Mars Orbiter Photographs another Mars Orbiter 187
rde writes "We're all familiar with blurry photographs of UFOs, but NASA have gone one better; the Mars Global Surveyor has photographed fellow satellite Mars Odyssey as it whizzed past. This is the first instance of one extraterrestrial satellite photographing another."
Look, Ma, there are two of them! (Score:1, Interesting)
Re:Look, Ma, there are two of them! (Score:1)
Re:Look, Ma, there are two of them! (Score:3, Funny)
Re:Look, Ma, there are two of them! (Score:5, Funny)
Re:Look, Ma, there are two of them! (Score:1)
Re:Look, Ma, there are two of them! (Score:5, Informative)
Its the same frame exposed twice. Think about what happens when you take a picture, but set the exposure time too long.
Re:Look, Ma, there are two of them! (Score:2)
The closest analog for this is actually the way digital cameras (and film cameras, with less help) allow you to take panoramic shots on a regular sized frame sensor/film stock and then stitch the images together. In this case the rate of movement of the camera and satellite caused the satellite to jump from one part of the frame to a part o
Re:Look, Ma, there are two of them! (Score:4, Informative)
Score:5, Informative?? Score:-1, Factually Incorrect.
It is a single exposure, but the frame is sweep-scanned. The closest analogy I can think of is the way a fax machine sweepscans a page one line at a time. It's like scanning a fax and half way through you reverse direction of the rollers pulling in the paper. It would sweep-scan the same half of the page on the way out. The printed fax would be a single exposure, but the two halves would have the same thing twice.
A simpler (but really rotten) analogy would be a photo with a mirror across half a room. It's a single exposure, but everything appears twice.
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Re:Look, Ma, there are two of them! (Score:5, Informative)
They read their imaging array one line at a time. It saw the Odyssey once, which is the image you see on the left (I think). It continued to move, and then caught it again on the right. For the complete logistics of how it happened, we'd have to know more about their imaging array, and the relative speeds. Ya, I'd think there should be a blur in there somewhere, but aparently there isn't.
Think of a flat top copy machine. With the top open, put your hand at the left (if it scans from that side). After it passes your hand, put it on the right side. It'll see your hand again.
When I was in middle school, we took at trip to Washington DC. They did a panoramic picture of the class. The photographer had the girl on the left side of the picture move, as soon as she was out of the shot, and run around to the right side. She showed up twice, like twins. It was easier than editing her in later, or at least then it was. Now, it's a piece of cake in Photoshop.
Re:Look, Ma, there are two of them! (Score:5, Funny)
So you used Photoshop to replace the second instance of the girl with a piece of cake. But that wouldn't look like there were twins.
Re:Look, Ma, there are two of them! (Score:2)
It isn't inverted, though (Score:2)
I suspect that they used some sort of filter on their raw data, to correct for distortions, and also to correct for the inversion effect.
Re:It isn't inverted, though (Score:2)
Re:It isn't inverted, though (Score:2)
A possible explanation was that Odyssey was in fact scanned 3 times, and that they've cropped out the middle time. However, the article doesn't say that.
I've sent off an emai
Re:It isn't inverted, though (Score:2)
I'm sure you're familiar with the file. It's commonly marked "Trash"..
If you're right, and you think it should have been 3 times to get the right alignment, then maybe you are 100% correct. Maybe the second time around, it wasn't quite in the frame.
I have my own theories on fake pictures with NASA, but under my ideas, this one would be real.
My thoughts on 'em are that, any really pretty, clear, c
Viking lander did it too (Score:2)
Re:Look, Ma, there are two of them! (Score:2)
Re:Look, Ma, there are two of them! (Score:5, Funny)
Clearly the larger so-called "satellite" is a Romulan Bird of Brey that has come to hunt down the Odyssey satellite before it either A) discovers the Romulans cloaked mission control base for Earth domination (by crashing into it) or B) becomes sentient like "V---ger" did.
