If you are willing to travel through time, you can get a second chance to shoot down Gulliver's UFO. If you see his UFO flying across the sky but are unable to shoot it down, log the precise time and then save and quit your game.

Reset your clock to the previous day and then move forward to the day when he is scheduled to appear. Make certain that you set the clock to a point that is about half an hour earlier than his first appearance because he usually will appear a bit earlier each time you see him.

In other words, if he flew across the sky at 7.45 a.m. on Tuesday, be ready, slingshot in hand, at 7.20 a.m. You will see him fly across the sky again and have a second chance to shoot him down. (Going back in time within the same day only does NOT work. You first must go back to the previous day.)

Note that Time Travel will keep turnip prices in your town below 100 Bells.