Before NASA’s New Horizons spacecraft made its famous flyby of Pluto last year, the dwarf planet wasn’t much more than a mystery to the world. New images of Pluto’s North Pole released by NASA on Thursday, while stunning, serve to prove that the more we see of Pluto, the more mysterious it gets.
The new image reveals that the landscape of and around Pluto’s North Pole is not only dotted with giant canyons, valleys, and strange pits, but it also appears to be yellow in color — particularly interesting because the rest of Pluto’s landscape is bluish-grey. According to Smithsonian Magazine, it is only in higher elevations near the North Pole where the yellow color of the terrain dominates. NASA scientists haven’t found this color at any other spot on the planet’s surface.
Though it is not a certainty, one possibility for the change in color, says Will Grundy, a NASA researcher at the Lowell Observatory in Flagstaff, Arizona, is that the area surrounding the North Pole — known as the Lowell Regio, named after Percival Lowell, whose work led to Pluto’s discovery — is covered in methane ice, as opposed to the nitrogen ice that covers the rest of Pluto’s surface.
“One possibility is that the yellow terrains may correspond to older methane deposits that have been more processed by solar radiation than the bluer terrain.”
In the highlighted photo provided by NASA, we can see that aside from the yellow tint of the surface, the area around Pluto’s North Pole is also noteworthy because of the valleys and canyons that spot its surface. Running on either side of the North Pole are two narrow canyons — highlighted in green — that measure roughly six miles wide. In the middle is an exceptionally large canyon — highlighted in yellow– with a long, winding valley in the middle of it that is shown in blue in NASA’s photo. The large canyon is approximately 45 miles wide.
What makes these geological features even more mysterious, according to Tech Insider, is the fact that the walls of these canyons are crumbling and degraded, a stark contrast to canyon systems elsewhere on Pluto, which are sharply defined, and not degrading at all. This suggests that the canyons closest to Pluto’s North Pole are far more ancient than those found on the rest of the planet — which hints at possible evidence that these canyons were formed during an ancient period of tectonic plate-like movement. The younger canyons across the rest of the planet are believed to be roughly 10 million years old. The ones around Pluto’s North Pole, however ancient they are, have not been dated as of yet.
Another interesting feature found in the new image of Pluto’s North Pole are giant pits, found at the bottom right corner of the highlighted picture, shown in red. These pits span up to 45 miles across, and 2.5 miles deep. What is fascinating about these pits is their irregular shapes, ruling out meteor impacts as the cause of them. Instead, these giant caverns might indicate an area of subsurface ice melting, causing cave-ins on Pluto’s surface.
These new images of Pluto’s North Pole were taken during New Horizons’ flyby on July 14, 2015. The reason they were only released this week is due to the fact that the spacecraft is only equipped with a small antenna with which to transmit the photos back to Earth. As well, at the moment, it is travelling away from Earth at a speed of 32,000 miles per hour. It may well take until the end of this year before all the photos of the flyby are transmitted back to Earth.
If the photos of Pluto’s North Pole haven’t whetted your space travel appetite just yet, in a few short months, NASA’s Juno spacecraft will finally come to the end of its five year journey to Jupiter, and will likely have some brilliant images of the gas giant to transmit back to Earth.
[Photo by NASA/JHUAPL/SwRI]