Fireball Hazards in Space and on Earth
Once considered the final frontier, space is no longer an abstract concept. We have landed on the Moon, launched observation satellites to Mars and other planets in our solar system, and explored the Martian landscape with rovers on multiple occasions. Since the first telecommunications satellites took up positions in their geostationary orbits, space applications have become evermore present in our daily lives. From texting and tweeting to NORAD defence systems, all Canadians are united by the growing need for reliable and secure access to space. Thousands of spacecraft, including satellites perform crucial functions while navigating the hostile environment of low-Earth orbit.
To the naked eye, shooting stars are magnificent streaks of light searing across the night sky. A closer look reveals their rocky reality. Travelling at dozens of kilometers per second, these meteors, depending on their trajectories, pose a critical threat to our telecommunications infrastructure. Much like a forecast considers numerous variables to predict possible paths of a hurricane, accurate forecasts of meteor showers and their potential impact zones are crucial to ensuring the endurance and function of assets in space.
Having an accurate picture of the meteor showers headed toward earth is essential for mitigation strategies to protect space assets; satellites can be re-oriented to minimize the likelihood of impact and shelter sensitive equipment from damage. [See right image, All-Sky Camera Network device] Impact mitigation techniques result in satellites going off-line as they can no longer orient as required to perform their functions, and in the case of defence satellites, for example, this can be perilous. Therefore, high-resolution tracking of meteor showers can ensure the highest degree of safety for satellites while minimizing loss of function.
Research by Peter Brown and his colleagues Margaret Campbell-Brown and Paul Wiegert, as well as their collaborations with government and industry partners globally, positions Western University as a world leader in planetary defence. The Brown group’s fully-autonomous meteor observatories are on the pioneering edge and provide exceptionally precise details of meteor trajectories and fragmentation, down to millimetre-sized pieces. This level of precision vastly exceeds the capacity of technologies available in the rest of the field today. They are also creating predictive models for incoming showers, augmenting detailed forecasts beyond simply the observable characteristics.
The direct result of this research safeguards global governmental and industrial investments in telecommunications and defence. This saves billions of dollars annually on repairs while minimizing disruption to the essential services accessed from the ground.
The total replacement value of telecommunications satellites currently on orbit is estimated between 100 and 200 billion dollars. However, the importance of this research is not restricted to low-Earth orbit. Smaller meteors impact the earth on a daily basis, and on average, a meteor of greater size strikes the earth annually, causing an explosion equivalent to 5,000 tonnes of TNT. As recently as 2013, a meteor exploded over Chelyabinsk, Russia causing over $60 million US in window damage. More than 1,500 people sustained injuries caused mainly by flying glass shards, as well as ultraviolet burns.
After the Chelyabinsk explosion, governments and scientific communities around the world turned to Peter Brown’s analysis of the meteor and its subsequent devastation in order to gain a better understanding of the tangible cosmic threats posed to our planet and infrastructure. Analysis by the Brown group of the Chelyabinsk fireball has redefined the parameters used globally to characterize incoming meteors as being potentially damaging to human life and infrastructure.
Results continue to improve meteor detection and tracking techniques so that detailed and accurate communications are now shared with inhabitants of predicted impact zones. With high-resolution meteor tracking and analysis, governments know with much greater certainty which outcomes to expect and how best to act in order to minimize panic and casualties.