This figure shows a 400-kilometer-long (250-mile-long) section of the MLA
profile from MESSENGER’s second Mercury flyby superposed on a
high-resolution NAC departure mosaic acquired during the same encounter.
The blue dots indicate the spacecraft ground track, and the yellow dots
show the altimetry data points; the blue arrow shows the spacecraft’s
direction of travel. Near the center of this profile, the MLA track
crosses two craters of comparable sizes but different depths (outlined by
yellow circles in the lower left figure). The deeper crater in the center
of the track is Machaut crater (see PIA11249), while the unnamed crater to
Machaut’s east is considerably shallower. The lower right figure compares
the depths of the two craters, indicating the difference measured by MLA
with orange arrows. From the NAC mosaic it is apparent that the shallower
crater has been filled, probably by volcanic material. By making such
measurements systematically over the surface, it will be possible to
measure the volumes of volcanic material erupted over Mercury’s history.
Date Acquired: October 6, 2008
Instrument: Mercury Laser Altimeter (MLA), Narrow Angle Camera (NAC)
Scale: Machaut crater is 106 kilometers (66 miles) in diameter
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.
