How does Mars get its red color?
Hemoglobin
Historically, an association between the color of blood and rust occurs in the association of the planet Mars, with the Roman god of war, since the planet is an orange-red, which reminded the ancients of blood. Although the color of the planet is due to iron compounds in combination with oxygen in the Martian soil, it is a common misconception that the iron in hemoglobin and its oxides gives blood its red color. The color is actually due to the porphyrin moiety of hemoglobin to which the iron is bound, not the iron itself, although the ligation and redox state of the iron can influence the pi to pi* or n to pi* electronic transitions of the porphyrin and hence its optical characteristics.
Chestnut (coat)
Red hair color in horses ("e") is created by a missense mutation in the code for MC1R, which results in a protein that cannot bind to the Melanocyte-stimulating hormone (MSH), which is released by the pituitary gland, and stimulates the production and release of melanin in skin and hair. So long as one functional copy ("E") is present, the protein is formed normally and black pigment is produced. However, when only mutant copies ("e) of the gene are available, non-functional MC1R proteins are produced. As a result, no black pigment is deposited into the hair and the entire coat is red-based. However, the skin of chestnut horses is still generally black, unless affected by other genes. Some chestnut foals are also born with lighter eyes and lightened skin, which darken not long after birth. This is not the same as the blue eyes and pink skin seen at birth in foals carrying the champagne gene. It is a genetic mechanism not fully understood, but may be related to the pheomelanistic characteristics of "e".
The recessive nature the chestnut or "red" coat in horses occurs because a single copy of the "E" allele is dominant over the "e" allele. Therefore, for example, bay and black horses may be heterozygous for "e" and if so, could produce a chestnut foal when bred to another horse with at least one copy of "e". However, all chestnut horses are homozygous for the "e" allele and thus breeding a chestnut to another chestnut will always produce a chestnut foal. Thus, unlike many coat colors, chestnut can be true-breeding; if any color other than chestnut occurs, then one of the parents was not chestnut.
Red weed
In Steven Spielberg's 2005 "War of the Worlds" film, the presence of the red weed on Earth is intentional. Once they have a strong hold of the planet, the invaders take captured humans and drain their blood, which act as a fertiliser for the red weed, helping it grow and cover the planet. Spielberg did state that these invaders did not come from Mars (the "Red Planet"), the script indicates the weed is abundantly present on their world as well, suggesting the two share a superficial resemblance. However, what exactly makes up their red weed, whether it is a natural vegetation or what gives it its colour on their world, is unknown; though the human blood possibly adds to its redness. In one scene, the Tripods used their tentacles to dig fiercely at the ground, which could have been when and how they planted the red weed. It grows so quickly that it can be seen growing, and it can grow on just about anything. It is also stated in the script that the weed is fierce enough to flourish in spite of the conditions that had forced the aliens to find refuge on a new world. But despite its tenacity to survive such a harsh environment, much like in the novel, Earth's pathogens kill the red weed. Crows eat some of the remains and the rest eventually become an ash-like dust which is blown away in the wind.
Roussin's red salt
Roussin's red salt anion is an edge-shared bitetrahedron, wherein a pair Fe(NO) units are bridged by a pair of sulfide ligands. The Fe-NO bonds are linear indicating NO is acting as a three electron donor. The diamagnetic compound obeys the 18-electron rule. The dark red colour of the complex is attributed to a number of charge-transfer interactions between the iron core and nitrosyl ligands.
Atmosphere of Mars
The atmosphere is quite dusty, giving the Martian sky a light brown or orange-red color when seen from the surface; data from the Mars Exploration Rovers indicate suspended particles of roughly 1.5 micrometres in diameter.
Shades of red
Displayed at right is the web color "fire brick". 
Displayed at right is the color "madder". It is named for a dye produced from plants of the genus "Rubia".
History of Mars observation
During the 1920s, French astronomer Bernard Lyot used a polarimeter to study the surface properties of the Moon and planets. In 1929, he noted that the polarized light emitted from the Martian surface is very similar to that radiated from the Moon, although he speculated that his observations could be explained by frost and possibly vegetation. Based on the amount of sunlight scattered by the Martian atmosphere, he set an upper limit of 1/15 the thickness of the Earth's atmosphere. This restricted the surface pressure to no greater than . Using infrared spectrometry, in 1947 the Dutch-American astronomer Gerard Kuiper detected carbon dioxide in the Martian atmosphere. He was able to estimate that the amount of carbon dioxide over a given area of the surface is double that on the Earth. However, because he overestimated the surface pressure on Mars, Kuiper concluded erroneously that the ice caps could not be composed of frozen carbon dioxide. In 1948, American meteorologist Seymour L. Hess determined that the formation of the thin Martian clouds would only require of water precipitation and a vapor pressure of .
Atmosphere of Jupiter
It is not known exactly what causes the Great Red Spot's reddish color. Theories supported by laboratory experiments suppose that the color may be caused by complex organic molecules, red phosphorus, or yet another sulfur compound. The GRS varies greatly in hue, from almost brick-red to pale salmon, or even white. The higher temperature of the reddest central region is the first evidence that the Spot's color is affected by environmental factors. The spot occasionally disappears from the visible spectrum, becoming evident only through the Red Spot Hollow, which is its niche in the South Equatorial Belt (SEB). The visibility of GRS is apparently coupled to the appearance of the SEB; when the belt is bright white, the spot tends to be dark, and when it is dark, the spot is usually light. The periods when the spot is dark or light occur at irregular intervals; in the 50 years from 1947 to 1997, the spot was darkest in the periods 1961–1966, 1968–1975, 1989–1990, and 1992–1993. In November 2014, an analysis of data from NASA's Cassini mission revealed that the red color is likely a product of simple chemicals being broken apart by sunlight in the planet's upper atmosphere
Red
The human eye sees red when it looks at light with a wavelength between approximately 625 and 740 nanometers. It is a primary color in the RGB color model and the light just past this range is called infrared, or below red, and cannot be seen by human eyes, although it can be sensed as heat. In the language of optics, red is the color evoked by light that stimulates neither the S or the M (short and medium wavelength) cone cells of the retina, combined with a fading stimulation of the L (long-wavelength) cone cells.
Iron
The mentioned iron compounds have been used as pigments (compare ochre) since historical time and contribute as well to the color of various geological formations, e.g. the Buntsandstein (British Bunter, colored sandstein). In the case of the Eisensandstein (a jurassic 'iron sandstone', e.g. from Donzdorf) in Germany and Bath stone in the UK, iron pigments contribute to the yellowish color of large amounts of historical buildings and sculptures. The proverbial red color of the surface of Mars is derived from an iron oxide-rich regolith.
Martius yellow
Martius yellow stains have been used to stain erythrocytes yellow so that they contrast well with red fibrin in trichrome staining methods such as Lendrum's Picro Mallory and Slidder's Martius, Scarlet and Blue (MSB). It can be combined with other small molecular weight yellow dyes to increase stain intensity.
Evidence of water on Mars found by Mars Reconnaissance Orbiter
For several reasons, the ice-rich clifts (scarps) are suspected to be ground ice instead of thin, temporary frost. Their blue color stays even after seasonal frost, indicated by blue color, has disappeared from the surroundings and from higher, colder locations. Also, Thermal Emission Imaging System (THEMIS) measurements show a temperature in the late-afternoon that is above the frost point. This means that any frost would have melted in the heat of the day.
"There is shallow ground ice under roughly a third of the Martian surface," said the study's lead author, Colin Dundas of the U.S. Geological Survey's Astrogeology Science Center in Flagstaff, Arizona. " This image confirms what was previously detected with the spectrometer on 2001 Mars Odyssey, the ground-penetrating radars on MRO and on Mars Express, and by the "Phoenix" lander "in situ" excavation. The Phoenix lander actually exposed an ice layer with its landing rockets.
Besides being of immense value to future explorers, these ice layers could help us better understand the climate history of Mars. They provide a record of the past. Since Mars experiences great variations in its tilt, it also goes through dramatic climate variations. These changes may be able to be tracked with study of these layers. Mars does not possess a large moon to keep its tilt stable. Today, ice is concentrated at the poles, with a greater tilt, more ice will exist at mid-latitudes.
Red weed
The weed does not appear in the modernised, 2005 The Asylum film "H.G. Wells' War of the Worlds" (also entitled "Invasion"), but later scenes in the film show a reddish-orange colour scheme, possibly used to adapt the red weed into a more realistic aspect and to resemble the colour of Mars to symbolise the aliens' control over mankind. It is confirmed that no such weed exists by Mars Rover recordings during the opening title sequence, and the surface of the planet seen on the sequel "".
Red blood cell
The color of red blood cells is due to the heme group of hemoglobin. The blood plasma alone is straw-colored, but the red blood cells change color depending on the state of the hemoglobin: when combined with oxygen the resulting oxyhemoglobin is scarlet, and when oxygen has been released the resulting deoxyhemoglobin is of a dark red burgundy color. However, blood can appear bluish when seen through the vessel wall and skin. Pulse oximetry takes advantage of the hemoglobin color change to directly measure the arterial blood oxygen saturation using colorimetric techniques. Hemoglobin also has a very high affinity for carbon monoxide, forming carboxyhemoglobin which is a very bright red in color. Flushed, confused patients with a saturation reading of 100% on pulse oximetry are sometimes found to be suffering from carbon monoxide poisoning.
History of Mars observation
In 1704, Italian astronomer Jacques Philippe Maraldi "made a systematic study of the southern cap and observed that it underwent" variations as the planet rotated. This indicated that the cap was not centered on the pole. He observed that the size of the cap varied over time. The German-born British astronomer Sir William Herschel began making observations of the planet Mars in 1777, particularly of the planet's polar caps. In 1781, he noted that the south cap appeared "extremely large", which he ascribed to that pole being in darkness for the past twelve months. By 1784, the southern cap appeared much smaller, thereby suggesting that the caps vary with the planet's seasons and thus were made of ice. In 1781, he estimated the rotation period of Mars as 24 39 21.67 and measured the axial tilt of the planet's poles to the orbital plane as 28.5°. He noted that Mars had a "considerable but moderate atmosphere, so that its inhabitants probably enjoy a situation in many respects similar to ours". Between 1796 and 1809, the French astronomer Honoré Flaugergues noticed obscurations of Mars, suggesting "ochre-colored veils" covered the surface. This may be the earliest report of yellow clouds or storms on Mars.
Betelgeuse
With the history of astronomy intimately associated with mythology and astrology before the scientific revolution, the red star, like the planet Mars that derives its name from a Roman war god, has been closely associated with the martial archetype of conquest for millennia, and by extension, the motif of death and rebirth. Other cultures have produced different myths. Stephen R. Wilk has proposed the constellation of Orion could have represented the Greek mythological figure Pelops, who had an artificial shoulder of ivory made for him, with Betelgeuse as the shoulder, its color reminiscent of the reddish yellow sheen of ivory.
Red Planet
Red Planet is a nickname for the planet Mars, due to its surface color.
It may also refer to:
Mars trilogy
Genetic engineering is first mentioned in "Red Mars"; it takes off when Sax creates an alga to withstand the harsh Martian temperature and convert its atmosphere into breathable air. Eventually this is done on a massive scale, with thousands of types of GE algae, lichen and bacteria being created to terraform the planet. In "Green Mars", GE animals began to be created to withstand the thin Martian atmosphere, and to produce a working planetary-biosphere. By "Blue Mars", GE is commonly being done on humans, willingly, to help them better adapt to the new worlds; to breathe thinner air (e.g. Russell), or to see better in the dimmer light of the outer planets.
Atmosphere of Mars
As reported by the European Space Agency (ESA) on September 29, 2013, a new comparison of spacecraft data with computer models explains how global atmospheric circulation creates a layer of ozone () above Mars's southern pole in winter. Ozone was most likely difficult to detect on Mars because its concentration is typically 300 times lower than on Earth, although it varies greatly with location and time. The SPICAM —an UV/IR spectrometer— on board Mars Express has shown the presence of two distinct ozone layers at low-to-mid latitudes. These comprise a persistent, near-surface layer below an altitude of 30 km, a separate layer that is only present in northern spring and summer with an altitude varying from 30 to 60 km, and another separate layer that exists 40–60 km above the southern pole in winter, with no counterpart above the Mars's north pole. This third ozone layer shows an abrupt decrease in elevation between 75 and 50 degrees south. SPICAM detected a gradual increase in ozone concentration at 50 km until midwinter, after which it slowly decreased to very low concentrations, with no layer detectable above 35 km. The reporting scientists think that the observed polar ozone layers are the result of the same atmospheric circulation pattern that creates a distinct oxygen emission identified in the polar night and also present in Earth's atmosphere. This circulation takes the form of a huge Hadley cell in which warmer air rises and travels toward the south pole before cooling and sinking at higher latitudes. Mars is on a quite elliptical orbit and has a large axial tilt, which causes extreme seasonal variations in temperature amongst the northern and southern hemispheres. Mars's temperature difference greatly influences the amount of water vapor in the atmosphere, because warmer air can contain more moisture. This, in turn, affects the production of ozone-destroying hydrogen radicals.
Vermilion
"China red" or "Chinese red" is the name used for the vermilion shade used in Chinese lacquerware. One version is shown in the color box at right; the shade could vary from dark to light depending upon how the pigment was made and how the lacquer was applied. Chinese red was originally made from the powdered mineral cinnabar, but beginning in about the 8th century it was made more commonly by a chemical process combining mercury and sulphur. Vermilion has significance in Taoist culture, and is regarded as the color of life and eternity.
Red weed
Wells may have been influenced by the theories of Camille Flammarion, who in 1873 claimed that Mars was red due to red vegetation growing on it.
Red
But, like many colors, it also had a negative association, with heat, destruction and evil. A prayer to god Isis states: "Oh Isis, protect me from all things evil and red." The ancient Egyptians began manufacturing pigments in about 4000 BC. Red ochre was widely used as a pigment for wall paintings, particularly as the skin color of men. An ivory painter's palette found inside the tomb of King Tutankhamun had small compartments with pigments of red ochre and five other colors. The Egyptians used the root of the rubia, or madder plant, to make a dye, later known as alizarin, and also used it as a pigment, which became known as madder lake, alizarin or alizarin crimson.
Red weed
The red weed (also referred to as the red creeper or the red swamp) is a fictional plant native to Mars in the novel "The War of the Worlds" by H. G. Wells. It is this plant that supposedly gives Mars its dull red colour. It is one of the several types of plants brought to Earth possibly accidentally by the invading Martians, but the only one that truly was able to adapt and grow widespread on Earth. When it is exposed to water, it grows and reproduces explosively, flooding the neighboring countryside as it clogs streams and rivers. The narrator mentions near the end of "The Man on Putney Hill" that the weed glows purple at night. He tries eating some, but it has a metallic taste. Though it engulfed the native plant life of Earth, it also succumbed to the effects of Earth bacteria.
Mars in fiction
Before the Mariner 4 spacecraft arrived at Mars in July 1965 and dispelled some of the more exotic theories about the planet, the conventional image of Mars was shaped by the observations of the astronomers Giovanni Schiaparelli, Camille Flammarion and Percival Lowell. Flammarion assumed its red surface came from red-colored vegetation, and Schiaparelli observed what he took to be linear features on the face of Mars, which he thought might be water channels. Because the Italian for channels is "canali", English translations tended to render the word as "canals", implying artificial construction. Lowell's books on Mars expanded on this notion of Martian canals, and a standard model of Mars as a drying, cooling, dying world was established. It was frequently speculated that ancient Martian civilizations had constructed irrigation works that spanned the planet in an attempt at saving their dying world. This concept spawned a large number of science fiction scenarios.
Exploration of Mars
Mars has long been the subject of human interest. Early telescopic observations revealed color changes on the surface that were attributed to seasonal vegetation and apparent linear features were ascribed to intelligent design. Further telescopic observations found two moons, Phobos and Deimos, polar ice caps and the feature now known as Olympus Mons, the solar system's tallest mountain. The discoveries piqued further interest in the study and exploration of the red planet. Mars is a rocky planet, like Earth, that formed around the same time, yet with only half the diameter of Earth, and a far thinner atmosphere; it has a cold and desert-like surface.
Lunar eclipse
The amount of refracted light depends on the amount of dust or clouds in the atmosphere; this also controls how much light is scattered. In general, the dustier the atmosphere, the more that other wavelengths of light will be removed (compared to red light), leaving the resulting light a deeper red color. This causes the resulting coppery-red hue of the Moon to vary from one eclipse to the next. Volcanoes are notable for expelling large quantities of dust into the atmosphere, and a large eruption shortly before an eclipse can have a large effect on the resulting color.
Basics of blue flower colouration
Blue flower colour was always associated with something unusual and desired. Blue roses especially were assumed to be a dream that cannot be realised. Blue colour in flower petals is caused by anthocyanins, which are members of flavonoid class metabolites. We can diversify three main classes of anthocyanin pigments: cyaniding type (two hydroxyl groups in the B-ring) responsible for red coloration, pelargonidin type (one hydroxyl group in the B-ring) responsible for orange colour and delphinidin type (three hydroxyl groups in the B-ring) responsible for violet/blue flower and fruits coloration. The main difference in the structure of listed anthocyanins type is the number of hydroxyl groups in the B-ring of the anthocyanin. Nevertheless in the monomeric state anthocyanins never show blue colour in the weak acidic and neutral pH. The mechanism of blue colour formation are very complicated in most cases, presence of delphinidin type pigments is not sufficient, great role play also the pH and the formation of complexes of anthocyanins with flavones and metal ions.
Liver (color)
In dogs, the Liver color is caused by dilution of the eumelanin (black) pigment by the B locus. The gene that causes Liver is recessive, so a BB or Bb dog has normal black pigment. Only a bb dog is Liver. There are several different recessive b genes, but they all turn the coat brown. They are only distinguishable through genetic testing. Liver may also be called different names such as Brown, Chocolate, or Red. Red is a very misleading term, and should be avoided when referring to the color liver because it can be confused for phaeomelanin pigment. This second pigment is what colors all the "true red" or yellow parts of a dog.
Liver dilution can also be combined with other genes that dilute a dog's coat. The D locus dilutes black pigment to a blue-grey color usually called Blue. It is a recessive trait like Liver. When a dog has both Liver and Blue dilution, it will appear to be a light, warm-gray color known as Isabella. This is the color of Weimaraners. This color also has alternate names such as Liliac or Silver. When Liver is combined with Merle, the eumelanin (black) pigment is further diluted in random patches. This usually creates a light reddish-gray dog with dark brown patches. This color is often called "Red Merle" even though that is misleading. A more correct name would be Liver Merle or Chocolate Merle.
There are many other dog colors that can look like brown, but are not Liver. A dog that is very dark red, like an Irish Setter may sometimes appear brown. Dogs with a blend of Black and Red/Yellow fur can also look like they have brown areas. An easy way to tell if a dog is Liver or not is to look at their nose. Eumelanin (black) pigment colors a dog's nose, so a Liver dog will have a Liver colored nose. If the nose is black, the dog is not a liver. A pink nose has nothing to do with liver dilution, and will not help determine if a dog is liver or not. Liver will also dilute a dog's brown eyes to amber/yellow.
Common surface features of Mars
Many locations on Mars have sand dunes. An erg (or sand sea), made up of aeolian dune fields referred to as the Circumpolar Dune Field surrounds most of the north polar cap. The dunes are covered by a seasonal carbon dioxide frost that forms in early autumn and remains until late spring. Many martian dunes strongly resemble terrestrial dunes but images acquired by the High-Resolution Imaging Science Experiment on the Mars Reconnaissance Orbiter have shown that martian dunes in the north polar region are subject to modification via grainflow triggered by seasonal CO2 sublimation, a process not seen on Earth. Many dunes are black because they are derived from the dark volcanic rock basalt. Extraterrestrial sand seas such as those found on Mars are referred to as "undae" from the Latin for waves.
Mars Black (pigment)
Mars Black is an iron oxide pigment developed in the 20th century. Also known under the names of black iron oxide, magnetic oxide, Pigment Black 11, and ferrous ferric oxide (FeO), it has no known health hazards and is considered non-toxic, with an ASTM lightfastness rating of I. It is more opaque and less toxic than other black pigments. Artists' paint manufacturers have rated it one of the most satisfactory black pigments for acrylic paints with regard to opacity, lightfastness, and permanence. It takes its name from Mars, the god of war and patron of iron.
Mars surface color
There is also evidence that hematite might form from magnetite in the course of erosion processes. Experiments at the Mars Simulation Laboratory of Aarhus University in Denmark show that when a mixture of magnetide powder, quartz sand, and quartz dust particles is tumbled in a flask, some of the magnetite converts to hematite, coloring the sample red. The proposed explanation for this effect is that when quartz is fructured by the grinding, certain chemical bonds get broken at the newly exposed surfaces; when these surfaces come in contact with magnetite, oxygen atoms may be transferred from quartz surface to magnetite, forming hematite.
Scientific information from the Mars Exploration Rover mission
Scientists have wanted to find out which of these processes created grey hematite on Mars since 1998, when Mars Global Surveyor spotted large concentrations of the mineral near the planet's equator (seen in the right picture). This discovery provided the first mineral evidence that Mars' history may have included water.
Red Planet (film)
Burchenal explains to Gallagher that the biochemistry of alien insects' respiratory metabolism is capable of producing oxygen far more efficiently than human science is currently able to. Studying the insects' biochemistry is the key to terraforming Mars, and may even lead to discoveries which will allow Earth's polluted atmosphere to be repaired. However, Burchenal is attacked by swarms of the insects when blood drips from an open wound. Rather than be eaten alive, he passes his sample vial of insects to Gallagher before immolating himself and his attackers.
Mars
Mars is named after the Roman god of war. In different cultures, Mars represents masculinity and youth. Its symbol, a circle with an arrow pointing out to the upper right, is used as a symbol for the male gender.
Atmosphere of Jupiter
Why Oval BA turned red is not understood. According to a 2008 study by Dr. Santiago Pérez-Hoyos of the University of the Basque Country, the most likely mechanism is "an upward and inward diffusion of either a colored compound or a coating vapor that may interact later with high energy solar photons at the upper levels of Oval BA." Some believe that small storms (and their corresponding white spots) on Jupiter turn red when the winds become powerful enough to draw certain gases from deeper within the atmosphere which change color when those gases are exposed to sunlight.
Ismenius Lacus quadrangle
Sand dunes have been found in many places on Mars. The presence of dunes shows that the planet has an atmosphere with wind, for dunes require wind to pile up the sand. Most dunes on Mars are black because of the weathering of the volcanic rock basalt. Black sand can be found on Earth on Hawaii and on some tropical South Pacific islands.
Sand is common on Mars due to the old age of the surface that has allowed rocks to erode into sand. Dunes on Mars have been observed to move many meters.
Some dunes move along. In this process, sand moves up the windward side and then falls down the leeward side of the dune, thus caused the dune to go toward the leeward side (or slip face).
When images are enlarged, some dunes on Mars display ripples on their surfaces. These are caused by sand grains rolling and bouncing up the windward surface of a dune. The bouncing grains tend to land on the windward side of each ripple. The grains do not bounce very high so it does not take much to stop them.
Mars
The depiction of Mars in fiction has been stimulated by its dramatic red color and by nineteenth century scientific speculations that its surface conditions might support not just life but intelligent life. Thus originated a large number of science fiction scenarios, among which is H. G. Wells' "The War of the Worlds", published in 1898, in which Martians seek to escape their dying planet by invading Earth.
Red red
Red red is a Ghanaian dish composed of black eyed peas cooked in palm oil with plantain. The dish derives its name from the red color it takes on from the red palm oil ("zomi") and the fried plantain. Red Red typically consists of fish, such as tinned mackerel or pilchards, black eyed peas, scotch bonnet, onions, oil and tomatoes.
Pomace
In red wine production, pomace is produced after the free run juice (the juice created before pressing by the weight of gravity) is poured off, leaving behind dark blackish-red debris consisting of grape skins and stems. The color of red wine is derived from skin contact during the maceration period, which sometimes includes partial fermentation. The resulting pomace is more alcoholic and tannic than pomace produced from white wine production. Pomace from the Italian wine Amarone is macerated in Valpolicella wine to produce Ripasso.
Scientific information from the Mars Exploration Rover mission
The next picture shows a mineral map, the first ever made on the surface of another planet, which was generated from a section of the panorama picture overlaid with data taken from the rover's Mini-TES. The Mini-TES spectral data was analyzed in a way that the concentration of the mineral hematite was deduced and its level coded in color. Red and orange mean high concentration, green and blue low concentration.
Terraforming of Mars
Any climate change induced in the near term is likely to be driven by greenhouse warming produced by an increase in atmospheric carbon dioxide () and a consequent increase in atmospheric water vapor. These two gases are the only likely sources of greenhouse warming that are available in large quantities in the Mars environment. Large amounts of water ice exist below the Martian surface, as well as on the surface at the poles, where it is mixed with dry ice, frozen . Significant amounts of water are located at the south pole of Mars, which, if melted, would correspond to a planetwide ocean 5–11 meters deep. Frozen carbon dioxide () at the poles sublimes into the atmosphere during the Martian summers, and small amounts of water residue are left behind, which fast winds sweep off the poles at speeds approaching . This seasonal occurrence transports large amounts of dust and water ice into the atmosphere, forming Earth-like ice clouds.
Red Rising
It has been seven hundred years since mankind colonized other planets. The powerful ruling class of humans has installed a rigid, color-based social hierarchy where the physically superior Golds at the top rule with an iron fist. Sixteen-year-old Darrow is a Red, a class of workers who toil beneath the surface of Mars mining helium-3 to terraform the planet and make it habitable. He and his wife Eo are captured after leaving a forbidden area and are arrested. While she is publicly whipped for her crime, Eo sings a forbidden folk tune as a protest against their virtual enslavement. She is subsequently hanged on the orders of Mars' ArchGovernor Nero au Augustus. Darrow cuts down and buries his wife's body, a crime for which he is also hanged. However, Darrow awakes to find that he has been drugged and delivered into the hands of the Sons of Ares, a terrorist group of Reds who fight against the oppression of the "lowColors". They have adopted the video of Eo's song and execution as a rallying vehicle for their cause. Darrow joins the Sons when he learns that Mars was already terraformed centuries before and that the Reds have been tricked into perpetual servitude and subjugation.
The Red Solstice
In the year 117 AE (After Earth), a storm rages across the surface of Mars, a planet now colonized by humans driven from their home planet. Although terraforming is well under way, the alignment of the Martian northern winter solstice with the planet's closest approach to the Sun still triggers global dust storms sometimes lasting up to several weeks. During an exceptionally violent storm dubbed "The Red Solstice", the human colonies of Mars lost all contact with Tharsis, the colony referred to as "The Capital". Soldiers in service of the Elysium Corporation, elite marine troops, were sent to find out what happened to the colony.
Red hair
The genetics of red hair, discovered in 1997, appear to be associated with the melanocortin-1 receptor (MC1R), which is found on chromosome 16. Red hair is associated with fair skin color because low concentrations of eumelanin throughout the body of those with red hair caused by a MC1R mutation can cause both. The lower melanin concentration in skin confers the advantage that a sufficient concentration of important Vitamin D can be produced under low light conditions. However, when UV-radiation is strong (as in regions close to the equator) the lower concentration of melanin leads to several medical disadvantages, such as a higher risk of skin cancer.
Rosé
With the exception of very few varieties, known as teinturiers, most wine grapes produce clear or colorless juice. This includes such well known red wine grape varieties such as Cabernet Sauvignon and Pinot noir. The color in red wine comes from phenolics in the skin called anthocyanins that react with other components in wine (such as tannins, acetaldehyde and pyruvic acid) to form polymeric pigments. The anthocyanins are extracted from the skin during the process of maceration which can last from a few hours in the case of some rosés (which usually only have 20–50 mg/l of anthocyanins) to several days in the case of most red wines (which often have in excess of 250 mg/l of anthocyanins).Anthocyanins have the ability to change into three different forms—colorless, red and blue—depending on the pH/acidity levels of the solution they are in. At wine pH (typically 2.9-4.0), most of the grape anythocyanins are in the colorless form unless they have reacted with tannins or other molecules (such as tannins also extracted from the skin as well as grape seeds, stems and from oak wine barrels) to form a stabilized pigment. So producers wishing to make rosé work to not only limit the amount of anthocyanins extracted into the wine but also limit the wines exposure to tannins (either by less maceration time, gentle pressing of the grapes or use only stainless tanks instead of oak) as well as protective anti-oxidative winemaking techniques that limit the development of acetaldehyde and other browning pigments that could add color to the wine.
Rosé
Rosés can be produced in a variety of ways with the most common method being early pressing of red grape varieties after a very short period, usually 12–24 hours, of skin-contact (maceration). During maceration, phenolics such as the anthocyanins and tannins that contribute to color as well as many flavor components are leached from the skins, seeds and any stems left in contact with the must. In addition to adding color and flavor, these phenolics also serve as antioxidants, protecting the wine from degradation of oxygen exposure. While red wines will often have maceration last several days to even several weeks, the very limited maceration of rosés means that these wines will have less stable color, potential flavor components and oxygen protection. This contributes to wines with shorter shelf-life that are meant to be consumed soon after release.
Macaulayite
Macaulayite is a red, earthy, monoclinic mineral, with the chemical formula (Fe, Al)SiO(OH). It was discovered in the 1970s by Dr Jeff Wilson and named after the Macaulay Institute in Aberdeen, Scotland. The only known source of macaulayite in the world is a quarry at the foot of Bennachie, Aberdeenshire, and it is formed by granite which has been weathered by tropical climates from before the last Ice Age. The substance is currently being studied by NASA, as it is speculated that this is the substance which gives the planet Mars its colour and it could prove that life on Mars can be sustained.
Red diamond
Red color can be produced by irradiating a colorless diamond by high-energy particles and then annealing it at high pressures and high temperatures.
Chronology of discoveries of water on Mars
Rocks on Mars have been found to frequently occur as layers, called strata, in many different places. Columbus Crater is one of many craters that contain layers. Rock can form layers in a variety of ways. Volcanoes, wind, or water can produce layers. Many places on Mars show rocks arranged in layers. Scientists are happy about finding layers on Mars since layers may have formed under large bodies of water.
Sometimes the layers display different colors. Light-toned rocks on Mars have been associated with hydrated minerals like sulfates. The Mars Rover Opportunity examined such layers close-up with several instruments. Some layers are probably made up of fine particles because they seem to break up into fine dust. In contrast, other layers break up into large boulders so they are probably much harder. Basalt, a volcanic rock, is thought to form layers composed of boulders. Basalt has been identified all over Mars. Instruments on orbiting spacecraft have detected clay (also called phyllosilicates) in some layers. Scientists are excited about finding hydrated minerals such as sulfates and clays on Mars because they are usually formed in the presence of water. Places that contain clays and/or other hydrated minerals would be good places to look for evidence of life.
HiWish program
Many locations on Mars have sand dunes. The dunes are covered by a seasonal carbon dioxide frost that forms in early autumn and remains until late spring. Many martian dunes strongly resemble terrestrial dunes but images acquired by the High-Resolution Imaging Science Experiment on the Mars Reconnaissance Orbiter have shown that martian dunes in the north polar region are subject to modification via grainflow triggered by seasonal CO2 sublimation, a process not seen on Earth. Many dunes are black because they are derived from the dark volcanic rock basalt. Extraterrestrial sand seas such as those found on Mars are referred to as "undae" from the Latin for waves.
Demining
The mustard "Arabidopsis thaliana", one of the best-studied plants in the world, normally turns red under harsh conditions. But using a combination of natural mutations and genetic manipulation, scientists from Danish biotechnology company Aresa Biodetection, created a strain that only changes color in response to the nitrous oxide that leaks from landmines and other explosives. Because nitrous oxide can also be formed by denitrifying bacteria, there is some risk of false positives using this technique, and researchers are attempting to make the plant less sensitive. The plants would aid demining by indicating the presence of mines through color change, and could either be sown from aircraft or by people walking through demined corridors in minefields. As of February 2005, no studies have been conducted with actual landmines, though successful studies have been done in greenhouses. In order to prevent the spread of this genetically modified organism into the wild, the plants have been further modified so that they will only sprout when provided with an external growth factor.
Mangala
Mangala (Sanskrit: मङ्गल, IAST: ) is the name for Mars, the red planet, in Hindu texts. Also known as Lohit (Made of Iron), he is born from Shiva's sweat or blood drop. also he is the god of war, celibate and sometimes linked to god Karttikeya (Skanda). His origins vary with different mythological texts; in some, he is the son of Bhumi, the Earth Goddess and Vishnu, born when he raised her from the depths of water in Varaha avatar.
Terraforming of Mars
The novel series by Kim Stanley Robinson known as the "Mars trilogy" chronicles the colonization and terraforming of Mars. The novels are titled according to the dominant color in the stage of terraforming achieved in each volume: "Red Mars" (1992), when Mars is still in its natural state; "Green Mars" (1993), when plants are able to grow in the atmosphere; and "Blue Mars" (1996), when the atmospheric pressure and temperature have risen high enough for seas and rivers to form.
Arabia quadrangle
Certain areas of Mars show ground that has a much lighter-tone than most other areas. Much of the surface of Mars is dark because of extensive flows of the dark lave rock basalt. Studies with spectroscopes from orbit have shown that many light-toned areas contain hydrated minerals, and/or clay minerals. That means that water was once there in order to produce these substances. In short, light-toned materials are markers for the past presence of water.
Impact craters generally have a rim with ejecta around them, in contrast volcanic craters usually do not have a rim or ejecta deposits. As craters get larger (greater than 10 km in diameter) they usually have a central peak. The peak is caused by a rebound of the crater floor following the impact. Sometimes craters display layers. Since the collision that produces a crater is like a powerful explosion, rocks from deep underground are tossed unto the surface. Hence, craters can show us what lies deep under the surface.
Lunar eclipse
The Moon does not completely darken as it passes through the umbra because of the refraction of sunlight by Earth's atmosphere into the shadow cone; if Earth had no atmosphere, the Moon would be completely dark during the eclipse. The reddish coloration arises because sunlight reaching the Moon must pass through a long and dense layer of Earth's atmosphere, where it is scattered. Shorter wavelengths are more likely to be scattered by the air molecules and small particles; thus, the longer wavelengths predominate by the time the light rays have penetrated the atmosphere. Human vision perceives this resulting light as red. This is the same effect that causes sunsets and sunrises to turn the sky a reddish color. An alternative way of conceiving this scenario is to realize that, as viewed from the Moon, the Sun would appear to be setting (or rising) behind Earth.
Mineralogy of Mars
Spirit
One of its instruments the Mössbauer spectrometer (MIMOS II) was designed to look at the iron bearing minerals on mars. It is responsible for determining the presence of many specific iron oxides, which give the planet a red color.
Blood red
In the RGB color spectrum blood red often consists only of the color red, with no green or blue component; in the CYMK color model blood red has no cyan, and consists only of magenta and yellow with a small amount of black. It is frequently darker than either maroon or dark red.
Different sources have proposed different color schemes for the color blood red. Below are some of these.
April 2014 lunar eclipse
A lunar eclipse occurs when the Moon passes within Earth's umbra (shadow). As the eclipse begins, the Earth's shadow first darkens the Moon slightly. Then, the shadow begins to "cover" part of the Moon, turning it a dark red-brown color (typically - the color can vary based on atmospheric conditions). The Moon appears to be reddish because of Rayleigh scattering (the same effect that causes sunsets to appear reddish) and the refraction of that light by the Earth's atmosphere into its umbra.
Mars surface color
One oxygen-(O)-independent process involves a direct chemical reaction of ferrous iron (Fe) (commonly present in typical igneous minerals) or metallic iron (Fe) with water (HO) to produce ferric iron (Fe(aq)), which typically leads to hydroxides such as goethite (FeO•OH) under experimental conditions. While this reaction with water (HO) is thermodynamically disfavored, it may be sustained nevertheless, by the rapid loss of the molecular hydrogen (H) byproduct. The reaction can be further facilitated by dissolved carbon dioxide (CO) and sulfur dioxide (SO), which lower the pH of brine films increasing the concentration of the more oxidative hydrogen ions (H).
Mars
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System after Mercury. In English, Mars carries a name of the Roman god of war, and is often referred to as the "Red Planet" because the reddish iron oxide prevalent on its surface gives it a reddish appearance that is distinctive among the astronomical bodies visible to the naked eye. Mars is a terrestrial planet with a thin atmosphere, having surface features reminiscent both of the impact craters of the Moon and the valleys, deserts, and polar ice caps of Earth.
Mars surface color
However, higher temperatures (c. 300 °C) are usually needed to decompose Fe (oxy)hydroxides such as goethite into hematite. The formation of palagonitic tephra on the upper slopes of the Mauna Kea volcano may mirror such processes, as consistent with the intriguing spectral and magnetic similarities between palagonitic tephra and Martian dust. In spite of the need for such kinetic conditions, prolonged arid and low pH conditions on Mars (such as diurnal brine films) may lead to the eventual transformation of goethite into hematite given the thermodynamic stability of the latter.
Martian surface
The albedo of a surface usually varies with the wavelength of light hitting it. Mars reflects little light at the blue end of the spectrum but much at red and higher wavelengths. This is why Mars has the familiar reddish-orange color to the naked eye. But detailed observations reveal a subtle range of colors on Mars' surface. Color variations provide clues to the composition of surface materials. The bright areas are reddish-ochre in color, and the dark areas appear dark gray. A third type of area, intermediate in color and albedo, is also present and thought to represent regions containing a mixture of the material from the bright and dark areas. The dark gray areas can be further subdivided into those that are more reddish and those less reddish in hue.
Mare Tyrrhenum quadrangle
Sand dunes have been found in many places on Mars. The presence of dunes shows that the planet has an atmosphere with wind, for dunes require wind to pile up the sand. Most dunes on Mars are black because of the weathering of the volcanic rock basalt. . Black sand can be found on Earth on  Hawaii and on some tropical South Pacific islands. 
Sand is common on Mars due to the old age of the surface that has allowed rocks to erode into sand. Dunes on Mars have been observed to move many meters. 
Some dunes move along. In this process, sand moves up the windward side and then falls down the leeward side of the dune, thus caused the dune to go toward the leeward side (or slip face). 
When images are enlarged, some dunes on Mars display ripples on their surfaces. These are caused by sand grains rolling and bouncing up the windward surface of a dune. The bouncing grains tend to land on the windward side of each ripple. The grains do not bounce very high so it does not take much to stop them.
Mineralogy of Mars
The surface geology of Mars is somewhere between the basalt or andesite rocks on Earth. This led to the formation of minerals similar to what is found on Earth. The presence of iron oxide gives the surface the “rust” color that is associated with Mars, the Red Planet. The presence of perchlorate, in high percentages, forms highly saline soils, which could produce liquid water. Chemical alteration of Martian rocks into carbonate and phyllosilicate minerals occurred earlier in Mars history when water was present in large quantities. Orbital instruments and Landers not only identified new minerals but in some cases also confirmed the presence of minerals detected by the others.Orbital crafts sent to Mars provided data on surface geology mostly through spectroscopy. This data is used to determine possible minerals on the surface, and the types of instruments Landers would need in order to narrow down those minerals.
Extraterrestrial skies
It is now known that during the Martian day, the sky is a butterscotch color. Around sunset and sunrise, the sky is rose in color, but in the vicinity of the setting Sun it is blue. This is the opposite of the situation on Earth. Twilight lasts a long time after the Sun has set and before it rises because of the dust high in Mars's atmosphere.
Mars
The mean apparent magnitude of Mars is +0.71 with a standard deviation of 1.05. Because the orbit of Mars is eccentric, the magnitude at opposition from the Sun can range from about −3.0 to −1.4. The minimum brightness is magnitude +1.86 when the planet is in conjunction with the Sun. At its brightest, Mars (along with Jupiter) are second only to Venus in luminosity. Mars usually appears distinctly yellow, orange, or red. NASA's "Spirit" rover has taken pictures of a greenish-brown, mud-colored landscape with blue-grey rocks and patches of light red sand. When farthest away from Earth, it is more than seven times farther away than when it is closest. When least favorably positioned, it can be lost in the Sun's glare for months at a time. At its most favorable times—at 15- or 17-year intervals, and always between late July and late September—a lot of surface detail can be seen with a telescope. Especially noticeable, even at low magnification, are the polar ice caps.
Red
Red by a large margin is the color most commonly associated with seduction, sexuality, eroticism and immorality, possibly because of its close connection with passion and with danger.
Atmosphere of Mars
In 1864, William Rutter Dawes observed "that the ruddy tint of the planet does not arise from any peculiarity of its atmosphere seems to be fully proved by the fact that the redness is always deepest near the centre, where the atmosphere is thinnest." Spectroscopic observations in the 1860s and 1870s led many to think the atmosphere of Mars is similar to Earth's. In 1894, though, spectral analysis and other qualitative observations by William Wallace Campbell suggested Mars resembles the Moon, which has no appreciable atmosphere, in many respects.
Maceration (wine)
Maceration is the winemaking process where the phenolic materials of the grape—tannins, coloring agents (anthocyanins) and flavor compounds—are leached from the grape skins, seeds and stems into the must. To macerate is to soften by soaking, and maceration is the process by which the red wine receives its red color, since raw grape juice (with the exceptions of teinturiers) is clear-grayish in color. In the production of white wines, maceration is either avoided or allowed only in very limited manner in the form of a short amount of skin contact with the juice prior to pressing. This is more common in the production of varietals with less natural flavor and body structure like Sauvignon blanc and Sémillon. For Rosé, red wine grapes are allowed some maceration between the skins and must, but not to the extent of red wine production.
Red wine
Red wine is a type of wine made from dark-colored (black) grape varieties. The actual color of the wine can range from intense violet, typical of young wines, through to brick red for mature wines and brown for older red wines. The juice from most purple grapes is greenish-white, the red color coming from anthocyan pigments (also called anthocyanins) present in the skin of the grape; exceptions are the relatively uncommon teinturier varieties, which produce a red-colored juice. Much of the red-wine production process therefore involves extraction of color and flavor components from the grape skin.
Red Star (novel)
At this point in the novel, Bogdanov details some of the aspects of the socialist Martian society as seen through Leonid’s eyes. First, Leonid comments that the red hue of Mars is actually due to the red vegetation that covers the planet. Secondly, he remarks on the living conditions of the Martians, noting that they are indistinguishable from one another. Thus, even a Martian like Menni, whom Leonid perceives to be more accomplished individually than most of his peers, lives in the same housing as the rest of his Martian compatriots. Thirdly, Leonid learns that there is no professional specialization among Martians such that an individual can enroll himself for work in a clothing factory one day and switch to food production the next day. In fact, job assignments are chosen based on societal need, and there is furthermore no requirement for an individual to work at all; yet, almost all Martians decide to work a varying number of hours anyway in order to feel fulfilled and accomplished. Leonid soon learns that there is no focus on or appreciation for the individual whatsoever in this Martian society, but rather admiration arises for collective effort.
Mars in fiction
Fictional representations of Mars have been popular for over a century. Interest in Mars has been stimulated by the planet's dramatic red color, by early scientific speculations that its surface conditions might be capable of supporting life, and by the possibility that Mars could be colonized by humans in the future. Almost as popular as stories about Mars are stories about Martians engaging in activity (frequently invasions) away from their home planet.
Compact Reconnaissance Imaging Spectrometer for Mars
To understand Mars' ancient climate, and whether it might have created environments habitable for life, first we need to understand Mars' climate today. Each mission to Mars has made new advances in understanding its climate. Mars has seasonal variations in the abundances of water vapor, water ice clouds and hazes, and atmospheric dust. During southern summer, when Mars is closest to the Sun (at perihelion), solar heating can raise massive dust storms. Regional dust storms - ones having a 1000-kilometer scale - show surprising repeatability Mars-year to Mars-year. Once every decade or so, they grow into global-scale events. In contrast, during northern summer when Mars is furthest from the Sun (at aphelion), there is an equatorial water-ice cloud belt and very little dust in the atmosphere. Atmospheric water vapor varies in abundance seasonally, with the greatest abundances in each hemisphere's summer after the seasonal polar caps have sublimated into the atmosphere. During winter, both water and carbon dioxide frost and ices form on Mars' surface. These ices form the seasonal and residual polar caps. The seasonal caps - which form each autumn and sublimate each spring - are dominated by carbon dioxide ice. The residual caps - which persist year after year - consist mostly of water ice at the north pole and water ice with a thin veneer (a few 10's of meters thick) of carbon dioxide ice at the south pole.
Mars
Mars can easily be seen from Earth with the naked eye, as can its reddish coloring. Its apparent magnitude reaches −2.94, which is surpassed only by Jupiter, Venus, the Moon, and the Sun. Optical ground-based telescopes are typically limited to resolving features about across when Earth and Mars are closest because of Earth's atmosphere.
Chloryl
The red color of is caused by electron transitions into an antibonding orbital. The analogous transition in is not in the visible spectrum, so is colorless. The strength of interaction with the counterion affects the energy of this antibonding orbital; thus, in colorless chloryl compounds, strong interactions with the counterion, corresponding with the higher covalent character of the bonding, shift the transition energy out of the visible spectrum.
Amalthea (moon)
The surface of Amalthea is very red. The reddish color may be due to sulfur originating from Io or some other non-ice material. Bright patches of less red tint appear on the major slopes of Amalthea, but the nature of this color is currently unknown. The surface of Amalthea is slightly brighter than surfaces of other inner satellites of Jupiter. There is also a substantial asymmetry between leading and trailing hemispheres: the leading hemisphere is 1.3 times brighter than the trailing one. The asymmetry is probably caused by the higher velocity and frequency of impacts on the leading hemisphere, which excavate a bright material—presumably ice—from the interior of the moon.
R Leporis
R Leporis has often been reported as an intense smoky red color, although this is not pronounced when the star is near its maximum brightness. It is reddest when it is dimmest, which occurs every 14.5 months. During these periods it is a candidate for the most-visible reddest star, but this claim is questionable. The red coloration may be caused by carbon in the star's outer atmosphere filtering out the blue part of its visible light spectrum. The star's discoverer, Hind, reported that it appeared "like a drop of blood on a black field."
Teinturier
Teinturier (French: to dye or to stain) is a wine term applied to grapes whose flesh and juice is red in colour due to anthocyanin pigments accumulating within the pulp of the grape berry itself. In most cases, anthocyanin pigments are confined to the outer skin tissue only, and the squeezed grape juice of most dark-skinned grape varieties is clear. The red color of red wine comes from anthocyanins extracted from the macerated (crushed) skins, over a period of days during the fermentation process.
The Angry Red Planet
Once the MR-1 returns to Earth, O'Bannion's infected arm is cured by medical staff using electric shocks. Mission control technicians also examine the MR-1's data recorders from the expedition and find a recording of an alien voice, which announces that the ship's crew were allowed to leave Mars so they could deliver a message to their home planet. The voice then states that "we of Mars" have been observing human development on Earth for many thousands of years and have determined that humanity's technology has far outpaced progress in cultural advancement. The alien then accuses humankind of invading Mars, warning that if future expeditions ever return to the Red Planet, the Earth would be destroyed in retaliation."The Angry Red Planet" began as "The Planet Mars", a treatment written by Sidney Pink about a space voyage to Earth's mysterious neighbor. "It was written on my kitchen table", Pink said in an interview a few years before his 2002 death. "My kids were my critics, they'd tell me what was good and what just fell flat". Pink gave his treatment to Melchior after meeting him at a party. Melchior believed the project had potential, so he offered to help write the screenplay if Pink allowed him to direct the film. While Melchior worked on establishing a working script, Pink met Maurer, who was developing CineMagic, a "revolutionary" filming process for creating special effects by combining hand-drawn images with live action. However, it soon became apparent the process would not be able to deliver what had been promised with respect to the quality of its effects. "The damn Cinemagic didn't work like it should", Pink recalled. "It was supposed to be sort of a 3-D effect. What we came up with was great anyway".
Mars surface color
The surface of the planet Mars appears reddish from a distance because of rusty dust suspended in the atmosphere.
From closeup, it looks more of a butterscotch, and other common surface colors include golden, brown, tan, and greenish, depending on minerals.
Outline of Mars
Mars – fourth planet from the Sun and the second-smallest planet in the Solar System, after Mercury. Named after the Roman god of war, it is often referred to as the "Red Planet" because the iron oxide prevalent on its surface gives it a reddish appearance. Mars is a terrestrial planet with a thin atmosphere, having surface features reminiscent both of the impact craters of the Moon and the valleys, deserts, and polar ice caps of Earth.
Maratus
Male "Maratus" species mostly display to the females, in courtship dances, brilliantly coloured upper surface of their abdomen, often with extensions and fringes. Colours are produced by two main methods using scales (or modified hairs). One mechanism uses pigments to produce reds, whites, and creams in barbed scales that help scatter light. To produce blues the spiders use arrays of nanostructures reflecting light of particular wavelengths, in the case of "Maratus splendens" a shiny, sometimes violety blue. The nanostructures are embedded in flat, convex, sac-like scales, amplifying reflected light, according to University of Groningen’s Doekele Stavenga. This is the only animal where this kind of reflection has been shown. Stavenga compared Maratus colours with patterns on butterfly wings, the colors of flowers, and the feathers of the parotia bird. The blues produced by nanostructures in "Maratus" do not fade over time, unlike the normal pigmenting method. Other blue animals, like beetles, are rare but also use nanostructures. Nathan Morehouse of the University of Pittsburgh found "Maratus volans" have four different photoreceptors (tetrachromats) allowing them to see red, blue, green, and ultraviolet and also resolve the intricacies of the male’s display designs.
Red
Red hair varies from a deep burgundy through burnt orange to bright copper. It is characterized by high levels of the reddish pigment pheomelanin (which also accounts for the red color of the lips) and relatively low levels of the dark pigment eumelanin. The term redhead (originally "redd hede") has been in use since at least 1510. Cultural reactions have varied from ridicule to admiration; many common stereotypes exist regarding redheads and they are often portrayed as fiery-tempered. (See red hair).
Eris (dwarf planet)
Unlike the somewhat reddish Pluto and Triton, Eris appears almost white. Pluto's reddish color is thought to be due to deposits of tholins on its surface, and where these deposits darken the surface, the lower albedo leads to higher temperatures and the evaporation of methane deposits. In contrast, Eris is far enough from the Sun that methane can condense onto its surface even where the albedo is low. The condensation of methane uniformly over the surface reduces any albedo contrasts and would cover up any deposits of red tholins.
Syrtis Major quadrangle
Many areas of Mars change their shape and/or coloration. For many years, astronomers observing regular changes on Mars when the seasons changed, thought that what they saw was evidence of vegetation growing. After close-up inspection with a number of spacecraft, other causes were discovered. Basically, the changes are caused by the effects of the wind blowing dust around. Sometimes, fine bright dust settles on the dark basalt rock making the surface appear lighter, at other times the light-toned dust will be blown away; thus making the surface darken—just as if vegetation were growing. Mars has frequent regional or global dust storms that coat the surface with fine bright dust. In the THEMIS image below, white streaks are seen downwind of craters. The streaks are not too bright; they appear bright because of contrast with the dark volcanic rock basalt which makes up the surface.
Some places on Mars show inverted relief. In these locations, a stream bed may be a raised feature, instead of a valley. The inverted former stream channels may be caused by the deposition of large rocks or due to cementation. In either case erosion would erode the surrounding land and leave the old channel as a raised ridge because the ridge would be more resistant to erosion. Images below, taken with HiRISE show sinuous ridges that are old channels that have become inverted.
Red Planet (novel)
The background of Mars presented in the novel, as a desert planet crisscrossed by giant canals built by an ancient civilization to bring water from the polar ice caps, is a common scenario in science fiction novels of the early 20th century, and was actually put forward as a plausible theory by some astronomers around the turn of the last century, notably Percival Lowell mentioned in the novel. It stems from early telescope observations of Mars by 19th century astronomers who, beginning with the Italian Giovanni Schiaparelli in 1877, believed they saw straight lines on the planet. Schiaparelli called them "canali" (grooves), which was popularly mistranslated into English as "canals".
Sunset
The colors of the Martian sunset differ from those on Earth. Mars has a thin atmosphere, lacking oxygen and nitrogen, so the light scattering is not dominated by a Rayleigh Scattering process. Instead, the air is full of red dust, blown into the atmosphere by high winds, so its sky color is mainly determined by a Mie Scattering process. One study also reported that Martian dust high in the atmosphere can reflect sunlight up to two hours after the sun has set, casting a diffuse glow across the surface of Mars.
Crimson
Crimson is a strong, red color, inclining to purple. It originally meant the color of the kermes dye produced from a scale insect, "Kermes vermilio", but the name is now sometimes also used as a generic term for slightly bluish-red colors that are between red and rose.
Green star (astronomy)
The (blackbody) colors of stars are sometimes confused with the colors of the spectrum. The spectral (rainbow) colors are those on the curved part of the boundary of the diagram on the right. As can be seen, the red, orange, yellow and blue rainbow colors happen to be much the same as blackbody colors. However, stars whose peak emission is green light also emit much red and blue light, and the human visual system happens to interpret this mixture of colors as whitish rather than green. So the fact that some spectral colors appear as star colors is more a quirk of human color vision than a property of stars: if one uses an instrument such as a spectroscope that is better at distinguishing wavelengths of light, then all spectral colors look completely different from star colors. All sufficiently hot stars look about the same shade of blue (and not violet as claimed in some popular accounts). The reason for this is that at sufficiently large temperatures (above about 20,000 K) all blackbody spectra look about the same in visible light, though they can differ a lot at shorter wavelengths. Although their maximum output at visible wavelengths is at violet, they put out enough light at other wavelengths to look light blue: the color at the end of the Planckian locus rather than the color at the end of the spectrum.
