In less than a week the DART mission will reach its objective: Didymos. The purpose is to evaluate the possibility of developing similar missions to deflect asteroids that could pose a danger to life on Earth.
The first planetary defense test.
If all goes well, between September 26 and 27, the DART mission will hit the asteroid Dimorphos as it passes near Earth’s orbit. DART is the acronym for Double Asteroid Redirection Testand can also be translated as “dart”.
The mission will try to alter the movement of an asteroid. To do this, a space probe will collide with the smallest of the asteroids that make up the Didymos system, a rock about 160 meters long called Dimorphos. Dimorphos orbits Didymos, an asteroid of about 780 meters that shares a name with the system.
None of the asteroids that make up this system pose a danger to Earth. The mission also encompasses the analysis of the data collected after the impact. It is not simply about moving Dimorphos, but about doing it in a controlled way, as Isabel Herreros and Jens Ormö explain in a recent article published in The Conversation.
The mission does not end with the crash.
After the impact, those responsible for DART will have to evaluate the data sent by the probe and those that are collected from Earth. With this data, simulations can be created to help us deflect potential future threats in the form of an asteroid.
These simulations will be used when, in the event of encountering a threat, a planetary defense mission has to be prepared. They will help us understand where, how and when to hit the asteroid to make sure we deflect it.
But numerical models also have a leading role before the impact. Herreros and Ormö work at the Center for Astrobiology (CAB), in whose laboratories part of the work has been carried out thanks to which DART is being able to “point” at its target.
The problem here is that we have little information about Didymos, so the task of calculating where to hit to achieve the best results is complex (precisely the task that DART wants to make easier in the future). “To date, neither the composition nor the shape of the asteroid is known, so this decision will have to be made when the DART spacecraft is close enough to Dimorphos, just a few days before impact.”
Herreros and Ormö continue explaining: “we have carried out the validation tests of one of the numerical models with which the mission has been designed and based on which critical decisions will be made days before impact”. Both are also co-authors of an article published in Earth and Planetary Science Letters in which the details of the process are reported.
In charge of data collection “in situ” will be another European contribution to the mission: LICCAcube. This probe separated from the main mission vehicle overnight on Sunday. This probe will be in charge of closely observing the impact of its mother ship against the asteroid. After that, he will be able to tell us from his privileged position in the front row the effects of this spatial collision.
Almost a year waiting.
The DART mission took off in November 2021, but its journey had begun more than five years ago, with joint plans between the North American space agency, NASA, and the European Space Agency (ESA), to develop the first planetary defense mission to the deflection of dangerous asteroids.
NASA Administrator Bill Nelson enthusiastically explained that “it’s kind of like a replay of the Bruce Willis movie ‘Armageddon,’ although that was totally fictional.” The mission departed on November 24 of last year from the Vandenberg Space Force Base, California, aboard a Falcon 9 rocket.
China is also on board.
DART is not the only planetary defense plan humanity has in development. China announced a few months ago that it had started developing its own plans. Little has transpired but according to the announcement the first step was to improve early warning and monitoring of near-Earth objects or NEOs.
This is just one of the projects of a Chinese space program that is advancing by leaps and bounds, and that intends to compete with Western agencies both in taking astronauts to the Moon and in returning the first samples of Martian soil to Earth.
Image | POT