DART Mission |
This is how we managed to deflect an ASTEROID!
DART MISSION
For the first time in history, an asteroid has been deflected; no, it is not a science fiction movie; it is the DART mission, a spacecraft that intentionally collided with an asteroid to change its orbit. Do you want to know how he did it and what possible consequences it could bring to earth? Let's start! On September 26 of this year, NASA put the DART mission to the test; this space mission consisted of a 610 kg spacecraft that did not have any payload, that is, unlike other missions such as space exploration probes that carry several essential scientific instruments, the DART mission had as its sole objective to hit an asteroid. In addition to the spacecraft, the mission also had on board a small CubeSat; these are small cubic ships that are intended to monitor a particular event; in this case, the CubeSat installed by the Italian Space Agency had the purpose of trying to acquire images of the impact and ejecta as it passes by the asteroid and then sends that information to earth. The DART mission took off on November 24, 2021, from the Vandenberg space base in the United States aboard a Falcon 9, and traveled approximately 1 million kilometers for one year to reach its target, the binary asteroid Didymos.
ASTEROID SYSTEM
The target of the DART mission is the asteroid Dymorphos, a small asteroid of 170 meters in diameter that orbits around Didymos, an asteroid of 780 meters in diameter; both asteroids are classified as binary asteroids since Dymorphos orbits around Didymos every 11 days as if it were its moon. Why was this asteroid chosen and not any other? First, by deflecting this asteroid, changes in its velocity can be measured by observing as Dimorphos passes in front of Didymos, causing a drop in light that can be seen by ground-based telescopes and accurately measuring how much has deviated. Dimorphos was also chosen for its proper size; it is in the size range of Apollo-type asteroids, which are the most dangerous for the Earth in the short term; we will discuss this later. It was also chosen because the binary system was relatively close to the Earth at this time, and finally, and the most important reason, is that by slightly changing the trajectory of Dimorphos, it will continue to orbit around Didymos, that is, it will continue within the binary asteroid system, so changing its orbit does not pose a risk to the Earth. In fact, according to the words of the Planetary Defense Coordination Office, this binary system is perfect for testing planetary defense technology and serves as a laboratory where we can experiment without putting our planet at risk.
MOMENT OF TRUTH
Before impacting the asteroid Dimorphos, the DART spacecraft had to travel an enormous distance from Earth to its encounter with the asteroid for a year. Although this journey seems long, it is within the range where most of the asteroids that pose a danger to the Earth are located. On September 26, the DART spacecraft reached its destination. On Earth various telescopes were monitoring the situation to capture as much information as possible; the solar panels were in the direction, the rockets were at full power, and the point of impact was marked. The spacecraft approached quickly and finally hit the asteroid by firing off many materials that shot out into space and could be seen with Earth's telescopes. To this day, we still do not know if that impact will be enough to change the orbit of the asteroid; for this, we will have to wait a couple of weeks. The DART impactor has as its primary objective to delay the speed of the asteroid a little, not much, just a little, but why do you want to do this? Many may not know it, but this is one of the most effective ways to deflect an asteroid. If we discover an asteroid heading to the Earth, we only have to divert it a little, either delaying it or rushing it into its orbit around the sun so that when it reaches the meeting point with the Earth, they do not meet. This is what we know as an asteroid redirection mission; in the case of the DART mission, the objective is to collide head-on with Dimorphos to reduce a little, but very, very, very little, its speed, in this way, over several orbits accumulated for weeks, months or years its final trajectory compared to before the impact will be very different. This is the same as what we would do to deflect an asteroid heading for Earth.