Is this truly the video that UFO skeptics have been dreading? Actually, a compilation of 17-month-old video clips from a Chilean military air show is stirring up predictable responses from both sides of the UFO debate, but no dread.

For those who are inclined to believe that some unidentified flying objects exhibit characteristics beyond what our technology seems capable of, the El Bosque case could represent the latest, greatest evidence for flying saucers.

"This is a very, very unusual case, and I'm hoping that this case will help move forward the recognition that there really is something here that's worthy of further study. ... It has the possibility of being a breakthrough case," said investigative journalist Leslie Kean, the author of the book "UFOs: Generals, Pilots and Government Officials Go On the Record."

But for those who think even the toughest cases can be explained away as video glitches, bugs or other tricks of the eye, the El Bosque case is just more of the same. 

"They're 'unexplained cases' only if you ignore the explanation," self-described debunker Robert Sheaffer told me. "That's what's going to happen in this case."

Genesis of an anomaly
The case goes back to an air show that was staged in November 2010, at Chile's Air Force academy, which is headquartered at the El Bosque Air Force Base in Santiago. Nothing untoward was noticed by anybody during the show itself, but Kean said an engineer at the nearby aircraft factory noticed an anomalous spot as he was sifting through video taken from the show, looking for an image that could be used as a poster photo.

The spot appeared to move quickly from frame to frame, and the engineer thought it looked enough like some sort of craft to notify the Chilean government agency in charge of investigating anomalous aerial phenomena, known by the Spanish acronym CEFAA.

The way Kean tells it, CEFAA investigators looked around for other video clips of the event and pieced together six additional views of the spot-shaped phenomena. Ricardo Bermudez, a retired Chilean Air Force general who is now CEFAA's director, told a UFO conference last month that his agency consulted with other officials, image-processing experts and "non-believer astronomers." CEFAA's conclusion was that the spots were caused by an object traveling through the scene at speeds in excess of 4,000 mph — so fast that it went unnoticed by air-show spectators.

"Humans inside this object could not survive," Kean and a co-author, former New York Times investigative reporter Ralph Blumenthal, wrote in a Huffington Post report appearing on Tuesday. "And, somehow, it made no sonic boom..."

Kean told me that the El Bosque case was notable for several reasons: "I think what's exceptional about this is that the investigation was thoroughly managed by a government agency."  Also, she said, "it's something you can actually see with your own eyes." The fact that the object shows up on seven videos from the same event, recorded from different vantage points, adds to the intrigue, she said.

The El Bosque case fits the pattern that Kean laid out in her book, in which she highlights UFO accounts from experienced pilots, military observers and government officials. Even measured by that standard, the Chilean case stands out, Kean said. "In some ways, I think it's more explosive than many of the cases in the book," she told me.

Skeptics unconvinced
In their article, Kean and Blumenthal wondered whether El Bosque would turn out to be "the case UFO skeptics have been dreading" — but experts on the other side of the UFO debate said their skepticism was unshaken.

"It's a tiny thing in a low-res video," astronomer Phil Plait, the myth-buster behind the Bad Astronomy blog, told me in an email. "If this is the best she can come up with, dread is not exactly what I feel."

Sheaffer, a columnist for The Skeptical Inquirer magazine and author of the book "UFO Sightings," joked about the reference to dread. "I'm shaking," he told me during a telephone interview. "You just can't see it on the phone."

Sheaffer said there wasn't yet enough data available to judge what really happened at El Bosque. "It's going to be like the Phoenix Lights in 1997. We're going to have to go and sit down and look at it," he said. (Coincidentally, Kean and Blumenthal's story came out on the 15th anniversary of the Phoenix Lights incident in Arizona.)

Some of the key missing points in the story have to do with the six other videos that are said to show the flying spot. Kean said that as far as she knew, those videos have not been seen by anyone outside CEFAA's investigative group. Another must-have for outside investigators would be the identity of the shooters behind the seven videos. If they turned out to be seven random people, with no relationship to one another, that would at least argue against the incident being an intentional hoax, Sheaffer said.

The fact that no one reported hearing or seeing anything out of the ordinary during the air show itself would suggest that the anomalous object is a trick of the eye — or, more accurately, a trick of the video.

For some of the denizens of the Above Top Secret online forum, the nature of the spot, or spots, was obvious: It's a bug, or bugs. An insect flying at regular speed through the foreground of the video could have been misinterpreted as an aircraft flying at super-fast speed through the background. One forum member posted several animated GIF images showing a similar effect. Different bugs could conceivably have flown through the viewing fields of different cameras, leading to the impression that the same super-fast craft was shown in each video — particularly if the six videos identified during CEFAA's follow-up were pulled out of a larger set.

"Maybe we'll find out it's a bug, but I seriously doubt it," Kean told me. She said she took Bermudez and his fellow investigators at their word. "All I know is that people who know way more about photo analysis than I have ruled that out," Kean said.

Even though Kean has made a name for herself as a UFO writer, she insisted that she's not wedded to a woo-woo explanation. "I just wanted to get this story out there," she said. "I'm hoping that some American scientists will now take on the analysis of this."

Update for 8:30 p.m. ET: I'm getting additional information from both sides of the debate. Leslie Kean sent me a follow-up email on the bug hypothesis:

"I went back to the CEFAA official re the bugs, and he said that's what they all thought at first when they got the first film (the one I posted). But when they went and got additional footage from very different vantage points which showed the same thing, they knew that was impossible.  I don't think they're that stupid to claim this is a UFO if it was a bug, given that so many experts looked at it."

And there's this from UFO skeptic Tim Printy:

"I am very skeptical of this story the more I read it. There are no high-quality videos available, and the frame grabs/brief clips I have seen appear to be vague and indistinct.  The idea they may be birds, insects or possibly a small Mylar balloon has crossed my mind but I can't tell much from the data at hand. 

"There are some big red flags for me:

"1) This happened over a year ago and people are still working on analyzing this? If the evidence was truly that good, it would take a few months at best to come up with a reasonable analysis to demonstrate it was something not of this earth. 

"2) It is being leaked out to various UFO blogs instead of publishing in a scientific journal. If it were good evidence, that is where it would appear, and not the Huffington Post.

"3) The videos are unavailable to be analyzed from outside sources. Perhaps they learned from the Mexican Air Force video debacle. Once the videos were revealed in sufficient length, many people identified the source of the images as being from oil wells in the gulf.  A lot of people had egg on their face from that one. NARCAP was initially involved with that one, but then later stated they could not properly analyze the video because of the provenance being questionable or some excuse similar to that. 

"4) The videos have no provenance. We don't know what has been done to them since the day of the event.

"Just my thoughts on this one. I can probably come up with a few more red flags, but I would rather wait for the report to appear or the raw videos to surface.  Meanwhile, I will hit my snooze button while the UFOlogists proclaim it the latest 'smoking gun.' So far all of these 'smoking guns' have turned out to be empty water pistols that have never fired a squirt."

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• Cosmic Log archive on UFOs

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.