APOD 2005-02-28

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Expand view Topic review: APOD 2005-02-28

by makc » Wed Mar 02, 2005 7:52 am

dawnk wrote:...[original] photo is not like the image posted in Makc's reply... The two large craters are in the upper right and they look like domes (1). I downloaded the image from ESA, dumped it into Photoshop, and flipped the image horizontally, and came up with the image Makc posted (2).
(1) First of all, things look like something as long as somebody (in this case - you) looks at them; the image itself is absolutely flat - it has no neither craters nor domes on it - it is all just about light pixels and dark pixels... which brings me to (2) - I made exactly same thing.

You may check this and this out of interest.

by dawnk » Tue Mar 01, 2005 4:14 pm

On second thought:
I went to the ESA website, where this photo originally came from. It is at http://www.esa.int/SPECIALS/Mars_Expres ... M4E_0.html
and this photo is not like the image posted in Makc's reply. It is like the one that I have asked my original question about. The two large craters are in the upper right and they look like domes. I downloaded the image from ESA, dumped it into Photoshop, and flipped the image horizontally, and came up with the image Makc posted. But the credits on the bottom are also flipped and read backwards. So, Makc, could you re-post your photo with the credits intact? Your image makes more sense, but it's not the same as the image on the ESA website.

by dawnk » Tue Mar 01, 2005 2:43 pm

Makc, thank you for posting that image. The one I was confused about is inverted! I checked the original image out in the APOD archives, and it's coming up on my screen as inverted, so that's where the problem lies.

What are you seeing

by Boldra » Tue Mar 01, 2005 11:16 am

I've looked at this pic again since you mentioned it, but I don't see what you're seeing.

Firstly, the light source is coming from the right, not the left.

Secondly, I only see two craters (large) and not three as you said.

Thirdly, what "two objects in the upper right"?

Perhaps you could load the image in a paint program and mark the features you're talking about. I get the feeling we're looking at two different pictures.

I see two big craters (with sort of mushy/splattered-edges, very interesting!) a mountain on the right (which seems to have influenced the flow of water coming from the right) and a dark feature in the bottom left.

BTW, Please don't post a full size image in your reply.

Boldra

by makc » Tue Mar 01, 2005 8:11 am

EDITED: Since the problem resolved... Converting image to LINK

APOD 2005-02-28

by dawnk » Mon Feb 28, 2005 10:48 pm

The picture on 02-28 APOD site shows what might be frozen water plates covered by dust, but there are two features I am curious about. The light source is coming from the left; there is illumination on the left side of the plates, and shadows on the right. The three small craters have shadows on the left and highlights on the right, consistent with a depression, but the two objects in the upper right have illumination on the left, and shadows on the right, which suggests they are domes. The illumination immediately to the right of the domes could be the edge of an old crater, but what would make the ground within the crater to bulge up above the level plane of the surface? It reminds me of the new dome forming on Mt. St. Helens. Would water filling the craters create a dome?

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