What color is Mars?

    Today I will tackle a topic that is already completely beaten up, but it still steadily pops up in almost any discussion of Runet, where the words "Mars" and "NASA" appear. Let's talk about the color of Mars. I know that many already have this topic in my liver, just like mine, but that’s why I took up it. It is necessary once and for all to sort through all the arguments and dot all.
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    To begin with, we will analyze all the main arguments of the supporters of the NASA theory reveals the color of Mars. They have not much evidence, but if they are not explained, doubts may arise even for a person far from conspiracy theories.
    The favorite method of conspiracy theorists is to pull the facts, ignore the explanations and present them under their own interpretation. Therefore, it is only necessary to show how manipulative all these conspiracy theories are. Yes, I think that the initiators of all these conspiracy revelations perfectly understand their absurdity, but losers are a valuable RuNet resource that can be converted into traffic and hundreds of links to your website or youtube channel.

    So let's get started.
    This whole story and hysteria began when in large numbers photos began to come from the twin rovers Spirit and Opportunity. It seemed strange to some that Mars had burgundy soil and a beige sky, and then they caught the eye of an official photograph of the Spirit landing platform.
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    “What is this?” - then American losers gasped, not able to read the descriptions under the photo - “Why is the NASA emblem burgundy and not blue?”.

    And really, why? NASA won’t be so stupid as it is: to hide the true color of Mars (let’s ignore the question, what’s necessary at all), and at the same time leave color hints that any conspiracy theorist could expose the conspiracy.

    But all that was needed was to look at the description of the photo and find out that these frames were made using not a red filter, but an infrared. Color photographs on twin rovers were created by shooting a black and white camera through different color filters. There, on each camera, there were seven filters with different wavelengths, slightly different on the right and left, among which was red and infrared.
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    Read more about obtaining color images from the rover cameras: it has been written for a long time .

    A little theory: a color frame is obtained if you shoot through three filters: red, green and blue (RGB format: red, green, blue), and then combine the three frames in Photoshop to get one color.
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    In some cases, NASA did not use a red filter, but an infrared filter. This was necessary in order to receive advanced information about the properties of the soil and the objects under study. After all, the rover’s camera is primarily a scientific device and only then a means to entertain taxpayers. So the panorama, with the Spirit landing platform, was shot using an infrared filter. But at the same time, the Opportunity platform was removed using red and in normal colors, which is evident from the difference.
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    The NASA logo is not visible, but the blue electrical tape immediately catches the eye. But if you look at the difference in soil in these two photos, then it is not so significant. Through infrared, it is “redder”, but you still can’t see it on the original green grass and blue sky.

    The peculiarity of obtaining color images through three filters caused another accusation by NASA that they upload a lot of black and white images and very few color ones. Firstly, “little color” is nonsense, because even before Curiosity thousands of color frames of Spirit and Opportunity were published , and dozenshuge 360-degree panoramas. Secondly, by uploading raw black and white frames made through color filters, NASA gives everyone the opportunity to independently produce color images of Mars. But conspiracy theorists master Photoshop only to the Autocolor function, which they "restore the true color of Mars", and they are not familiar with the subtleties of working with color channels.
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    The next argument of the followers of the “Marsnekrasniy” doctrine is a certain BBC report on the work of NASA specialists. According to the plot of the program, the scientist is sitting at a working laptop, then journalists enter his office and they ask something there.
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    But the conspiracy theorist shouts “Aha!” And pokes at the monitors behind the scientist, and there is not red Mars and the blue sky. Moreover, the organization of global conspirators looks more than strange, where journalists with cameras calmly walk around their offices, looking where they like it. But those who dream of catching NASA in a lie do not think about it.

    So what on that monitor? It depicts the Cape Verde site of Victoria Crater, which explored Opportunity.
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    NASA scientists use ground-based processing in order to facilitate the identification of rocks that are found on rovers. Since the eyes of geologists are accustomed to terrestrial conditions, then the change in the color gamut of Martian images is made in the same direction. And these photos are not secret at all.
    Here is Cape St. Cape Mary, adjacent to Cape Verde
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    Source
    A, is generally the vigorous Cape St. Vincent.
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    Or the Santa Maria crater that Opportunity drove last year
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    But this photo was taken using 13 color filters.
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    Imagine what would happen if journalists caught a scientist editing this photo? "NASA hides that rovers landed on a rainbow!"
    It’s just that the published photos always indicate an explanation of the type: It is presented in false color to accentuate differences in surface materials. Or in the case of this rainbow photo: The image was taken by the panoramic camera on NASA's Mars Exploration Rover Opportunity using all 13 color filters. But those who everywhere see signs of a conspiracy cannot read.

