Two weeks ago, on January 14, 2008, MESSENGER became the first spacecraft
to see the side of Mercury shown in this image. The first image
transmitted back to Earth following the flyby of Mercury (PIA10172), and
then released to the web within hours, shows the historic first look at
the previously unseen side. This image, taken by the Wide Angle Camera
(WAC) of the Mercury Dual Imaging System (MDIS), shows a closer view of
much of that territory.
Just above and to the left of center of this image is a small crater with
a pronounced set of bright rays extending across Mercury's surface away
from the crater. Bright rays are commonly made in a crater-forming
explosion when an asteroid strikes the surface of an airless body like the
Moon or Mercury. But rays fade with time as tiny meteoroids and particles
from the solar wind strike the surface and darken the rays. The prominence
of these rays implies that the small crater at the center of the ray
pattern formed comparatively recently.
This image is one in a planned set of 99. Nine different views of Mercury
were snapped in this set to create a mosaic pattern with images in 3 rows
and 3 columns. The WAC is equipped with 11 narrow-band color filters, and
each of the 9 different views was acquired through all 11 filters. This
image was taken in filter 7, which is sensitive to light near the red end
of the visible spectrum (750 nm), and shows features as small as about 6
kilometers (4 miles) in size. The MESSENGER team is studying this
previously unseen side of Mercury in detail to map and identify new
geologic features and to construct the planet's geological history.
Mission Elapsed Time (MET) of image: 108827618
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.