Mars is interesting as a potential habitation
site in the future because of the presence of volatiles such as CO2
and H2O on the planet. These can supply water, oxygen and fuel, but
our ability to plan settlements on Mars depends on our understanding of the
long term behaviour of these volatile reservoirs. The clue lies in the sand. Sand
movement on Mars is sensitive to atmospheric density, which in turn is
modulated by cyclic release or absorption of CO2 and H2O
from Martian ice caps (and soil) during hot or cold climates, respectively. Currently,
Martian climate-landscape interaction models predict where and when the
volatiles (CO2 and H2O) will or will not be absorbed; however,
there is no experimental validation of such models. If it were possible to date
the episodes of sand formation, then one can directly assess the reliability of
such models. Just like on Earth, such a validation can be obtained using in-situ
dating of the Martian landscape (obtaining the time when it formed).
2. The project
This project is about enabling the necessary
transfer of luminescence dating technology to Martian conditions. The aim of
the project is to give basic insights into the luminescence and dosimetric
behaviour of a whole new class of hitherto poorly studied natural dosimeters. State
of the art experiments based on photoluminescence and optically stimulated
luminescence will be
carried out to study the optical behaviour of Martian analogue
samples. The focus will be to understand signal stability, luminescence
lifetimes (for signal separation), and the effect of low temperature and deep
UV radiations on Mars using the newly discovered IRPL signal (https://www.nature.com/articles/s41598-017-10174-8).
Experiments will mainly
be performed on Risø TL OSL readers and COLUR
(station for Cryogenic luminescence research) at DTU Nutech.
The results of this project will provide
important new knowledge in luminescence/solid state physics. The activity has
important spinoffs in terms of developing methods for luminescence dating on
Earth, by enabling sediment dating in Martian-like volcanic sediments that
cover large areas of the Earth (e.g. basalt provinces etc.). This work
complements European Space Agency’s activity on the development of a
miniaturised instrument for in-situ sediment dating on Mars (21506/08/NL/IA);
this is an important step towards allowing future Mars landers to directly date
sand deposits using robots.
3. Learning objectives
At the end of the project you will be able to:
Describe the luminescence dating technique and
the effect of ionising radiation on wide bandgap materials.
Understand and describe the photonic
techniques involved in dosimetry: optically stimulated luminescence,
photoluminescence, low temperature pump-probe measurements, time resolved luminescence
Determine the OSL age of a sand sample.
Demonstrate the use of the relevant scientific
instruments and data analysis techniques.
Write a scientific report, potentially a
(Picture Credits: NASA)
curious mind; inclination to do experiments; an interest in solid state physics/photonics will be helpful