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S C I E N T I F I C H I G H L I G H T S

E N V I R O N M E N T , E A R T H A N D P L A N E T A R Y S C I E N C E S

The planets of the solar system and beyond are fascinating objects, from their cores, subject to Dantean conditions of pressure and temperature, to their surface, where, in the rare conditions of our planet, life could develop. Understanding the structure and dynamics of these astronomical systems tells us about the conditions of their formation and evolution on geological timescales. This chapter also covers topics directly related to our current environment. Ensuring a high level of development in our societies inevitably involves the production of carbonated and carbon-free waste, potentially harmful to the health of humans, animals and plants. Reducing these risks is certainly one of the most important challenges of our time. In this context, the exceptional characteristics of the ESRF's Extremely Brilliant Source (EBS) can play a key role in understanding and reducing these risks. This chapter provides several examples of how researchers are using the unique capabilities of ESRF-EBS to solve important environmental problems and gain new insights into planetary interiors.

Beauty of nature

Since the ESRF-EBS is located in Grenoble, in the French Alps, let s start with snow. With their purity of detail and the beauty of their structure, these aggregates of ice crystals have always been a subject of astonishment and curiosity. In the first highlight article, A. Robledano et al. conducted microtomography combined with Monte Carlo calculations at beamline ID19 to take a new look at these unique objects that may provide more accurate predictions in climate modelling (page 124).

Deep knowledge

In his famous book, Journey to the Center of the Earth, Jules Verne offers us a fanciful excursion into the depths of our planet. Thanks to the exceptional characteristics of the ESRF-EBS, powerful X-rays add a new (slightly more realistic) chapter to this story. Earth science research has shown that our planet is an extremely complex dynamic system that is far from completely understood.

V. Cerantola et al. have investigated carbon trapping at the boundary between the Earth s core and the mantle (page 126) using non-resonant inelastic X-ray scattering (XRS) at the oxygen K-edge at beamline ID20 and X-ray diffraction (XRD) via pair distribution function (PDF) at ID15A and ID15B. To an even greater depth, A. Dewaele et al. have studied and shed new light on the elastic properties of iron, the main element composing the Earth s core, using inelastic X-ray scattering at ID28 and XRD at ID27 (page 128).

Another way to obtain information about the Earth s interior consists of studying trapped elements contained in the form of inclusions and brought to the surface thanks to the convection movements of the Earth s mantle. This is precisely what H. Moreira et al. have done using X-ray microabsorption near-edge structure spectroscopy at ID21 (page 130).