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First maps of Charon and Pluto

Many features on Charon informally named from science fiction, particularly Star Trek and Star Wars. Lord of the Rings, Stanley Kubrick also honored.

A portion of the first preliminary map on Pluto.

A portion of the first preliminary map on Pluto. See below for the complete map.

Following New Horizons’ history-making sweep past Pluto on July 14, 2015, the mission has released maps of Pluto and Charon with preliminary designations for the features found on these distant worlds. A month ago, we’d never seen these worlds as more than blurry balls, and now we have maps of their surfaces! Amazing. The names – which still need to be made official – on Pluto come from many cultures in all parts of Earth. Those on Pluto fall into four major categories: space missions and spacecraft; scientists and engineers; historic explorers; and underworld locales, beings, and travelers.

View larger. | Preliminary map of Pluto.  Images via NASA / JHU-APL / SwRI / New Horizons spacecraft

View larger. | Complete preliminary map of Pluto. Images via NASA / JHU-APL / SwRI / New Horizons spacecraft

And guess who named the features on Pluto? You did. In early 2015, the New Horizons mission invited people to submit names corresponding to specific thematic guidelines. NASA released an initial list of the most popular names earlier in July.
The International Astronomical Union (IAU) still has to approve the names before they become official, but the New Horizons team is using these names already. Cathy Olkin, a New Horizons scientist who was part of the group in charge of assigning informal names, told BuzzFeed:

We need names to call things. We are working with these data. You can’t just keep on saying, ‘Oh, that canyon up to the left.

Let’s look for a moment at an enhanced image of Pluto as a whole:

View larger. | Four images from New Horizons’ Long Range Reconnaissance Imager (LORRI) were combined with color data from the Ralph instrument to create this enhanced color global view of Pluto. (The lower right edge of Pluto in this view currently lacks high-resolution color coverage.) The images, taken when the spacecraft was 280,000 miles (450,000 km) away, show features as small as 1.4 miles (2.2 km). Image via NASA/JHUAPL/SwRI.

View larger. | Four images from New Horizons’ Long Range Reconnaissance Imager (LORRI) were combined with color data from the Ralph instrument to create this enhanced color global view of Pluto. (The lower right edge of Pluto in this view currently lacks high-resolution color coverage.) The images, taken when the spacecraft was 280,000 miles (450,000 km) away, show features as small as 1.4 miles (2.2 km). Image via NASA/JHUAPL/SwRI.

That heart-shaped region is called Tombaugh Regio, named for Clyde Tombaugh, who discovered Pluto in 1930. Now here’s a close-up of Tombaugh Regio, with its newly named features:

View larger. | Preliminary map of Tombaugh Regio

View larger. | Preliminary map of Tombaugh Regio

Buzzfeed, which became one of the first to publish these maps earlier this week, did an excellent job explaining what some of the unfamiliar names mean:

Everyone knows what a crater is. Here’s what some of those other words mean: Cavus (deep-sided depression), Chasma (chasm), Colles (small knobs or hills), Dorsa (ridges), Fossa (long, narrow depression), Linea (elongated marking), Macula (dark spot), Mons (mountain), Montes (mountains), Planum (plateau or high plain), Regio (large bright or dark region), Terra (extensive land mass), Vallis (valley).

Now let’s take a look at the first preliminary map of Charon.

View larger. | Preliminary map of Charon. Images via NASA / JHU-APL / SwRI. New Horizons spacecraft.

View larger. | Preliminary map of Charon. Image via NASA / JHU-APL / SwRI. New Horizons spacecraft.

The naming scheme for Charon fell under four categories as well: fictional explorers and travelers; fictional origins and destinations; fictional vessels; and exploration authors, artists, and directors.

Many features are informally named after science fiction characters, particularly from Star Trek and Star Wars. Some from Alien and Dr Who. Mordor Macular covering the north polar region including the North Pole of Charon, is from The Lord of the Rings.

Kubrick Mons named after Stanley Kubrick, is the curious Mountain in the Moat, the lofty mountain in a depression that does not appear to be an impact crater.

By the way, Charon, largest moon of Pluto is 751 miles (1,207 km) wide. The map above has variable resolution. On the Pluto-facing side – in the middle of the map – the resolution is 1,250 feet ( 400 meters) in places. On the anti-Pluto-facing side – ends of the map – the resolution is typically 25 miles (40 km).

The clearer, higher resolution areas on the Pluto facing side will increase as more images are returned.

Here's Charon without the map labels.

Here’s Charon without the map labels. Image via NASA / JHU-APL / SwRI. New Horizons spacecraft.

Bottom line: Preliminary maps of Pluto and Charon, from New Horizons’ July 14, 2015 flyby.

Andrew R. Brown

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