The arrival of the New Horizons spacecraft at the Pluto system was considered by scientists and space enthusiasts alike to be the start of discovering the many secrets that the dwarf planet has kept hidden all these years.
While NASA's ongoing exploration of Pluto has provided experts with a treasure trove of new data, the latest images sent back the New Horizons probe have left scientists at the space agency bewildered by Pluto's unique geological features.
The new photographs of Pluto were taken during the spacecraft's flyby of the dwarf planet on July 14.
Alan Stern, principal investigator of NASA's New Horizons project, said the images show diverse landforms and complex processes present on Pluto — which agency experts believe could rival anything that they have observed in the solar system.
Stern added that if an artist had made a depiction of the dwarf planet showing these surface features, he would have likely considered it over-the-top. But these images represent the real Pluto.
The New Horizons probe started its download of the latest Pluto images and other important data over the Labor Day weekend. The number of images sent back by the spacecraft has doubled the number of samples observed at 440 yards per pixel resolution.
The images reveal new characteristics of Pluto's surface, including flows of nitrogen ice seemingly coming from the dwarf planet's mountainous regions, networks of valleys and even potential dunes. They also show vast sections of the surface that display jumbled mountain ranges similar to the terrains seen on Europa, the icy moon of Jupiter.
Dunes on Pluto
According to NASA, something scientists did not expect to find is the presence of dunes on the surface.
But Stern said they were able to detect large areas on Pluto that have dunes, though they are trying to be careful in labeling the features as such until they have confirmed the observation.
Dunes are typically formed when tiny particles are piled up by wind, eventually creating undulating ridges on the ground.
What the scientists find baffling is that the air present on modern-day Pluto is much too weak and thin to form these fields of dunes, which could even stretch to several kilometers across. This suggests that the dwarf planet could have possessed a stronger and denser atmosphere at some point in its history.
The scientists believe that if these features on Pluto's surface prove not to be dunes, then some other force than wind could have created them.
The origin of the dune-like structures has yet to be determined, and whether they are formed with particles of ice or tiny pieces of rock. Some of these structures appear very dark, while others appear relatively bright, possibly because of the presence of ice.
