Misidentifying Natural Phenomena as UFOs
(How Many UFOs Have Natural Explanations)

While it is a fact that many UFOs are the product of hoaxing, imagination, mass delusion, and hysteria, there remains a tiny fraction of reports made each year that do not fit into any of these categories. These are reports made by competent observers not normally prone to making mistakes or to letting their imaginations run wild, forcing us to consider other possible explanations to account for the bulk of these sightings. To do so, however, it will be necessary to first consider some of the more prosaic explanations for UFOs usually given by skeptics.

Debunkers generally dismiss the bulk of UFO sightings as the misidentification of some astronomical/natural phenomena or some man-made object of some kind, and while many dismiss such explanations as simplistic, the fact is that many, if not most, UFOs can usually be explained away as unusually bright stars and planets, high altitude balloons, orbiting satellites and misidentified aircraft. As such, it's important we examine each of these possibilities, if only in an effort to better appreciate the difficulties investigators frequently face when looking at the phenomena from a scientific perspective. This list is by no means exhaustive, but I believe it does cover the bulk of alternative explanations usually given to explain UFOs.

The planet Venus: It's no coincidence that UFO reports go up sharply whenever Venus makes an especially bright appearance in the night sky, so this explanation is not as far-fetched as it seems. Under the proper conditions, Venus can be among the brightest objects in the sky—especially on a moonless night—and has even been known to be visible in the daytime under the proper conditions, making it a frequent explanation for many a mysterious "bright light in the sky." Further, it has been my experience that most people are unaware of Venus' potential luminosity and so are often surprised by just how bright it can sometimes appear, so for those already predisposed towards accepting any unusual light in the sky as a potential close encounter, Venus makes an especially good candidate for being a UFO. This is especially true when it is seen low on the horizon from a moving automobile (when it can appear to be following), or on a partly cloudy night when it will seem to abruptly appear and disappear as fast moving clouds obscure it from view. Additionally, it can be extremely difficult to convince people that the bright light in the sky they saw "chasing them" was merely sunlight reflecting off a nearby planet, largely because of the natural human reluctance to admit error as well as the trauma such an experience can induce.

Unfortunately, this explanation has permitted many in the skeptical community to use Venus as a convenient "catch all" explanation for almost any mysterious light seen in the sky (especially when the planet is present). This, however, is a bit disingenuous. Venus is a fixed point of light and as such is unlikely to be mistaken as a UFO by those who possess some basic knowledge of astronomy, nor is it likely to be interpreted as anything other than what it is by pilots, police officers, or other trained observers. Additionally, it is also a simple matter of determining Venus' location and luminosity on any given evening, making it a fairly easy task to either confirm or reject it as a possible explanation. As such, it is not generally a good explanation for the better eye-witness accounts reported-especially in those cases where an unidentified light is seen to maneuver in the sky.

Meteors, Comets, and Fireballs: This is a less common explanation, especially since most people are familiar with meteors (or "shooting stars" as they are commonly called) and so are unlikely to mistake one for a UFO. Comets are even less likely to be mistaken for a UFO, especially since they remain fixed in the sky, can be seen for weeks at a time and are usually not particularly bright in the first place. A fireball, however—basically a large, brightly lit meteor observed at close range—is a better candidate, especially as they can be very bright, last several seconds, appear to split into smaller pieces, and even abruptly disappear from sight as though it were "zooming away at great speed" as many UFO witnesses describe. I'd imagine seeing a fireball head-on would be particularly impressive as it would appear to be an extremely bright and slow moving object that suddenly vanishes from view, much like a UFO frequently does. They are not, however, an adequate explanation for an object observed to make abrupt course changes in mid-flight, change color (or show multiple colors) or that last more than a few seconds, and as such they probably constitute only a very tiny fraction of all UFO reports.

Lenticular clouds: Technically known as altocumulus standing lenticularis, lenticular clouds are stationary lens-shaped clouds that form at high altitudes, normally where stable moist air flows over a mountain or a range of mountains. Normally these air currents form long strings of lenticular clouds, creating a formation known as a wave cloud, but sometimes, under the right conditions of wind and thermal currents, they can take on a roundish or oval shape that can be extraordinarily unnatural and even "saucer-like" in appearance, which in turn can be confused for an extremely large disk by people unfamiliar with such meteorological phenomenon. Further, their exotic nature is often further enhanced when seen alone against a clear blue sky or when they quickly dissipate due to rapidly changing air pattern, giving the impression that they have "sped away". Only those entirely unfamiliar with this phenomenon are likely to be fooled by a lenticular cloud, however, especially once they observe one for a while and realize it is not moving nor that it appears to be mechanical in nature. Still, for the unaware, it can be a strange sight and one that might be easily confused for something otherworldly.

