The Dart mission was successful: for the first time in history we have deflected an asteroid

Centered in full. In the end, the crash was just as planned: at1:14 on Tuesday 27 September, the spacecraft Dart it crashed at a speed of 24,000 kilometers per hour (6 kilometers per second) against the smaller of the two asteroids in the binary system Didymos – Dimorphos, hitting the latter and causing a deviation (still to be quantified) of its trajectory. Thus the so-called double asteroid redirection test (Double Asteroid Redirection Testhence the acronym Dart), which cost NASA just over $ 300 million, was a first-time success, a spatial tamponade organized in the smallest details 11 million kilometers from here, without any risk for our planet and which had the merit of demonstrating that humanity today possesses the technological capability to change the trajectory of an asteroid. The one that would be indispensable, in the future, in case it is discovered that there is an asteroid really on a collision course with the Earth.

After a full (terrestrial) day of blind autonomous navigation, the spacecraft weighing just 570 kilograms aimed and hit the Saxon 10 million times more massive and roughly the size of the Colosseum. In approaching its target, Dart sent to Earth with the frequency of one frame per second razor sharp images that he was collecting thanks to the optical systems installed on board, which showed Didymos – Dimorphos getting bigger and bigger as the impact approached. Spectacular photographs that even showed the morphology of the asteroid (very similar to that of the simulation videos), while from Earth the NASAL’Hex And millions of viewers all over the world they watched totally helpless, as in the final stages of the Dart approach it could not be commanded from here.

An exciting impact

Two and a half minutes after impact, Dart also had to suspend any type of maneuver, letting himself go by inertia until self-destruction. And if the impact itself wasn’t particularly spectacular – in practice, at one point broadcasts with Dart stopped due to the crash – especially the last frames collected by the spacecraft, which managed to show even the finest details of the asteroid, were thrilling. few meters away from the surface. “The resolution of the images we collected went beyond our expectations”the mission coordinator said Nancy Chabot immediately after impact, “And it is a great satisfaction to have fully achieved the desired result on which we have worked from 2015 to today“.