In West Texas in the Chihuahuan Desert mysterious orbs have appeared for years near the small town of Marfa. The state even built a million dollar viewing park for visitors to stop and have a look. I've been there but I didn't see anything unusual. I know many people who have seen the Marfa Lights multiple times. The lights usually appear in groups of five or more and bounce up and down near the horizon. Here's the Wiki article:
Marfa lights
There are also videos on YouTube. Search for "Marfa Lights."