Final answer:
Knowledge of gravitational interactions allows us to use technology to change an asteroid's trajectory, averting potential collisions. Early detection is vital for these interventions to work, and creative methods must be considered in conjunction with potential misuse risks.
Step-by-step explanation:
Knowing how gravity works helps us prevent a future asteroid collision with Earth by understanding the gravitational interactions that affect asteroid orbits (option c). This knowledge can be applied to devise methods for changing the trajectory of an asteroid. For instance, crashing a spacecraft into an asteroid or using a nuclear explosion are both ways to deflect an asteroid off its course. Another creative approach includes redirecting an asteroid between Earth and Jupiter to transfer orbital energy and move Earth, although this would need extreme precision to avoid catastrophic results.
These deflection techniques come with challenges, such as the possible misuse of asteroid deflection technology as a weapon, as pointed out by Carl Sagan. Given the gravity of the potential threat of asteroid collisions, scientists argue for the development of defensive technologies while also acknowledging the risks and advocating for international agreements to prevent misuse.
Awareness and early detection are critical, as interventions to redirect an asteroid require years of advance notice to be effective. The unique characteristic of an asteroid impact is that it's a natural disaster we could prevent with technology, highlighting the importance of continued research into NEAs and their orbits.