Reassuring news for those waiting to delay the apocalypse for as long as possible: A new study suggests that our last line of defense against an Earth-hitting asteroid is finally an effective strategy.
That line of defense known as small-body disruption of late is exactly what it sounds like. It is intended to blow relatively small asteroids to pieces when we have very little warning time that they are on a collision course with Earth.
These latest calculations show that such a defense is “very effective” at protecting against asteroid hits when the impact time is less than a year away – so we can all sleep a little more comfortably in our beds.
“One of the challenges in estimating deflection is that you need to model all the segment orbits, which is usually much more complex than modeling a simple deflection,” says physicist Patrick King of Johns Hopkins University in Maryland. “
“Still, we need to try to address these challenges if we are to assess disruption as a potential strategy.”
The models the researchers came up with looked at the impact of a 1-megaton-yield nuclear bomb hitting a 100-meter (328-foot) wide asteroid (about a fifth the estimated size of Bennu).
Five different asteroid orbits were analysed, with the eruptions taking place anywhere from a week to six months before. For scenarios where we might hit two months before the asteroid’s expected arrival, it is possible to reduce the rain of destruction to just 0.1 percent of the original mass.
If the asteroid is a huge pile of rock, it has a chance of reducing its impact mass to just 1 percent if we can hit it six months before the due date.
That’s a good result, but it’s still a last resort option that scientists don’t want to rely on: the preferred option is to get the asteroid further away from Earth, a strategy that has been thoroughly researched. and tested.
“We focused on studying ‘late’ disruptions, meaning the body has broken down shortly before its impact,” King says. “When you have a lot of time – usually on a decade-long timescale – it is generally preferred that dynamic impactors are used to create an impressive body effect.”
Figuring out where a multitude of fragments will end up once an asteroid breaks apart is no easy task, and the team used a special software called Spherel to figure out how these pieces of rock were held together by gravity. And where will be taken by other forces.
Get the calculations to misfire an incoming object, and an asteroid impact can quickly turn into multiple impacts in many different places on Earth – the stakes may not be too high.
NASA and other agencies continue to invest in planetary defense systems, especially when it comes to finding potentially dangerous asteroids as quickly as possible. Longer periods are important for maximizing our chances of pushing an asteroid away from its course.
Lawrence Livermore physicist Megan Brooke Syall says, “Our group continues to refine our modeling approach for nuclear deflection and disruption, including ongoing improvements in modeling X-ray energy deposition, which are useful for the problem of nuclear disruption.” determines the initial shock and shock conditions.” National Laboratory (LLNL).
“This latest paper is an important step in demonstrating how our modern multi-physics tool can be used to simulate this problem on many relevant physics regimes and timescales.”
research has been published in acta astronautica.