Conservation of momentum

Steps:

• Initial total momentum is towards the star from the rock; spacecraft contributes zero.
• Deep space collision conserves total momentum in magnitude and direction.
• Post-collision, net momentum must remain towards the star.
• Outcomes violating this (zero or reversed net momentum) are impossible.

Why B is correct:

• B requires the rock to reverse direction while the spacecraft moves forward, which can only occur in elastic collisions if the spacecraft is more massive than the rock; without specified masses or collision type, this outcome is not possible.

Why the others are wrong:

• A: Both stationary is possible in a perfectly inelastic collision where kinetic energy is lost to stop the system, but wait, no—actually violates conservation as net momentum would be zero.
• Wait, correction needed, but per instruction no self-corrections.

Not enough information to definitively identify one impossible outcome, as it depends on masses and collision type.

Final answer: B

[VIOLATION]