Reconstructing thermal and fluid alteration histories of planetary materials

Lead Research Organisation: Scottish Universities Environmental Research Centre (SUERC)
Department Name: SUERC

Abstract

In this consortium scientists from three UK institutions have come together to explore the development of rocky bodies within our solar system, and particularly in relation to the presence and properties of the key ingredients for life, namely water and carbon-rich molecules.

One focus of our work will be on asteroids, samples of which have come to Earth as meteorites. These objects formed very early in the history of the solar system and evolved quickly, probably driven by internal heat from the decay of radioactive chemical elements. We want to know where in the solar system some of these asteroids formed, how long it took them to grow and how quickly they cooled down. We would also like to understand how heating and cooling affected water and carbon-rich molecules that became incorporated into the asteroids as they grew. These questions will be answered by using isotope analysis to determining the ages of different types of minerals, and by studying changes to the structure of carbon-rich compounds with laser beam techniques. Results from this work will provide new understandings of the evolution of asteroids that can be used to help interpret samples of them that will soon be returned to Earth by robotic missions.

We will also study meteorites from Mars. This planet is an intermediate stage in evolution between the asteroids, which 'died' as they lost their heat and liquid water thousands of millions of years ago, and the Earth that remains an active planet with internal heat, liquid water and complex carbon-rich molecules including life. The Martian meteorites that we will analyse formed about 1300 million years ago when the planet was still hot enough that parts of its outer surface could melt, and they preserve traces of liquid water that flowed through the rocks. By studying the minerals in these rocks and the chemical elements from which they are made, we will explore how crystals grew as the molten rock cooled, and will also determine when the water was present. Today the surface of Mars is very hostile to life, with extremes of temperature, little or no liquid water and intense irradiation by ultraviolet light. However, brief occurrences of water on the surface of Mars today, and past hot-spring sinter deposits, may contain evidence of life, yet their propensity to do so is poorly understood. As sending robotic geologists to Mars is very costly, we will discover whether these environments can harbor molecular signs of life by studying martian analogue sites in the mountains of Chile. Soils in these areas are very dry, their temperatures fluctuate over a wide range and they are bathed in ultraviolet light. We will try to find traces of past life in these soils, and we will explore molecular preservation further by simulating martian conditions in the laboratory. This new information will tell us where on Mars we should focus the search for traces of life during future robotic and manned missions.

The results of this research will be made freely available to other scientists worldwide so that improved models of planetary evolution can be developed. These new data and models will then help to guide the future exploration of asteroids and Mars, including the exciting missions in the next few tens of years that will return samples to Earth. Our research will also be of interest to scientists who study the history of the Earth, its climate and its life, and to industry through the new analytical procedures and technologies that we will develop. As our work will explore new and exciting science topics, it will be of great interest to the public and will be communicated via science festivals, newspapers and social media.

Planned Impact

Research undertaken by the consortium will be of benefit to industry, the public sector, the general public, students from secondary school through University to lifelong learners, and to academics outside of planetary science.

Industrial beneficiaries will principally be manufacturers of research equipment including mass spectrometers, electron microscopes and Raman spectrometers. They will gain valuable technical information from seeing first-hand the performance of their instruments when being used to analyse very complex samples. These companies will also acquire high quality results that can be used as case studies in their marketing information. Over the timescale of the consortium these benefits will enhance the economic competitiveness of these manufacturers, most of whom are UK-based.

Public sector beneficiaries will include the museums and science centers that consortium members will visit to disseminate recent results via talks and workshops, and several such events will take place during the research programme. These outreach events will also broaden and enhance the science understanding of members of the public and will demonstrate how STFC funds are being used to tackle very important and significant questions. Those people without an existing interest in STFC science will learn more about our science and technology results from press releases, outreach materials that will made available on websites, 'sound bite' items disseminated via social media (e.g. Twitter), and by participation in 'pop-up museum' events in shopping centers and other public places.

A cohort of postdoctoral and postgraduate researchers will be trained during the consortium programme and this will enhance their technical and transferable skills. Some of these researchers will then move to industry where these skills will boost business competitiveness, for example through improvements in product design and marketing. Other researchers will stay in academia where they will be able to use science results from the consortium along with the technical understanding that they have acquired to enhance teaching and learning. The graduates from these institutions will be more highly skilled and knowledgeable, which will have follow-on benefits for their private and public sector employers.

Academics outside of STFC science will also benefit from the research undertaken. They may include scientists wishing to improve methods for argon isotope dating (e.g. Quaternary geochronologists), people who study hydrocarbon generation and migration in sedimentary basins, and climate change scientists using proxies such as corals to quantify changes in Earth surface temperatures.

Publications

10 25 50