The Marfa Lights or Marfa Ghost Lights, are a series of lights visible on Mitchell Flat, east of Marfa in Texas.
Although research has put forth a number of possible explanations, none have been definitively proven.
Marfa Lights are typically described as glowing basketball-sized lights in white, yellow, orange and red, although blue and green have both been reported, as well.
They typically hover at around shoulder height and move slowly and laterally across the landscape, with occasional reports of fast-moving lights that move in all directions.
Because of the proximity to an Army air field, conspiracy theorists have suggested UFOs as the source of the Marfa Lights, along with Army test projects and experiments.
Ghosts and spirits have been mentioned, often tying into apocryphal reports of the Marfa Lights being visible back into the 19th century. There have been a number of explanations for the Marfa Lights over the years. Auto headlights were the favored explanation from two studies by Texas State University and the University of Texas at Dallas. Other explanations include a sharp difference in temperature between warm and cold air layers because of Marfa's 4688 above sea level altitude, ball lightning and swamp gas.