That is absolutely a great thought. People are responding to you saying that it's not the solution, but I had a discussion with someone working on DART who is a co-author of the paper this post is about. A nuke provides the greatest amount of energy per mass that can be delivered to an asteroid, so it absolutely is a 100% feasible option for planetary protection.
The largest issue with the nuke is the timing. DART impacted going roughly 6 kilometers per second. This means that a nuke would need to be timed within a few milliseconds of impact so it would be able to transfer energy to the asteroid without wasting it, but needs to be detonated before impact as the speed is so extreme if the spacecraft impacted the asteroid first the nuke would be destroyed without detonating.
Detonating a nuke in space is actually rather trivial though, the largest issue is navigating and guiding a spacecraft to the asteroid. DART was able to locate Didymos over a month out, but only was able to see Dimorphos a few hours before impact. Didymos is nearly 1,000 meters in diameter, Dimorphos is about 170 meters while the asteroids we are actually worried about are closer to 50 meters. Since they are smaller than we can detect from Earth, we would likely only discover it possibly weeks or months before impact, whereas something much larger would be discovered years earlier.
I have heard from people who worked on DART, that a potential DART-2 mission is a dry-run of nuking an asteroid without the actual nuke onboard, so that the design would already be finished if we discovered an asteroid with limited time before impacting Earth. That way they could re-build from existing designs, add the nuke and launch considerably faster in the case of an emergency.
Breaking it into multiple pieces/re-directing it both end up going together, at some point of pushing it you're going to break it up anyway because of the force required. One concern of breaking it up is that if it still impacted Earth, while it would be less likely to kill us all, it would have a high likelyhood of damaging many of our satellites in orbit. In 2014 a comet nearly hit Mars, and all the satellites (since there are not many around Mars) navigated to be on the opposite side of the planet to where it was likely to hit. Earth satellites wouldn't realistically have the same ability.
ItsMyImPulse t1_iqxoao9 wrote
Reply to comment by D3ATHfromAB0V3x in After DART: Using the first full-scale test of a kinetic impactor to inform a future planetary defense mission by EricFromOuterSpace
That is absolutely a great thought. People are responding to you saying that it's not the solution, but I had a discussion with someone working on DART who is a co-author of the paper this post is about. A nuke provides the greatest amount of energy per mass that can be delivered to an asteroid, so it absolutely is a 100% feasible option for planetary protection.
The largest issue with the nuke is the timing. DART impacted going roughly 6 kilometers per second. This means that a nuke would need to be timed within a few milliseconds of impact so it would be able to transfer energy to the asteroid without wasting it, but needs to be detonated before impact as the speed is so extreme if the spacecraft impacted the asteroid first the nuke would be destroyed without detonating.
Detonating a nuke in space is actually rather trivial though, the largest issue is navigating and guiding a spacecraft to the asteroid. DART was able to locate Didymos over a month out, but only was able to see Dimorphos a few hours before impact. Didymos is nearly 1,000 meters in diameter, Dimorphos is about 170 meters while the asteroids we are actually worried about are closer to 50 meters. Since they are smaller than we can detect from Earth, we would likely only discover it possibly weeks or months before impact, whereas something much larger would be discovered years earlier.
I have heard from people who worked on DART, that a potential DART-2 mission is a dry-run of nuking an asteroid without the actual nuke onboard, so that the design would already be finished if we discovered an asteroid with limited time before impacting Earth. That way they could re-build from existing designs, add the nuke and launch considerably faster in the case of an emergency.
Breaking it into multiple pieces/re-directing it both end up going together, at some point of pushing it you're going to break it up anyway because of the force required. One concern of breaking it up is that if it still impacted Earth, while it would be less likely to kill us all, it would have a high likelyhood of damaging many of our satellites in orbit. In 2014 a comet nearly hit Mars, and all the satellites (since there are not many around Mars) navigated to be on the opposite side of the planet to where it was likely to hit. Earth satellites wouldn't realistically have the same ability.