Resolves YES when humanity becomes aware of any spaceship travelling at >10% of the speed of light (either domestic or alien origin)

Resolves no in 9999 but it could be re-resolved if we meet aliens after 9999 and they say they were totally doing that before 9999.

from comments: "“A spaceship, at the bare minimum, has to contain either a computer or a brain, and some capability for receiving and transmitting signals intelligently. So a bullet or a relativistic jet is not a spaceship.”