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Mars Space

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."
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Mars Orbiter Photographs another Mars Orbiter

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  • Can someone explain to me why the Odyssey appears twice in the image? I can't for the life of me figure it out, and the explanation they posted really isn't helping.
    • it was just 2 pictures as they flew past each other.
    • Holy shit! How'd that swampgas get to Mars?!
    • I'm guessing it's two separate photos... either that or it's ghosted or something
    • by FireballX301 ( 766274 ) on Friday May 20, 2005 @02:35AM (#12586678) Journal
      The two views of Mars Odyssey in this image were acquired a little under 7.5 seconds apart as Odyssey receded from a close flyby of Mars Global Surveyor. The geometry of the flyby (see Figure 1) and the camera's way of acquiring an image line-by-line resulted in the two views of Odyssey in the same frame. The first view (right) was taken when Odyssey was about 90 kilometers (56 miles) from Global Surveyor and moving more rapidly than Global Surveyor was rotating, as seen from Global Surveyor. A few seconds later, Odyssey was farther away -- about 135 kilometers (84 miles) -- and appeared to be moving more slowly. In this second view of Odyssey (left), the Mars Orbiter Camera's field-of-view overtook Odyssey.

      Its the same frame exposed twice. Think about what happens when you take a picture, but set the exposure time too long.
      • Well, not quite. From TFA:

        The geometry of the flyby and the camera's way of acquiring an image line-by-line resulted in the two views of Odyssey in the same frame.

        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

      • by Alsee ( 515537 ) on Friday May 20, 2005 @01:27PM (#12592172) Homepage
        Its the same frame exposed twice.

        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.

        -
    • by JWSmythe ( 446288 ) * <jwsmythe&jwsmythe,com> on Friday May 20, 2005 @02:35AM (#12586680) Homepage Journal

      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. :)
      • by fireman sam ( 662213 ) on Friday May 20, 2005 @02:39AM (#12586697) Homepage Journal
        "Now, it's a piece of cake in Photoshop."

        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.

      • From the description, one of the images should be the mirror image of the other - one is from a forward scan, and one is from a backwards scan. Someone pointed this out to me.

        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.
        • Are you sure one should have been inverted? I didn't consider spin or anything, but if it was just passing from left to right, the position should have remained the same.

          • But it wasn't passing from left to right. According to the article, the camera started off ahead of the Odyssey, which then overtook it and was scanned from front to rear. Next, the camera catches up with the craft, which would cause it to be scanned in the opposite direction - from rear to front. So the two images should be mirrored.

            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
            • I'd bet your email has been filed in the "conspiracy nut says our pictures are fake" file.

              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
      • No, not pictures of another spacecraft, but the Viking lander team testing the (scanning) camera system had it take a group shot of the team out in the desert. As the camera scanned past individual team members, they'd run around and join the group from the other end. Several people show up in that picture two and three times.
    • by vistic ( 556838 ) on Friday May 20, 2005 @02:42AM (#12586711)
      Ok so the explanation [nasa.gov] is pretty clear to most everyone... if you believe that propaganda!!!

      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.
    • Do the math (Score:3, Informative)

      by Bazman ( 4849 )

      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
      • 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).

        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
    • The picture they posted here
      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.
    • Obviously Mars Odyssey was using the Picard maneuver. [ccdump.org]
    • OH MY GOD! THERE MUST BE TWO OF THEM!

      And who put those letters up there! Martians not only speak english, they use metric measurements!

      Oh, wait, it's just two pictures.
    • Put your hand on the left side of a photocopier pane. Press copy. After it scans your hand once, move your hand to the right side of the pane and it will scan your hand again.

      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.

  • Some Camera (Score:4, Interesting)

    by wakejagr ( 781977 ) on Friday May 20, 2005 @02:30AM (#12586657) Journal
    The Mars Orbiter Camera can resolve features on the surface of Mars as small as a few meters or yards across from Mars Global Surveyor's orbital altitude of 350 to 405 kilometers (217 to 252 miles). From a distance of 100 kilometers (62 miles), the camera would be able to resolve features substantially smaller than 1 meter or yard across.

