引用自 Silver Paw：

The first UFO is directly to the front-right side of the first wind turbine and in front of the "Hilltop Store"

The second UFO is far out to sea. It's directly back from the middle viewpoint of the tree in between the summit bank and 5-cent coffee.

Upon hitting both UFOs, I used the black mesa proportion device to hit them, perhaps others can suggest a better way. A third UFO will crash behind the two satellite dish operation building.

Its possible that you have to be in the operation or close to it for the third UFO to crash.