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Headshot of Emily Lakdawalla

A feast of new OSIRIS photos from comet 67P

Posted By Emily Lakdawalla

11-05-2016 16:19 CDT

Topics: Rosetta and Philae, pretty pictures, comets, amateur image processing, comet Churyumov-Gerasimenko, explaining image processing

Last week, the Rosetta mission released a large quantity of science data to the worldwide public. The release included data from many of its instruments, but I only have eyes for one of them, at least initially: OSIRIS, the high-resolution camera. The new image data covers the mission through December 19, 2014, which means that it covers two especially important periods. One of them was the Close Observation Phase of October 15 to 31, 2014, when Rosetta surveyed the comet from a height (measured from the comet's center) of only 10 kilometers. At that range, OSIRIS Narrow-Angle Camera pixels subtended fewer than 20 centimeters, giving us incredibly detailed views. And then, of course, was landing day on November 12, when OSIRIS watched as Philae fell toward the comet, landed, and then bounced.

Before I post a ton of pretty pictures, let me tell you how you can browse the data for yourself. Here are the official sites:

But as always I made my own browse pages that provide information on the filter choices and interweave the Narrow-Angle, Wide-Angle, and NavCam data. My pages are split up into mission phases:

Without further ado, here are some of my favorite things from the latest data release. User "Herobrine" at unmannedspaceflight.com put together this cool spinny animation:

Rotating comet 67P

ESA / Rosetta / MPS for OSIRIS Team MPS / UPD / LAM / IAA / SSO / INTA / UPM / DASP / IDA / "Herobrine"

Rotating comet 67P
An animation of Rosetta OSIRIS Wide-Angle Camera images of comet 67P taken on November 22, 2014, over a period of about 12 hours.

I thought it would be fun to take that animation and align it on the stars I could see in the background:

Rotating comet 67P (aligned on background stars)

ESA / Rosetta / MPS for OSIRIS Team MPS / UPD / LAM / IAA / SSO / INTA / UPM / DASP / IDA / "Herobrine" / Emily Lakdawalla

Rotating comet 67P (aligned on background stars)
An animation of Rosetta OSIRIS Wide-Angle Camera images of comet 67P taken on November 22, 2014, over a period of about 12 hours. This version of the animation has been aligned on the background stars.

It was neat to see the full science-quality images of the lander. I put together this 2-image mosaic showing the lander floating in space above the comet's surface ("above" here referring to the local gravity gradient; in the photo, the teeny lander is near the bottom left, off in space). You have to click through twice to enlarge it to its full resolution in order to appreciate all the detail on the little lander. In general, you need to click through to enlarge all these images to truly appreciate them. OSIRIS has a much larger CCD than most previous space cameras -- a 4-megapixel CCD, 2048 pixels square.

Philae descending

ESA / Rosetta / MPS for OSIRIS Team MPS / UPD / LAM / IAA / SSO / INTA / UPM / DASP / IDA / Emily Lakdawalla

Philae descending
A mosaic of two OSIRIS photos taken at 14:40 and 14:45 on November 12, 2014, shows the tiny Philae lander (a speck near the bottom of the photo) descending toward comet Churyumov-Gerasimenko (top). Philae's first landing happened at 16:03.

Here's another view of the lander afloat above the surface. A postage stamp version of this photo cropped around the lander was released by ESA shortly after the landing, but I don't think I've never seen the full-resolution views with the teeny tiny lander over the huge expanse of comet before. In the caption to the photo I give a clue to where the lander is -- see if you can find it without reading the caption.

Philae afloat

ESA / Rosetta / MPS for OSIRIS Team MPS / UPD / LAM / IAA / SSO / INTA / UPM / DASP / IDA

Philae afloat
Rosetta captured this photo with its OSIRIS camera at 15:18 on November 12, 2014, 45 minutes before Philae's touchdown on the surface. The tiny lander is visible as a triple cluster of bright pixels below and to the right of the image center.

But enough staring at the lander; let's check out those amazing views from the Close Observation Phase, where the terrain breaks out into all kind of fascinating detail. Here's a small sampling. Almost all of these observations were actually taken in color, through many different filters; I didn't have time to try to process them into color views by warping one image to match the next. I did try to do some 3D processing but the 3D anaglyphs were not as easy to make as they were for the period when Rosetta was farther away from the comet.

Boulders and blocks on comet Churyumov-Gerasimenko

ESA / Rosetta / MPS for OSIRIS Team MPS / UPD / LAM / IAA / SSO / INTA / UPM / DASP / IDA

Boulders and blocks on comet Churyumov-Gerasimenko
The largest boulders visible here are approximately 50 meters across. Rosetta took this photo with its OSIRIS Narrow-Angle Camera during the "Close Observation Phase" from a distance of only 10 kilometers on October 28, 2014.
Pitted terrain on comet 67P

ESA / Rosetta / MPS for OSIRIS Team MPS / UPD / LAM / IAA / SSO / INTA / UPM / DASP / IDA

Pitted terrain on comet 67P
Photo captured October 19, 2014 from a distance of 10 kilometers.
Pitted and fractured terrain with a bright block on comet 67P

ESA / Rosetta / MPS for OSIRIS Team MPS / UPD / LAM / IAA / SSO / INTA / UPM / DASP / IDA

Pitted and fractured terrain with a bright block on comet 67P
Photo captured October 22, 2014 from a distance of 10 kilometers.
Granular plains on comet Churyumov-Gerasimenko

ESA / Rosetta / MPS for OSIRIS Team MPS / UPD / LAM / IAA / SSO / INTA / UPM / DASP / IDA

Granular plains on comet Churyumov-Gerasimenko
Parts of comet 67P are covered with terrain that appears very smooth, from a distance. But seen up close, at a distance of only 10 kilometers, the smooth plains begin to break up into a terrain that appears granular at the scale of the images, about 20 centimeters per pixel.
Varied terrain on comet 67P

ESA / Rosetta / MPS for OSIRIS Team MPS / UPD / LAM / IAA / SSO / INTA / UPM / DASP / IDA

Varied terrain on comet 67P
In a photo captured on October 19 from a distance of 10 kilometers, Rosetta spies a wide variety of different terrains on the comet. In some places the comet appears to be a coherent block, crossed with long fissures; in other places, this material appears to break up into boulders. Yet other areas seem smooth, with what appear to be collapse pits.
Dramatic landscape on comet 67P

ESA / Rosetta / MPS for OSIRIS Team MPS / UPD / LAM / IAA / SSO / INTA / UPM / DASP / IDA

Dramatic landscape on comet 67P
Taken on October 19, 2014, during the Close Observation Phase, from a distance of 10 kilometers.
Cliff on comet 67P

ESA / Rosetta / MPS for OSIRIS Team MPS / UPD / LAM / IAA / SSO / INTA / UPM / DASP / IDA

Cliff on comet 67P
Captured October 28, 2014

So very cool. I hope that some of you explore the data through the links at the top of this post and see for yourself what Rosetta saw in 2014!

Rotating comet's jets

ESA / Rosetta / MPS for OSIRIS Team MPS / UPD / LAM / IAA / SSO / INTA / UPM / DASP / IDA / "Herobrine"

Rotating comet's jets
An animation of Rosetta OSIRIS Wide-Angle Camera images of comet 67P taken on November 28, 2014, over a period of about 2 hours.
 
See other posts from May 2016

 

Read more blog entries about: Rosetta and Philae, pretty pictures, comets, amateur image processing, comet Churyumov-Gerasimenko, explaining image processing

Comments:

A. Cooper: 05/11/2016 07:16 CDT

Hi Emily I can identify the exact location of 6 of the 9 photos. I've made a stab at the rough area of the other three and made it clear which I'm sure of and which is rough. I've listed them below in the order they appear in the post, along with what is hopefully some interesting extra context. 1. (Sure). The Nut depression is at top right. The large, flat, dusty area of Serquet is in front of it and in shadow. 2. (Sure). The Nut depression again. The massif covered in dust (at middle-bottom and which Philae has just flown over) is the same massif as the one at the very top-right in photo 1. 3. (Sure). The boulders in Hapi as viewed from the base of Anuket. The cave at the other end is just visible at the top of the frame with the 'washed beach' scree in front of it. Mattias Malmer's recent viewpoint on his shape model is just this side of the biggest rock in the foreground. His view is interesting in that it's an impossible viewpoint for Rosetta and therefore of scientific value. 4. (Sure). A view 'down' the head lobe at Ma'at towards the Nut depression. You can just about see the scree of Nut in the distance. 5. (Sure). This is just to the right of photo 4. You can see that the edge of the 'pancake' on the far left is the same as the one on the right in photo 4. The dark, semi-circular crater in the foreground is at the edge of the Hatmehit depression. It's slightly triangular from a distance and forms one 'corner' of the somewhat rhombic shape of Hatmehit. 6. (Not sure). Almost certainly Ash, somewhere 'below' Landing site A, as viewed in upright duck mode. 7. (Not sure). Probably on or near the circular feature on Imhotep. 8. (Not sure). Possibly the Hapi neck next to Anuket. 9. (Sure). The easternmost section of the cliffs of Aten but viewed from the Babi side (in fact it's viewed by OSIRIS from above the head lobe at Ma'at, almost through the dipped section of the head lobe, and skimming across Babi on the body 'below'). The very well-defined dog-leg ridge that leads up to it and which runs all the way from Hapi, is on the left in this view but not very obvious from this low-down angle. This chunk, sometimes referred to as a mesa or scarp on the Rosetta blog , had a jet start up in the low area just in front of it. It was one of the first obvious, defined jets to be identified by non mission scientists, using NAVCAM photos in the early stages of the mission. I first heard it from space blogger, Elisabetta Bonora. The jet must have started just after October 28th 2014 when this photo was taken.

Karen: 05/12/2016 06:48 CDT

Very confusing, those bounders with the linear fractures. What could possibly be cementing them together? On earth I'd expect a hydrothermal mineral infill, but clearly that's not going to happen here. Recondensed water vapour would be a possibility, but then the rocks would fall apart when heated. Could they possibly just be fractured all the way through, yet experiencing so little force that they don't fall apart?

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