Engineers and scientists have drawn up an official plan for the US government in the eventuality that we discover an asteroid on a collision course with Earth.

Neither of the two options presented are particularly elegant, but both would hopefully be sufficient in preventing a major impact. If we have enough time, we could send out a fleet of spacecraft to knock it out of orbit. But if we don’t see it coming until the last minute, then it leaves us with few options but to nuke it.

These are the conclusions drawn by researchers in a new study published in the journal Acta Astronautica, in which they reveal a concept spacecraft called Hypervelocity Asteroid Mitigation Mission for Emergency Response (HAMMER) that could protect us from these potentially destructive interlopers. The plans are to be discussed further next month at a conference in Japan.

They are based on NASA’s current spacecraft OSIRIS-REx, which is on its way to have a look at the asteroid Bennu that is roughly on the same orbit as us and will likely rush by sometime in 2135, with a one-in-2,700 chance of hitting us. The researchers estimate that any anti-asteroid craft would likely weigh in at 8 tonnes (8.8 tons) and cost $800 million, something that current funding is nowhere near ready for.

While the lump of space rock is known to be roughly on the same orbit as Earth, one of the main difficulties is actually knowing where the asteroid is going to hit in the first place. This is because there are all sorts of factors that could influence where it will be in 100 years’ time, from solar wind to the gravity of other large planets in the Solar System.

This becomes of great importance when considering our options on how to prevent it from hitting us, particularly if we’re considering the smashing it with a spacecraft option. If, for example, we attempt to slow the asteroid down by smacking it with a spacecraft and causing its orbit to degrade, we could run the risk of pushing it further into our path rather than out of the way.

All this requires us spotting the asteroid far enough in advance. If we suddenly find that there is a rock on an imminent collision course with our planet with little warning – which is a very real possibility – knocking it out of orbit with a spacecraft simply won’t do. This means we’d only have one other realistic option – we’d have to go nuclear.

For some fairly obvious reasons, blasting a rocket containing a nuclear warhead into space in a bid to shatter a fast-approaching asteroid is not something that many nations are particularly keen on. The study suggests that when it comes to the nuke, bigger is better. Those currently owned by the US would probably be sufficient in preventing an impact.

All we need now is to make sure Bruce Willis lives for another 100 years.