DART collision with Dimorphos leads to unexpected consequences

The mission, during which the DART spacecraft collided with asteroid Dimorphos to alter its trajectory, has had unexpected consequences: as a result of the impact, Dimorphos' orbit has lost stability, began to shrink, and as a result, the asteroid has begun to approach Didymos, the larger asteroid it orbits.

Scientists initially expected to change the speed and trajectory of Dimorphos’ movement; before that, it orbited Didimos in 11 hours and 55 minutes, but when the DART hit Dimorph at 22,500 km/h, the revolution period reduced by 32 minutes. However, not everything ended there: not only did Dimorphos’ orbit change; it lost stability and began to shrink.

Jonathan Swift, a teacher at Thatcher School (California, USA), recently decided to study this phenomenon with his students. Observations showed that the orbit of Dimorphos continued to shrink; in addition to the fact that the period of one revolution of the asteroid around Didymos was shortened by 32 minutes immediately after the collision with the NASA probe, during this time it has additionally shortened by 2 minutes.

The teacher presented the results of their observations to the American Astronomical Society. At first, he thought that a mistake was made in the observation or calculations, but the data was confirmed.

Now scientists are trying to find out this unexpected "behavior" of the asteroid. According to one hypothesis, it now moves "chaotically", and before the collision with the DART probe, its orbit was stable, in the state of tidal capture.

The European Hera mission, scheduled for October, is expected to provide new information about Dimorphos and its orbit. The device will study the crater formed on the asteroid after the collision with DART and more precisely determine the mass and composition of the two asteroids. The obtained data will help to better understand the "behavior" of the two asteroids and expand the knowledge about space objects in the Solar System.