    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?

    • I'd assume it's a focus problem. It's probably set up to focus at the surface, not at an object at that distance. They can probably change the focus, but it probably wasn't worth it.

      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!" :)
    • by apache guevara ( 776292 ) on Friday May 20, 2005 @02:59AM (#12586754)
      It is a simple question of dispersion in the atmosphere. Take telescopes for instance ...Ground-based telescopes can seldom provide resolution better than 1.0 arc-seconds while the Hubble's resolution is about 10 times better, or 0.1 arc-seconds. Not just because its a good camera but because it is up where it doesnt have to deal with the atmosphere.

      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.
  • by Anonymous Coward
    They're one happy family, going on trips to exotic places and taking pictures of each other!
  • by __aaclcg7560 ( 824291 ) on Friday May 20, 2005 @02:34AM (#12586675)
    I guess that would a be near miss... no, a near hit... wait a minute... it's a near miss...
  • by Anonymous Coward on Friday May 20, 2005 @02:35AM (#12586679)
    This is the first instance of one extraterrestrial satellite photographing another
    No, I'm fairly sure that Oprah took a photo of Star Jones at one point.
    • This is the first instance of one extraterrestrial satellite photographing another

      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.

    • >>This is the first instance of one extraterrestrial >>satellite photographing another
      >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)

    by Anonymous Coward on Friday May 20, 2005 @02:40AM (#12586700)
    I think I can see the Virgin Mary in that blury photo. The scientologists are right, it really is true that we came from another planet!
    • I think I can see the Virgin Mary in that blury photo.

      Really? I thought it was Bill Clinton with his pants down. That guy gets around now that his wife is stuck in the Senate.
      • Wow, a Bill Clinton joke. Talk about your topical humor. Got any Nixon knock knock jokes or Spiro Agnew riddles to really keep up with the times? :P
        • Three Texas surgeons were playing golf together and bragging about surgeries they had performed.

          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
        • Got any Nixon knock knock jokes or Spiro Agnew riddles to really keep up with the times?

          Try this one [slashdot.org] out. ;)
    • I'm content with the idea that the Scientologists came from another planet, but the rest of us evolved here.
  • Voyager (Score:5, Interesting)

    by apache guevara ( 776292 ) on Friday May 20, 2005 @02:43AM (#12586713)
    This is infact tougher than it seems. Both satellites are on a polar orbit and at different speeds. And the camera on the MGS rotates as it takes pictures over this. Pretty awesome for the sheer mathematical probabilites involved

    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!!
    • 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

  • by datafr0g ( 831498 ) <datafrog AT gmail DOT com> on Friday May 20, 2005 @02:44AM (#12586716) Homepage
    ...when NASA employees with a warped sense of humour get their hands on a copy of Photoshop
  • Sweet! (Score:3, Interesting)

    by Ariane 6 ( 248505 ) on Friday May 20, 2005 @02:48AM (#12586726)
    It's amazing what they've been able to get MOC to do...I can't wait to see what HiRiSe can accomplish! I'll be working with Mars Odyssey imagery in grad school next year and this image will make a fine addition to my cubicle.
  • by .orvp ( 208389 ) on Friday May 20, 2005 @03:41AM (#12586852)
    If you RTFA, you will see it mentioned that this picture and one other picture taken by the Mars Global Surveyor were the first, not that this particular photo was the first. The European Space Agency's Mars Express was the first extraterrestrial satellite [nasa.gov] imaged in this method. The Mars Express was imaged April 20, 2005, and it seems Mars Odyssey was imaged this month (can't see a date, I've looked several places).
  • First time? (Score:4, Interesting)

    by Groote Ka ( 574299 ) on Friday May 20, 2005 @03:56AM (#12586891)
    What about the Apollo 12 crew that managed to land the eagle at walking distance from the Surveyor II probe?

