MESSENGER spacecraft provides first global topographical model of Mercury
Using data captured by NASA's MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft, a team of scientists has constructed the first complete digital elevation model (DEM) of the planet Mercury. The newly-released map reveals the geographical highs and lows of the innermost planet in our solar system, as well as highlighting a number of fascinating surface characteristics.
In total, the MESSENGER spacecraft spent four years in orbit around the planet Mercury. During this time, and under the constant protection of its ceramic cloth sunshade, the resilient little spacecraft characterized Mercury with a suite of advanced scientific instruments, and captured almost 300,000 images of the planet's baked, barren surface.
The publishing of the new global map represents the 15th and final release of data from the MESSENGER mission. The spacecraft itself ended its tenure around Mercury almost a year ago today. Having run out of the all-important fuel needed to maintain its orbit, the probe was left to smash into the surface of the planet it had spent its brief operational life observing.
Stitched together from over 100,000 smaller images, the newly-released map serves as a fitting embodiment of the work carried out by the late robotic adventurer. The map displays in great detail the topographical characteristics of the tortured planet, most notably the vast collection of impact craters that have accrued in part thanks to Mercury's lack of any significant from of atmosphere.
At its lowest point, Mercury's surface plunges some 3.34 miles (5.38 km) beneath its average level. This deepest depth is located in a double impact crater known as the Rachmaninoff basin. Conversely the highest point on the planet's surface stretches 2.78 miles (4.48 km) towards Mercury's tenuous exosphere.
Previous attempts by MESSENGER to create a topographical map of Mercury's surface were thwarted by the spacecraft's highly eccentric mapping orbit, which made it difficult for the probe's Mercury Laser Altimeter (MLA) instrument to acquire accurate readings on the planet's southern hemisphere.
Furthermore there are inherent difficulties in imaging Mercury's north polar region. Ordinarily, the Sun is low relative to the polar horizon, creating long shadows that work to mask the characteristics of the rocks present in the terrain. However, by utilizing the probe's Mercury Dual Imaging System (MDIS) to capture the region in five separate narrow-band filters when the shadows were at their least obtrusive, the team was able to complete the global map.
Whilst the map is the final major release of data from the MESSENGER, it is not the end of the spacecraft's legacy. Beyond characterizing one of our closest planetary neighbors, mission scientists believe that the 10 terabytes of data provided by the probe will be of great use to astronomers attempting to unlock the complex formation process that created the rich and beautiful Solar System we exist in today.
Scroll down to view an animation of the newly released map of Mercury.