Deflecting an asteroid’s collision with Earth, through a controlled impact, that’s the challenge for DART, successfully completed
Deflecting an asteroid on a collision course with Earth, through a controlled impact at full speed using a space probe. This was the challenge of the mission DART (Double Asteroid Redirect Test) of NASA, successfully concluded on September 26, 2022, in which the Polytechnic was directly involved as part of the science team. The first results of the DART mission have been published in the authoritative journal Nature in three different articles, co-authored by researcher Fabio Ferrari of the Department of Space Science and Technology at Milan Polytechnic. Article “Successful kinetic impact on an asteroid for planetary defense” Describes the successful test of the kinetic impact technique on the asteroid Dimorphos. The DART mission was the first to test this technology on a large scale, and it proved to be one Effective planetary defense technology against potential asteroid threats. I study “Ejected from the active asteroid Dimorphos product DARTDescribes observations made with the Hubble Space Telescope of material ejected from a DART impact with the asteroid Dimorphos. Observations showed a complex form of ejecta morphology (typically, in volcanology, ejecta is the result of an explosive eruption in which large amounts of gases dissolve into highly viscous lava), conditioned by the gravitational interaction between the asteroid and dust, under the influence of solar radiation pressure. Finally, the effectiveness of the kinetic effect of the satellite in avoiding a possible collision with the Earth is shown in “Momentum transfer from the DART mission kinetic impact on the asteroid Dimorphos“, co-authored by Professor of Aeronautical Mechanics at the Polytechnic Michel Lavagna. The article outlines the effect deviation (physical deflection is the event in which an object strikes a flat surface) resulting from the high-velocity impact on the orbit of the Didymos binary system, showing how the ejection of the generated fragments contributed to the more efficient energy exchange between the spacecraft and the asteroid.
The critical role of the Italian flag in the DART mission
Politecnico di Milano is part of the science team for the DART mission and has contributed to the study of the evolutionary dynamics of the binary asteroid Didymus. These include the motion and stability of the binary system as well as the internal structure of the asteroids Didymos and Dimorphos. The Polytechnic also played a crucial role in characterizing the motion and morphology of ejected fragments after impact observed through orbital and ground-based telescopes.
“DART is a historic moment for space exploration: not only is it the first test of planetary defense, but it is also the first time we have visited a binary asteroid (a system in which two asteroids orbit a common center of gravity) and in which we have the opportunity to observe how an asteroid can react to external stress.” explains Fabio Ferrari, co-author of the scientific studies on DART. This has allowed us – and will allow us again in the coming months – to study the structure and evolutionary history of these celestial bodies, so close to us but still unknown.”
LICIA Cube, the Italian probe, the first European to travel in deep space, played a fundamental role in obtaining images during and after the DART impact: images that help to understand the formation and structure of Dimorphos and the dynamics of the asteroid binary system, thanks to the recording of the sequence of formation of fragments after the impact and their expansion in the surrounding space in minutes following a DART collision. “It is the first time that an attempt has been made to deflect a celestial body from its normal orbital path in a significant and perceptible way, while measuring its effectiveness at the same time,” adds Michele Lavagna. It is above all the first time that a small impact satellite has witnessed the impact. Politecnico di Milano, together with the National Institute of Astrophysics (INAF), contributed to the design and management of this small scientific satellite and is actively involved in the scientific analysis of the acquired images to reconstruct the evolution of the motion of the generated matter. crumbs.
A film of algae and graphene that will change the way you monitor your health: light, safe and wearable
“Infuriatingly humble social media buff. Twitter advocate. Writer. Internet nerd.”
