Blue skies, frozen water detected on Pluto

October 8, 2015
Pluto's haze layer shows its blue color in this picture taken by the New Horizons Ralph/Multispectral Visible Imaging Camera (MVIC). The high-altitude haze is thought to be similar in nature to that seen at Saturn’s moon Titan. The source of both hazes likely involves sunlight-initiated chemical reactions of nitrogen and methane, leading to relatively small, soot-like particles (called tholins) that grow as they settle toward the surface. This image was generated by software that combines information from blue, red and near-infrared images to replicate the color a human eye would perceive as closely as possible. Credit: NASA

Pluto has blue skies and patches of frozen water, according to the latest data out Thursday from NASA's unmanned New Horizons probe, which made a historic flyby of the dwarf planet in July.

Never before has Pluto—a resident of the distant Kuiper Belt, a frigid region of the solar system beyond Neptune that is home to many comets and asteroids—been observed in such detail.

"Who would have expected a blue sky in the Kuiper Belt? It's gorgeous," said Alan Stern, New Horizons principal investigator from Southwest Research Institute in Boulder, Colorado.

Along with the announcement, NASA released an image showing a blue layer of haze around Pluto, taken by the New Horizons spacecraft's camera.

Blue skies are seen on Earth because of the scattering of sunlight by very small particles of nitrogen.

"On Pluto they appear to be larger—but still relatively small—soot-like particles we call tholins," said science team researcher Carly Howett, also of SwRI.

NASA said the "second significant finding" from New Horizons' latest trove of data is that there are numerous small, exposed regions of frozen water on Pluto.

Using a tool called a spectral composition mapper on New Horizons, scientists have been able to map the signatures of water ice on various parts of the planet's surface.

"Large expanses of Pluto don't show exposed water ice," said science team member Jason Cook of SwRI. "Because it's apparently masked by other, more volatile ices across most of the planet."

Pluto's haze layer shows its blue color in this picture taken by the New Horizons Ralph/Multispectral Visible Imaging Camera (MVIC). The high-altitude haze is thought to be similar in nature to that seen at Saturn’s moon Titan. The source of both hazes likely involves sunlight-initiated chemical reactions of nitrogen and methane, leading to relatively small, soot-like particles (called tholins) that grow as they settle toward the surface. This image was generated by software that combines information from blue, red and near-infrared images to replicate the color a human eye would perceive as closely as possible. Credits: NASA/JHUAPL/SwRI

"Understanding why water appears exactly where it does, and not in other places, is a challenge that we are digging into."

The areas that seem to contain the most water ice also appear bright red in recent color images of Pluto.

"I'm surprised that this water ice is so red," said Silvia Protopapa, a science team member from the University of Maryland, College Park.

"We don't yet understand the relationship between water ice and the reddish tholin colorants on Pluto's surface."

Scientists have previously reported seeing flowing nitrogen ice glaciers on the surface of Pluto.

On July 14, New Horizons, a nuclear-powered spacecraft about the size of a baby grand piano, became the first spaceship to pass by Pluto. It will continue to send data back to Earth until late next year.

NASA says the spacecraft is pressing on and is in good working order some 3.1 billion miles (five billion kilometers) from Earth.

Explore further: Lead scientist of Pluto expedition has book deal

Related Stories

New Horizons mission exceeds expectations

August 24, 2015

(Phys.org)—NASA's New Horizons mission, as the name suggests, is all about broadening our scientific horizons. The spacecraft, visiting the unexplored world of dwarf planet Pluto and its moons, continues to deliver more ...

New Pluto images from NASA's New Horizons

September 11, 2015

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.

New Horizons data hint at underground ocean

July 30, 2015

Pluto wears its heart on its sleeve, and that has scientists gleaning intriguing new facts about its geology and climate. Recent data from NASA's New Horizons probe—which passed within 7,800 miles of the surface on July ...

Recommended for you

Galaxy murder mystery

January 17, 2017

It's the big astrophysical whodunnit. Across the Universe, galaxies are being killed and the question scientists want answered is, what's killing them?

ALMA reveals sun in new light

January 17, 2017

New images from the Atacama Large Millimeter/submillimeter Array (ALMA) reveal stunning details of our Sun, including the dark, contorted center of an evolving sunspot that is nearly twice the diameter of the Earth.

Astrophysicists discover dimming of binary star

January 16, 2017

A team of University of Notre Dame astrophysicists led by Peter Garnavich, professor of physics, has observed the unexplained fading of an interacting binary star, one of the first discoveries using the University's Sarah ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.