It seems like a day does not go by without at least one new UFO video appearing on YouTube. And it's not surprising, given all the cameras so easily within reach of so many people around the world.
Do these allegedly unexplained objects stand up to expert scrutiny? Is it possible that, among the thousands of videos taken by people, maybe there's one "smoking gun" UFO that's really from another planet?
The Huffington Post examined a few recent YouTube video posts and sent them to an expert for analysis.
This video of lights moving over a field near a Texas farm on the night of May 15, 2012 was posted by the user ShadoXAV.
In the video the lights seem to move slowly above the treeline, then below the trees. ShadoXAV also compared a daytime image of the trees with frames of the nighttime video, in an attempt to show how the unexplained lights were too high in the sky to be harvester combines.
"The Texas video shows a nice little image analysis, but what they failed to do, to my satisfaction, is make their case," said Marc Dantonio, chief photo and video analyst for the Mutual UFO Network.
"It seems clear that these [UFOs] were above the horizon from the vantage point of the control photograph they were using," said Dantonio, who has contracts with the U.S. Navy, Congress and the Joint Chiefs of Staff in Washington and creates special effects for television channels.
The Texas UFO footage could have been of harvester combines and possibly videotaped from a higher elevation point above the ground, Dantonio told The Huffington Post. "That control photo, while taken on the ground, superimposed with the video taken from a higher angle, is going to show ground objects looking like they were in the sky. I looked up harvester combines and guess what? They have multiple lights horizontally across them. If I saw it at night, that would look almost exactly like what I'm seeing in this video."
The next video, posted on June 19, 2012, by YNETGLOBALMEDIA, is from a Russian city.
An odd-shaped UFO is shown moving above the city and appearing to have numerous flashing lights around its perimeter.
"In this video, I saw alternating lights, one side to another, like an aircraft," said Dantonio. "It's certainly not moving at any odd speed. As it zooms in, the lens does some weird things with the light, but I can see the dark shape of the object," he added.
"The lights on each side of it are what could be called aircraft strobes, and this is the kind of thing you wouldn't expect to see on a UFO," Dantonio said. "I'm seeing what would be consistent with aircraft lighting and I see a possible wing, fuselage and a tail."
"While I don't disagree that it looks odd, it's not jumping out [at] me as something that we should label as an extraterrestrial craft -- not yet," he said.
Another Russian video, shot over Moscow on May 2, 2012, was posted by olegen77.
"It looks like the same craft from the previous video, as if somebody else caught the same one," Dantonio suggested. "It could be an aircraft that was being tested or flown around, and it certainly wasn't trying to hide or moving at an extraordinary speed. And it's hard to determine its distance."
Dantonio speculated that the object in this video may even have been a radio-controlled aircraft with lights on it that was flown by someone at night. Last year, he created such a craft for a National Geographic special, "The Truth Behind: UFOs."
One common factor is shared by these three videos and just about every videotape or photograph of a UFO at night: lights.
"There isn't any reason why they should illuminate themselves or even have flashing lights," Dantonio said. "We put flashing lights on flying objects so they don't hit each other; it's for navigational safety. But UFOs don't follow the same tenets that we follow."
Said Dantonio: "This is anthropomorphizing, where you apply a human characteristic to an unknown object."
Humans put lights on almost all types of vehicles, including planes, trains, automobiles, blimps and bicycles. On the other hand, if the objects result from an entity from very far away that does not require headlights, perhaps it's being done for human benefit, so people can better see them at night and take better, clearer pictures and videos.
Are these UFOs?
This is a composite image of how three alleged UFOs maneuvered about in the sky over Melbourne, Australia, in early February, 2013. The final verdict isn't in yet on whether they're birds, aircraft, balloons, bugs or something truly unidentified.
These candle-lit Chinese lanterns can rise high into the sky and are often mistaken for UFOs.
On Dec. 20, 2012, a bright, circular object (pictured at the top of this composite image) was videotaped exploding in the skies above Sacramento, Calif. It wasn't immediately identified, resulting in speculation that it was either an alien spacecraft, military top secret weapon, runaway planet, North Korean satellite, among others. Within a short period of time, it became apparent that this was a weather balloon. The bottom part of this image shows such a balloon as it ascended over Tampa Bay, Fla., on July 2, 2012, and exploded in an identical manner as the Sacramento object, probably much to the dismay of all true ET believers out there.
