a US space agency release.
The best way to look at "scales" is to browse the new high-resolution enhanced colour view of Pluto that has been made available (PNG file, 70MB). The features are on the far eastern edge.