Enhanced color image shows Pluto’s rugged highlands; new textbook will discuss mission findings
The latest image released by NASA’s New Horizons spacecraft mission team centers on a dark region of rugged highlands known as Krun Macula, which borders the bottom of Sputnik Planum, the icy plain comprising the left side of Pluto’s ‘heart’.
Krun Macula has the dark red color produced by tholins, complex molecules created by the interaction of solar radiation with organic compounds, such as methane or ethane.
The term “macula” refers to dark regions on the surface of a planet, while the name Krun is that of an underworld lord in the Mandaean religion.
Enhanced color was used to create the image, and photographs taken during three separate observations by New Horizons were combined to produce a highly detailed single image of the region.
Two of the three images used were taken by the spacecraft’s Long Range Reconnaissance Imager (LORRI) approximately six minutes apart at about 23 and 29 minutes before the July 14, 2015, closest approach.
All three come from the highest- and second-highest-resolution images collected by the spacecraft.
The right side of the picture, which shows the dark highlands, was captured by LORRI just 9,850 miles (15,850 km) from Pluto’s surface, about 23 minutes before closest approach at a resolution of 260 feet (80 meters) per pixel.
The left side of the composite photo, which highlights the smooth terrain of Sputnik Planum bordering Krun Macula, was taken from a distance of 15,470 miles (24,900 km), about 29 minutes before closest approach, with a resolution of 410 feet (125 meters) per pixel.
A third, color image captured by the Ralph / Multispectral Visual Imaging Camera (MVIC) about 45 minutes before closest approach, from a distance of 21,100 miles (33,900 km) with a resolution of 2,230 feet (680 meters) per pixel, was combined with the two LORRI photos to create the final image.
At a height 1.5 miles (2.5 km) above adjoining Sputnik Planum, Krun Macula is a dark, rugged area spotted with numerous round, connected pits with depths up to 1.5 miles (2.5 km) and diameters ranging from five to eight miles (eight and 13 km).
The pits bordering Sputnik Planum extend into valleys more than 25 miles (40 km) long and 12.5 miles (20 km) wide.
With floors made up of nitrogen ice, the valleys are twice as deep as the Grand Canyon on Earth.
Mission scientists theorize that the pits were created by some type of surface collapse but do not know what might have caused that event.
In a June 10 blog entry titled Rewriting the Playbook on Pluto, mission scientist Richard Binzel announces plans for the publication of a new textbook that will encompass all the findings of the New Horizons mission.
Tentatively titled Pluto After New Horizons, the book will be a follow-up to a 1997 book named Pluto and Charon, edited by New Horizons Principal Investigator Alan Stern of the Southwest Research Institute (SwRI) and David Tholen of the University of Hawaii.
The first book played a key role in determining New Horizons’ science objectives.
Like its predecessor, Pluto After New Horizons will be part of the Space Science Series textbooks, written at a level appropriate for a first-year science graduate student.
Stern will head the team of editors. Writing is scheduled to begin in 2018, with publication planned for 2020.
Binzel notes his hope that the new book will play a similar role in setting science goals for future Pluto exploration.
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.