Why won't Pluto collide with Neptune?
A) Pluto orbits the Sun exactly two times for every three Neptune orbits, which ensures they never come close together.
B) Pluto is always much farther from the Sun than Neptune.
C) Pluto's orbit never comes anywhere close to Neptune's orbit.
D) Actually, a collision of the two is inevitable within the next billion years.

Question

Quizplus · Accepted Answer

Pluto and Neptune are in a 3:2 orbital resonance, meaning Pluto orbits the Sun twice for every three Neptune orbits, preventing them from coming close enough to collide.

Why Won't Pluto Collide with Neptune