Emily LakdawallaOct 02, 2015

New Horizons releases new color pictures of Charon, high-resolution lookback photo of Pluto

Now that New Horizons is regularly sending back data, the mission is settling into a routine of releasing a set of captioned images on Thursdays, followed by raw LORRI images on Friday. The Thursday releases give us the opportunity to see lovely color data from the spacecraft's Ralph MVIC instrument. This week, the newly available color data set covered Charon.

Wow, what a fascinating moon! Look at how many different shades of red cross its surface. Look how different the more-cratered, higher-elevated north is from the smoother, lower south. It's a crustal dichotomy much like Mars'. Look how red Charon's pole is. Look how varicolored its craters are.

Color global portrait of Charon from Ralph MVIC
Color global portrait of Charon from Ralph MVIC New Horizons captured this high-resolution enhanced color view of Charon just before closest approach on July 14, 2015. The image combines blue, red and infrared images taken by the spacecraft's Ralph/Multispectral Visual Imaging Camera (MVIC); the colors are processed to best highlight the variation of surface properties across Charon. Charon's color palette is not as diverse as Pluto's; most striking is the reddish north (top) polar region. Charon is 1,214 kilometers across; this image resolves details as small as 2.9 kilometers. NASA / JHUAPL / SwRI

The more cool photos I see of Charon, the sadder I feel about our limited photo coverage of the Uranian moons. They're all (except Puck and Miranda) similar in size to Charon, and possess tantalizing hints of similar landscapes. But Voyager 2 flew far from any of them (except Miranda).

Colors and sizes of Uranus' moons
Colors and sizes of Uranus' moons The six largest moons of Uranus, to scale with each other, showing their relative colors and brightnesses. From left to right: Puck, Miranda, Ariel, Umbriel, Titania, and Oberon. Color data is from Voyager 2, except for tiny Puck, whose color is derived from Hubble data. NASA / JPL / Ted Stryk

Another of this week's releases compares the colors of Pluto and Charon. They processed the color layers the same way for both worlds in this montage in order to show you how different are the brightnesses of Pluto and Charon -- and how similar are the colors of Charon's north pole and Pluto's dark equatorial regions. What is going on to make that happen, I have no idea.

Pluto and Charon in enhanced color from Ralph MVIC
Pluto and Charon in enhanced color from Ralph MVIC A composite of enhanced color images of Pluto (lower right) and Charon (upper left), taken by New Horizons as it passed through the Pluto system on July 14, 2015. This image highlights the striking differences between Pluto and Charon. The color and brightness of both Pluto and Charon have been processed identically to allow direct comparison of their surface properties, and to highlight the similarity between Charon's polar red terrain and Pluto's equatorial red terrain. Pluto and Charon are shown with approximately correct relative sizes, but their true separation is not to scale. The image combines blue, red and infrared images taken by the spacecraft's Ralph/Multispectral Visual Imaging Camera (MVIC). NASA / JHUAPL / SwRI

I waited to post these until today in order that I could see what else would show up on the mission's raw image website. MVIC images are not included in the raw image releases. There were eight new photos today, all part of a high-resolution portrait of Pluto's atmosphere taken about three hours after closest approach, with Pluto about 200,000 kilometers away. I don't know if there will be more images in this portrait or not, but I've combined today's new frames with ones that were released last week to make this lovely partial portrait.

Looking back at Pluto: high-res mosaic (partial product)
Looking back at Pluto: high-res mosaic (partial product) NASA / JHUAPL / SwRI / Emily Lakdawalla

Here is a visual index of what LORRI images have been released to the raw images website so far. If you look down the right-hand side, you'll see a lot of text. At the resolution at which it's embedded, the text is not legible. But it gives you a sense of how much more we have to wait for: blue text signifies observations for which we have seen images, and gray text signifies image sets that have not yet been downlinked and released. There is so much more to come. And this is just for Pluto! Now to create a similar catalog for Charon and the other moons....

Catalog of New Horizons' close-approach images of Pluto as of October 2, 2015
Catalog of New Horizons' close-approach images of Pluto as of October 2, 2015 New Horizons will take a year to return all its science data to Earth. This image compiles the data released for Pluto from the period of 48 hours around closest approach to date. Text at the right side gives an idea of what kinds of data are missing in between the images already returned to Earth. Images are taken as part of specific science observations. If any data from an observation has reached Earth, the text for that observation is blue. The numbers for time, range, and resolution represent the actual metadata for the first image taken in any observation. Gray italic text represents observations that were commanded, but for which data have not yet appeared on the raw images website. This text comes from a table of planned observations given to Emily Lakdawalla by Leslie Young in July 2014. Times, ranges, and resolutions in that document are not precisely correct; they may be off by the actual values by up to ten minutes, thousands of kilometers, and tens of meters, respectively. There is no public information regarding how many images are supposed to be in all of these observations. Observations for which data are on this compilation may include more images not yet returned from the spacecraft. New Horizons LORRI images can be found here. The click-to-enlarge version of this image shows the data at 25% resolution; click here for a full-resolution PNG version. NASA / JHUAPL / SwRI / Emily Lakdawalla

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