Pluto’s peaks are ice volcanoes, scientists conclude

Existence of volcanoes makes idea that dwarf planet is inert ball of ice look increasingly improbable

Strung out in the icy reaches of our solar system, two peaks that tower over the surface of the dwarf planet Pluto have perplexed planetary scientists for years. Some speculated it could be an ice volcano, spewing out not lava but vast quantities of icy slush - yet no cauldron-like caldera could be seen.

Now a full analysis of images and topographical data suggests it is not one ice volcano but a merger of many - some up to 7,000 metres tall and about 10-150km across. Their discovery has reignited another debate: what could be keeping Pluto warm enough to support volcanic activity?