UFO: Nocturnal Lights
Because their lack of detail impedes serious investigation, of the six classifications of UFOs, nocturnal lights (NL), although the most reported2 are perhaps the most mysterious of UFOs.
Although as developed by J. Allen Hynek, nocturnal lights were meant to classify a type of UFO, the term is also used to describe another group of objects—IFOs or Identifiable Flying Objects. These include explainable phenomena such as the Northern Lights, celestial bodies, satellites, aircraft, balloons, flares, meteors, and re-entry materials from satellites and rocket bodies3. Of these, meteors are visible throughout the world in every season and at any time of night.
However, reports of unexplained nocturnal lights continue to come from around the world, in all times of the year as well. Some singular in appearance and some similar although photographed thousands of miles and several years apart. For instance, when you enlarge the Queens image and the New Zealand image, you'll see distinct similarities in the lights, although the photos were taken several years apart and are several thousand miles in distance.
Although most sightings are one-time-only, at least two locations claim multiple phenomenal occurrences of nocturnal lights.
As far back as 1883, the citizens of Marfa, a small town in Texas, have witnessed a series of small moving lights just above the horizon. The lights appear most clear nights all year around4. Half a world away, in Australia's Outback, the citizens of Boulia (a Queensland town about 900 miles northwest of Brisbane) have noticed similar shimmering lights in the night sky. However, unlike the Marfa Lights, sightings of Australia's "Min Min" lights date back far more than 100 years. The Min Mins have held a place in Aborigine legends for thousands of years5.
Another thing the Marfa Lights and Min Min have in common is that the scientific community has offered various theories on their origin: swamp gas, natural gas, and static electricity are among possible explanations. Most recently, in both cases, science has concluded that the lights are due to a temperature inversion1, produced when the cooling nighttime air from the earth meets the warm air in the atmosphere. Australian professor, John Pettigrew, explained it as an "atmospheric refraction" that produces an "inverted mirage"6.
2. “The J. Allen Hynek Center for UFO Studies.” n.d . 27 Jul 2008 <http://www.cufos.org/FAQ_English_P1.html>.
3. Joe Nickell. “Exciting UFOs Become Bland IFOs .” Skeptical Inquirer Feb 2008. 27 Jul 2008 <http://www.csicop.org/si/2008-01/nickell.html>.
4. “Cause of ``Marfa Lights'' Either UFOs or Car Headlights .” 12 Apr 1994. 27 Jul 2008 <http://www.highbeam.com/doc/1P1-28259316.html>.
5. Kathy Marks. “Outback's UFO claims are proved to be a lot of hot air.” The Independent on Sunday 20 Apr 2003. 27 Jul 2008 <http://www.highbeam.com/doc/1P2-1768991.html>.