[meteorite-list] New Pluto Images from NASA's New Horizons: It's Complicated

[Ron Baalke]

http://www.nasa.gov/feature/new-pluto-images-from-nasa-s-new-horizons-it-s-complicated

New Pluto Images from NASA's New Horizons: It's Complicated
September 10, 2015

[Image]
This synthetic perspective view of Pluto, based on the latest high-resolution 
images to be downlinked from NASA's New Horizons spacecraft, shows what 
you would see if you were approximately 1,100 miles (1,800 kilometers) 
above Pluto's equatorial area, looking northeast over the dark, cratered, 
informally named Cthulhu Regio toward the bright, smooth, expanse of icy 
plains informally called Sputnik Planum. The entire expanse of terrain 
seen in this image is 1,100 miles (1,800 kilometers) across. The images 
were taken as New Horizons flew past Pluto on July 14, 2015, from a distance 
of 50,000 miles (80,000 kilometers).
Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest 
Research Institute

New close-up images of Pluto from NASA's New Horizons spacecraft reveal 
a bewildering variety of surface features that have scientists reeling 
because of their range and complexity.

"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), 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."

New Horizons began its yearlong download of new images and other data 
over the Labor Day weekend. Images downlinked in the past few days have 
more than doubled the amount of Pluto's surface seen at resolutions as 
good as 400 meters (440 yards) per pixel. They reveal new features as 
diverse as possible dunes, nitrogen ice flows that apparently oozed out 
of mountainous regions onto plains, and even networks of valleys that 
may have been carved by material flowing over Pluto's surface. They also 
show large regions that display chaotically jumbled mountains reminiscent 
of disrupted terrains on Jupiter's icy moon Europa.  
 
"The surface of Pluto is every bit as complex as that of Mars," said Jeff 
Moore, leader of the New Horizons Geology, Geophysics and Imaging (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."

New images also show the most heavily cratered -- and thus oldest -- terrain 
yet seen by New Horizons on Pluto next to the youngest, most crater-free 
icy plains. There might even be a field of dark wind-blown dunes, among 
other possibilities. 

"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 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."

Discoveries being made from the new imagery are not limited to Pluto's 
surface. Better images of Pluto's moons Charon, Nix, and Hydra will be 
released Friday at the raw images site for New Horizons' Long Range Reconnaissance 
Imager (LORRI), revealing that each moon is unique and that big moon Charon's 
geological past was a tortured one.  

Images returned in the past days have also revealed that Pluto's global 
atmospheric haze has many more layers than scientists realized, and that 
the haze actually creates a twilight effect that softly illuminates nightside 
terrain near sunset, making them visible to the cameras aboard New Horizons.

"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."

[Image]
Mosaic of high-resolution images of Pluto, sent back from NASA's New Horizons 
spacecraft from Sept. 5 to 7, 2015. The image is dominated by the informally-named 
icy plain Sputnik Planum, the smooth, bright region across the center. 
This image also features a tremendous variety of other landscapes surrounding 
Sputnik. The smallest visible features are 0.5 miles (0.8 kilometers) 
in size, and the mosaic covers a region roughly 1,000 miles (1600 kilometers) 
wide. The image was taken as New Horizons flew past Pluto on July 14, 
2015, from a distance of 50,000 miles (80,000 kilometers).
Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest 
Research Institute

[Image]
In the center of this 300-mile (470-kilometer) wide image of Pluto from 
NASA's New Horizons spacecraft is a large region of jumbled, broken terrain 
on the northwestern edge of the vast, icy plain informally called Sputnik 
Planum, to the right. The smallest visible features are 0.5 miles (0.8 
kilometers) in size. This image was taken as New Horizons flew past Pluto 
on July 14, 2015, from a distance of 50,000 miles (80,000 kilometers).

[Image]
This 220-mile (350-kilometer) wide view of Pluto from NASA's New Horizons 
spacecraft illustrates the incredible diversity of surface reflectivities 
and geological landforms on the dwarf planet. The image includes dark, 
ancient heavily cratered terrain; bright, smooth geologically young terrain; 
assembled masses of mountains; and an enigmatic field of dark, aligned 
ridges that resemble dunes; its origin is under debate. The smallest visible 
features are 0.5 miles (0.8 kilometers) in size. This image was taken 
as New Horizons flew past Pluto on July 14, 2015, from a distance of 50,000 
miles (80,000 kilometers).
Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest 
Research Institute

[Image]
This image of Pluto's largest moon Charon, taken by NASA's New Horizons 
spacecraft 10 hours before its closest approach to Pluto on July 14, 2015 
from a distance of 290,000 miles (470,000 kilometers), is a recently downlinked, 
much higher quality version of a Charon image released on July 15. Charon, 
which is 750 miles (1,200 kilometers) in diameter, displays a surprisingly 
complex geological history, including tectonic fracturing; relatively 
smooth, fractured plains in the lower right; several enigmatic mountains 
surrounded by sunken terrain features on the right side; and heavily cratered 
regions in the center and upper left portion of the disk. There are also 
complex reflectivity patterns on Charon's surface, including bright and 
dark crater rays, and the conspicuous dark north polar region at the top 
of the image. The smallest visible features are 2.9 miles 4.6 kilometers) 
in size.
Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest 
Research Institute

[Image]
This image of Pluto from NASA's New Horizons spacecraft, processed in 
two different ways, shows how Pluto's bright, high-altitude atmospheric 
haze produces a twilight that softly illuminates the surface before sunrise 
and after sunset, allowing the sensitive cameras on New Horizons to see 
details in nighttime regions that would otherwise be invisible. The right-hand 
version of the image has been greatly brightened to bring out faint details 
of rugged haze-lit topography beyond Pluto's terminator, which is the 
line separating day and night. The image was taken as New Horizons flew 
past Pluto on July 14, 2015, from a distance of 50,000 miles (80,000 kilometers).
Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest 
Research Institute

[Image]
Two different versions of an image of Pluto's haze layers, taken by New 
Horizons as it looked back at Pluto's dark side nearly 16 hours after 
close approach, from a distance of 480,000 miles (770,000 kilometers), 
at a phase angle of 166 degrees. Pluto's north is at the top, and the 
sun illuminates Pluto from the upper right. These images are much higher 
quality than the digitally compressed images of Pluto's haze downlinked 
and released shortly after the July 14 encounter, and allow many new details 
to be seen. The left version has had only minor processing, while the 
right version has been specially processed to reveal a large number of 
discrete haze layers in the atmosphere. In the left version, faint surface 
details on the narrow sunlit crescent are seen through the haze in the 
upper right of Pluto's disk, and subtle parallel streaks in the haze may 
be crepuscular rays- shadows cast on the haze by topography such as mountain 
ranges on Pluto, similar to the rays sometimes seen in the sky after the 
sun sets behind mountains on Earth.
Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest 
Research Institute

The New Horizons spacecraft is now more than 3 billion miles (about 5 
billion kilometers) from Earth, and more than 43 million miles (69 million 
kilometers) beyond Pluto. The spacecraft is healthy and all systems are 
operating normally. 

Follow the mission at http://www.nasa.gov/newhorizons and http://pluto.jhuapl.edu. 
 
New Horizons is part of NASA's New Frontiers Program, managed by the agency's 
Marshall Space Flight Center in Huntsville, Alabama. The Johns Hopkins 
University Applied Physics Laboratory in Laurel, Maryland, designed, built, 
and operates the New Horizons spacecraft and manages the mission for NASA's 
Science Mission Directorate. SwRI leads the science mission, payload operations, 
and encounter science planning.