    In addition, conspiracy therapists, apparently, do not know about the existence of dust. Otherwise, they would not have taken this photo for another proof of the NASA conspiracy.
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    This is a memorial flag placed in memory of 9/11 victims on the Opportunity manipulator. And attention is drawn to the fact that it seems like it is tinted in red. Conspirologists think this is proof of the use of a red filter, although it's just red Martian dust. The shot was taken in 2011, and if you look at the photographs taken in 2004 at the beginning of the research operation for 31 sol (Martian day), then there is a clean flag in the colors we are used to.
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    When Curiosity's large self-portrait appeared , some also tried to look for signs of a conspiracy.
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    “Something the NASA logo is kind of gray, but it's blue,” but they also forgot about the dust. MSL landing was carried out not with the help of inflated cocoons, like the previous Mars rovers, but with the help of Sky Crane, so that it was given in dust from the first seconds on Mars.
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    UPD The use of the brush on the surface of Mars showed its natural color.
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    They also tell a certain story about how the first picture of Mars from the Viking 1 lander was obtained.
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    A book whose authors argue that there is life on Mars and NASA hides it (Mars: The Living Planet, by B. Di Gregorio, G. Levin and P. Straat, Frog Ltd, Berkeley, 1997) provides a story about the circumstances of the acquisition first shot. According to their testimonies, journalists were gathered in the JPL, color TVs were placed everywhere, and, having received a picture from Mars, they immediately brought it to the screens. The picture allegedly had a blue sky and green spots on the stones. After that, as the description in the book reads, NASA experts ran from monitor to monitor, twisting their color setting so that the photograph of Mars turned out to be in red. It is already impossible to verify the reliability of this story, but there are two significant points: firstly, the Viking color frame was obtained in the same way as on the twin rovers - by combining three black and white images, therefore, there was no signal from Mars that would have to be immediately displayed on monitors; secondly, if the monitors broadcast the image from the next office, where they made the color information, it wasn’t easier to replace it with “red” and continue broadcasting, than to attract attention by adjusting the monitors in front of everyone's eyes?

    Thanks to the hysteria fueled by conspiracy theorists, many began to worry about the question: so what color is Mars and the Martian sky in reality? Let's figure it out.

    The main culprit of the red color of Mars is iron oxides, or just rust. The Martian crust was very rich in iron ore. For example, the Meridiani Plateau, where the Opportunity rides, is simply strewn with hematite - iron balls formed in shallow reservoirs or groundwater.
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    Under the influence of water in an oxidizing atmosphere, iron turns into rust, which, as those who work with metal can know, easily becomes fine fine dust. And there was once a long and long liquid water on the planet, so Mars had time to blush. According to NASA, all dust on Mars has magnetic properties, i.e. contains impurities of iron.

    Martian storms carry dust even to places where there is not much iron in the ground. For example, in Gale Crater, at the Curiosity landing site, the jet of the landing craft blew away dust and a gray surface appeared.
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    But in a matter of days, everything returned to the familiar red-haired picture.
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    But in general, the landscapes there are lighter than on the Miridiani plateau.
    The Mars rover itself was covered with dust in the same way, therefore, considering its color markers and body, or trying to restore the “true color”, it should be borne in mind that it contains red Martian dust.

    I do not want to touch on the subtleties of the color calibration of white balance. We tried it somehow , but I'm not happy with the results and am already used to the “raw” colors of Curiosity.
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    Formats are more

    I will only say that Curiosity color cameras, unlike their predecessors, have a standard color Bayer filteron the Kodak KAI-2020 CCD matrix, so they shoot like ordinary SLR cameras. The difference in color reproduction depends on the white balance setting. But on Earth, adjustments to the color balance of the camera were made by people who knew what a particular color would look like at a particular color temperature. There were no people on Mars yet, so there is no one who could say “This color is correct” and slight color variations take place. For supporters of the theory that NASA removes everything through a red filter to hide the green Mars, I will share the secret that in the raw images of Curiosity there is just a slight bend to yellow-green.
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    With what Mars looks from space is much easier. We have photos of "Viking"
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    " Hubble "
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    the Mars Odyssey
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    If someone does not trust NASA can look at the pictures of the European satellite Mars Express. The
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    photo at the beginning of the article is also his.

