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APOD: Stereo Itokawa (2010 Jun 19)

Posted: Sat Jun 19, 2010 4:07 am
by APOD Robot
Image Stereo Itokawa

Explanation: Get out your red/blue glasses and float next to asteroid Itokawa, a diminutive world of the solar system only half a kilometer across. Boulders strewn across its rough surface and the lack of craters indicate that this asteroid is a rubble pile, formed as smaller pieces collected and were kept together by gravity. The stereo view was constructed from images made by the Hayabusa spacecraft when it encountered the asteroid in 2005. After a long journey, the spacecraft re-entered the atmosphere on June 13 over Australia, successfully parachuting a capsule to Earth. Hayabusa's capsule could contain a small sample of material from rubble pile asteroid Itokawa.

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Re: APOD: Stereo Itokawa (2010 Jun 19)

Posted: Sat Jun 19, 2010 4:43 am
by orin stepanek
Itokawa reminds me a little of another asteroid; Eros! :) http://apod.nasa.gov/apod/ap090607.html Both are rather potato shaped

Re: APOD: Stereo Itokawa (2010 Jun 19)

Posted: Sat Jun 19, 2010 5:40 am
by moonstruck
What an amazing photograph. I hope the capsule will contain some of the sample from the rubble pile asteroid Itokawa. When will we know? Will it be published on this forum?
Another question I have is this: We took our three grandaughters to see "Toy Story 3" today and it was in 3D. I copped my 3D glasses and brought them home with me. Todays
APOD is in 3D. When I look at todays APOD picture with the glasses it doesn't do anything at all, but when I put on my cheapie red/blue glasses the picture jumps out at me like it's supposed to. Is there different kinds of 3D or whut? The movie was funny as heck by the way even for an old grandpaw like me. Plus when you aren't laffin you get kinda :cry: teary eyed.

Re: APOD: Stereo Itokawa (2010 Jun 19)

Posted: Sat Jun 19, 2010 6:06 am
by Case
moonstruck wrote:Is there different kinds of 3D or whut?
Exactly. Anaglyph images (e.g. red/blue) filter different colors for each eye, so that each eye sees a different image. Modern 3D movies in theaters use a several different techniques, many based on polarized images, to separate left eye view from right eye view. The upcoming 3D tv seems to use high refresh rate to send images alternating to the left and right eye, by blocking the image from the other eye, using LCD glasses that can go dark and transparent very fast.

Re: APOD: Stereo Itokawa (2010 Jun 19)

Posted: Sat Jun 19, 2010 6:46 am
by Beyond
I don't know about calling it a rubble pile. I see it looks smooth in the middle and there looks to be at least one crater there also. But Alas! I have no 3-D glasses :( Maybe a couple of root :b: will ease my pain.

Re: APOD: Stereo Itokawa (2010 Jun 19)

Posted: Sat Jun 19, 2010 10:47 am
by hobobill
how about a regular photo so the visually impared that can't see 3D have a better understanding of this space rock?

Turd dimension

Posted: Sat Jun 19, 2010 11:37 am
by neufer
hobobill wrote:
how about a regular photo so the visually impaired that can't see 3D have a better understanding of this space rock?
http://antwrp.gsfc.nasa.gov/apod/ap070422.html

However, you really need the turd dimension to appreciate Itokawa:
http://www.3dglassesonline.com/how-do-3d-glasses-work/
http://www.amazon.com/3D-Glasses-Blue-A ... B001D5VCBC

Re: APOD: Stereo Itokawa (2010 Jun 19)

Posted: Sat Jun 19, 2010 12:34 pm
by orin stepanek
beyond wrote:I don't know about calling it a rubble pile. I see it looks smooth in the middle and there looks to be at least one crater there also. But Alas! I have no 3-D glasses :( Maybe a couple of root :b: will ease my pain.
A awhile back Wal-mart gave a way free 3D glasses for a movie that came out so I grabbed a couple. :wink: Every once in a while APOD has a 3D view and I had the same problem until I got a pair. I keep them right above my computer :D

Re: APOD: Stereo Itokawa (2010 Jun 19)

