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Emily Lakdawalla • Oct 22, 2015

Dawn data from Ceres publicly released: Finally, color global portraits!

A few days ago, Dawn officially released the first big pile of data from the Ceres mission phase. The Framing Camera portion of the release amounts to roughly 4500 images. The data release includes everything through "Rotation Characterization 3," when Dawn was about 14,000 kilometers above Ceres and could still see the whole globe in a single photo.

This is huge news, because for reasons I've never understood, the Dawn mission has yet to release a color global portrait of Ceres. But there is a ton of data to make color global portraits, and now that it's been released, amateur image processors can do that! So, without further ado: the first views of Ceres as they might look to your eyes, if you were riding aboard Dawn.

First, one that shows the famous bright spots in Occator crater:

Ceres in color
Ceres in color Ceres, approximately as a human would see it. The photos were taken during Dawn's "Rotation Characterization 3," on May 4, 2015. Occator crater, at center, contains Ceres' enigmatic bright spots.Image: NASA / JPL-Caltech / MPS / DLR / IDA / Daniel Macháček

When Daniel Macháček made that one, he had a little fun playing with contrast and saturation to bring out some of the variety in Ceres' terrain:

Four color views of Ceres
Four color views of Ceres Dawn captured the images for these global views of Ceres on May 4, 2015 through red, green, and blue filters. All four pictures are made from the same data, processed in different ways. On top left, it is processed to simulate what a human might see. At top right, color saturation has been increased, revealing a relatively blue inner splash and relatively red outer splash around the crater Occator and other, smaller craters. At lower left, the contrast has been increased, emphasizing relatively brighter and darker regions. At lower right, both contrast and saturation have been increased.Image: NASA / JPL-Caltech / UCLA / MPS / DLR / IDA / Daniel Macháček

And here are three more views focusing on different parts of Ceres. The first two were processed by Justin Cowart, the third by Daniel Macháček. Justin's are a little browner than Daniel's. None of these is calibrated color; the balance between channels has been subjectively adjusted until they look "right" to the individual doing the procesing.

Color global view of Ceres: Oxo and Haulani craters
Color global view of Ceres: Oxo and Haulani craters This approximately true-color image was taken at 4:13 on May 4, 2015, as Dawn was surveying Ceres in its "Rotation Characterization 3" orbit 13,642 kilometers above the surface. Oxo crater makes a small bright splash near center; Haulani is the larger one to its right. Near the bottom of the disk is the odd cone-shaped mountain, Ahuna Mons.Image: NASA / JPL-Caltech / UCLA / MPS / DLR / IDA / Justin Cowart
Color global view of Ceres: Dantu crater
Color global view of Ceres: Dantu crater This approximately true-color image was taken at 11:18 on May 4, 2015, as Dawn was surveying Ceres in its "Rotation Characterization 3" orbit 13,637 kilometers above the surface. Dantu crater is near the top of the visible disk, associated with a spatter of brighter spots.Image: NASA / JPL-Caltech / UCLA / MPS / DLR / IDA / Justin Cowart
Color global view of Ceres: Urvara and Yalode basins
Color global view of Ceres: Urvara and Yalode basins This approximately true-color image was taken at 15:27 on May 7, 2015, as Dawn was surveying Ceres in its "Rotation Characterization 3" orbit 13,583 kilometers above the surface. At the terminator, near the top, is Urvara, a large crater with radiating troughs. Closer to the center of the disk is the large Yalode basin, with its flat floor and faint inner ring. Farther down the terminator is the large Mondamin crater. Haulani crater makes a bright splash near the lower right edge of the disk. The cone-shaped Ahuna mons is near center.Image: NASA / JPL-Caltech / UCLA / MPS / DLR / IDA / Daniel Macháček

4500 images is a lot to wrap one's head around, so I downloaded the index tables and created a set of web pages that helps you browse the data. In addition to the colorful Rotation Characterization 3 global images, there was another set taken through clear filters as Dawn took an excursion over the night side of Ceres, seeing its disk at very high phase. Here is the highest-phase image in the collection, showing Ceres as a skinny crescent.

Skinny crescent Ceres
Skinny crescent Ceres Dawn took this photo of Ceres from the dwarf planet's night side on April 29, 2015. It has a phase angle of 155.6 degrees.Image: NASA / JPL-Caltech / UCLA / MPS / DLR / IDA

With 4500 images, there are plenty of possibilities for image processing fun. There are many more color portraits to be made, as well as animations of the rotating globe, and comparisons of features seen at different angles and under different lighting. Playing around with contrast can reveal subtle features on Ceres' plains. Use this map of Ceres' feature names (PDF) as your guide, and have fun exploring!

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