First-Ever Complete Map of Mercury Reveals Its Violent Volcanic Past

For the first time ever, planetary oddball Mercury comes to life in stunning new images that hint at its violent, volcanic past.

NASA's new global digital elevation model (DEM) of Mercury has finally mapped the planet's strange, ancient surface in its entirety. Up until now, Mercury's southern hemisphere has remained largely a mystery.

The MESSENGER mission began in 2011, traveled 4.9 billion miles, and marked the first time a spacecraft had successfully orbited Mercury. Of all the terrestrial worlds that occupy our solar system, this tiny rocky planet was the least explored and understood. And although the probe completed 4,104 orbits around Mercury, previous attempts to detail its south pole were foiled by the mission's highly erratic and egg-shaped trajectory at the outset of its orbit.

MESSENGER's expeditions ceased one year ago when the probe made an unexpected impact with Mercury's surface, but researchers are continuing to extract and archive mission data, such as the remarkably detailed topographical images released by the agency today.

"The creation of this map is a prime example of the utility and beauty that can come out of overcoming complex cartographic problems," Lazlo Kestay, USGS Astrogeology Science Center Director, said in a statement. "This highly aesthetic product literally provides a whole new dimension to the study of Mercury images, opening many new paths to understanding the surface, interior, and past of the closest planet to the sun."

More than 10,000 images were compiled to create the new digital topography model. An exciting array of never-before-seen volcanos and craters are now clearly visible, and combined with other MESSENGER data sets, have allowed researchers to identify many of Mercury's landforms.

Astrogeolgists are especially interested in the planet's lowest elevation point, which bottoms out more than three miles below Mercury's average. Located on the floor of the Rachmaninoff basin, this region is believed to feature some of the planet's most recent volcanic deposits.

"This has become one of my favorite maps of Mercury," said Nancy Chabot, a project scientist at the Johns Hopkins University Applied Physics Laboratory. "Now that it is available, I'm looking forward to it being used to investigate this epic volcanic event that shaped Mercury's surface."

Mercury's north pole—which researchers found covered in now-extinct volcanic activity—is highlighted in striking color. Every last crater, ridge, and pyroclastic deposit can be seen in high-resolution. With these maps, NASA and its mission partners hope to fully piece together Mercury's geologic history that's unlike any other known terrestrial planet.

So far, the archival organization Planetary Data System has release more than 10 terabytes of Mercury science data, including 300,000 images, maps, and interactive tools for public use. And through these continued scientific revelations, MESSENGER's intrepid legacy lives on.