    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)

      by Saggi ( 462624 )
      In a sense you are right, but there is a more obvious case. When the lander seperated from the command module during landing, they both filmed the other ship. Here it is not even on the ground but in mid space fligt.
      • Yes but since the moon is in orbit around the Earth and they where in orbit around the moon you could argue that they was not extraterrestrial space craft. It all comes down to what hairs you want to split.
        But first of not it is still pretty cool

    • Re:First time? (Score:2, Interesting)

      by Jivecat ( 836356 )
      Surveyor III, not II. Surveyor II never reached the moon: a vernier engine failure during a midcourse correction manoeuvre caused it to tumble.
    • Re:First time? (Score:4, Informative)

      by blueturffan ( 867705 ) on Friday May 20, 2005 @09:51AM (#12589309)
      "The Apollo 12 crew that managed to land the eagle"

      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!)

  • This is the first instance of one extraterrestrial satellite photographing another

    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)

      by erlando ( 88533 ) on Friday May 20, 2005 @04:21AM (#12586952) Homepage
      I think they are defining "extraterrestrial" as "not orbiting Earth". As opposed to a terrestrial satellite orbiting Earth.

      But hey.. What do I know..?

    • The lunar command module and landers photographed and filmed each other on all six successful Apollo missions to the moon. Also, Apollo 8 (which didn't land), filmed a rendezous with a lander as it took place around the moon.
      The article uses the wording, not "extraterrestrial", but "while orbitting another planet..."
      The article is correct, article poster is wrong.
  • by AndroidCat ( 229562 ) on Friday May 20, 2005 @06:43AM (#12587505) Homepage
    Later that day, Mars Odyssey filed a restraining order against Mars Global Surveyor with claims of stalking.
  • by PeeAitchPee ( 712652 ) on Friday May 20, 2005 @07:22AM (#12587751)

    ~ 135 km range: *-x

    ~ 90 km range: o--X

    :-D

  • by TripMaster Monkey ( 862126 ) * on Friday May 20, 2005 @08:02AM (#12588118)


    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.

  • by KlomDark ( 6370 ) on Friday May 20, 2005 @08:11AM (#12588189) Homepage Journal
    That's a couple of the vipers launched from Battlestar Galactica. They think they've finally found Earth, and are quite confused as to why they've renamed it Barsoom. The damn cleric in the Tombs of Kobol was a bit drunk when he made the map to Earth.
  • by 1800maxim ( 702377 ) on Friday May 20, 2005 @08:17AM (#12588260)
    I mean, we really are in stone age. That could be anything. That could be a blob, it could be a light bulb exploding in a dark room. I need concrete evidence that that was what NASA claims it was.

    If I saw something like this
    http://wso.williams.edu/~rfoxwell/starwars/pics/De vastator2.jpg [williams.edu]

    there would be no doubts in my mind.

    But NASA? Pffffft.
  • Photo of Huygens probe from Cassini [nasa.gov]

    Cassini did this just last year... I can't believe NASA forgot already ;)

  • Does this remind anyone of this bit from the Simspsons?
  • This is the first instance of one extraterrestrial satellite photographing another.

    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.

  • by WormholeFiend ( 674934 ) on Friday May 20, 2005 @08:50AM (#12588649)
    Google Map shows a snapshoot of... swamp gas? Weather balloon? UFO? [google.com]
  • "Crackpot Photographs Truman Again."

  • That's a space station..

  • No, this is the first reported instance. Reported in public, on Earth, at least.
  • http://www.msss.com/mars_images/moc/2005/01/24/ind ex.html [msss.com]

    Here's a cool picture of the Opportunity rover as imaged from orbit.

    Like many geeks, I love this space exploration stuff!
  • by i41Overlord ( 829913 ) on Friday May 20, 2005 @12:58PM (#12591815)
    Seriously, what is it with Slashdot and this common grammatical error? It seems as if the majority of people on this site use the wrong form of verbs when referring to a company or organization.

    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.
  • More details are available for Malin Space Science Systems [msss.com]. Additional photos, diagrams, and the like. Including an image of the Mars Express orbiter.

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