"The spider" now has an official name: Pantheon Fossae. As first presented
at the NASA press conference on January 30 (see PIA10397), when MESSENGER
flew by Mercury on January 14, 2008, the Mercury Dual Imaging System
(MDIS) snapped images of an intriguing and previously unknown feature on
the surface of Mercury. Near the center of the Caloris basin, a set of
troughs (called graben by geologists) was observed to radiate outward in a
pattern unlike anything ever seen on Mercury. The Science Team nicknamed
this unique feature "the spider." The International Astronomical Union
(IAU) recently approved the official name of Pantheon Fossae, as detailed
in the MESSENGER press release issued last week.
The word fossa is Latin and means trench. The term is used in planetary
geology to name features that are long, narrow, shallow depressions.
Fossae, the plural of fossa, have been named on planetary bodies including
Mars, Venus, and the Moon, but Pantheon Fossae are the first to be named
on Mercury. The name is taken from the Pantheon in Rome, an ancient temple
with a classic domed roof. The dome of the Pantheon has a series of sunken
panels that radiate from a central circular opening at the top of the
dome, and Mercury's Pantheon Fossae is reminiscent of this pattern.
Consequently, the crater near the center of Pantheon Fossae is now named
Apollodorus, who is credited by some as being the architect of the
Pantheon. Apollodorus, shown in the middle of this Narrow Angle Camera
(NAC) image, has a diameter of 41 kilometers (25 miles). MESSENGER
scientists are debating whether Apollodorus played a role in the formation
of Pantheon Fossae or whether the crater is simply from a later impact
that occurred close to the center of the radial pattern.
Image Mission Elapsed Time (MET): 108828901
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.