Sept 6/2005 APOD

Comments and questions about the APOD on the main view screen.
makc
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Sept 6/2005 APOD

Post by makc » Tue Sep 06, 2005 6:55 am

APOD[/url] [url=http://saturn.jpl.nasa.gov/news/press-release-details.cfm?newsID=598]Cassini aug 30 pressrelease wrote:...the moon's southern pole is active. The pole had episodes of geologic activity as recently as 10 years ago. ...When NASA's Voyager 2 spacecraft flew over the moon's north pole in 1981, it did not observe the tiger stripes.
So, did its surface changed since '81, or stripes simply were not visible? Where can I take a look at those '81 photos?

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BMAONE23
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Post by BMAONE23 » Tue Sep 06, 2005 9:29 pm


makc
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Post by makc » Wed Sep 07, 2005 6:41 am

thanks. we have:
Voyager vs Cassini

Image

indeed, they are not there! in composite image above you can see how much did it changed for 20 years. I've marked details that seem to be same on both images.

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orin stepanek
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Post by orin stepanek » Wed Sep 07, 2005 2:01 pm

The icy asteroids might suggest an abundance of water in the solar system. Could the tiger stripes suggest liquid might be present under the frozen surface?
Orin

Odegard
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Post by Odegard » Wed Sep 07, 2005 4:16 pm

Wow, makc, nice work! May I use that picture on my site for a newsitem?

How would you like to be reffered to? I guess we need to put NASA in there somewhere...

-Odegard
Maintainer of the Norwegian mirror

makc
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Post by makc » Wed Sep 07, 2005 5:03 pm

everybody can use it anywhere - nasa images are in public domain. if you really insist, use my e-mail makc.the.great@gmail.com, but you don't have to.

EDIT: now, when I've looked at it 2nd time... so many details do not fit... maybe these "matching" patterns are simply my imagination?

craterchains
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Post by craterchains » Thu Sep 08, 2005 2:51 am

Sorry Makc, I can't see any reference points that match up to be able to check for changes. Over the past three years I have done allot of crater comparisons and searching images for changes on Mars. There are many, but you have to first get a reference point that matches up in both images, like sets of craters, or ridges that are easily identifiable in
both images. then look for changes. Lat. and Long are a big help ,,,,,, when they bother giving those details.

QUOTE
EDIT: now, when I've looked at it 2nd time... so many details do not fit... maybe these "matching" patterns are simply my imagination?

Patterns may be different, but until we have a known view of the same area, we won't know for sure. I am now looking at a bunch of pics trying to find one that shows the same area. None ,,,,,,, yet.

I take it that you can't just transfer posts in this BB? Bummers.
Norval
"It's not what you know, or don't know, but what you know that isn't so that will hurt you." Will Rodgers 1938

crosscountry
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Post by crosscountry » Thu Sep 08, 2005 12:53 pm

craterchains wrote:Sorry Makc, I can't see any reference points that match up to be able to check for changes. Over the past three years I have done allot of crater comparisons and searching images for changes on Mars. There are many, but you have to first get a reference point that matches up in both images, like sets of craters, or ridges that are easily identifiable in
both images. then look for changes. Lat. and Long are a big help ,,,,,, when they bother giving those details.

QUOTE
EDIT: now, when I've looked at it 2nd time... so many details do not fit... maybe these "matching" patterns are simply my imagination?

Patterns may be different, but until we have a known view of the same area, we won't know for sure. I am now looking at a bunch of pics trying to find one that shows the same area. None ,,,,,,, yet.

I take it that you can't just transfer posts in this BB? Bummers.
Norval
maybe they changed too? just a little?

craterchains
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Post by craterchains » Sat Sep 10, 2005 1:01 pm

Crosscountry, "maybe they changed too? just a little?".
Yes, that is a very distinct possibility. But, we still need reference points before we can determine any changes. Scientists seem to have them, but aren't sharing. :?

Makc, I'd say lock the other thread and do your post transfer thingy. :)
Norval
"It's not what you know, or don't know, but what you know that isn't so that will hurt you." Will Rodgers 1938

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BMAONE23
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Post by BMAONE23 » Sat Sep 10, 2005 4:41 pm

The images from the Voyager 2 probe passed over the North Pole of the moon. If you look at the cassini images of the polar regions you will see the crater paterns you are looking for. I do not believe that there are any Voyager images of the south polar region, at least none that I have been able to find.

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BMAONE23
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Post by BMAONE23 » Sat Sep 10, 2005 4:48 pm

in the Voyager image the North Pole sits in the lower right quadrant of the image at the ternimator between day and night. In the Cassini image the South Pole sits in the middle of the "Tiger Stripes"

makc
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Post by makc » Mon Sep 12, 2005 6:25 am

I'm affraid BMAONE is right. Here's what he said in PM (why PM, anyway ?):
It would appear that the older voyager image is of the north polar region.

Look at:
http://www.nasa.gov/mission_pages/cassi ... 07721.html
And compare it to
http://Voyager.jpl.nasa.gov/image/image ... celadx.gif
.

Now,
Makc, I'd say lock the other thread and do your post transfer thingy.
Norval
since this thread (my question) is now resolved, I will lock it instead :wink: