How does Mars get its red color?
13483#82
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.
Hemoglobin
14548654#2
Modern observations indicate that Mars's redness is skin deep. The Martian surface looks reddish primarily because of a ubiquitous dust layer (particles are typically between 3 µm to 45 µm across ) that is typically on the order of millimeters thick. Even where the thickest deposits of this reddish dust occur, such as the Tharsis area, the dust layer is probably not more than 2 m (7 feet) thick. Therefore, the reddish dust is essentially an extremely thin veneer on the Martian surface and does not represent the bulk of the Martian subsurface in any way.
Martian dust is reddish mostly due to the spectral properties of nanophase ferric oxides (npOx) that tend to dominate in the visible spectrum. The specific npOx minerals have not been fully constrained, but nanocrystalline red hematite (α-FeO) may be the volumetrically dominant one, at least at the less than 100 µm sampling depth of infrared remote sensors such as the Mars Express OMEGA instrument. The rest of the iron in the dust, perhaps as much as 50% of the mass, may be in titanium enriched magnetite (FeO). Magnetite is usually black in colour with a black streak, and does not contribute to the reddish hue of dust.
Mars surface color
25825#0
Red is the color at the end of the visible spectrum of light, next to orange and opposite violet. It has a dominant wavelength of approximately 625–740 nanometres. It is a primary color in the RGB color model and the CMYK color model, and is the complementary color of cyan. Reds range from the brilliant yellow-tinged scarlet and vermillion to bluish-red crimson, and vary in shade from the pale red pink to the dark red burgundy. The red sky at sunset results from Rayleigh scattering, while the red color of the Grand Canyon and other geological features is caused by hematite or red ochre, both forms of iron oxide. Iron oxide also gives the red color to the planet Mars. The red colour of blood comes from protein hemoglobin, while ripe strawberries, red apples and reddish autumn leaves are colored by anthocyanins.
Red
14548654#1
The apparent colour of the Martian surface enabled humans to distinguish it from other planets early in human history and motivated them to weave fables of war in association with Mars. One of its earliest recorded names, Har decher, literally meant "Red One" in Egyptian. Its color may have also contributed to a malignant association in Indian astrology, as it was given the names "Angaraka" and "Lohitanga", both reflecting the distinctively red color of Mars as seen by the naked eye. Modern robotic explorers have shown that not only the surfaces, but also the skies above may appear red under sunlit conditions on Mars.
Mars surface color
25825#78
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.
Red
5047537#3
The design of the flag was originally conceived by NASA planetary scientist Pascal Lee during the 1998 Haughton-Mars Project arctic expedition to Devon Island, Canada. In addition to symbolizing liberty as a tricolour flag, the design evokes a vision of the "future history" of Mars in which the planet is transformed from red, to green, and then blue like the Earth. The red bar, which lies closest to the mast, symbolizes Mars as it is today. The green and blue symbolize stages in the possible terraforming of Mars, should humanity ever have the ability and will to undertake such a task; the ethics of terraforming remaining a matter of debate. Kim Stanley Robinson's popular science-fiction trilogy "Red Mars", "Green Mars", and "Blue Mars" also provided inspiration for the flag. Beyond any human-induced terraforming, the color sequence also depicts the environmental change Mars might experience on astronomical timescales as the Sun evolves into a red giant and Mars becomes warmer. In the Pantone Color Matching System (PCMS), the red is the "Red Clay" (18-1454), the green is the "Mint Green" (17-6333), and the blue is the "Imperial Blue" (19-4245).
Flag of Mars
245067#30
In a press release on the removal of the food dyes, the company wrote that "replacing artificial colors across all our products is a complex task. We expect it will take about five years to develop the full range of alternatives that guarantee the integrity and great taste of the products you know and love, and to go through the process of obtaining regulatory approval for all new ingredients in development." Mars has frequently used dyes and artificial colors in many of its products over the years. Due to public outcry calling for change, and a petition that gained more than 217,000 signatures that was created by Change.org, the company wanted to bring about a significant change to the way it was viewed by consumers. There have been two different arguments presented about the use of artificial colors in foods. Many studies have shown that their use in food could be linked to illnesses such as ADHD and cancer. There has seemed to be an issue with the use of red 40, yellow 3, yellow 5 and yellow 6 and how they bind to the DNA in humans. Other additives such as Blue 2 have been linked to the cause of brain tumors in rodents and in 1981, Green 3 was found to be a direct link to bladder cancer. Given the fact that the company will be replacing the artificial dyes in its products, the company has also said that consumers should prepare themselves for the transition process in terms of special packaging and colors being used as to indicate that the changes have taken place. It has been said that the company is not likely to stop using coloring entirely, but that the use of artificial coloring will be going away.
Instead Mars will use natural colors like turmeric in India.
Mars, Incorporated
55308957#30
"M. rubra" gets its red color from consuming cryptophytes, or algae, that contain a red pigment called phycoerythrin in their chloroplasts.  In the Columbia River estuary, "M. rubra" commonly preys on the cryptophyte "Teleaulax amphioxeia." From its prey, "M. rubra" also acquires specialty cellular organs in order to photosynthesize and effectively absorbs these compounds into its own body. This process is referred to as "acquired phototrophy", and for "M. rubra" includes the assimilation of chloroplasts, nuclei, and mitochondria During the day, the ciliates stay near the surface of the water to photosynthesize, which is how the red blooms are easily observed.
Nutrient cycling in the Columbia River Basin
20257#0
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.
Mars in fiction
14640471#84
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.
Mars