Is Pluto Evaporating? New ‘Ice Retreat’ Image Shows Nowhere is Safe from Climate Change
RETREATING ice, exposed bed rock… it sounds like the latest discussion on how global warming is affecting Earth’s poles.
But the disintegrating ice in question is actually frozen methane which is being lost from Pluto’s surface at a rapid rate.
NASA revealed the methane is now subliming into gas, exposing eroded cliff faces and plains.
The US space agency statement also suggested Pluto’s water ice bedrock was being exposed to the surface in these affected areas.
Sublimation – the transition straight from a solid state into gas without a liquid water stage – happens to methane when atmospheric pressure lowers, meaning there could have been a climatic change on the dwarf planet.
NASA studied images of the dwarf planet’s cratered plateau uplands, known as Vega Terra.
The area has a jagged scarp, or wall of cliffs, known as Piri Rupes, which borders the young, nearly crater-free plains of Piri Planitia.
A NASA spokesman said: “Compositional data from the New Horizons spacecraft indicates that the plateau uplands south of Piri Rupes are rich in methane ice.
“Scientists speculate that sublimation of methane may be causing the plateau material to erode along the face of the cliffs, causing them to retreat south and leave the plains of Piri Planitia in their wake.
“Compositional data also show that the surface of Piri Planitia is more enriched in water ice than the higher plateaus, which may indicate that Piri Planitia’s surface is made of water ice bedrock, just beneath a layer of retreating methane ice. “
On the image, the mottled pattern of Piri Planitia in the left inset has lighter areas corresponding to those richer in methane.
The spokesman added: “These may be remnants of methane that have not yet sublimated away entirely.”
NASA has yet to indicate what may happen next to the exposed water ice, but the surface is currently never believed to get warm enough for it to melt as well.
