Martian sky is BLUE, tell NASA!

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JonClarke

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The properly done ones don't show a blue sky. If your images show a blue sky you are missing a step. Everyone else who uses the methodology outlined by Daniel Crotty has theirs turn out OK. This will be my last post here for a week, as I am going into the field.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>
 
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voyagerwsh

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Mars atmosphere may have been covered fine dust particles, with thinner air and lighter gravity, in all season. To have an ideal cleansed martian blue sky you would prefere to visit north polar regions where are more dust free. <br /><br />Or, if you would spot a blue water-ice cloud in the martian sky. <br /><br />http://science.ksc.nasa.gov/mars/ops/cloads_pic.jpg
 
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extrasense

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Jon,<br /><br />instead of using "metodology" and "steps", I have taken L4 L5 L6 rad images, and found average density over the same sky area.<br /><br />The blue is higher 1.5%.<br /><br />ES<br />
 
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tom_hobbes

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You either need more drugs or less. Adjust scenario according to whichever is more likely... <div class="Discussion_UserSignature"> <p><font size="2" color="#339966"> I wish I could remember<br /> But my selective memory<br /> Won't let me</font><font size="2" color="#99cc00"> </font><font size="3" color="#339966"><font size="2">- </font></font><font size="1" color="#339966">Mark Oliver Everett</font></p><p> </p> </div>
 
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telfrow

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<font color="yellow">So, I have used the radiometrically corrected images...</font><br /><br />Ah, yes, but are you using the <i>orthrectified</i> images?<br /><br /><img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> <strong><font color="#3366ff">Made weak by time and fate, but strong in will to strive, to seek, to find and not to yeild.</font> - <font color="#3366ff"><em>Tennyson</em></font></strong> </div>
 
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telfrow

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Sorry, that was a little joke directed to Jon...I just replied to the last post.<br /><br />As for the sky color, I think Jon has pretty well summed it up, but from what I've read and understand, on a perfectly clear day (no dust in the air), the sky would be a shade of blue...but since the Martian atmosphere is rarely (if ever) perfectly "clear," it has always has a 'pinkish" hue. That's a fairly simple explanation...but it works for me. <div class="Discussion_UserSignature"> <strong><font color="#3366ff">Made weak by time and fate, but strong in will to strive, to seek, to find and not to yeild.</font> - <font color="#3366ff"><em>Tennyson</em></font></strong> </div>
 
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extrasense

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--- Is the martian sky blue or not? ---<br /><br />OK,<br /><br />clearly it is not of that dull browne-reddish, surface like, uniform color, that you see on the official pictures.<br /><br />It is <b>mostly</b> white or gray, depending on the time of the day. <br />The color of a <b>particular area</b> of sky is modified by light blueish, sometimes reddish tint.<br /><br />PS.<br />The blueish tint comes from skattering of Sun light.<br />The reddish tint comes from skattering of the light, reflected from Mars surface.<br /><br />e <img src="/images/icons/smile.gif" /> s<br /><br />
 
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rlb2

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I have found through processing of the thousand of images that the reason that the sky looks blue at first is that these raw images were meant for extracting all the scientific information out of each image, as mentioned numerous times on this thread. therefore when you combine all the RGB images together the sky looks blue because the images are way oversaturated. Note when you first do this it is a very obvious false color image. <br /><br />When you first combine the RGB filters, the rocks first appear as partially shaded in blue or green tint that should give you a hint, the more exacting color of the rocks is mostly a shade of grey, red [from Iron oxide dust color] or brownish color - not blue or green. When I use my settings for a combination of RGB filters used, L2,L4,L5,L6,L7 sometimes you don’t get the L filtered channels you want from the images beamed down from Mars, so all my setting are different depending on what filters I use. <br /><br />At first I had trouble dealing with the over saturation until I refined my processes, I listened to some of the experts in this field, and did my own investigation into what I thought true color of Mars should look like. I did that by comparing the natural color of the rovers as they appear on Earth from a flash bulb or when stationed outside in the sunlight with color of the rovers on Mars, just like what the old TV repairman use to do when he came out to fix your TV. <br /><br />I have found that most the time the color of the sky at the horizon is either a shade of pink, yellow and orange at both Opportunities and Spirit sites. The farther you go above the horizon the more of a slight bluish tint you get. What is even more remarkable and probably can be explained very easily is that the sky color directly above the rover at the spirit site is different than the color above Opportunities site. At the Opportunity site the sky color is more of a medium tint of orange- grey - bluish color where at the Spirit site it is more <div class="Discussion_UserSignature"> Ron Bennett </div>
 
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extrasense

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rlb2,<br /><br />the fact that sky tint seems more reddish close to horizon, to some extent is probably result of the fact, that the browny light from the surface gets scattered inside the optical system, thus polluting the image.<br /><br />Next, using of the filtered images other than L4 L5 L6, does a capital screw up of the tints. Anything that uses those other filters is useless as to the sky color question.<br /><br />ES<br /><br />
 