Ball Lightning:
Among the more unusual and lesser understood electrical curiosities known to science is something called "ball lighting", a phenomenon that has only been identified within the last fifty years or so. Basically, ball lightning is a sphere of static electricity that has the ability to glow intensely for several minutes at a time and, when seen in broad daylight, can even take on a fluid silvery-like sheen that can be easily mistaken for metal, giving them a "disk-like" appearance. Additionally, though usually seen to move randomly, sometimes the discharge is described as being attracted to a certain object-normally an aircraft-giving these orbs the appearance of "following" a plane and even matching it in terms of speed and maneuvers (thereby giving it the impression of being under intelligent control). Commonly described as spherical, ovoid, teardrop, or rod-like in shape, and with colors that vary from red to yellow (though other colors have been observed) it's not difficult to see how they could easily be mistaken for an unnatural object, making ball lightning a perfectly adequate explanation for some of the more erratic lights seen in the sky—especially those observed from aircraft.

Weather Balloons: Though frequently lampooned by ufologists as the most simplistic of explanations for aerial phenomenon, the fact is that helium filled weather balloons make excellent UFOs, especially when seen from below when their spherical shape can appear especially disk-like. Further, these balloons can be quite large, are often coated in a highly reflective material (giving them a polished or shiny appearance), and can fly at altitudes as high as 120,000 feet where winds aloft can push them along at hundreds of knots, giving them the illusion of moving at high speeds. More than once I have had to study a fast moving object in the sky for some time before determining it to be something as innocuous as a child's balloon, so the weather balloon theory is not only valid, but needs to be taken seriously.

Satellites: As more countries join the space race and the demand for improved communications, weather forecasting and aerial surveillance grows, the orbital lanes around our planet are growing increasingly cluttered with a wide array of fast moving and highly reflective satellites of all sizes and configurations. To give you some idea of how cluttered our skies are getting, the United States Space Surveillance Network (SSN) currently tracks more than 8,000 man-made objects orbiting the planet, of which about seven percent (approximately 560) are operational satellites.
Often trapped in their orbits for years at a time, however, these silent sentinels of the skies can usually be picked out by anyone with a pair of binoculars and some patience, so they are not an uncommon sight. Additionally, as they can often appear to pulsate in intensity (a natural illusion created by atmospheric inversion layers) and even "wink out" when their angle to the sun changes, they can sometimes be mistaken for a UFO.

Flares: Military aircraft often drop flares while conducting night training operations (or, in combat areas, as a means of diverting heat-seeking anti-aircraft missiles). These flares, unlike the tiny ones used to mark highway obstacles or for emergency use, are quite large and will burn brightly for up to a half an hour at a time and, when suspended from parachutes, can remain airborne for some time. As such, if dropped in a cluster, they can take on a beaded necklace effect that gives them the impression of either aircraft hovering in formation or, if close enough together, can even appear to be a string of running lights or "portholes". To a public generally unfamiliar with such ordnance and its characteristics, however, the effect can be spectacular and even frightening, making flares an especially good candidate to be mistaken for a UFO. This, in fact, may be the explanation behind the mysterious lights that were seen hanging over Phoenix, Arizona in 1997 (which does in fact lie near a military training ground where evening bombing exercises are frequently held).

Swamp Gas: Essentially an accumulation of Methane gas (usually found in peat bogs, mud flats, marshes, and swamps or wherever stagnant water coincides with the decay of organic matter) that, under certain conditions, can take on a mildly luminous appearance and appear to hover just above the ground, swamp gas has had little success over the years being taken seriously by either proponents or opponents of the UFO phenomenon as a particularly plausible explanation for UFOs, largely due to their small size, general rarity, and lack of movement. Still, it is something to take into account, especially if one should spot something unusual over the Florida Everglades or a Louisiana bayou.

Birds, Lens flare, Reflections, and other abnormalities: Few people can accept the possibility that something as commonplace as a bird could be mistaken for a UFO, but it must be realized that under certain circumstances—and especially when flying at very high altitudes (some birds have been spotted flying as high as 40,000 feet or more)—birds can be highly reflective and, especially when wet, even appear to glisten like metal, giving them an artificial or metallic appearance. Additionally, bits of tin foil or panels of corrugated metal driven skyward by strong winds and powerful updrafts, falling chunks of ice broken off from a high altitude airliner, and other bits of aerial flotsam can also take on a silvery sheen and appear quite luminescent, making them occasional candidates for flying disks. Even cockpit lights reflecting off a canopy have been misidentified as high-speed UFOs (especially in the earlier years of UFO pursuits) making the need to be careful about what one thinks they are seeing especially important.

