The origin and evolution of the terrestrial planets

The Solar System we see today, comprised of a central star orbited by planets, formed from a cloud of dust and gas that collapsed over 4.5 billion years ago. We can learn about the early stages of the Solar System's history by studying meteorites - samples of rocky asteroids (and possibly comets) whose contents provide us with snapshots of the events they have experienced. Some asteroids have remained rather dormant throughout their history, and preserve the very materials that were once swirling around the newly forming Sun. By analysing the primitive meteorites that sample such asteroids, we plan to study the ancient grains they contain in order to find out more about the solar system environment prior to planet formation.

Other asteroids have been much more active, experiencing heating, melting and even igneous and volcanic activity. Any ices present in these bodies have melted, allowing liquid water to react with the rocky materials and produce water-bearing minerals. By studying the minerals in these processed meteorites we aim to learn more about the abundance and distribution of water in the early Solar System.

As well as water, many asteroids and comets also contain organics. These two components are key ingredients to life as we know it. It has been suggested that once the Earth was formed, the water and organic material necessary for the development of life were actually delivered by impacting asteroids and comets. We will therefore also study the transfer of these materials during impacts by mimicking the process in the laboratory using various targets and bolides.

The presence and action of water is not limited to the Earth, asteroids and comets. Missions to Mars have revealed its surface to be strewn with water-bearing minerals but have yet to return samples that we can study in the laboratory. We are fortunate to have a selection of meteorites that originated on Mars in our collection, and we plan to study these to learn about the action of water and the habitability of this planet.

The main people who will benefit from our work, aside from our academic colleagues, are the general public and other scientists who may require analysis at fine spatial scales.

The study of meteorites lends itself to knowledge exchange for two reasons. Firstly, they are typically small and precious samples, and so encourage the development of new techniques that allow for measurement at very high spatial resolution and/or in non-destructive ways. Secondly, meteorites appeal to the public imagination; they are pieces of rock from space, and lend themselves to literally "hands-on astronomy". Every year the group handles several dozen media enquiries (the Meteorites group is second only to Dinosaurs in the number of requests for interviews it receives).

The projects described here rely on innovative techniques that we will develop further to optimise them for extraterrestrial sample research. In particular, the development of synchrotron methods and experimental protocols for the non-destructive study of extraterrestrial materials will have implications and benefits for geoscientists, material scientists and physicists. Our group has been particularly innovative in the use of computed tomography (CT) for dense samples such as meteorites, and this work will continue to develop this aspect. Improvements in software for CT scanning that will form part of our work will have broader applications in the life and physical sciences. In collaboration with our unique X-ray diffraction laboratory, we have developed equipment and optimised methods specifically for the non-destructive analysis of meteorites. By collaboratively providing access to our expertise and specialised X-ray diffraction facilities, we aim to benefit and enhance research across the wider UK cosmochemistry community.

Working at a national museum, we have a remarkable opportunity to engage with the public. For example, we will participate in "Nature Live", a daily event in which a museum scientist describes their work to the public, "Science Uncovered", an annual event where the public can talk to scientists about their work and collections, and contribute to many annual mineral and fossil 'roadshows and festivals'.

In 2018, we will have a particularly exciting opportunity. The museum is planning a temporary gallery on Meteorites, which will give us an unprecedented opportunity to showcase our work and to enhance the cultural wealth of the country.