Posted: Sat Jun 19, 2010 12:51 pm
by Beyond
Actually i have the polarized kind which of course do not work on this Apod picture. But thanks to neufer's exploits into the Turd dimension, i now know there's more than one kind of 3-D and thanks to neufer's regular photo of the astroid, i think that it is basicly smooth and has collected a lot of stone somewhere along the line. Being covered with rubble is a lot different than being Rubble. Just ask Fred Flintstone. And as to neufer's journey's into the Turd Dimension -- lets hope more of that dimension does not rub off on him - too much :!:

Re: APOD: Stereo Itokawa (2010 Jun 19)

Posted: Sat Jun 19, 2010 1:14 pm
by León
The question obviously arises, the asteroid is the remnant of a larger body that has been severed or as a result of claims is the collection of material added by gravity. I personally tend towards the first alternative.

Re: APOD: Stereo Itokawa (2010 Jun 19)

Posted: Sat Jun 19, 2010 2:17 pm
by Chris Peterson
León wrote:The question obviously arises, the asteroid is the remnant of a larger body that has been severed or as a result of claims is the collection of material added by gravity. I personally tend towards the first alternative.
There is good evidence strongly suggesting that many asteroids, including this one, are just loose piles of rock and dust. That doesn't exclude it being formed from another body, however. Simulations of asteroidal collisions show that you can end up with one or more rubble piles that simply re-coalesce under self gravity quite quickly after the collision.

Re: APOD: Stereo Itokawa (2010 Jun 19)

Posted: Sat Jun 19, 2010 2:35 pm
by bystander
Even among the colored lense type 3D glasses, there are at least three varieties, red/cyan, amber/blue, and magenta/green. The colors chosen are diametrically opposed on the RGB color wheel.

I'm not sure how the different color combinations affect perception, but it seems to me that it should have some effect. It seems to me the anaglyphs would have to be colored with the appropriate colors for effect to show properly.

Re: APOD: Stereo Itokawa (2010 Jun 19)

Posted: Sat Jun 19, 2010 2:40 pm
by Chris Peterson
hobobill wrote:how about a regular photo so the visually impared that can't see 3D have a better understanding of this space rock?
There's no reason for somebody submitting an anaglyph like this to not also include a stereo pair. I wish that were a condition of even considering these images. The anaglyphys are just too poor quality, with the 3D effect weak and a lot of detail lost. To make this image in the first place required having the individual two frames as separate shots- there's no reason not to offer that presentation.

More than once with an interesting object presented as an anaglyph, I've gone back to the source to get the individual channels, or separated the frames in Photoshop so they could be properly viewed as a stereo pair. Here is the original APOD image just split by color channels. I set up this one for cross-eyed viewing.
Itokawa_split.jpg

Re: APOD: Stereo Itokawa (2010 Jun 19)

Posted: Sat Jun 19, 2010 2:46 pm
by Chris Peterson
bystander wrote:Even among the colored lense type 3D glasses, there are at least three varieties, red/cyan, amber/blue, and magenta/green. The colors chosen are diametrically opposed on the RGB color wheel.
They don't need to be diametrically opposed. You just need a scheme that allows for the channels to be separated by filters. That simply means that you need to isolate the image across the red, green, and blue pixels (phosphor or LCD filters). Red/cyan works because one channel is pure red, and the other is split across green and blue. But red/blue, red/green, green/blue single channel combinations work well, too. Red/blue is more common than red/cyan, and red/green used to be popular. By using red/cyan, three common types of glasses are supported, however.

Re: APOD: Stereo Itokawa (2010 Jun 19)

Posted: Sat Jun 19, 2010 3:20 pm
by neufer
Chris Peterson wrote:
Red/blue is more common than red/cyan,
and red/green used to be popular.
Image

Re: APOD: Stereo Itokawa (2010 Jun 19)

Posted: Sat Jun 19, 2010 4:25 pm
by Beyond
Ok neufer, i see you've been to THAT dimension again. It took me a couple of seconds to get your last post as i've only seen the red/green once a long time ago.

