text | Xin Yu
The asteroid after being hit has a fragmented "tail". Image source: CTIO/NOIRLab/SOAR/NSF/AURA
NASA Dual-Asteroid Redirection Test (DART) spacecraft hit the asteroid Dimorphos on September 26. A photo taken two days after the impact showed that the fragments produced by the impact kept flowing out, causing Dimorphos to grow a long fragmented tail.
Dimorphos is only 170 meters in diameter, while the newly formed dust and rock columns are about 10,000 kilometers long. This is a picture taken by astronomers using the Southern Astrophysics Research Telescope in Chile .
The goal of this impact is to change the orbit of Dimorphos orbiting the slightly larger Didymos planet. Observing the consequences of collisions, especially the distances moving in orbits, will help researchers protect the Earth from potentially dangerous asteroids in the future. The image taken when
hits shows that there is a large cloud of dust clouds around Dimorphos . In the following days, most of the dust clouds extended into the tail behind the asteroid.
By observing the debris left by the impact, astronomers can understand the internal structure of Dimorphos, which will be key to designing asteroid deflection missions in the future. At the same time, it is also one of the main determinants of how impacts change the asteroid’s trajectory – the solid rock inside is more likely to deflect in the impact rather than break directly.
Once the clouds dissipate, researchers will be able to check the new surface left after the impact. The European Space Agency plans to launch a detector named Hera in 2024 to observe the impact from close range, while other observations will be conducted using telescopes on the ground or on orbit.