Human color vision is in fact more complicated than suggested by the explanation above, and in particular the perceived color of an object depends not only on the light it emits, but also on the colors of nearby objects. For example, a blue object close to a red object may appear somewhat greenish; this effect accounts for many apparently green stars.
Red hair
Early artistic representations of Mary Magdalene usually depict her as having long flowing red hair, although a description of her hair color was never mentioned in the Bible, and it is possible the color is an effect caused by pigment degradation in the ancient paint.
Red
Oxygenated blood is red due to the presence of oxygenated hemoglobin that contains iron molecules, with the iron components reflecting red light. Red meat gets its color from the iron found in the myoglobin and hemoglobin in the muscles and residual blood.
Mars surface color
Approximately true-colour "in situ" images from the Mars Pathfinder and Mars Exploration Rover missions indicate that the Martian sky may also appear reddish to humans. Absorption of sunlight in the 0.4-0.6 µm range by dust particles may be the primary reason for the redness of the sky. An additional contribution may come from the dominance of photon scattering by dust particles at wavelengths in the order 3 µm, which is in the near-infrared range, over Rayleigh scattering by gas molecules.
Hematite
The spectral signature of hematite was seen on the planet Mars by the infrared spectrometer on the NASA Mars Global Surveyor ("MGS") and 2001 Mars Odyssey spacecraft in orbit around Mars. The mineral was seen in abundance at two sites on the planet, the Terra Meridiani site, near the Martian equator at 0° longitude, and the Aram Chaos site near the Valles Marineris. Several other sites also showed hematite, e.g., Aureum Chaos. Because terrestrial hematite is typically a mineral formed in aqueous environments or by aqueous alteration, this detection was scientifically interesting enough that the second of the two Mars Exploration Rovers was sent to a site in the Terra Meridiani region designated Meridiani Planum. In-situ investigations by the Opportunity rover showed a significant amount of hematite, much of it in the form of small spherules that were informally named "blueberries" by the science team. Analysis indicates that these spherules are apparently concretions formed from a water solution.
"Knowing just how the hematite on Mars was formed will help us characterize the past environment and determine whether that environment was favorable for life".
Blood orange
The distinctive dark flesh color is due to the presence of anthocyanins, a family of antioxidant pigments common to many flowers and fruit, but uncommon in citrus fruits. Chrysanthemin (cyanidin 3-"O"-glucoside) is the main compound found in red oranges. The flesh develops its characteristic maroon color when the fruit develops with low temperatures during the night. Sometimes, dark coloring is seen on the exterior of the rind, as well, depending on the variety of blood orange. The skin can be tougher and harder to peel than that of other oranges. Blood oranges have a unique flavor compared to other oranges, being distinctly raspberry-like in addition to the usual citrus notes.
The blood orange is a natural mutation of the orange, which is itself a hybrid, probably between the pomelo and the tangerine,
Within Europe, the "arancia rossa di Sicilia" (red orange of Sicily) has Protected Geographical Status. In the Land of Valencia, it was introduced in the second half of the 19th century.
Red Faction (video game)
"Red Faction" takes place on Mars around the year 2075. Earth's minerals are being depleted and humans need more of them to survive. The vast Ultor Corporation runs the mining operation on Mars. The living conditions are deplorable, human rights for the miners are few, and a disease called "The Plague" is running rampant throughout the colony with no known antidote available—predominantly within the confines of the mine complex. Parker, a downtrodden miner, came to Mars to make a new start in his life—taken in by the promises and advantages Ultor has to offer in the mines of Mars. After a routine day in the mine with the typical aggression toward miners and cramped living conditions and poor nutrition, he witnesses the spark that starts a rebellion when a security guard abuses a miner at the end of his shift and heartlessly kills him. Parker takes up arms, with the help of Hendrix, a rebellious Ultor security technician who guides Parker through the complex. Hendrix tries to get Parker to join up with a group of miners who are about to steal a supply shuttle and escape the complex, but Parker arrives too late. The shuttle takes off, and is destroyed by missiles moments later.
Rose madder
Natural rose madder supplied half the world with red, until 1868, when its alizarin component became the first natural dye to be synthetically duplicated by Carl Gräbe and Carl Liebermann. Advances in the understanding of chemistry, such as chemical structures, chemical formulas, and elemental formulas, aided these Berlin-based scientists in discovering that alizarin had an anthracene base. However, their recipe was not feasible for large-scale production; it required expensive and volatile substances, specifically bromine.
Tricolour (flag)
In 1999, a red, green, and blue tricolour was proposed as the Flag of Mars. The design symbolizes liberty, and also the terraforming of Mars by humanity from a red planet to a green one, and eventually an Earth-like blue one.
Mars trilogy
"Red Mars" starts in 2026 with the first colonial voyage to Mars aboard the "Ares", the largest interplanetary spacecraft ever built and home to a crew who are to be the first hundred Martian colonists. The ship was built from clustered space shuttle external fuel tanks which, instead of reentering Earth's atmosphere, had been boosted into orbit until enough had been amassed to build the ship. The mission is a joint American–Russian undertaking, and seventy of the First Hundred are drawn from these countries (except, for example, Michel Duval, a French psychologist assigned to observe their behavior). The book details the trip out, construction of the first settlement on Mars (eventually called Underhill) by Russian engineer Nadia Cherneshevsky, as well as establishing colonies on Mars' hollowed out asteroid-moon Phobos, the ever-changing relationships between the colonists, debates among the colonists regarding both the terraforming of the planet and its future relationship to Earth. The two extreme views on terraforming are personified by Saxifrage "Sax" Russell, who believes their very presence on the planet means some level of terraforming has already begun and that it is humanity's obligation to spread life as it is the most scarce thing in the known universe, and Ann Clayborne, who stakes out the position that humankind does not have the right to change entire planets at their will.
Trouvelot (Martian crater)
Many places on Mars show rocks arranged in layers. Rock can form layers in a variety of ways. Volcanoes, wind, or water can produce layers.
Sometimes the layers are of different colors. Light-toned rocks on Mars have been associated with hydrated minerals like sulfates. The Mars Rover Opportunity examined such layers close-up with several instruments. Some layers are probably made up of fine particles because they seem to break up into fine dust. Other layers break up into large boulders, so they are probably much harder. Basalt, a volcanic rock, is thought to be present in the layers that form boulders. Basalt has been identified on Mars in many places. Instruments on orbiting spacecraft have detected clay (also called phyllosilicate) in some layers. Recent research with an orbiting near-infrared spectrometer, which reveals the types of minerals present based on the wavelengths of light they absorb, found evidence of layers of both clay and sulfates in many places, especially craters. This is exactly what would appear if a large lake had slowly evaporated. Moreover, since some layers contain gypsum, a sulfate which forms in relatively fresh water, life could have formed in some craters.
Human hair color
Red hair ranges from light strawberry blond shades to titian, copper, and completely red. It is caused by a variation in the "Mc1r" gene and is recessive. Red hair has the highest amounts of pheomelanin, around 67%, and usually low levels of eumelanin. At 1–2% of the population, it is the least common hair color in the world. It is most prominently found in the British Isles. Scotland has the highest proportion of redheads; 13 percent of the population has red hair and approximately 40 percent carry the recessive redhead gene.
Red
While red is the color most associated with love, it also the color most frequently associated with hatred, anger, aggression and war. People who are angry are said to "." Red is the color most commonly associated with passion and heat. In ancient Rome, red was the color of Mars, the god of war—the planet Mars was named for him because of its red color.