LIBS Component of the Argon Geochemistry Experiment (AGE)
Understanding the geologic history of
Mars is a fundamental goal of the current Mars exploration program.
The ages of most of the surfaces on Mars are at present very unconstrained.
Crater counts of various terrains give some information on the relative
ages of surface units. However, these can be off due to the possibility
that ice layers covered various portions of the Mars surface in earlier
times. More importantly, the absolute ages are quite highly unconstrained
because the crater production rates as a function of time are relatively
poorly constrained at the orbit of Mars. Are crater production rates
at Mars similar to the Moon, which is at least somewhat better known, or
is Mars’ cratering rate significantly different due to its closer proximity
to the asteroid belt?
Under the direction of Tim Swindle at
the University of Arizona, the Argon Geochronology Experiment is a MIDP
development that combines LIBS and mass spectrometry to perform potassium-argon
dating from a landed spacecraft. Our team is responsible for the
LIBS portion of the instrument, which would determine the major element
composition, particularly the potassium abundance. The sample is
then inserted into an oven to extract the noble gases for analysis, particularly
argon, using a mass spectrometer being developed by JPL. The major
element abundances, combined with helium and neon-21 analyses should also
enable cosmic-ray exposure age dating.
The AGE instrument was the centerpiece
of a Mars Scout proposal named Urey, submitted by Dr. Jeff Plescia.
AGE Prototype