This figure shows about a 1,600 kilometer-long (1,000 mile-long) section
of the MLA profile from MESSENGER’s second Mercury flyby superimposed on a
portion of the NAC approach mosaic from the mission’s first Mercury
encounter (see PIA10605). The blue line indicates the spacecraft ground
track, and the yellow dots show the altimetry data points; the blue arrow
shows the spacecraft’s direction of travel. This hemisphere has about 70%
of the range in topography sampled by MLA during the first Mercury flyby
(see PIA10394) and so this part of the equatorial hemisphere is smoother
than that sampled last January. Near longitude -97° (263°E) there is a
wrinkle ridge nearly 1 kilometer high (yellow arrow and white box
containing a magnified view) that indicates horizontal shortening of the
crust, possibly the result of global contraction associated with the
cooling of the interior. In the longitude range of -115° to -120° (245°E
to 240°E), the instrument sampled several craters of different depths with
tilted floors (tilts of -0.5° to -0.2°; example indicated with a white
arrow) that may have been the result of deformational processes.
Date Acquired: January 14 and October 6, 2008
Instrument: Mercury Laser Altimeter (MLA), Narrow Angle Camera (NAC)
Scale: The MLA track shown is about 1,600 kilometers (1,000 miles) long
These images are from MESSENGER, a NASA Discovery mission to conduct the
first orbital study of the innermost planet, Mercury. For information
regarding the use of images, see the MESSENGER image use policy.