The first high resolution images of Pluto taken by spacecraft New Horizons during a fly-by of the dwarf planet have already given scientists much to think about with unexpected icy mountains featuring on the surface.
New imaging of Pluto’s major moon Charon also surprised scientists with its unexpectedly youthful and varied terrain.
“New Horizons is returning amazing results already. The data look absolutely gorgeous, and Pluto and Charon are just mind blowing,” said Alan Stern, principal investigator for New Horizons at the Southwest Research Institute (SwRI) in Boulder, Colorado.
A close-up image of an equatorial region near the base of Pluto’s bright heart-shaped feature shows a mountain range with peaks jutting as high as 3,500 metres above the surface.
Scientsists believe the mountains were probably formed no more than 100 million years ago – much younger than expected, leaving open the possibility that the region may still be geologically active today.
“This is one of the youngest surfaces we’ve ever seen in the solar system,” said Jeff Moore of the New Horizons Geology, Geophysics and Imaging Team (GGI) at NASA’s Ames Research Center in Moffett Field, California.
But that opens up the question as to what may be driving any activity. Unlike the icy moons of giant planets, Pluto cannot be heated by gravitational interactions with a much larger planetary body. Some other process must be generating the mountainous landscape.
“This may cause us to rethink what powers geological activity on many other icy worlds,” says GGI deputy team leader John Spencer at SwRI.
Scientists are surprised by the apparent lack of craters while cliffs and valleys stretching about 1,000 kilometres suggest widespread fracturing of the moon’s crust, probably due to internal geological processes.
The image also shows a canyon estimated to be up to 9 kilometres deep.
In Charon’s north polar region, the dark surface markings have a diffuse boundary, suggesting a thin deposit or stain on the surface.
New Horizons also observed the smaller members of the Pluto system, which includes four other moons: Nix, Hydra, Styx and Kerberos. A new sneak-peak image of Hydra is the first to reveal its apparent irregular shape and its size, estimated to be about 43 by 33 kilometres (image below).