Re:Look, Ma, there are two of them! (Score:2)
Do the math (Score:3, Informative)
If you do the math its because for certain values of the exact geometry there are multiple solutions in the range [0,pi] for t in the equation k.t+phi = tan(v.t) (where k is the rotational rate of the camera, v is the velocity of the flyby probe, phi is the angle of the camera to the probe at time t=0).
Obviously there are other solutions as the camera rotates round again, and I've assumed the camera is static and the probe is in a constant speed linear path.
The above maths is pretty simple, every graduate
Re:Do the math (Score:2)
Gotta love Slashdot, where that actually *is* an Informative explanation.
I wrote a post before explaining it like the way a fax machine scans one line at a time, and reversing the paper direction half way through. Bah, I mig
Re:Look, Ma, there are two of them! (Score:2, Informative)
http://photojournal.jpl.nasa.gov/figures/PIA07941_ fig1.jpg [nasa.gov]
does help a bit- the camera is rotating and because it builds up the image over time it sees (the relatively near by) object twice.
I guess when imaging the surface they have to rotate the orbiter/camera to account fo the fact the orbiter is moving relative to the planet surface faster than they can take the picture.
Re:Look, Ma, there are two of them! (Score:2, Funny)
Re:Look, Ma, there are two of them! (Score:2)
Re:Look, Ma, there are two of them! (Score:2)
And who put those letters up there! Martians not only speak english, they use metric measurements!
Oh, wait, it's just two pictures.
Re:Look, Ma, there are two of them! (Score:2)
The speed and direction of the copier's scanning head and the speed and direction of your hand can vary greatly and cause all sorts of combinations and duplicates of the same hand all in one finished product image.
Re:RTFA... - Re:Look, Ma, there are two of them! (Score:2, Informative)
Except of course its not like TV at all which scans in horizontal lines.
The picture was scanned from the right hand side in vertical strips. As the picture is being scanned, the viewed Mars Odyssey is moving from right to left. The camera is also rotating from right to left.
Picture a car on the opposite side of the road moving in opposite direction flying by the side window of your car as
Re:RTFA... - Re:Look, Ma, there are two of them! (Score:2)
Some Camera (Score:4, Interesting)
My understanding of optics isn't too good. Isn't this the kind of thing where you trade amazing resolution for something else? Does this camera require massive amounts of light? Would it work when photographing something not directly reflecing the light of the sun, such as on the night side of Mars?
Re:Some Camera (Score:2)
I'm thinking someone did this for fun. I would have.
"Hey Bob, spin the satellite around, I wanna see if we can catch a picture of the other one! Look! It worked!"
Not just good optics! (Score:5, Informative)
And the cameras on the MGS do not rely on a good lens as much as they do rely on the electronics. It uses a linear array CCD which will scan the night sky one line at a time (much like a CRT actually). And it is not limited to the visible region of the spectrum. UV and near infrared have way too much information to give than just an optical picture.
Most the pics released finally are almost always digitally enhanced and represented in the visible region of the spectrum. The kids these days will not be fired up about astronomy if all they see is an output of wavelets in an array.
Re:Some Camera (Score:2)
The Mars Orbiters (Score:2, Funny)
Call the FTA...! (Score:3, Funny)
Re:Call the FTA...! (Score:5, Funny)
"They always say it was a near miss, well I say fuck them. There is no such thing as a near miss, its a near hit. A near miss is when they hit; and you say, 'Oh look, they nearly missed'. "
Not the first instance (Score:4, Funny)
Re:Not the first instance (Score:2)
ok, Cassini took a picture of huygens back in December when both were satellites of Saturn. And before that Mars Express took a picture of Beagle 2 when both were satellites of the Sun.
Re:Not the first instance (Score:2)
>No, I'm fairly sure that Oprah took a photo of Star Jones at one point
He said "satellite" - not "parasite".
Brett
Cool... (Score:4, Funny)
Re:Cool... (Score:2)
Really? I thought it was Bill Clinton with his pants down. That guy gets around now that his wife is stuck in the Senate.
Re:Cool... (Score:2)
Best GWB Joke, Ever. (Score:2)
One of them said, "Hellyeah, I'm the best surgeon in Texas. A concert pianist lost 7 fingers in an accident, I reattached them, and 8 months later
he performed a private concert for the Queen of England."
One of the others said. "Y'all, that's nothing. A young man lost both arms and legs in an accident, I reattached them, and 2 years later he won a
gold medal in field events in the Olympics."
The third surgeon sai
Re:Cool... (Score:2)
Try this one [slashdot.org] out.
Re:Cool... (Score:2)
Voyager (Score:5, Interesting)
For sheer probabilites, imagine the Voyager out there in the beyond. It would be nothing short of a miracle to be spotted by a satellite from another planet.
Unless of course it bumps into the dear old gluttonous friend of ours from Trall!!
Re:Voyager (Score:2)
Pretty awesome for the sheer mathematical probabilites involved
Satellite visiblity calculations are pretty simple. Let the position of MGS be a vector a in Mars centric coordinates. Let the position of Mars Odyssey be a vector b. b - a is the desired camera direction. Not such a big deal. To take the picture all you require is that this vector does not intersect the Martian surface. That is probably a little rare for low orbiting satellites. Since the positions versus time of both satellites are known
This is what happens.... (Score:3, Funny)
Sweet! (Score:3, Interesting)
Mars Express was photographed first (Score:5, Informative)
Re:Mars Express was photographed first (Score:2)
First time? (Score:4, Interesting)
OK, a purist may say that the moon lander does not qualify as a satellite, but I beg to differ here.
Re:First time? (Score:3, Informative)
Re:First time? (Score:2)
But first of not it is still pretty cool
Re:First time? (Score:2, Interesting)
Re:First time? (Score:4, Informative)
It was the Apollo 11 crew (Armstrong/Aldrin) that managed to land the Eagle with less than a minute of fuel remaining.
The Apollo 12 LEM was called Intrepid. It was quite a feat that Conrad & Bean set it down so close to the Surveyor probe. (Not to mention the amazing job done by the mission planners to place them so close to the target!)
Re:First time? (Score:3, Insightful)
Compare it to these three settings:
Re:First time? (Score:2)
I think it's more like capturing a picture of a baseball, while riding a baseball in a different direction and telling the guy riding the first baseball to wave and capturing that wave.
Redundant? (Score:2)
Aren't all satellites extraterrestrial? Do we have any *intra*terrestrial or *inter*terrestrial satellites? I guess, if they crash to earth, but then, after that, I guess they're not Satellites any more.
Solomon
Re:Redundant? (Score:5, Informative)
But hey.. What do I know..?
Not the first (Score:2)
The article uses the wording, not "extraterrestrial", but "while orbitting another planet..."
The article is correct, article poster is wrong.
Re:Not the first (Score:2)
Re:Not the first (Score:2)
Darn Probe-arazzi! (Score:5, Funny)
Mirror in case of slashdotting . . . (Score:5, Funny)
~ 135 km range: *-x
~ 90 km range: o--X
:-D
Re:Mirror in case of slashdotting . . . (Score:2)
~ 90 km range: o--X
Good God, where did that giant Martian emoticon come from?!!! We're dooooooooommmmmed!!!!
Re:Mirror in case of slashdotting . . . (Score:2)
It's the cydonian mars face, DOH!
Just like Americans. (Score:5, Funny)
Amazing...we send probes all the way to Mars to they can photograph...each other.
Kinda like when Americans visit other countries...all they want to do is talk to other/i> Americans.
Re:Just like Americans. (Score:2)
Colonial Vipers (Score:4, Funny)
NASA needs to improve quality of their pictures (Score:3, Funny)
If I saw something like this
http://wso.williams.edu/~rfoxwell/starwars/pics/D
there would be no doubts in my mind.
But NASA? Pffffft.
NOT the first -Cassini did it with Huygens already (Score:2)
Cassini did this just last year... I can't believe NASA forgot already ;)
"I...have...a...H.A.M...Radio" (Score:2)
Blinked (Score:2)
Oh no! Mars Odyssey blinked!
Well, back it up and take another picture. Make sure the "red eye" setting is on too.
