Final answer:
Controlling a collision involves steering to collide at an angle, which helps distribute impact forces. For deflecting asteroids, kinetic impactors, nuclear devices, and gravity tractors are possible solutions, each with pros and cons, including efficacy, risk of fragmentation, and need for lead time.
Step-by-step explanation:
The best way to control consequences if you cannot avoid a collision is to steer to collide at an angle with an object. This method helps spread out the impact forces and can reduce the severity of the collision both for vehicles and potential collisions with larger objects like asteroids. If humanity were to discover an Earth-approaching asteroid early enough, there are some ways to deflect or destroy it, including:
- Kinetic impactors, which involve hitting the asteroid with a high-speed spacecraft to change its trajectory.
- Nuclear devices, where an explosion near or on the asteroid's surface would either destroy it or alter its path.
- Gravity tractors, which utilize a spacecraft's gravitational pull to slowly alter the asteroid's orbit over time.
Pros and cons exist for each method; kinetic impactors are simple and have a lower risk of fragmenting the asteroid but require precise targeting and may not be effective for larger objects. Nuclear devices could work on larger asteroids and provide a significant change in trajectory but carry risks of nuclear fallout and unpredictability if the asteroid fragments. Gravity tractors offer a gentle and precise approach but require a long lead time and sustained effort to nudge the asteroid's course.
Therefore the correct option is C. steer to collide at an angle with an object.