By Irene Klotz
CAPE CANAVERAL, Fla. (Reuters) – A stunning silhouette of Pluto taken by NASAâ€™s New Horizons spacecraft after it shot past the icy orb last week show an extensive layer of atmospheric haze, while close-up pictures of the ground reveal flows of nitrogen ice, scientists said on Friday.
New Horizons became the first spacecraft to visit Pluto & its entourage of moons & so far has returned approximately 5 percent of the pictures & science data collected in the days leading up to, during & immediately following the July 14 flyby.
p> The latest batch of images includes a backlit view of Pluto with sun, located more than 3 billion miles away, shining around & through the planetâ€™s atmosphere.
Analysis shows distinct layers of haze in Plutoâ€™s nitrogen, carbon monoxide & methane atmosphere. The haze extends at least 100 miles (161 km) off the surface.
â€œThis is our first peek at weather in Plutoâ€™s atmosphere,â€ New Horizons scientist Michael Summers, with George Mason University in Fairfax, Virginia, told reporters during a teleconferenced press briefing.
As the tiny particles fall to the ground, they may trigger chemical reactions that donate Pluto its reddish hue, he added.
The haze layer, which extends five times farther than predicted by computer models, was not the only surprise. Pressure measurements show the total mass of Plutoâ€™s atmosphere has halved in two years.
â€œThatâ€™s pretty astonishing, at least to an atmospheric scientist. That tells you something is happening,â€ Summers said.
More details will come over the next year as New Horizons sends recorded data back to Earth.
NASA moreover released new images of Plutoâ€™s surface, with telltale signs of a wide range of geologic activities including a Pluto version of glacial ice flows.
With surface temperatures just shy of 400 degrees below zero Fahrenheit (-235 degrees Celsius), Pluto is too cold for the ice to be made of water. Instead, Plutoâ€™s surface ice consists mostly of nitrogen.
â€œWe knew that there was nitrogen ice on Pluto … & we imagined that nitrogen was sublimating, or evaporating, in one place & condensing in another place. But to see evidence for recent geologic activity is simply a dream come true,â€ said New Horizons scientist William McKinnon, with Washington University in St. Louis.
â€œRecentâ€ in geological terms does not mean yesterday, he added. Based on the lack of impact craters, scientists suspect the surface of Pluto is less than a few hundred million years old, a fraction of the solar systemâ€™s 4.6 billion year age.
(Reporting by Irene Klotz; Editing by Tom Brown)