Where to Find UFO?
Near Heartland Overflow there is a small lake and a small hut above it. There, you will find a few murdered people. One of them died with a note in hand. Take it out and read it. This will tell you when to look for aliens.
To find the aliens, you’ll have to return to the place at 2 AM. You need to remember though, that the UFO won’t appear during a full moon.