[meteorite-list] Different Faces of Pluto Emerging in New Images from New Horizons

[Ron Baalke]

http://www.nasa.gov/feature/different-faces-of-pluto-emerging-in-new-images-from-new-horizons

June 11, 2015

Different Faces of Pluto Emerging in New Images from New Horizons

The surface of Pluto is becoming better resolved as NASA's New Horizons 
spacecraft speeds closer to its July flight through the Pluto system. 

A series of new images obtained by the spacecraft's telescopic Long Range 
Reconnaissance Imager (LORRI) during May 29-June 2 show Pluto is a complex 
world with very bright and very dark terrain, and areas of intermediate 
brightness in between. These images afford the best views ever obtained 
of the Pluto system. 

New Horizons scientists used a technique called deconvolution to sharpen 
the raw, unprocessed pictures that the spacecraft beams back to Earth; 
the contrast in these latest images has also been stretched to bring out 
additional details. Deconvolution can occasionally produce artifacts, 
so the team will be carefully reviewing newer images taken from closer 
range to determine whether some of the tantalizing details seen in the 
images released today persist. Pluto's non-spherical appearance in these 
images is not real; it results from a combination of the image-processing 
technique and Pluto's large variations in surface brightness. 

Since April, deconvolved images from New Horizons have allowed the science 
team to identify a wide variety of broad surface markings across Pluto, 
including the bright area at one pole that scientists believe is a polar 
cap. 

"Even though the latest images were made from more than 30 million miles 
away, they show an increasingly complex surface with clear evidence of 
discrete equatorial bright and dark regions - some that may also have variations 
in brightness," says New Horizons Principal Investigator Alan Stern, of 
the Southwest Research Institute, Boulder, Colorado. "We can also see 
that every face of Pluto is different and that Pluto's northern hemisphere 
displays substantial dark terrains, though both Pluto's darkest and its 
brightest known terrain units are just south of, or on, its equator. Why 
this is so is an emerging puzzle."

"We're squeezing as much information as we can out of these images, and 
seeing details we've never seen before," said New Horizons Project Scientists 
Hal Weaver, from the Johns Hopkins University Applied Physics Laboratory 
in Laurel, Maryland. 'We've seen evidence of light and dark spots in Hubble 
Space Telescope images and in previous New Horizons pictures, but these 
new images indicate an increasingly complex and nuanced surface. Now, 
we want to start to learn more about what these various surface units 
might be and what's causing them. By early July we will have spectroscopic 
data to help pinpoint that."

New Horizons is approximately 2.9 billion miles (4.7 billion kilometers) 
from Earth and just 24 million miles (39 million kilometers) from Pluto. 
The spacecraft and payload are in good health and operating normally.
 

[Images]
These images, taken by New Horizons' Long Range Reconnaissance Imager 
(LORRI), show four different "faces" of Pluto as it rotates about its 
axis with a period of 6.4 days. All the images have been rotated to align 
Pluto's rotational axis with the vertical direction (up-down) on the figure, 
as depicted schematically in the upper left.From left to right, the images 
were taken when Pluto's central longitude was 17, 63, 130, and 243 degrees, 
respectively. The date of each image, the distance of the New Horizons 
spacecraft from Pluto, and the number of days until Pluto closest approach 
are all indicated in the figure.
Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest 
Research Institute

[Images]
These images show dramatic variations in Pluto's surface features as it 
rotates. When a very large, dark region near Pluto's equator appears near 
the limb, it gives Pluto a distinctly, but false, non-spherical appearance. 
Pluto is known to be almost perfectly spherical from previous data.
Credits: : NASA/Johns Hopkins University Applied Physics Laboratory/Southwest 
Research Institute

[Images]
These images are displayed at four times the native LORRI image size, 
and have been processed using a method called deconvolution, which sharpens 
the original images to enhance features on Pluto. Deconvolution can occasionally 
introduce "false" details, so the finest details in these pictures will 
need to be confirmed by images taken from closer range in the next few 
weeks. All of the images are displayed using the same brightness scale.
Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest 
Research Institute

Last Updated: June 11, 2015
Editor: Tricia Talbert