How specific asteroids and comets make repeat appearances after so many years of space is an endless and ever expanding vacuum.

Question

I feel like the answer can only be “ping pong” with another gravitational body, but that seems far too coincidental.

In: Planetary Science

Answer 1

They have an orbit. Halley’s comet, for example, orbits our sun. It has a highly elliptical orbit meaning that its distance from both the sun and Earth and so it’s only visible from Earth every 70 years or so.