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Posted by: Decepticon Jan 21 2006, 08:05 PM

I found it odd that most astronomy books that I read never mentioned that they where imaged.
Here are some images from the book.
http://history.nasa.gov/SP-349/ch6.htm (Figure 6-5)

1. What hemispheres where imaged by the Pioneer's?

2. Has anyone used current moons maps to create what Pioneer could of imaged if it had better imaging capabilities?

3. If Pioneer 11 imaged IO what area could have been seen? (I understand Pioneer experience radiation exposure and caused a failed imaging attempted?)

4. Any why does Ganymede look so odd in the above link?(Figure 6-5)

Posted by: PhilCo126 Jan 21 2006, 08:16 PM

Well, Pioneer 10 was surely battered by the radiation at Jupiter
I suppose those photos of the Jovian moons are the 'corrected' versions, as the raw Pioneer images were heavily distorted and computer programs were used to clear out those images..
I don't know if Io was imaged by Pioneer

Posted by: JRehling Jan 21 2006, 08:27 PM

This display seriously oversamples the data, which was not obtained with a ccd grid, but rather sampled from a rotating pushbroom. Some combination of pointing error or mapping of the camera output causes a wavy distortion. Also, I think the imaging system may have been optimized for the bright cloudtops of Jupiter, making Ganymede a bit dark as a target. That said, if you downsample this image to about 1/7 or so the size in which it is presented, it shows us the image for what it is worth: Ganymede at about 150 to 200 km/pixel, and as such, there's nothing else odd about it. It's impressive that the text presented a valid interpretation of the polar frosts given such limited data. Incidentally, this is about the resolution now achieved by HST.

Posted by: JRehling Jan 21 2006, 08:29 PM

Pioneer 11's image of Io is here:

http://www.solarviews.com/cap/jup/pio.htm

Posted by: ljk4-1 Jan 21 2006, 09:19 PM

Here are the "best" photos taken by the Pioneers of the Galilean moons.

http://history.nasa.gov/SP-349/p180.htm

In Murmurs of Earth (1978), Carl Sagan speculated that Io may be covered in salts, as it did not display an ice signature like the other moons. One of the main Voyager team scientists also said just before the Voyager 1 flyby in 1979 that they hoped and assumed that Io would be the "Rosetta Stone" for understanding the Jovian system. They were rather surprised and disappointed at first when they didn't see any obvious craters. Then they got another surprise.

I can remember when the showed the images of Ganymede from Pioneer 10 in Sky & Telescope in 1974 and trying my darndest to discern anything recognizable from the images.

Posted by: tasp Jan 21 2006, 09:44 PM

IIRC, Pioneer made what would have been a nice 25,000 km flyby of Amalthea, if only it had a Voyager camera.

{yeah, don't remind me what Galileo did, arg!}

Posted by: tedstryk Jan 21 2006, 11:48 PM

Here are some attempts I made to improve Pioneer images of the Galileans and Titan a while back.



Also, here is a version of the Io image from the original digital data (the only one of the satellite images for which, to my knowlege, a full digital set still exists).

Posted by: Decepticon Jan 22 2006, 07:39 AM

Aggravating ehh!?

tedstryk Wonderful work. When my son is old enough this sample you posted will be used to show him.

I want my son to experience everything I did. And so far The Moon and Stars do have his attention at night!

This thread has great links and pics, Thanks everyone!

Posted by: Tayfun Öner Jan 22 2006, 05:33 PM

Here is a scan of the best print I have ever seen of the Galilean satellites from Pioneer, from Nasa SP-439 Voyage to Jupiter. I have B&W copy of another picture of Callisto which is nearly as good as the above image showing a larger portion of the disk. I will post, if I can find it.

Posted by: Decepticon Jan 22 2006, 06:57 PM

WOW Great stuff! ^^^

Looking forward to Callisto!

Posted by: Tayfun Öner Feb 5 2006, 11:43 AM

Here is the Callisto image I promised. I know it doesn't look great but this is an image not seen very often.