Ellie Sansom (Curtin University)

Ellie Sansom Colloquium: A Global Fireball Observatory for planetary defence: a multidisciplinary approach

Kensington/Teams

Abstract

When asteroids hit the Earth's atmosphere, they produce light, heat and shock waves. Observing these phenomena, from the fireball to the seismic and infrasound, gives us a huge amount of information about the impacting object. We can calculate where they came from (their orbit), what they're made of (geochemistry), size of the object, and even where any meteorites might land. Large, hazardous asteroid impacts are rare, and civilisation-ending events from km-sized asteroids are relatively well constrained. But, metre sized objects are still capable of posing a threat to people and property. Understanding these larger (>1 m diameters) events is fundamental to understanding the numbers of hazardous objects in the inner solar system; a key component to planetary defence.

The Global Fireball Observatory is a planetary-scale observational facility for rare, fireball events occurring when asteroids hit our atmosphere. Multi-sensor observations allows us to characterise these objects and inform the size frequency distribution of near Earth objects, underlying planetary defence efforts.