Mercury, located nearest the Sun, has no atmosphere and features an unassuming gray hue.
Scientists have long wondered about Mercury’s true hue ever since the MESSENGER probe sent back photos from its third flyby of this planet, with added colors enhancing chemical and mineralogical differences across regions of Mercury.
It’s a Silver Metal
Mercury is the most minor planet in our solar system and the closest to the sun, giving it a special place in our galaxy. Due to these characteristics, it stands out amongst most rocky planets with its unique dark hue and closeness to our sun.
Mercury, with its heavily cratered surface and lack of atmosphere, features few colorful atmospheric effects visible to observers – giving it its dark gray appearance.
Mercury stands out among our solar system planets by possessing intriguing spectral characteristics. As shown in the graph, its spectrum slopes steeply from shorter wavelengths of light towards longer ones – an effect known as redshift that indicates it contains more carbon than any of the other rocky planets in our system.
Redshift on a planet’s surface is another telltale sign of space weathering over time, mainly if its color turns reddish, like with Mercury.
Before recent studies, experts believed that mercury’s surface was stained dark due to high amounts of iron. But new evidence revealed otherwise; instead, graphite – an earthly material used for making pencils – gives its dark hue.
It’s a Liquid at Room Temperature
Mercury is an intriguing metal, as it is a liquid at room temperature and supports coins while magically dissolving other metals. Furthermore, mercury’s unique chemical makeup enables it to act as a thermometer, while its silvery white hue reflects light differently and produces many colors when lit from within.
Astronomers use color analysis to investigate the composition and history of planets, moons, asteroids, and other celestial bodies in space. By looking at its colors, scientists can understand its mineralogical makeup and how its evolution occurred over time.
The MESSENGER probe captured many true-color images of Mercury’s surface. These intricate photographs reveal an array of vibrant hues on this world, which at first glance appears dull gray to human eyes but can reveal that there is more color here than meets the eye!
Mercury features dark patches of material dispersed across its surface, similar to those seen dotted amongst lunar craters. At first, astronomers thought these dark regions derived their color from iron-rich compounds; however, thanks to MESSENGER data, it seems likely that sulfur-rich combinations give these dark regions their color instead.
Mercury may not be toxic in small doses, but it remains a dangerous material that can poison the body at higher exposures. Mercury may cause symptoms including tremors, pins and needles sensation, loss of coordination, memory issues, mood swings, irritability, and more when consumed or inhaled. Furthermore, mercury contamination of water supplies or even damage to the gastrointestinal tract.
It’s a Dark Metal
Like our Moon, Mercury is a terrestrial planet, meaning its surface is covered with numerous craters. But unlike our Moon, Mercury does not possess an atmosphere, which could explain why it appears darker. Furthermore, being closer to the Sun increases its chances of encountering space debris which further darkens its appearance.
Researchers have long been puzzled by Mercury’s curiously dark hue. But they may now understand its source. Data collected by the MESSENGER satellite, which orbited Mercury from 2011-2015, have shown patches of carbon-rich material covering the surface that obscures it as dark gray. Carbon has the unique property of absorbing and reflecting light differently from other materials on its surface while being immune from volcanic activity that darkens other worlds like Mars or Jupiter.
Scientists have used observations of Mercury to produce a false-color image, depicting regions as lighter or darker than others. With this image, they can study its craters and impacts and compare colors with nearby planets to understand the relative abundance of various elements such as iron or other substances; areas containing more iron will appear darker on Mercury than those without.
It’s a Red Metal
Mercury may appear unassuming from space, but it reveals more color up close than once thought. Thanks to MESSENGER’s four-year exploration of Mercury, scientists now understand its surface is tinted dark gray by patches of carbon-rich material–like that used in pencils–formed when its liquid surface hardened billions of years ago and began cooling and hardening into hard rock.
But that doesn’t make Mercury dull! Astronomers have found that its color allows astronomers to pinpoint regions with higher concentrations of iron – this provides us with insight into its history; areas with an abundance of iron may have been expelled by Mercury’s volcanoes early on, and regions with less iron could be older and more solid terrains.
This color-enhanced global shot of Mercury was produced using images acquired during MESSENGER’s initial flyby and shows its diversity: from its many craters and broad flat spaces where lava has been expelled during volcanic eruptions to regions with blueish hues caused by the presence of argon gas (note that colors in planetary images may vary considerably due to lighting conditions and image processing). You can learn more by visiting the MESSENGER website.
