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."

Comments

Re:Look, Ma, there are two of them!

[krusadr]

Its the same frame exposed twice. Think about what happens when you take a picture, but set the exposure time too long.

Yeah you get blur.

Re:That's just not right! Where's the mirror image

[richie2000]

Ah, I see what you're saying. But it can't be so, because that would cause both images to be total blurs. Each image of the Odyssey must be within a single scanline of the camera. Actually, come to think of it, the camera probably takes an instant shot of a vertical strip, waits until the craft has rotated and then takes another strip. It doesn't scan like a scanner at all, it just wouldn't work, methinks.

Re:First time?

[cnettel]

And the difference is quite important. It's (relatively) easy to get a synchronization to the orbit of the celestial body that's controlling you with its gravitational pull. It's harder to pinpoint the position of another object, also spinning around the same celestial body.

Compare it to these three settings:

• Just capturing a picture of a baseball, lying on the ground.
• Capturing a picture of the same ball, while in flight.
• Capturing a picture of the same ball, while you yourself is going in a comparably sized object in a different direction.

• It's important that it is a satellite. That makes it more impressive than localizing ground structures with known positions... unless those structures are very small, like the polar lander. Then, it's also kind of impressive, but for mostly different reasons.