Re: APOD: Stereo Itokawa (2010 Jun 19)

Posted: Sat Jun 19, 2010 8:12 pm
by rstevenson
Chris Peterson wrote:More than once with an interesting object presented as an anaglyph, I've gone back to the source to get the individual channels, or separated the frames in Photoshop so they could be properly viewed as a stereo pair. Here is the original APOD image just split by color channels. I set up this one for cross-eyed viewing.
Unfortunately, cross-eyed viewing often doesn't work when the viewer is wearing reading glasses. I'm not sure why. The best I could manage this time was four overlapping images. I always keep a good pair of red-blue glasses at the ready, so I prefer that sort of stereo image.

I understand that asteroids are often piles of rubble, but in this case I can see what appear to be layers. The left part of the 'roid has them most obviously, and the right part's layers -- less clearly -- may be roughly at a right angle to the left's. It would be odd for accreted rocks to line up so nicely.

Rob

Re: APOD: Stereo Itokawa (2010 Jun 19)

Posted: Sat Jun 19, 2010 8:25 pm
by Beyond
Dag-nab-it, rstevenson - every time you post i start to get hungry :!:

Re: APOD: Stereo Itokawa (2010 Jun 19)

Posted: Sat Jun 19, 2010 9:01 pm
by Chris Peterson
rstevenson wrote:Unfortunately, cross-eyed viewing often doesn't work when the viewer is wearing reading glasses. I'm not sure why. The best I could manage this time was four overlapping images. I always keep a good pair of red-blue glasses at the ready, so I prefer that sort of stereo image.
Sure, I'm not suggesting just one kind of view is best. When I make 3D images, I normally make three: stereo pairs for both cross-eyed and parallel-eyed viewing, and an anaglyph. It's almost no extra work to do all of them, and this accommodates nearly everybody capable of viewing 3D images at all.

Re: APOD: Stereo Itokawa (2010 Jun 19)

Posted: Sat Jun 19, 2010 9:19 pm
by Beyond
Chris -- could you define "cross eyed". If i "cross" my eyes on the picture that was shown for that - I get 3 images. So it must be something other than just crossing your eyes :?:

Re: APOD: Stereo Itokawa (2010 Jun 19)

Posted: Sat Jun 19, 2010 9:27 pm
by Chris Peterson
beyond wrote:Chris -- could you define "cross eyed". If i "cross" my eyes on the picture that was shown for that - I get 3 images. So it must be something other than just crossing your eyes :?:
There are two ways of viewing stereo pairs. Cross-eyed means you cross your eyes so that your right eye is pointing at the left image, and vice versa. You are basically telling your eyes to view something close, but keep their focus distant. Parallel-eyed means your right eye sees the right image, and your left sees the left image. You are positioning your eyes for something very distant, but focusing them closer. It's easier to do than to describe. Either way, it's normal to see three images- just direct your mind towards the center one, which will be stereo.

Re: APOD: Stereo Itokawa (2010 Jun 19)

Posted: Sat Jun 19, 2010 11:47 pm
by Beyond
AH, ok, thanks. i didn't see it mentioned that the middle one would be the one in stereo.

Re: APOD: Stereo Itokawa (2010 Jun 19)

Posted: Sun Jun 20, 2010 2:24 am
by Howie Glatter
Has anyone else noticed the similarity in shape to the native Australian boomerang? Maybe those Aboriginees knew something more about the design of cyclically recurring objects than modern science does.

Re: APOD: Stereo Itokawa (2010 Jun 19)

Posted: Sun Jun 20, 2010 2:46 pm
by hughhyatt
Two or three times, I've sought out online vendors of cheap—like $5 a pair—red/blue viewing glasses, sent money and gotten nothing in return. Can anyone point me to a vendor that will actually send me glasses when I purchase them? Or any national retail chains that sell them?

Thanks!
Hugh

Re: APOD: Stereo Itokawa (2010 Jun 19)

Posted: Sun Jun 20, 2010 3:24 pm
by Prizzeldfitzgerald
Is this Itokawa also known as the "Potatoe Asteroid"?