Janaury 09, 2008
Image Mission Elapsed Time (MET):
Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Mercury has a diameter of 4,880 km (3,033 mi.)
This is one of the earliest images of Mercury returned by the MESSENGER spacecraft.
It was taken in January 2008, when MESSENGER was about to embark upon a seven-year period of exploration and discovery of the innermost planet that would feature three flybys and four years of orbital operations. When this image was taken, our knowledge of Mercury came almost entirely from the flybys of the Mariner 10 spacecraft in the 1970s.
As the end of MESSENGER's long and fruitful journey looms, it's worth looking back at where we started in 2008. We didn't know to expect evidence of volatile loss
across the planet, nor how much of Mercury was covered in volcanic plains
, nor the amount by which the planet contracted as it cooled
, nor even the true size of the mighty Caloris basin
. We did not know what the entire planet's surface looked like
Now, our understanding of Mercury's geological, geophysical, geochemical, atmospheric, and magnetospheric character has been changed forever - the lasting legacy of the MESSENGER mission.
Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
For information regarding the use of MESSENGER images, see the image use policy.