Operation of the UK Desert Fireball Network

陨石是我们能找到的最有科学价值的岩石之一，但我们对它们的来源几乎没有任何限制。由于没有空间背景，解释它们所包含的早期太阳系过程的记录变得非常困难。人们试图通过获取单个陨石福尔斯坠落的轨道来提供这种背景（使我们能够跟踪样本回到它的起源）。这可以通过有组织的火球观测站网络（设计用于拍摄火球，计算轨道，三角测量坠落位置和回收陨石）或通过偶然观察和回收来实现。但经过几十年的工作，只有少数陨石的轨道已被恢复。问题不在于陨石福尔斯坠落的数量-仅加拿大陨石观测和回收项目就观测到50多起陨石坠落事件。问题是位置。陨石是黑色的小岩石，在以前的网络所在的植被地区很难找到。事实上，在地球表面上，实地搜索可以获得实际成功机会的地方相对较少。虽然这是一个重要的问题，但它有一个相对简单的解决方案：在已知适合回收陨石的地方建造一个网络。到2007年12月，我已经在澳大利亚沙漠中完成了一个由四个火球观测站组成的试验网络的建设，以证明这一概念。我的团队于2008年10月进行了第一次搜索。在搜寻的第一天，我们在预测坠落位置的100米范围内找到了陨石。描述这项工作的论文于2009年9月发表在《科学》杂志上，引起了媒体的极大兴趣，包括在线新闻媒体的70多篇文章。我们的近期目标是寻求资金，使我们能够建立一个完整的沙漠火球网络的~16个观测站，检测火球超过100万平方公里的澳大利亚和观察10-15福尔斯每年。这是一个类似数量的观测站到以前的网络，和一个类似的检测区域。不同的是，在澳大利亚沙漠中建立一个网络将使我的团队能够恢复陨石。在这种类型的网络中，我们将在一年内提供比200年观测中回收的更多的陨石。在3-4年的时间里，我们将拥有一个统计上庞大的陨石轨道数据集--这样的数据集不仅会给这个领域带来革命性的变化，而且会产生远远超出这个领域的影响，教科书将被重写。通过轨道和反射光谱的相似性将陨石与特定的近地小行星联系起来，将有效地为我们提供对这些物体的采样返回任务，而不需要航天器。此外，我们的计算表明，有真实的潜力，以观察和恢复彗星陨石-一个真正的“圣杯”方面的行星科学样本分析。星尘号（2.12亿美元）、深度撞击号（3.3亿美元）和罗塞塔号（约9.8亿美元）太空任务证明了彗星样本作为早期太阳系过程见证者的价值。然而，在寻求资金以大幅扩大该系统的同时，我们需要保持我们的试验网络的持续运作。这就是本建议的目的。维持当前的网络运营，开发数字系统和组织实地工作需要一个全职的PDRA。我们目前的模拟系统每年观测到约2-3次福尔斯：我们还要求提供实地调查资金，以涵盖这些搜索。更多的回收将支持扩大该系统的理由。

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.