NASA’s Earth asteroid diversion mission could turn into chaos, scientists say

A new simulation shows that when the target asteroid is hit as part of the Dual Asteroid Redirection Test (DART) mission, it can cause space rock to begin to rotate and oscillate chaotically.

Later this year, NASA will launch a mission to test how we could in the future divert an asteroid in order to protect the Earth from this kind of threat, points out the Technology Review portal.

It is estimated that the launch will take place on November 24, or no later than February 2022, and will take a year to reach its goal – Dimorphos, a stadium-sized asteroid that is orbiting a much larger space rock called Didymos.

The plan is to hit Dimorphos at a speed of 6.5 kilometers per second with the DART spacecraft, which is the size of a car and weighs just over 300 kilograms, altering its orbit around Didymos.

The impact will have only a small effect on the object’s orbit, however this should be enough to deflect an asteroid out of Earth’s path in the future, of course if it is hit early enough and far enough away from our planet.

Artistic illustration of the DART mission

The potential changes in Didymos’ orbit have been well studied. But until now it was not known what would happen to Dimorphos after the impact.

In the study led by Harrison Agrusa of the University of Maryland (USA) and published in the journal Icarus, the researchers modeled how DART might alter the rotation or rotational movement of Dimorphos by calculating how the moment of impact will alter the asteroid’s roll, heave and yaw. The results can be dramatic.

“He [o asteroide] it may start swaying wildly and go into a chaotic state,” commented Agrusa, adding that “this was a really big surprise.”

The unexpected rotation presents several challenges and can make future attempts to deflect an asteroid from Earth more complicated, as any rotation can affect the path of an asteroid through space.

When DART hits Dimorphos, the impact energy will be comparable to the explosion of three tons of TNT hurling thousands of rock fragments and debris into space.

Some time later, Dimorphos will start to wobble slightly, but that wobble will grow as the impact thrust unbalances the rotation, since in the space vacuum there is no friction that can slow the asteroid down.

In a few weeks, Dimorphos could start to spin in such a way that it could go into an uncontrollable chaotic state around its axis. In more extreme scenarios, the attraction link with Didymos could break completely and he would start to move “crazy”, concludes Agrusa.