Planetary Science
The planetary science group within the ICC studies: the distribution of near-surface hydrogen/water ice on the Moon, Mars and Mercury; the consequences of giant planetary impacts with high resolution simulations; the lunar argon exosphere and its connection with potassium in the Moon; and the distribution of lunar thorium and what it tells us about the internal structure of the Moon.We use data from a variety of instruments and various analysis and modelling techniques: neutron spectroscopy, gamma-ray spectroscopy, synthetic aperture radar measurements, image reconstruction, Monte Carlo exospheric simulations and smooth particle hydrodynamical simulations.
| Simulation of a collision between the proto-Earth and a Mars-sized impactor. Different colours represent the iron core and rocky mantle of each body. After the collision, a Moon-like satellite with a small iron core is left in orbit around the Earth. | |
Video description: A smooth particle hydrodynamics (SPH) simulation showing a giant impact between the proto-Earth and a Mars-sized body. The iron cores (shown in one colour) and rocky mantles (shown in another) of each body are tracked through the collision. The simulation shows how the impact ejects material into orbit, eventually forming the Moon with a small iron core, consistent with lunar samples.
Planetary giant impacts.
We use high-resolution hydrodynamical simulations using SWIFT on the COSMA
supercomputer, operated by the ICC on behalf of DiRAC, to investigate
collisions between planetary bodies. These studies have explored the
formation of the Moon, the origin of Uranus's extreme tilt, the effects of
giant impacts on planetary atmospheres, if a collision of icy moons can lead
to Saturn's rings, and a hypothesis for mixing distinct material layers in
the deep interior of Jupiter.
We also develop the hydrodynamical methods in SWIFT and the WoMa and SEAGen
python software to create efficient initial conditions for planetary impact
simulations.
See http://icc.dur.ac.uk/giant_impacts for more animations and details.
 | Mid-collision snapshots from a smoothed particle hydrodynamics (SPH) simulation with over 10 million particles, coloured by their internal energy. |
Water ice in the inner Solar System.
We use a variety of remote sensing techniques: neutron spectroscopy, radar
and laser altimetry, combined with advanced image reconstruction techniques
to map hydrogen near the surface of the Moon, Mars and Mercury.
These studies have: demonstrated that permanently shadowed lunar polar
regions contain enhanced hydrogen concentrations, providing strong evidence
for water ice; produced the best available near-surface seasonal hydrogen
maps across the entirety of Mars, showing how widespread hydrogen is even in
equatorial regions; placed an upper limit on the thickness of Mercury's ice
deposits in polar craters, helping constrain the origin and long-term
evolution of water ice in the inner Solar System.
The lunar interior.
We also study the lunar interior indirectly by seeing what has come out
through the surface. This can be in the form of thorium, which is an
important tracer of lunar differentiation and volcanic activity. Using
gamma-ray observations and image reconstruction techniques, we study its
distribution across the lunar surface to better understand the Moon's
geological history and the evolution of unusual volcanic regions such as
Compton-Belkovich.
Argon released from the lunar interior also provides a unique probe of both
the Moon's geology and its interaction with the space environment. Using
Monte Carlo simulations, we investigate the transport and trapping of argon
within the lunar exosphere and explore what it reveals about outgassing,
volatile migration and polar cold traps.