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.
ARE THESE TYPES OF ASTEROIDS A DANGER?
Didymos is classified as a NEO asteroid.
NEOs, Near Earth Objects, are the asteroids that cross the Earth's orbit from time to
time.
The Binary System of Didymos is an Apollo-type asteroid; these are a type of asteroids that
are within the orbit of the Earth and from time to time come very close to our planet;
according to the most conservative estimates, there are currently about 70 million of these
asteroids orbiting close to the Earth.
But rest assured, most of these asteroids are the size of a house, which is not exactly
good news since the Cheliabynsk bolide that hit Russia in 2013 was just an Apollo-type
asteroid, and we all know the damage it caused.
Fortunately, none of these asteroids are on a collision course with Earth, or so we believe.
Since the sad and disturbing reality is that today it is estimated that we still have to
discover several thousand of these types of asteroids, let's hope that none of those that
we have not yet discovered will head to Earth just now.
Can an asteroid of this size destroy the world?
The asteroid Dimorphos measures 170 meters in diameter and Didymos 780 meters in diameter;
neither reaches one km in diameter, so it is impossible for either of them to destroy
the planet, however.
If an asteroid 170 meters in diameter like Dimorphos were to fall on Earth, it could
quickly destroy several countries claiming millions of lives.
If an asteroid the size of Didymos were to hit Earth, it could destroy a continent and
cause environmental seriousness worldwide.
As you can see, asteroids of these sizes cannot destroy the planet, but they can destroy a
part of it, causing severe damage to the world and eradicating many living things.
Want to know what the worst part is?
The worst part is that the asteroids that astronomers are most concerned about are just
these.
Observational astronomers estimate that all large asteroids like Didymos have already
been discovered, and there are no more to discover; this is because asteroid discovery
graphs indicate that when we started monitoring the sky for asteroids in the 40s, we initially
found many large asteroids like Didymos.
Still, as time has passed, we have stopped discovering giant asteroids, and each time,
we continue to find small asteroids.
Even though our observational technology, such as space telescopes and astronomical
observatories, has improved considerably, we are no longer finding giant asteroids.
The simplest explanation for this is that we have already found them all.
However, the same is not true of small asteroids, which continue and continue to appear.
While small asteroids do not pose a threat to all life on Earth, they are a threat to
small regions of Earth.
Most of these asteroids still being discovered are smaller than Dimorphos, so managing to
deflect this asteroid is an unprecedented achievement for planetary defense.
If we can deflect Dimorphos, we will also be able to deflect a potentially dangerous
asteroid heading for Earth in the coming years.
A BIG STEP FOR THE DEFENSE OF THE WORLD This is not the first time in history that
an object created by the human race collides with an asteroid; the first attempt to test
this maneuver was with the Deep Impact spacecraft in 2005, which launched an impact that hit
the nucleus of comet Tempel 1.
While this impact failed to deflect the comet's trajectory, it served as part of the DART
mission.
Suppose the technology for planetary defense continues to advance as it has so far.
In that case, the most certain thing is that in the coming years, we will continue to see
more missions like this, that help us prepare and defend ourselves from space threats so
that the same thing that happened to the dinosaurs does not happen to us 65 million years ago.