Operation of the UK Desert Fireball Network

Meteorites are amongst the most scientifically valuable rocks available to us, but we have virtually no constraint on where they come from. With no spatial context, interpreting the record of early Solar System processes that they contain becomes extremely difficult. Attempts have been made to provide that context, by getting orbits for individual meteorite falls (allowing us to track a sample back to its origin). This can be accomplished either by organised networks of fireball observatories (designed to photograph fireballs, calculate orbits, triangulate fall positions, and recover meteorites), or through chance observation and recovery. But after decades of work only a handful of meteorites with orbits have been recovered. The problem was not numbers of meteorite falls - the Canadian Meteorite Observation and Recovery Project alone observed over 50 meteorite-dropping events. The problem was location. Meteorites are small dark rocks, which are difficult to find in the vegetated areas where previous networks were sited. In fact, there are relatively few places on the Earth's surface where field searches can be mounted with a realistic chance of success. Although this is a significant problem, it has a relatively simple solution: construct a network in a place known to be suitable for recovering meteorites. By December 2007 I had completed construction of a trial network of four fireball observatories in the Australian desert to prove the concept. My team's first search was conducted in October 2008. We recovered the meteorite within 100m of the predicted fall position, on the first day of the search. The paper describing this work appeared in Science in September 2009 and generated substantial media interest, including over 70 articles in online news outlets. Our near-term goal is to pursue funding that would allow us to build a full Desert Fireball Network of ~16 observatories, detecting fireballs over ~1 million km2 of Australia and observing 10-15 falls per year. This is a similar number of observatories to previous networks, and a similar detecting area. The difference here is that putting a network in the Australian desert will allow my team to recover the meteorites. In a single year with this type of network we would deliver more meteorites with orbits than have been recovered in 200 years of observations. In a 3-4 year period we would have a statistically large dataset of meteorites with orbits - a dataset like that would not only revolutionise this field, it would have repercussions far beyond it. Textbooks would be re-written. Linking meteorites to specific near-Earth asteroids through similarities in orbits and reflectance spectra would effectively provide us with sample-return missions to those objects, but without the need for spacecraft. In addition, our calculations show that there is the real potential to observe and recover a cometary meteorite - a true 'Holy Grail' in terms of planetary science sample analysis. The Stardust (US$212 million), Deep Impact (US$330 million), and Rosetta (~US$980 million) space missions are testimony to the value placed on cometary samples as witnesses of early Solar System processes. However, while pursuing funding to significantly expand the system we need to maintain the continuous operation of our trial network. That is the purpose of this proposal. Maintaining current network operations, developing a digital system, and organising fieldwork requires a full-time PDRA. Our current analogue system is observing ~2-3 falls per year: we are also requesting fieldwork funding to cover those searches. Additional recoveries will bolster the case for expanding the system.