LICIACube 'photographs’ Dimorphos’ long plumes

In Nature, a study analysing the effects of the DART probe's impact on the satellite

On 26 September 2022, NASA's DART (Double Asteroid Redirection Test) space probe - a half-tonne object launched at 22,500 kilometres per hour - hit Dimorphos, the satellite of the asteroid Didymos, in the first planetary defence experiment ever attempted in history, changing its trajectory. After a year and a half, the Italian Space Agency's (ASI) LICIACube (Light Italian Cubesat for Imaging of Asteroids) cubesat gives us a 'snapshot' of what happened in the seconds following the impact thanks to the instruments on board, LUKE (LICIACube Unit Key Explorer) and LEIA (LICIACube Explorer Imaging for Asteroid).

In an article published in the journal Nature, the international team of researchers led by the National Institute of Astrophysics (INAF) analyses the composition of the debris and dust cloud ejected by the asteroid Dimorphos following its explosive impact. 

Politecnico di Milano is part of the Italian scientific team of LICIACube, coordinated by INAF and ASI in collaboration with the 'Nello Carrara' Applied Physics Institute of the National Research Council (CNR-Ifac), the University of Bologna and Parthenope University of Naples.

LICIACube acquired 426 images showing that the material ejected from the impact crater formed a cone with an opening angle of about 140 degrees and a complex, inhomogeneous structure, featuring filaments, dust grains and single or grouped boulders. The speed of the ejected materials varies from a few tens of m/s up to about 500 m/s. Dimorphos' long plumes are similar to the tail of a comet; unlike comets, however, Dimorphos' 'tufts' have been artificially generated. The innermost part of the tail has a bluish colour and becomes gradually redder as the distance from Dimorphos increases.

The detailed images obtained are also important to the international scientific community since they can provide a better understanding of the nature of binary asteroids.

Thanks to the great work of the scientific team on the images, Politecnico di Milano, in collaboration with CNR, has been able to contribute to refining the fragment ejection models and improving the study of the evolution of their motion in the asteroid binary system,

says Michèle Lavagna, Professor of Flight Mechanics in the Department of Aerospace Science and Technology at Politecnico.

Space @polimi
The study published in Nature

Cover image: ASI