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Mars Orbiter Photographs another Mars Orbiter
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."
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.
Serious? Seriousness is well above my pay grade.
"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.
it is only after a long journey that you know the strength of the horse.
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!!
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.
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 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).
My other sig is just as lame
Obligatory Carlin quote:
"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'. "
Frylock: "We should have cloned twenties, Jackson wouldn't have given a fuck."
Later that day, Mars Odyssey filed a restraining order against Mars Global Surveyor with claims of stalking.
One line blog. I hear that they're called Twitters now.