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rlb2

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<font color="orange">Next, using of the filtered images other than L4 L5 L6, does a capital screw up of the tints. Anything that uses those other filters is useless as to the sky color question.<font color="white"><br /><br /><br />That's not true, there have been some very good links that were given to you to explain that. <br /><br />The L4, L5, L6 is my first preferred RGB filters I look for, if available. Every image has to be manipulated even L4,L5,L6. If you just combine those RGB channels together when you look at the rover you get different colors than what you see on Earth.....<br /><br /><font color="orange">the fact that sky tint seems more reddish close to horizon, to some extent is probably result of the fact, that the browny light from the surface gets scattered inside the optical system, thus polluting the image.<font color="white"><br /><br />Viking was a different system and got similar results........I too wanted to know the truth and have verified for myself that indeed, experts in this feld are right about this, some of those links to those experts in this field were presented to you.... <br /></font></font></font></font> <div class="Discussion_UserSignature"> Ron Bennett </div>
 
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extrasense

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1. --- L4,L5,L6. If you just combine those RGB channels together when you look at the rover you get different colors than what you see on Earth..... ---<br />Yes, the color needs more, but the tint/ the difference from the white/ can only use L456<br /><br />2. You may chose to disregard the color pollution, but it is there.<br /><br />3. Also, using raw images instead of the RAD corrected, might contribute to the problem.<br /><br />ES<br />
 
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silylene old

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Thanks rlb2. I know you are an expert on this subject, and your explanation was very clear. <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>
 
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rlb2

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<font color="orange">Yes, the color needs more, but the tint/ the difference from the white/ can only use L456<font color="white"><br /><br />I can get differences in white using L2,L5,L7 filters....<br /><br />Read this site that tefrow recommended from NASA, this is very informative and explains it well enough for the laymen. <br /><br />http://www.atsnn.com/story/30048.html<br /><br /><font color="orange">Quite a big deal has been made of NASA not sending 'True Color' images back from Mars. The problem with this argument is the fact that no digital images are ever 'True Color'. They are all composites. We cannot at present make a digital camera that sees images as the human eye does. The human eye also has 3-color receptors, but, being biological, there is a range over which the receptors pick up the colors.<font color="white"><br /><br />That’s why some of us refer to Viking because that was transmitted radio to analog - not digital<br /></font></font></font></font> <div class="Discussion_UserSignature"> Ron Bennett </div>
 
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rlb2

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Thanks<br /><br />Over the last year and a half I have refined the way I process the images by trying to make it a more exacting color match while adding contrast and darkening most of them a bit from the over-exposure look to get a sharper image therefore you can see more detail.<br /> <div class="Discussion_UserSignature"> Ron Bennett </div>
 
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extrasense

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OK,<br /><br />You've beaten me into submission.<br /><br />es<br /> <br />
 
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JonClarke

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I'm back from the bush, and just had to revive this comatose thread that reached its climax while I was away.<br /><br />rlb2 wrote:<br /><br />"What is even more remarkable and probably can be explained very easily is that the sky color directly above the rover at the spirit site is different than the color above Opportunities site. At the Opportunity site the sky color is more of a medium tint of orange- grey - bluish color where at the Spirit site it is more of a lighter orange yellowish color; probably more dust (different color of dust than Opportunity) at the Spirit site that scatters the light. Is it also possible that we are seeing the reflection of the surface of Mars off the atmosphere?"<br /><br />I think this is a most interesting observation. Certainly I have often noticed out in the desert the bottom sof clouds take on a pink or reddish tint from light reflected off the red desert below. The fact that the sky tint at Gusev is lighter than at meridiani is consistent withg the fact that Meridiani is one of the classic dark areas on Mars whereas Gusev is in Zephyria, one of the classic light areas.<br /><br />Jon<br /> <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>
 
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maxtheknife

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I feel your pain, Extrasense. <img src="/images/icons/wink.gif" /> <img src="/images/icons/crazy.gif" />
 
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yevaud

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Nothin' like a good beatin' to make the neighborhood get that "I feel good" feeling, is there?!<br /><br /><img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>
 
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telfrow

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<font color="yellow">I feel your pain, Extrasense. </font><br /><br />He was being serious. He was carrying on the debate in two locations, and through discussions at both sites, he realized he was wrong. See Post 29 here:<br /><br />http://www.markcarey.com/cgi-bin/mt/mt-view.cgi/18/entry/26840/discussion_page?start=21&show=20 <br /> <div class="Discussion_UserSignature"> <strong><font color="#3366ff">Made weak by time and fate, but strong in will to strive, to seek, to find and not to yeild.</font> - <font color="#3366ff"><em>Tennyson</em></font></strong> </div>
 
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centsworth_II

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So what does this do for the "Blue Flowers on Mars" theory? <div class="Discussion_UserSignature"> </div>
 
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JonClarke

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I think it is good that E_S has changed his position, it shows that it is worthwhile persisting and also arguing civilly. Telfrow - do you contribute to the Mark Cary site? I posted there for a while but gave it up as a bad job.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>
 
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telfrow

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No...I visit it every once in a while to see what's going on. I noticed you'd stopped posting....and I understand why. <div class="Discussion_UserSignature"> <strong><font color="#3366ff">Made weak by time and fate, but strong in will to strive, to seek, to find and not to yeild.</font> - <font color="#3366ff"><em>Tennyson</em></font></strong> </div>
 
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centsworth_II

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I wonder if all the colors-of-Mars questions will be put to rest when MSL gets there in several years with its real color cameras.<br /><br /><br /><br /><br /><br /> <div class="Discussion_UserSignature"> </div>
 
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