Help Shape the Future of Space Exploration

Join The Planetary Society Now  arrow.png

Join our eNewsletter for updates & action alerts

    Please leave this field empty
Blogs
Facebook Twitter Email RSS AddThis

Headshot of Emily Lakdawalla

Dawn Ceres image bonanza: Grab your 3D glasses!

Posted By Emily Lakdawalla

09-09-2015 20:04 CDT

Topics: pretty pictures, amateur image processing, asteroids, Dawn, asteroid 1 Ceres, 3D

All the time that I've been distracted by the New Horizons mission at Pluto, the other dwarf planet mission has been steadily, methodically sharing dozens of images of brand-new sights of a previously unexplored icy world. I'm talking about the Dawn mission to Ceres, of course, and for the last couple of days I've been making up for lost time, completely buried in the Dawn Ceres images that have been released over the last few months in NASA's Planetary Photojournal.

Lately, they have begun to release images taken from their High-Altitude Mapping Orbit (HAMO), just 1470 kilometers above the surface of Ceres. These images are super cool but because I haven't been paying close attention to the mission (distracted by Pluto!) I found it difficult to orient myself and understand the scale of the features. So, like any good geologist, I made a context map.

I began with this great map of Ceres that includes labels for the first craters to be named:

Ceres map with nomenclature as of August 2015

NASA / JPL-Caltech / UCLA / MPS / DLR / IDA

Ceres map with nomenclature as of August 2015
This map of Ceres shows the dwarf planet's surface with features that have been named as of August 14, 2015. It is a simple cylindrical projection centered on 0 degrees east longitude. A full list of crater names on Ceres is available at the USGS Planetary Nomenclature Gazetteer.

Named craters on this map include (from largest to smallest): Kerwan (284 km), Yalode (271 km), Urvara (163 km), Conirarya (136 km), Zadeni (129 km), Dantu (125 km), Ezinu (120 km), Kirnis (115 km), Occator (92 km), Toharu (88 km), Gaue (84 km), Nawish (79 km), Fejokoo (70 km), Rongo (68 km), Sintana (61 km), Asari (52 km), Haulani (32 km), and Kait (0.4 km). Tiny Kait marks Ceres' prime meridian.

Next, I looked at the more than 50 Survey Orbit images that have been released to date, and located their positions on the map. Now, if I were a Dawn researcher, I would have had access to mapping and geographic projection tools that could have automatically produced these footprints. I don't have access to either those tools or the necessary geometric information about image pointing, and anyway I don't need to be so accurate; I just need a pretty good location for the footprints so that I can identify which images overlap a feature that I'm interested in. So I just drew all the footprints as quadrilaterals. They're not perfectly accurate, but it's close enough for my needs. Once I had the Survey Orbit images located, I could dive in and locate the smaller footprints of the HAMO images -- with a lot of help from a similar map already produced by user "ZLD" at unmannedspaceflight.com. Et voilà:

Location Map for NASA-released Dawn images of Ceres

Basemap: ESA / DLR (Thomas Roatsch). Location map by Emily Lakdawalla.

Location Map for NASA-released Dawn images of Ceres
A quick-and-dirty location map for the images of Ceres released to date (September 9, 2015) at NASA's Planetary Photojournal. Blue and green footprints are for Survey orbit images, from an altitude of 4400 kilometers and a resolution of 410 meters per pixel; orange footprints are for High-Altitude Mapping Orbit images, from an altitude of 1470 kilometers and a resolution of 140 meters per pixel. Because all images are represented as quadrilaterals, locations are imprecise, particularly near the poles.

While I was going through the images to make the map, I made lots of notes on Ceres' fascinating craters and other features. That discussion will have to wait for a later post. But one thing that this map enabled me to do more quickly was to identify locations that had been imaged twice from slightly different angles, allowing me to assemble 3D views. So grab your 3D glasses or cross your eyes or click the flicker-gif links and enjoy Ceres in 3D!

