The wait is finally over as NASA has just released the most recent close-up images of everyone’s favorite dwarf planet – Pluto. The stunning new images reveal a varied and complex terrain.
“Pluto is showing us a diversity of landforms and complexity of processes that rival anything we’ve seen in the solar system,” said New Horizons Principal Investigator Alan Stern of the Southwest Research Institute (SwRI) in Boulder, Colorado. “If an artist had painted this Pluto before our flyby, I probably would have called it over the top – but that’s what is actually there.”
In the center of this image is broken terrain on the northwestern edge of Sputnik Planum. Image Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.
In the nearly two months since it flew through the Pluto system, New Horizons has traveled over 69 million kilometers (40 million miles) and has just begun a yearlong data download, beaming back images and precious science and engineering data. The latest images reveal incredibly complex surface features at resolutions of 400 meters (440 yards) per pixel with the smallest visible features just under a kilometer wide.
The new images highlight a host of diverse surface features, including dark, ancient terrain that is covered in craters alongside bright, smooth terrain that is geologically very young. Also visible are clusters of mountains and what appears to be dunes. The possibility of dunes is especially intriguing.
“Seeing dunes on Pluto – if that is what they are – would be completely wild, because Pluto’s atmosphere today is so thin,” said William B. McKinnon, a Geology, Geophysics and Imaging (GGI) deputy lead from Washington University, St. Louis. “Either Pluto had a thicker atmosphere in the past, or some process we haven’t figured out is at work. It’s a head-scratcher.”
Sent back from NASA’s New Horizons spacecraft from Sept. 5 to 7, 2015, the image is dominated by the icy plain Sputnik Planum, which is the smooth, bright region across the center. The smallest features visible are 0.8 kilometers (0.5 miles) in size. Image Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.
The icy plains of Sputnik Planum are highlighted in a high-resolution mosaic showing the smooth terrain bordered by the dark cratered region informally known as Cthulhu Regio. Evidence of nitrogen ice flows seeping out of mountainous regions and even a vast network of valleys have the science team reeling.
“The surface of Pluto is every bit as complex as that of Mars,” said Jeff Moore, leader of the New Horizons GGI team at NASA’s Ames Research Center in Moffett Field, California. “The randomly jumbled mountains might be huge blocks of hard water ice floating within a vast, denser, softer deposit of frozen nitrogen within the region informally named Sputnik Planum.”
This image was taken as New Horizons whizzed past Pluto on July 14, 2015, from a distance of 80,000 kilometers (50,000 miles). Image Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.
Thanks to New Horizons, we know that Pluto’s atmosphere is hazy; however, the new images reveal there’s more to Pluto’s haze that we thought. A higher resolution image of the haze has been downlinked showing a larger number of layers within the haze and even the possibility of a phenomena known as crepuscular rays – shadows cast on the haze by objects such as mountain ranges or when clouds block out sunlight like we see on Earth. With many more layers than first thought, Pluto’s atmospheric haze creates a twilight effect that allows New Horizons’ sensitive cameras to see features in the terrain just before and after sunset that would not otherwise be visible.
An image of Pluto’s haze layers. Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.
“This bonus twilight view is a wonderful gift that Pluto has handed to us,” said John Spencer, a GGI deputy lead from SwRI. “Now we can study geology in terrain that we never expected to see.”
On Friday, we can expect to see new images of three of Pluto’s five moons – Charon, Nix, and Hydra. The images will be uploaded to JHUAPL’s site for New Horizons LORRI instrument, showing just how unique each moon is and giving us a glimpse into Charon’s history.
Pluto's largest moon Charon. Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.