Reacción a "Reactions to the first controlled asteroid impact"

Once again, this mission - remember the 2005 impact of the Deep Impact probe on comet 9P/Tempel 1? - highlights the power of our knowledge of (astro)dynamics, and physics in general, to pilot a probe to hit an asteroid of only 160 metres in diameter 11 million kilometres away from the Earth - it is like throwing a tiny stone and hitting another 1mm in size 69 km away - and we will see in the coming weeks whether it is confirmed that, as a result of the impact of the DART probe, the velocity of the asteroid Dimorphos has been reduced to the expected amount. We will see in the coming weeks whether it is confirmed that, as a result of the impact of the DART probe, the speed of the asteroid Dimorphos has been reduced by the amount predicted. Here too, the "astronomical" numbers are worth noting: DART weighs only 570 kg, but its high impact speed (24,000 km/hour) is capable of deflecting the trajectory of a small but appreciable amount, a mass of 5 billion kg. 

This mission is a demonstration of a technique to free our planet from the possibility of a large asteroid impact. The question of whether asteroids are a real danger to our planet has no simple answer, because the effects depend on many factors, the main one being the size of the asteroid. 

It is worth highlighting the unceasing work of ground-based telescopes all over the world, including those in Spain, which continuously scan the sky to detect and then track these dangerous objects (NEOs, or Near Earth Objects). These observations allow us to conclude that there are no asteroids larger than 1 km in size - capable of producing disasters on a global scale on our planet - that could hit the Earth in the next hundred years, but there remains the possibility that asteroids the size of Dimorphos could hit and produce disasters on a regional scale - the probability of them also hitting a densely inhabited area is, in any case, extremely small.  

Is it worth investing so much effort and money for such a low-probability event? I believe that, given what is at stake, it is indeed necessary to continue studying the sky in search of potentially dangerous NEOs. But on the condition that we do not divert attention and effort from combating other threats to our ecosystem that are more certain, more serious and more urgent, such as climate change or the overexploitation of our (only) planet's resources.