A few days ago, a DART spacecraft deliberately crashed into an asteroid called Dimorphos.
On 26 September, the DART spacecraft successfully encountered a small asteroid at over 22,500 km/h during the world ' s first planetary defence test, which aimed to narrow the orbit around a larger parent asteroid. NASA is still studying crash data to determine the success of this diversion test, but some of the images taken from space and from the ground already make it possible to assess impact results.
One of these images was obtained from the Southern Astrophysical Research Telescope, located in the lowlands of the Andes in Chile, away from the sources of light pollution, for which astronomers Teddy Karet from the Lowell Observatory and Matthew Knight from the United States Naval Academy directed the telescope to the asteroid two days after the impact.
The image shows a long, expanding dust trail directed at the right corner. According to the NOIRLab press release, the tail of the debris extends by about 10,000 kilometres, and scientists estimate the width of Dimorphos to be about 160 metres before the impact.
Note that this discarded material initially formed a cloud around the asteroid and then formed a taillike structure when solar radiation pressure pushed debris away from the asteroid body; this is a well-known phenomenon in comets that are too close to the sun from the outer regions of the solar system.
Observations of these materials can enable researchers to better identify the nature of the surface of Dimorphos. More generally, a better understanding of the structure and composition of asteroids will help agencies to model the best ways to deviate from them in the event of a potential threat to the Earth.
China is also planning to change the orbit of a potentially dangerous asteroid by testing a kinetic impacter. The mission to be launched in 2026 on the Changjeng-3B missile will target NEO 202 PN1. The machine will consist of a separate impact engine and an orbital vehicle.