Say, "Fuzzy Pickle", Mars Odyssey.
meanwhile back on EArth (Score:3, Interesting)
Here is the photo (Score:2)
After looking at the photos here is what I thought (Score:2)
That's no moon... (Score:2)
Daily Planet (Score:2)
A little off topic: Opportunity Rover (Score:2)
Here's a cool picture of the Opportunity rover as imaged from orbit.
Like many geeks, I love this space exploration stuff!
NASA "has", not NASA "have". (Score:3)
My take on it is that they're trying to sound proper, but they aren't really that familiar with the proper rules of grammar.
When referring to the company or organization as an entity, it is a singular noun. Rarely will it be a plural noun. I see this incorrect usage in nearly every thread. Simply looking at the company's webpage and seeing how they refer to themself would give you a pretty good idea of the proper usage.
In NASA's case:
http://www.nasa.gov/about/highlights/index.html [nasa.gov]
NASA is, NASA has, etc. Singular.
Very interesting. (Score:2)
More details (Score:2)
Re:Hmmm...wonder what you could do with (Score:2)
Re:That's just not right! Where's the mirror image (Score:2)
And I believe the handheld scanner would not create a mirror image either since it'd sense it's going 'backwards' and arrange the scanlines accordingly. I am slightly ashamed to admit I never tried that while I had one though so it's possible no one ever implemented that 'feature'.
Re:That's just not right! Where's the mirror image (Score:2, Interesting)
Think of the picture a graph, the vertical axis being in space and the the horizontal being in time. The camera is spinning, so the bit of space it's looking at is moving, but the thing it's photograping is moving too. As the diagram on the NASA site explains, the object first overtakes the spinning camera, then as it moves further away and it's apparent speed slows, the camera overtakes i
Re:That's just not right! Where's the mirror image (Score:3, Insightful)
Re:That's just not right! Where's the mirror image (Score:3, Interesting)
Find the MD-80 taking off (runway 8R). Keep scrolling right, and you'll see the same airplane every 3/4 mile or so.
Re:That's just not right! Where's the mirror image (Score:2)
I count 5 copies of the plane.
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Re:That's just not right! Where's the mirror image (Score:2)
Re:It's another NASA coverup of life on Mars!!! (Score:4, Funny)
Hang on... the Martians are intelligent, and yet they're watching our TV?
Re:It's another NASA coverup of life on Mars!!! (Score:2)
Of course. Why else do you think they are HIDING from us?
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Re:keeping it in the news (Score:2)
You'd see it better if you took your head out of your ass.
It's meaningful because it's a dramatic demonstration of precision control in the imaging systems, and an impressive show that what we know about the orbital mechanics involved is spot on.
I guess that funding for them flows though the press
If it wasn't picked up in places like this, and by the press, then the only way that the tangible progress and twists and turns of t
Enough with the stature contest (Score:2)
In general I'm with you on that reponse. The parent was just being cynical. I'd go as far as the head up the *ss.
But the whole "is it NASA or the Europeans?" jealously thing seems completely one-sided to me. The parochial defensiveness is all coming from the US side of that fence. Where are all the Europeans gloating when something from NASA cracks up? I've never seen anything close to what happen
Re:Enough with the stature contest (Score:2)
Honestly, I only mention that because I can't otherwise understand the snide tone from the
Re:Enough with the stature contest (Score:2)
Re:keeping it in the news (Score:2)
Oh really, you must be a master debater?
Well, for what I've read, this was not the first close encounter by these two crafts. It was the first time this was captured on the camera. I'm not completely sure if they did this shot on purpose or not (the black
Re:keeping it in the news (Score:2)
Re:keeping it in the news (Score:2)
Well yes, it is. Kinda balances the jubilant euphoria about two vague dots in a black picture.
As for your prejudice against europeans or me: I don't care, please try to stay on topic.
Re:keeping it in the news (Score:2)
Well, I would be herding my cattle, but the Indians took them all when I ran out of ammo. I've switched over to German hunting dogs now, though they make terrible dairy products (the dogs, not the Germans).
Actually, I'll bet that many people in Europe would be surprised just how many gun-owning, horse-riding country-fo
Re:Mars history (Score:2, Interesting)