In the space domain, experimentation often complements theory. Unlike renaissance inventors, who tested a lot of things before hitting on the right idea, today's engineers can't design multibillion-dollar space missions without knowing what to expect.
Nevertheless, some missions remain big puzzles. Scientists do have an imprecise idea of the result, and the latter generally does not differ much. But as with all rules, there is an exception.
DART, an unusual mission
This exception is called DART for Double Asteroid Redirection Test. This mission led by NASA, imagined in the 1980s, did not really have an objective. The idea was to see if the collision between a man-made probe and an asteroid could release enough energy to knock the piece of celestial rock off course.
Completed in September 2022, this mission was a great success. A success such as NASA was the first surprised by the data collected. Even today, new images are circulating on social networks, demonstrating the full power of the shock between the small probe and the target asteroid pair.
On his Twitter account, astronomer Jacint Roger Perez, originally from Barcelona in Spain, published images of this shock, captured in the moment. He used images from the cameras of LICIAcube, a small Italian-made satellite, launched at the same time as the probe and tasked with photographing this historic encounter between a probe and an asteroid as close as possible.
NASA/ASI/j. Roger pic.twitter.com/2VNVgTgeqe
— landru79 (@landru79) November 3, 2023
The video above, visible in the form of a GIF, is a stack of photographs taken by LICIA during its flight close to the asteroid. We can see (after several viewings) the moment when the probe comes into contact with the asteroid.
A frightening success?
The initial objective of the NASA's DART mission was to see if sending a probe was capable of deflecting the trajectory of an asteroid. The answer therefore seems to be yes, but the data collected by NASA is worrying.
In fact, scientists had only counted on a diversion of the asteroid's trajectory by 7 minutes of angle, the change is finally 33 minutes. The change in trajectory is therefore almost 5 times more powerful than expected.
NASA also noted for months after the collision that a tail of material followed the asteroid. In total, more than 900,000 kilograms of material were ejected by the impact. The total mass of the asteroid was estimated, before the impact, around 5 billion kilograms.