Weird lights in the sky?!!?

Okay so first of all, no aliens. I dont believe in aliens... Okay so ive seen these weird white glowing balls of light above our neighbors cowfeild about three times in the past 4 months... They arrent stars or planes for sure. They float about 50 ish ft. Off the ground and they almost look like shooting stars but they float a little slower but move in straight lines and dissapear. Me and my mom and sister have seen them and they are really creeppyyyy O_o if you were right up close to one id say they'd be between the size of a golfball and a tennis ball. Only see them in the evening... And they fade... And im not crazy, its not a bug, its not a star or a plane, or aliens. WHAT IS IT?!! thankyou :) lol