Mariner 10, the only spacecraft to visit Mercury prior to the MESSENGER
mission, imaged about 45% of the planet’s surface. On January 14 of this
year, MESSENGER successfully completed its first of three planned flybys
of Mercury, and during that encounter MDIS snapped the first images from
spacecraft of an additional 21% of Mercury’s surface. On October 6, 2008,
one week from today, MESSENGER will again fly by Mercury, and this time
the 1287 planned MDIS images will cover much of the remaining portion of
Mercury’s surface not yet seen by spacecraft. This figure shows a map of
Mercury’s surface with images from Mariner 10 overlaid by NAC mosaics
(outlined in white) acquired during MESSENGER’s first Mercury flyby. The
map is shown using the planetocentric positive-east convention that has
been adopted by the MESSENGER project. MESSENGER’s first flyby of Mercury
covered two general areas of Mercury surface: the crescent view of Mercury
seen as the spacecraft approached the planet (see PIA10179) and the fuller view
of Mercury acquired as the spacecraft departed (see PIA10172). Similarly, Mercury
will appear as a thin crescent during the inbound portion of MESSENGER’s
second Mercury flyby and as a nearly full disk during the outbound portion
of the encounter, and the areas of the surface that will be imaged by the
NAC are shaded in purple. As seen in this figure, MESSENGER’s second flyby
will result in nearly global spacecraft imaging coverage of Mercury’s
surface for the first time.
Date Acquired: Mariner 10 images: 1974-1975. MESSENGER flyby 1
images: January 14, 2008
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging
System (MDIS)
Scale: Mercury’s diameter is 4880 kilometers (3030 miles)
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.