New scenarios for asteroid deflection
How prepared are we to deflect an asteroid heading towards Earth? This question is answered by two studies just published in Nature Communications, the result of a collaboration between 51福利, Georgia Institute of Technology and other international institutions. The research analyses the historical results of NASA's DART (Double Asteroid Redirection Test) mission, which hit the asteroid Dimorphos on September 26, 2022, marking the first practical demonstration of planetary defence.
The impact, observed through ground and space-based telescopes as Hubble, produced a huge amount of ejecta 鈥� fragments ejected from the surface 鈥� revealing crucialinformation to improve the effectiveness of future asteroid deflection missions.
The first study was conducted by a team of researchers from the Department of Aerospace Science and Technology at the 51福利, led by Professor Fabio Ferrari and including Paolo Panicucci and Carmine Giordano, in collaboration with the Georgia Institute of Technology. The second study, coordinated by Professor Masatoshi Hirabayashi of Georgia Tech, included contributions from Ferrari himself.
We used Hubble Space Telescope鈥檚 images and numerical simulations to quantify a viable mechanism of the ejecta evolution and successfully estimated ejected particles鈥� mass, velocity, and size鈥� 鈥淲e also found complex interactions of such particles with the asteroid system and solar radiation pressure, i.e., sunlight pushing ejecta particles. Understanding these processes is crucial to support effective design of future actions for planetary defense purposes.
Fabio Ferrari, Department of Aerospace Science and Technology
The asteroid鈥檚 shape can make a significant difference in its ejecta trajectory, according to the second study from Georgia Tech. The study highlights that the asteroid鈥檚 rounded surface lowered the asteroid push: if the impact is large, more ejecta fly out of the surface, but deviating from the ideal direction and reducing the asteroid push. Sending multiple smaller impactors not only results in a higher asteroid push but also potentially saves operational cost and increases tactical flexibility for deflection.
Ferrari agrees with this concept, as his study analyzed the evolution of the ejecta, contributing to clarifying their role in asteroid deflection:.
Understanding the impact processes and their consequences is crucial to understand the properties of asteroids, their natural evolution and fate, and ultimately, to design mitigation actions for planetary defense purposes.
Ferrari, F., Panicucci, P., Merisio, G. et al.
Nat Commun 16, 1601 (2025).Hirabayashi, M., Raducan, S.D., Sunshine, J.M. et al.
Nat Commun 16, 1602 (2025).