What is a characteristic of nongravitational accelerations of interstellar objects?

• A. They are several orders of magnitude weaker than gravitational accelerations.
• B. They are stronger than gravity.
• C. They are approximately equal to gravity.
• D. They cause immediate orbital capture.

Answer: (A)

Gravity from the Sun sets the dominant motion for objects traveling through the Solar System, and any nongravitational push acts as a tiny nudge on top of that. Nongravitational accelerations come from effects like outgassing or radiation pressure, but they are typically far weaker than the Sun’s gravitational pull—often by several orders of magnitude. Because of that, the trajectory is shaped primarily by gravity, with only small, long-term deviations from nongravitational forces. Only in special cases—very small, highly reflective bodies or active outgassing—might these pushes be noticeable, but they still remain much weaker than gravity in most interstellar-object scenarios.