This is a composite of images shot by two eyewitnesses of a boomerang-shaped UFO they reported seeing over their Burbank, Calif., home on Oct. 5, 2012. Mutual UFO Network photo/video analyst Marc Dantonio concluded the object was likely "a balloon, floating on the wind that has collapsed in half."
This four-image series of lights in the sky was recorded over Warren, Mich., on Jan. 10, 2013. The lights were seen changing into several patterns. The most logical explanation for these types of UFOs is a series of balloons or lanterns.
This composite image shows four different times that alleged UFO were photographed above Earth by either space shuttles or the International Space Station. The big question is whether or not they are truly unidentified objects or if they are more likely reflections from spacecraft windows, meteors or fast-moving spacecraft-generated debris.
What appear to be pink-red UFOs are actually lens flares from the Google Earth street view camera as it snapped images in Texas (left) and New Mexico (right).
These two flying saucer-shaped, pink-colored lens flares were created by the Google Maps camera as it drove through locations in Sedona, Ariz. (left) and Flagstaff, Ariz. (right). The images were snapped in April 2009. Submitted to HuffPost by trenna.
This skybound lens flare was created by a Google Maps camera in June 2008 over Whiteriver, Ariz. Submitted to Huffington Post by Cheryl Weeks.
This very Earthbound lens flare was created by a Google Maps camera in November 2007 at Gulfport, Miss. Submitted to Huffington Post by Jenni Parker.
This seemingly grounded lens flare was created by a Google Maps camera in January 2008 at Eureka Springs, Ark. Submitted to Huffington Post by SE.
This lens flare appears to be following a car. The Google Maps image was created in October 2008 at Escanaba, Mich. Submitted to Huffington Post by Mary Robinson.
On the night of Sept. 28, 2012, a group of strange-looking lights appeared in the sky near Cincinnati, Ohio. First there was one, then, two, then three lights, slowly descending. It turns out, however, that these lights were originating from a group of skydivers performing a pyrotechnics jump at the La Salle High School homecoming event.
Some UFO sightings may be due to a natural phenomenon known as sprites, like this one shown from 2006. "Lightning from [a] thunderstorm excites the electric field above, producing a flash of light called a sprite," said geophysicist Colin Price.
Clouds: Saucer-shaped or "lenticular" clouds that form at high altitudes have been confused with UFOs.
Blimps or advertising balloons: These can look like flying saucers from some angles, especially at night.
On June 19th the Swedish-based diving company Ocean Explorer discovered something they've never quite seen before. They were exploring in the Baltic Sea between Sweden and Finland looking for sunken treasures when a very unusual image suddenly appeared on the sonar. A 197 feet diameter cylinder shaped object was discovered at the depth of approximately 275 feet which resembles the Millennium Falcon from the movie Star Wars.
An image released on June 15, 2012, shows a close-up view of the unidentified object sitting on the bottom of the Baltic Sea.
Close-up of rock bed that forms the Baltic Sea UFO, which still mystifies researchers.
One of several odd stone circle formations, sitting on top of the unidentified object at the bottom of the Baltic Sea.
A circular UFO hovers above the Neumayer-Station III research facility in Antarctica on Aug. 10, 2012. Theories ranging from a simple weather balloon to a more elaborate ship from another planet have run the Internet gamut. The next slide shows a closeup of the object.
This is a closeup of the UFO from the previous slide. No official explanation has been offered about the object.
Pictured is a quad copter -- a deliberately manufactured UFO created by special effects wizard Marc Dantonio for a National Geographic special, "The Truth Behind: UFOs," which aired in December 2011. On the left is what the small device looks like resting on the ground, measuring 4 feet in circumference. At right, is how it appeared behind a tree in the night sky.
In February of 2012, this fireball was captured by a Texas police chief's A dashboard camera. F.A.A. say this was probably a meteor, falling to Earth. .
Meteors: Space debris can create a spectacular light show when it burns through the Earth's atmosphere, and sometimes reported as UFOs.
Civilian or military aircraft: Planes can look mysterious at night or in certain light conditions, thus confusing an observer.