MESSENGER spacecraft provides first global topographical model of Mercury
Using data captured byNASA's MErcury Surface, Space ENvironment, GEochemistry, and Ranging(MESSENGER) spacecraft, a team of scientists has constructed thefirst complete digital elevation model (DEM) of the planet Mercury. Thenewly-released map reveals the geographical highs and lows of theinnermost planet in our solar system, as well as highlighting anumber of fascinating surface characteristics.
In total, the MESSENGERspacecraft spent four years in orbit around the planet Mercury.During this time, and under the constant protection of its ceramiccloth sunshade, the resilientlittle 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 thenew global map represents the 15th and final release ofdata from the MESSENGER mission. The spacecraft itself ended itstenure around Mercury almost a year ago today. Having run out of theall-important fuel needed to maintain its orbit, the probe wasleft to smash into the surface of the planet it had spent itsbrief operational life observing.
Stitched together fromover 100,000 smaller images, the newly-released map serves as afitting embodiment of the work carried out by the late roboticadventurer. The map displays in great detail the topographicalcharacteristics 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 (5.38km) beneath its average level. This deepest depth islocated in a double impact crater known as the Rachmaninoff basin.Conversely the highest point on the planet's surface stretches 2.78miles (4.48 km) towards Mercury's tenuous exosphere.
Previous attempts byMESSENGER to create a topographical map of Mercury's surface werethwarted by the spacecraft's highly eccentric mapping orbit, whichmade it difficult for the probe's Mercury Laser Altimeter (MLA)instrument to acquire accurate readings on the planet's southernhemisphere.
Furthermore there areinherent difficulties in imaging Mercury's north polar region.Ordinarily, the Sun is low relative to the polar horizon, creatinglong 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 thefinal major release of data from the MESSENGER, it is not the end ofthe spacecraft's legacy. Beyond characterizing one of our closest planetaryneighbors, mission scientists believe that the 10 terabytes of dataprovided by the probe will be of great use to astronomersattempting to unlock the complex formation process that created the rich andbeautiful Solar System we exist in today.
Scroll down to view an animation of the newly released map of Mercury.