First, one of Ceres' splashier craters, Haulani:

Haulani crater, Ceres, in 3D

NASA / JPL-Caltech / UCLA / MPS / DLR / IDA / Emily Lakdawalla

Haulani crater, Ceres, in 3D
Haulani crater has long been known as "Spot 1," a bright spot on the surface of Ceres. Dawn revealed it to be an impact crater with bright ejecta. Haulani is 32 kilometers in diameter. This image is a combination of two Dawn images taken from Survey orbit on June 6 and 17, 2015.

Crossed-eye stereo

Parallel-eye stereo

Flicker gif

Here's another, as yet unnamed and much smaller splashy crater:

Oxo: A small, bright Cerean crater in 3D

NASA / JPL-Caltech / UCLA / MPS / DLR / IDA / Emily Lakdawalla

Oxo: A small, bright Cerean crater in 3D
A region in Ceres northern' latitudes contains a variety of craters including one small one with a very bright wall and a fainter splash of bright ejecta. North is to the right. It is a combination of two images taken on June 21 and 24, 2015, during the Survey phase of the Ceres mission. The image is about 270 kilometers wide by 240 tall. This crater has been named "Oxo."

Crossed-eye stereo

Parallel-eye stereo

Flicker gif

Urvara crater has quickly become one of my favorite regions on Ceres:

Urvara crater, Ceres, in 3D

NASA / JPL-Caltech / UCLA / MPS / DLR / IDA / Emily Lakdawalla

Urvara crater, Ceres, in 3D
Urvara is one of Ceres' larger and fresher craters, located adjacent to the large Yalode basin in Ceres' southern hemisphere. This anaglyph is composed of two images taken on June 9 and 25, 2015, during the Survey phase of Dawn's Ceres mission.

Crossed-eye stereo

Parallel-eye stereo

Flicker gif

But the spot with the best story to tell is this one, first noticed by some sharp-eyed folks at unmannedspaceflight.com, in the same images that contained the little unnamed splashy crater. In 3D you can really see the steepness of the crater wall, and the long runout of the landslide into the strangely hexagonal crater. (Ceres has a lot of those hexagonal craters.)

A landslide in Ceres' far north in 3D

NASA / JPL-Caltech / UCLA / MPS / DLR / IDA / Emily Lakdawalla

A landslide in Ceres' far north in 3D
Near Ceres' north pole, an asteroid crashed into the steep rim of a hexagonal-shaped crater, causing a large landslide. This 3D image has been rotated to place north down in order to make the lighting more intuitive, and upsized by a factor of two. The whole image is about 125 kilometers across. It is a combination of two images taken on June 21 and 24, 2015, during the Survey phase of the Ceres mission

Crossed-eye stereo

Parallel-eye stereo

Flicker gif

Now that I have my bearings on Ceres, I'll write more later about its strange landforms!

 
See other posts from September 2015

 

Read more blog entries about: pretty pictures, amateur image processing, asteroids, Dawn, asteroid 1 Ceres, 3D

Comments:

Andy Hastings: 09/09/2015 08:13 CDT

Fantastic work as usual, Emily. Unfortunately it seems that when you click on the 'parallel-eye' links, the pop-up only links to the left image and not the right. Any tips for getting a copy of both left and right images for parallel-eye stereo?

jumpjack: 09/10/2015 07:08 CDT

Have you got raw coordinates of images or did you guess them?

Gregk: 09/10/2015 09:20 CDT

I always appreciate the flicker gifs.

QubitsToy: 09/14/2015 07:35 CDT

Fantastic sets of images, the next orbit will make this type of image the most useful. Great post as always. Glad I bought those glasses as you recommended long ago.

Leave a Comment:

You must be logged in to submit a comment. Log in now.

Space in Images

Pretty pictures and
awe-inspiring science.

See More

Join The Planetary Society

Let’s explore the cosmos together!

Become a Member

Connect With Us

Facebook, Twitter, YouTube and more…
Continue the conversation with our online community!