The origin and evolution of the terrestrial planets

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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.