This colorful view of Mercury was produced by using images from the color base map imaging campaign during MESSENGER's primary mission. These colors are not what Mercury would look like to the human eye, but rather the colors enhance the chemical, mineralogical, and physical differences between the rocks that make up Mercury's surface.

( NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington)

One of the universe’s oldest mysteries that continues to puzzle scientists is the dark appearance of the planet closest to the sun, Mercury. However, new research offers a single element as an answer: Carbon.

Thanks to new information supplied by NASA’s MESSENGER, the spacecraft that orbited the shady planet from 2011 and 2015, carbon has been identified as the dark substance coating the planet’s surface.

If this proves to be true, it could mean that Mercury’s original crust was made of graphite, according to a recently published study in the journal Nature Geoscience.

"We think that what we're seeing is the remnants of Mercury's original crust that formed 4.6 billion years ago," lead author Patrick N. Peplowski, who studies MESSENGER data at the Johns Hopkins University Applied Physics Lab, told the Christian Science Monitor.

(More:Mars' Strange Moon Phobos Seen in New Light)

"When you think of charcoal or you think of pencil lead, it's really dark. So if there was a little bit of carbon mixed in with these materials, then that could easily account for the albedo," or the amount of light is reflected, he explained.

However, Mercury’s abundance of carbon would disagree with the amount found in the crust of other planets, like Earth and the moon. Peplowski has an idea of how that may have happened.

He and his team suggest that during the cooling of the terrestrial planets, which were so hot that molten rock oceans covered their surfaces, minerals would crystallize and the most buoyant would float to the top. Those that crept toward the surface would form the planet’s crustwhile the others would be buried beneath the surface.

That dark material sprayed out from the depths of the crater provides evidence that Mercury originally had a graphite crust.

(NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington)

The only mineral that would have floated toward the top of Mercury’s magma ocean? Graphite, a paper in the Journal of Geophysical Research calculates.

This would mean Mercury would’ve started off with a graphite crust, which would’ve later been coated by volcanic activity, giving us the surface we see today.

As for the dark carbon splotches mixed into the crust material we see, those were caused by the impacts of space rocks. The harder the rocks nailed the surface, thelarger the exposed area would appear.

After running a group of three tests on the planet’s coloring using the MESSENGER’s data, Peplowski and his team found they all supported carbon as the darkening agent.

(More:SpaceX's Falcon 9 Launch From an Airplane)

If their tests turn out to be accurate, it would make Mercury unique since the other terrestrial planets have floating surfaces, but not one of them was made up of graphite.

While carbon is an essential component for life, Mercury’s proximity to the sun all but eliminates the possibility of finding extraterrestrials there. However, understanding the levels of carbon is found on the first planet from the sun could give scientists a better idea of how much carbon was around during the formation of the solar system.

"There's so much carbon, it's so different from other planets that it forces us to stretch the boundaries of our understanding of how the solar system formed," said Peplowski.

MORE ON WEATHER.COM:Famous Mercury Craters

Lennon, for John Lennon (1940-1980), an English songwriter, musician, and singer who rose to worldwide fame as a founding member of the Beatles. (USGS/NASA/Getty Image, file)