    Or a beautiful true-color photo of the European satellite Rosetta
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    (The round "horseshoe" just to the left and below the center is the Gale crater )

    Or even the Soviet "Mars-5"
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    The last MRO satellite shoots in expanded colors, so you can’t call it “true”, it’s light gray as ultramarine looks, and dark gray as deep blue. But I recommend everyone to go to admire the photo on the official website .

    Upd. Two years later, after writing the article, you can add Mars from the Indian spacecraft Mars Orbiter :
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    But with the Martian atmosphere and the color of the sky is more interesting. If we turn again to the Martian images of the Hubble, then in many of them you can see the blue atmospheric shell of Mars.
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    For conspiracy theorists, this is proof of the Martian conspiracy, saying that here is the proof of the blue Martian sky. Proponents of this idea forget that both the Hubble and the Mars rovers are operated by the same NASA Jet Propulsion Laboratory (JPL). Therefore, it looks strange that they calmly publish incriminating evidence on themselves. But logic and conspiracy theology have never been friends, so let's continue.

    The problem with the Martian blue atmosphere is that it is too thin. The atmosphere of Mars is from 1% to 0.75% of the Earth’s atmosphere - seasons affect density. The pressure on the surface of Mars is such as at an altitude of 30-40 km above the Earth. Accordingly, the sky there should be the same. When Felix Baumgartner was jumping, everyone could see what the sky was like on a clear day.
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    Or recently, the Spaniards launched a prototype of a tourist stratostat at 32 km


    But there is no black sky on Mars. So what's the deal? And the answer is in the same Martian rusty dust. It is very shallow, dry, and the gravity there is three times weaker, due to this the dust can climb quite high even when there are no dust storms. There are even three types of clouds on Mars: water (from ice), carbon dioxide (also ice) and dust.
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    Thanks to dust, the color of the Martian sky has various shades from pink to beige, and in the storm and brown. Moreover, in calm weather, it darkens noticeably towards the zenith.
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    (Shooting Viking1 Lander, sol 1742 - dust storm)
    At the same time, at sunset and sunrise there is a unique chance to see the blue sky of Mars.
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    The color of the sky on Earth depends on Rayleigh scattering. The shortwave portion of the spectrum, from violet to blue, is scattered in the air, coloring our sky. When sunlight passes through a thicker layer of air - at sunset - longer waves up to red also undergo scattering, which we owe to our red sunsets. On Earth, sunlight near the horizon passes 38 times a thicker layer of air than at the zenith, and one can imagine comparable scales on Mars. But there, this thickness only allows you to see the blue in the sky, as we have on a clear day, and even then only around the disk itself. And only a violet wave manages to dissipate a little further.
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    Unfortunately, Curiosity has not yet shot sunrises and sunsets, but there is an explanation for this. Unlike previous rovers that worked on the plain, the "curious" is in a deep crater. It is surrounded by mountains, behind which the sun is hiding without having time to fade until it can be removed without a solar filter without fear of damaging the camera matrix with too much light.
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    Perhaps the danger of such a light would not be fatal, especially since when a local dust storm passed, but NASA is reinsured and removes only through the "welding mask".
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    (the black dot is Deimos)

    That's when Curiosity climbs the mountain and can look beyond the crater, then there is hope to see the sunset or sunrise in high quality, but wait for this at least a year.

    In conclusion, I want to say that the color of Mars is almost the same inconsistent indicator as on Earth. There are no oceans and green spaces on Mars, but the time of year, time of day, weather, and the geological structure of the surrounding rocks affect what colors will be in one place or another at one time or another. Blaming NASA for a conspiracy is a pointless business if it weren’t for it, we would still be drawing Martians floating in their junks through canals along rice fields. Of course, there was a Soviet research program, there is Mars Express, but 90% of the information we know about Mars we know thanks to NASA. And to check the reliability of their information, it is enough to know the school physics course and be able to read.

    Just three days after the publication of this post, Curiosity sent a shot of the Martian sky at its zenith. Shooting for 101 sol, when the rover covered with distant echoes of a dust storm. Visibility decreased from 30 to 10 km, but still the zenith is darker. The white edge to the left is from the proximity of the Sun.
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    Russian version: What color is Mars?

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