The small bodies of our and other planetary systems

拟议的研究计划旨在了解驱动行星系统从初始状态到现在状态的过程。这项研究将通过行星系统的较小天体--矮行星、小行星、彗星和流星体--亚行星体或简称SPBS的透镜进行。在我们自己的太阳系中，SPB数量丰富、分布广泛、大小和成分多样。我们银河系中的大多数恒星也有行星系统，其中许多已知也有SPBS。因此，SPBS是从行星系统到银河系本身的丰富信息来源。*这一研究问题将通过三个主要主题来解决：i)建立我们太阳系目前的亚行星体储存库；ii)利用流星作为低成本的“样本-返回任务”，向它们在太空中的父母了解情况；以及iii)利用我们对太阳系的理解来探索系外行星系统。*亚行星体具有重要的科学意义。1)它们是地球和其他行星(无论是在我们的系统内还是在系外系内)形成的成分，因此它们是行星诞生时代的“化石”。2)行星系内SPBS的当前位置是其内部大尺度变化的示踪物。例如，行星围绕恒星的轨道是否比现在更近或更远？3)与恒星同时形成的SPBS，为恒星的诞生过程提供了重要的洞察。*在更广泛的背景下，SPBS对于研究地球上的生命及其环境很重要，因为1)它们向我们的星球输送了水和碳基有机分子，2)SPBS通过大规模的小行星撞击和灭绝事件塑造了地球上的生命。*SPBS也与整个社会相关。1)流星雨很容易到达，让普通公众参与科学。2)最亮的流星事件(“火球”)，如2013年2月俄罗斯车里雅宾斯克市上空的流星事件，构成了一种尚未完全了解的公共危险。车里雅宾斯克爆炸事件在到达之前没有被发现，并在一个主要城市上空释放了30倍于广岛原子弹的能量。由此引发的爆炸给建筑物造成了3300万美元的损失，并导致1500人接受治疗。3)最大的小行星对我们整个地球构成了一个微小但不可忽视的威胁，并在最高政治级别产生了回应。例如，在1994年和2005年，美国国会明确授权NASA寻找危险的近地小行星，并分析偏离它们的选择，这一点已经被《纽约时报》(NY Times)(《NASA面临资金短缺寻找致命小行星》，2007年3月12日)和彭博社(Bloomberg)(《一颗小行星可能杀死我们所有人。国会正在勒紧钱币》，2017年5月11日)等报道过。由于所有这些原因，SPBS既具有科学意义，又与加拿大人和全球社会相关。**

The proposed research program is directed at understanding the processes that drive a planetary system from its initial to its present state. This research is to be conducted through the lens of a planetary system's smaller bodies -- dwarf planets, asteroids, comets and meteoroids – sub-planetary bodies or SPBs for short. SPBs are abundant, widespread and diverse in size and composition in our own solar system. Most stars in our galaxy also have planetary systems and many are known to contain SPBs as well. As a result, SPBs are rich sources of information at scales from planetary systems up to the Galaxy itself.***This research problem will be addressed through three major themes: I) establishing the current reservoirs of sub-planetary bodies in our solar system II) using meteors as low-cost 'sample-return missions' to learn about to their parents in space, and III) using our understanding of the Solar System to explore exoplanetary systems.***Sub-planetary bodies are important scientifically. 1) They are the ingredients from which Earth and other planets (both in our system and exoplanetary systems) formed, and so they are 'fossils' from the era of planet birth. 2) SPBs current locations within a planetary system are tracers of large-scale changes within it. For example, did the planets perhaps orbit their star closer to or farther away than they do now? 3) SPBs formed at the same time as their star, providing important insight into the process of star birth.***In a broader context, SPBs are important to the study of life on Earth and its environment because 1) they delivered both water and carbon-based organic molecules to our planet, 2) SPBs have shaped life on Earth through large asteroid impacts and extinction events.****SPBs are also relevant to society at large. 1) Meteor showers are easily accessible and engage the general public in science. 2) The brightest meteor events ('fireballs'), such as the one over the Russian city of Chelyabinsk in February 2013, constitute an incompletely understood public danger. The Chelyabinsk event was undetected prior to its arrival and released 30 times the energy of the Hiroshima bomb over a major city. The resulting explosion caused $33 million USD damage to buildings, and sent 1500 people for medical treatment. 3) The largest asteroids pose a small but non-negligible threat to our entire planet and have generated responses at the highest political level. For example, in 1994 and again in 2005, US Congress specifically mandated NASA find hazardous near-Earth asteroids and analyze options for deflecting them, This has been reported on by, for example, the NY Times ('NASA faces funding crunch to find killer asteroids', March 12 2007) and Bloomberg ('An Asteroid May Kill Us All. Congress Is Pinching Pennies', May 11 2017). For all these reasons, SPBs are both scientifically interesting and of relevance to Canadians and to the global community.**