[meteorite-list] NASA's New Horizons Team Finds Haze, Flowing Ice on Pluto

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Sun, 26 Jul 2015 21:14:40 -0700 (PDT)
Message-ID: <201507270414.t6R4EehW021333_at_zagami.jpl.nasa.gov>

July 24, 2015

RELEASE 15-158

NASA's New Horizons Team Finds Haze, Flowing Ice on Pluto

Flowing ice and a surprising extended haze are among the newest discoveries
from NASA's New Horizons mission, which reveal distant Pluto to be an icy
world of wonders.

"We knew that a mission to Pluto would bring some surprises, and now -- 10
days after closest approach -- we can say that our expectation has been more
than surpassed," said John Grunsfeld, NASA's associate administrator for
the Science Mission Directorate. "With flowing ices, exotic surface
chemistry, mountain ranges, and vast haze, Pluto is showing a diversity of
planetary geology that is truly thrilling."

Just seven hours after closest approach, New Horizons aimed its Long Range
Reconnaissance Imager (LORRI) back at Pluto, capturing sunlight streaming
through the atmosphere and revealing hazes as high as 80 miles (130
kilometers) above Pluto's surface. A preliminary analysis of the image
shows two distinct layers of haze -- one about 50 miles (80 kilometers) above
the surface and the other at an altitude of about 30 miles (50 kilometers).

"My jaw was on the ground when I saw this first image of an alien
atmosphere in the Kuiper Belt," said Alan Stern, principal investigator for
New Horizons at the Southwest Research Institute (SwRI) in Boulder, Colorado.
"It reminds us that exploration brings us more than just incredible
discoveries -- it brings incredible beauty."

Studying Pluto's atmosphere provides clues as to what's happening below.

"The hazes detected in this image are a key element in creating the complex
hydrocarbon compounds that give Pluto's surface its reddish hue," said
Michael Summers, New Horizons co-investigator at George Mason University in
Fairfax, Virginia.

Models suggest the hazes form when ultraviolet sunlight breaks up methane gas
particles -- a simple hydrocarbon in Pluto's atmosphere. The breakdown of
methane triggers the buildup of more complex hydrocarbon gases, such as
ethylene and acetylene, which also were discovered in Pluto's atmosphere by
New Horizons. As these hydrocarbons fall to the lower, colder parts of the
atmosphere, they condense into ice particles that create the hazes.
Ultraviolent sunlight chemically converts hazes into tholins, the dark
hydrocarbons that color Pluto's surface.

Scientists previously had calculated temperatures would be too warm for hazes
to form at altitudes higher than 20 miles (30 kilometers) above Pluto's
surface.

"We're going to need some new ideas to figure out what's going on,"
said Summers.

The New Horizons mission also found in LORRI images evidence of exotic ices
flowing across Pluto's surface and revealing signs of recent geologic
activity, something scientists hoped to find but didn't expect.

The new images show fascinating details within the Texas-sized plain,
informally named Sputnik Planum, which lies within the western half of
Pluto's heart-shaped feature, known as Tombaugh Regio. There, a sheet of
ice clearly appears to have flowed -- and may still be flowing -- in a manner
similar to glaciers on Earth.

"We've only seen surfaces like this on active worlds like Earth and
Mars," said mission co-investigator John Spencer of SwRI. "I'm really
smiling."

Additionally, new compositional data from New Horizons' Ralph instrument
indicate the center of Sputnik Planum is rich in nitrogen, carbon monoxide,
and methane ices.

"At Pluto's temperatures of minus-390 degrees Fahrenheit, these ices can
flow like a glacier," said Bill McKinnon, deputy leader of the New Horizons
Geology, Geophysics and Imaging team at Washington University in St. Louis.
"In the southernmost region of the heart, adjacent to the dark equatorial
region, it appears that ancient, heavily-cratered terrain has been invaded by
much newer icy deposits."

View a simulated flyover using New Horizons' close-approach images of
Sputnik Planum and Pluto's newly-discovered mountain range, informally
named Hillary Montes, in the video below:

http://go.nasa.gov/1MMEdTb

The New Horizons mission will continue to send data stored in its onboard
recorders back to Earth through late 2016. The spacecraft currently is 7.6
million miles (12.2 million kilometers) beyond Pluto, healthy and flying
deeper into the Kuiper Belt.

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, based in San Antonio,
leads the science team, payload operations and encounter science planning.
New Horizons is part of the New Frontiers Program managed by NASA's Marshall
Space Flight Center in Huntsville, Alabama.

For more information on the New Horizons mission, including fact sheets,
schedules, video and images, visit:

http://www.nasa.gov/newhorizons

-end-
Received on Mon 27 Jul 2015 12:14:40 AM PDT