Astronomy Picture of the Day - powered by LUNEXIT.IT

This dramatic Narrow Angle Camera (NAC) image was acquired by the NASA - MESSENGER Spacecraft during its 2nd Fly-By of Mercury, just when the aforementioned Unmanned Spacecraft approached the Planet's illuminated crescent. Prominent, toward the Mercurian Horizon (Limb) in this view of newly imaged Terrain, is well visible a long "Cliff Face". A small (and still Unnamed) Impact Crater, visible towards the upper left side of the frame, a little after the first half of the Cliff, overlies this lengthy Scarp. (note that, inside such a small Impact Crater, at least other 6 smaller Impact Craters can clearly be seen)

The Scarp extends for over 400 Km (about 250 miles) and likely represents a sign of aging unique to Mercury among the Planets in the Solar System. In fact, as time (actually, millions of years) passes by, the interior of any given Planet cools off; in this case, however, the relative size of Mercury's Central Metallic Core is larger than the one of the other Planets of the Solar System and hence it has significantly affected the Planet’s Geologic Evolution. The numerous long Scarps visible almost all over the Surface of Mercury are believed to be the Surface Expression of "Faults" that formed in the Rocks of Mercury's Crust as the interior of the Planet cooled off and contracted. This contraction caused a strong compression of the Surface and forced (---> pushed) some sections of the Crust over others, so creating long curving Cliffs, just like the one that we can see here.

Date Acquired: October 6, 2008
Image Mission Elapsed Time (MET): 131766454
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Resolution: aoorix. 420 meters/pixel (such as about 0,26 miles/pixel) on the right side of the image
Scale: the small Unnamed (and Multiple) Impact Crater superimposed on the long Cliff is about 30 Km (approx. 19 miles) in diameter
Spacecraft Distance from Mercury: about 16.500 kilometers (such as approx. 10.300 miles)

This frame has been colorized in Absolute Natural Colors (such as the colors that a human eye would actually perceive if someone were onboard the NASA - MESSENGER Spacecraft and then looked outside, towards the Planet Mercury), by using an original technique created - and, in time, dramatically improved - by the Lunar Explorer Italia Team.