Tom - Mars Reconnaissance Orbiter question

Both. Actually, everything more than a few hundred meters from the camera will be in focus.

Increasing the magnification of a thing you are looking at is the functional equivalent of looking at it from a smaller distance. (But without the loss of depth-of-field that would come with the smaller distance.)

LB

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Larry Burford</i>
<br />Here is my take on an answer to your question.



In such a situation the best you could do is observe the object from a distance that shows it as if it were a small number of merged dots. Much like your example feature that can be seen from 50 km altitude, but not more and not less.

I sure hope we don't find ourselves in such a situation ...

LB
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Yes, I think you're seeing the point I'm trying to make. The concept of seeing these things from a particular distance, and only from that particular distance and resolution.

In this case higher resolution is not going to help. Unless the camera attempts to mimic this distance and resolution in some way.

rd

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by rderosa</i>
<br />In other words, increasing the resolution makes it harder to see the original intent of the artists, not easier. Can you see any possibility of that at all?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">Sure, easily. The "artistic imagery" seen on Mars already has plenty of resolution in the sense you describe. Seeing the Cydonia Face at higher spatial resolution would indeed be like looking at the Mona Lisa under a microscope.

With MRO's "higher resolution", we have at least two different goals. The first is that we may see further direct evidence of the activity of builders. Among the possibilities I can readily imagine: We might find vehicles used to transport materials used in the construction, or doors or windows into the interior, or some kind of completely unexpected artifacts. For the Face, we might see flow lines in the "melt flow" feature of the east side, or further evidence that it emanated from the crater SE of the mouth. At one time, an image appeared to show markings along the under-edge of the west eyebrow, but that apparently was just a "trick of light and shadow". Other evidence that the mesa is made entirely of non-natural materials may also present itself.

The second goal is better resolution <i>in the contrast</i>, rather than better spatial resolution. This should enable us to see plainly whether we are picking illusions from a noisy background, versus a well-formed image that was clearly designed by intelligences. It may also tell us (through sharp albedo changes) if distinctive colors occur on distinctive parts of the images, which would be further evidence of intelligent design. (Now isn't that an ironic use of that phrase?)

On Earth, in the numerous places where we see faces or illusions in landscapes or clouds, they are either profiles or formed by shadows or other contrast features. What is common to all of them is that the illusions go away with different viewing or lighting angles. MRO may show some of that happening too.

We can already see in the test image how superior this camera is over the previous one on MGS. At this stage, we can only imagine what it may show us. But whenever we have a visual mystery, we always struggle to see it as clearly as possible to pick out all available clues. -|Tom|-

The size of the lens relative to the size of the object you are imaging can come into the mix. I think this is why microscopes have a fairly short depth of field, even though the lens is very far away in a "scale" sense, compared to the size of things typically viewed with a microscope. It gets back to the issue of whether or not the light rays entering the lens are parallel. I'm pretty sure it's not something we need to worry about here, though.

LB

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by tvanflandern</i>

With MRO's "higher resolution", we have at least two different goals. The first is that we may see further direct evidence of the activity of builders.
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Agreed, two entirely different issues.

Regarding the search for evidence of the activity of builders, the higher the resolution the better.

Regarding the "artworks", I guess the final point I would like to make is that we might make further progress in this quest by considering the likely distance these artworks were originally intended to be viewed from. If we knew that, we could selectively "tweek" the cameras occasionally to optimize the chances for seeing them. Anyone who has ever been to a museum and had the curator tell them to "step back" knows what I'm getting at. I think you got my point on your first reply when you said "we can always reduce the resolution". The question is, will they? We have to selectively look for these artworks, if we want to find them. There may be thousands of them.

rd

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by rderosa</i>
<br />you said "we can always reduce the resolution". The question is, will they?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">No, <i>WE</i> can always reduce the resolution. Given any image, we can readily render it as it would appear from farther away. It is only the appearance closer up that requires more data.

BTW, if artificial, the most likely viewing distance for surface art would be that of an orbiting space station. The MGS and MRO cameras are at a good approximation of that distance. -|Tom|-