Rosetta’s Comet, Now in 3-D

[n2doc]

A 3-D image from the Rosetta spacecraft showing Comet 67P/Churyumov-Gerasimenko and its boulder-strewn ‘neck’ region. Also visible is an exposed cliff face and numerous crater-like depressions. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA.

You always have a pair of those cardboard red-blue 3-D glasses by your desk, right? Well, grab them and take a look at this view of Comet 67P/Churyumov-Gerasimenko, just out from the Rosetta mission team. It almost feels like you’re right there with the spacecraft.

Notice the cliffs (see the exposed layers there?), boulders and depressions. The 3-D image was created using two images (you can see the two images here at the ESA blog) They were both taken on 7 August 2014, from a distance of 104 kilometres through the orange filter of the OSIRIS narrow-angle camera. ESA says the two images are separated by 17 minutes and the exposure time is 138 milliseconds.

http://www.universetoday.com/113916/rosettas-comet-now-in-3-d/

[William Seger]

1. Cross-view version

Cross-view stereo pairs can be viewed without any equipment by converging your eyes, as if looking at something about a foot in front of your face, such that the two images overlay and converge. It is far superior to anaglyphs; the 3D image appears to be even sharper and more detailed than the originals, whereas anaglyphs make a dull image with details squashed.

One way that I've taught people to cross-view is this: Looking at the pair, hold one finger up about a foot in front of your eyes. You should see two semi-transparent images of your finger in front of the picture pair. Keep looking at the picture pair and move your finger either closer or farther away until you have a semi-transparent finger-tip centered on each image. Now, converge your eyes to look at the finger-tip. That's the convergence angle you want, but try to keep focusing on the image pair rather than the finger tip. If you finger-tip images were centered, you should now see the two images overlay and converge, so adjust the distance if necessary to make that happen. Try to get the edges of pictures to snap into place first, and the rest of the 3D image will follow, and you can then move your finger out of the way. With a little practice, once your brain knows what you want it to do, it becomes very easy and natural.

Many of the larger shadows in this image have been manually corrected by cloning. That's because the images were shot 17 minutes apart and the shadows are different enough to cause a lot of "retinal rivalry," which is what happens when the eyes see images or parts of an image that are too different to be properly converged. Our brains try to make 3D sense of it but can't resolve the discrepancies.

[tridim]

2. It kind of stuns me that I'm looking at a real 3D picture of a comet

I want 3D x-view animations next!

Additional viewing tip: Use the palms of your hands on the side of your head to narrow your view, so you don't see the outside images at all, just the center image. It totally eliminates eye strain.