MPW London: Latest News
MPW tutor wins exciting research opportunity!
22 December 2016
As well as teaching A2 Geology at MPW, our tutor Martin Suttle is working towards a PhD in planetary science at Imperial College London. The title of his thesis is “Investigating the sources of fine-grained micrometeorites: past and present”. Which, in simpler terms means he aims to better understand which asteroids are producing significant quantities of dust and subsequently, sending this dust to Earth. The study of extra-terrestrial dust, or micrometeorites as they are called, is important, not only because this material provides a means of studying the early Solar System history but also because the Earth receives more than 40,000 tonnes of cosmic dust each year. Which, if considered over the entire of Earth’s history amounts to a global 4 metre thick deposit!
Today, scientists collect micrometeorites from Antarctic ice, by melting and filtering. The residues are then searched under a binocular microscope. The South Pole is the ideal location for micrometeorite collection as the ice is clean and free from urban pollutants which, under the microscope can look strikingly similar to extra-terrestrial dust. For example, little spherules formed from firework explosions, welding, smelting and car exhausts are common in dust on the rooftops of all buildings in the UK. Once the extra-terrestrial dust is recovered, it is analysed at the Natural History Museum using high resolution scanning electron microscopes (SEM). This allows scientists to chemically analyse material less than 1/100th the thickness of a human hair.
Specifically, in Martin’s project he wishes to compare the infrared spectra of dust grains analysed in the lab against the infrared spectra of individualasteroids, collected from ground-based telescopes. In doing so, he will be able to test the current hypothesis that the young Veritas asteroid family is responsible for the majority of cosmic dust arriving on Earth. To facilitate this, he recently travelled to the Institute of Planetary Research (in German the Deutsches Zentrum für Luft- und Raumfahrt which is abbreviated to the DLR) in Aldershof, Berlin. This facility is part of the larger European Space Agency (ESA). The DLR has some amazing analytical equipment and includes a lab designed specifically to collect infrared spectra from meteorites and analogue materials (that is, synthetic materials designed to simulate asteroids). Martin spent a week at the Berlin branch just before Christmas, collecting as much data as he could. As in any discipline, it’s important to make the most of the opportunities available and with this in mind he collected spectra from all of his micrometeorites (~50 individual grains) and from a selection of meteorites, on loan from the Natural History Museum. Due to the large volume of data he has yet to get his head around the results but hopes to have some conclusions on the Veritas hypothesis soon. In the meantime, it’s back to school and preparing our students for the mocks.