On anniversary of launch, New Horizons returns hi-res images of Pluto’s haze, possible cryovolcano
NASA’s New Horizons spacecraft has sent back the highest resolution images yet of Pluto’s layered blue atmospheric haze and of a large mountain suspected by scientists to be a cryovolcano. The spacecraft was launched on Jan. 19, 2006 – a decade ago today. Since that time, the spacecraft has revolutionized how we view the distant, icy sentinel of the Solar System.
Recently, the New Horizons‘ team used a mosaic of four panchromatic images taken by the Long Range Reconnaissance Imager (LORRI) along with photos captured by the Ralph / Multispectral Visible Imaging Camera (MVIC) with a four-color filter, mission team members created the highest-ever resolution color image of Pluto’s haze layers.
The image has a resolution of 0.6 miles (one km) per pixel and depicts Pluto backlit by the Sun on the right side. The color is a close approximation of the hazes’ true color as seen from this perspective.
According to scientists, Pluto’s layers of haze are composed of photochemical smog, created when sunlight interacts with methane and other atmospheric molecules, yielding a mix of complex hydrocarbons such as ethylene and acetylene.
The hydrocarbons join together forming tiny particles no larger than a fraction of a millimeter, which scatter the sunlight. As the particles fall through the atmosphere, they form complex hazes in horizontal layers extending up to 120 miles (200 km) above the surface as well as hundreds of miles around the planet.
Visible in the processed image are mountains on the right at Pluto’s limb as well as surface features within that limb and dark, finger-shaped shadows known as crepuscular rays to the left.

Possible Ice Volcano on Pluto. At about 150 km across and 4 km high, the feature – informally named Wright Mons – is enormous. If it is, in fact, a volcano, as suspected, it would be the largest such feature discovered in the outer Solar System. (Click to enlarge.) Image & Caption Credit: NASA/JHU-APL/SwRI
The highest resolution color images of Wright Mons, a giant mountain 90 miles (150 km) across and 2.5 miles (four km) high, one of two suspected cryovolcanoes, were used to create a composite close-up image of the 140-mile (230-km) region where it is located, adjacent to the bottom left of Sputnik Planum, the left side of Pluto’s iconic heart-shaped region known as Tombaugh Regio.
Like the processed haze image, this composite (above) was created by mission scientists, who combined LORRI images taken from a distance of 30,000 miles (48,000 km) and enhanced color data captured by Ralph/MVIC from a distance of 21,000 miles (34,000 km).
The LORRI data shows features as small as 1,500 feet (450 meters) wide. Overlaid on the LORRI images are Ralph/MVIC photos taken 20 minutes after the former at a resolution of approximately 2,100 feet (650 meters) per pixel.
Red material is sparse in this region, and scientists do not yet know why. Wright Mons has just one impact crater, suggesting its surface and possibly some of its subsurface crust are young.
The lack of additional craters indicates Wright Mons might be a cryovolcano that was active in Pluto’s recent history and could possibly remain active today.
If confirmed to be volcanic, Wright Mons would be the largest cryovolcano in the outer Solar System.
Amanda Zangari of Boulder, Colorado’s Southwest Research Institute and a member of New Horizons‘ Geology, Geophysics, and Imaging (GGI) team, discusses the way scientists compare ground-based observations of the Pluto system with those taken in situ by New Horizons at this blog: Studying Pluto from 3 Billion Miles Away
New Horizons successfully completed its historic flyby of Pluto in July of last year (2015). The ocean of data that the spacecraft beamed back to controllers on Earth is still being analyzed and likely won’t be completely available for some time to come.
“With that flyby New Horizons completed a long-held goal of the scientific community and also five-decade-long quest by NASA to explore all the planets known at the start of the space age,” said New Horizons Principal Investigator Alan Stern, of the Southwest Research Institute, Boulder, Colorado. “And that all got its start 10 years ago today with our launch.”
Video courtesy of NASA New Horizons
Laurel Kornfeld
Laurel Kornfeld is an amateur astronomer and freelance writer from Highland Park, NJ, who enjoys writing about astronomy and planetary science. She studied journalism at Douglass College, Rutgers University, and earned a Graduate Certificate of Science from Swinburne University’s Astronomy Online program. Her writings have been published online in The Atlantic, Astronomy magazine’s guest blog section, the UK Space Conference, the 2009 IAU General Assembly newspaper, The Space Reporter, and newsletters of various astronomy clubs. She is a member of the Cranford, NJ-based Amateur Astronomers, Inc. Especially interested in the outer solar system, Laurel gave a brief presentation at the 2008 Great Planet Debate held at the Johns Hopkins University Applied Physics Lab in Laurel, MD.