Aircraft: While it is difficult to imagine that anyone could mistake a modern airliner or military jet for an extraterrestrial vehicle nowadays, there are circumstances when an aircraft can appear quite peculiar, especially to a highly excitable observer. For example, anyone who has ever seen a jet's landing lights diffused by thick fog (or suddenly turned off during a steep ascent, making the object appear to abruptly vanish) could easily imagine they are witnessing something other worldly. Additionally, an aircraft flying through thick clouds on a dark and windy night (when the sound of engines is often masked) could easily appear as a mysterious, bright object winking on and off and changing brightness as it moves silently through the darkness. In daytime also, identifying a mysterious object in the sky as an aircraft can also be problematic; when flying at high altitude (where engine noise is often indiscernible) on a bright and sunny day, the brushed aluminum fuselage and wings of an aircraft can give off an eerie sheen which, when combined with the fact that most aircraft's navigation lights are invisible in daytime, can make it appear to be a silvery object moving swiftly across the sky. Also, if approaching straight on, an aircraft can appear to be hanging motionless, at least until it makes a sudden turn, thereby mimicking the sudden stops and start movement often associated with UFOs and further enhancing its otherworldly effect. Further, blimps, helicopters, and VTOL aircraft are also frequently mistaken as UFOs due to their unconventional flight characteristics—in particular their ability to hover and then suddenly fly away.

Experimental Military Aircraft: It's no secret that ever since the advent of flight over a century ago the military has been hard at work developing and testing new and ever improved versions of aircraft along with other experimental or "cutting edge" technologies, all with an eye on keeping ahead of—or at least pace with—our real or potential adversaries. Not surprisingly, this has led to a vast array of often unusual or, at very least, unconventional designs being introduced, which no doubt has probably resulted in more than a few UFO reports over the years. This hypothesis was especially popular during the early years of ufology, when it was widely assumed—even by our own government—that the strange vehicles seen in the skies were either test-flights of captured Nazi aircraft or new and exotic Soviet vehicles capable of penetrating our airspace with impunity. In fact, the Air Force's first official attempt to investigate UFOs—Project Sign—worked from the premise that UFOs were such weapons, thus necessitating both the urgency and the secrecy under which Sign operated.

The hypothesis does have a few flaws, however. First, the flight characteristics of UFOs are so far beyond our present technological capabilities that it is quickly apparent they are not of terrestrial manufacture. Even the most modern fighter aircraft cannot make ninety degree turns or ascend out of sight within mere seconds, making the "secret weapon" hypothesis increasingly problematic. Secondly, advanced aircraft are usually not extraordinarily alien in appearance. They may be unconventional looking—such as the Stealth fighter and the B-2 "flying wing" bomber—but for the most part advanced aircraft maintain a fairly traditional appearance, carry the same running and landing light configurations, and make much the same noises as do other aircraft. Truly exotic and unconventional designs (the saucer shape, for example) have consistently proven to be unstable configurations, aeronautically speaking, and were quickly abandoned. Third, most test flights are normally performed over mostly desolate areas of the country, making their wide-spread appearance over large population centers unlikely. The military has always been careful to ensure its test flights receive as little attention as possible so it's a near certainty that the unusual craft you see doing right angle turns, darting at incredible speeds across the sky, and changing color and intensity is not one of ours (or anyone else's, for that matter). While undoubtedly a few UFOs may well be misidentifications of secret aircraft on test flights, it's difficult to see how these would account for more than a tiny percentage of all reports.

The point to be made here is that it is not difficult to see how many good intentioned and sincere people can be misled by even the most common of astronomical, meteorological, or aerial phenomena, as well as how even the best trained observers are frequently no better at identifying such objects as is the common layman, thereby bolstering the skeptics case. However, it is also a fact that while hoaxes, delusion, and misidentification of natural or man-made objects do account for most UFO reports, they do not explain them all. There are those sightings that, despite the best efforts of science and the military to explain away, simply defy explanation and must be looked at more closely. Even the Air Force's own Project Blue Book couldn't find plausible explanations for some 6% of all sightings and if the Air Force couldn't explain them, despite the many resources at their command (and, arguably, an innate desire to want to explain them away) it would be a mistake for the skeptic to dismiss them out-of-hand by assuming the Air Force simply "missed something". That's neither fair nor honest, but merely an effort to avoid having to deal with the larger issue involved.

For more information on this phenomenon or to explore these issues in more detail, you may be interested in acquiring a copy of my latest book, UFOs: The Great Debate, recently released by Llewellyn Worldwide (just click on the cover to order). It is an objective attempt to examine the entire UFO phenomenon designed to leave you with a more balanced approach to the subject than is possible to achieve with most books about UFOs. Written for the person who likes to think for themselves and make up their own minds what to believe about this important issue that continues to grow in popularity every day, the book is a must for the serious student of the UFO phenomenon.