The Thunder of UFOs

The entire universe in blog form
April 24 2006 9:56 PM

The Thunder of UFOs


Man, I love the UFO proponents. You can always count on them for some great quotations.

Phil Plait Phil Plait

Phil Plait writes Slate’s Bad Astronomy blog and is an astronomer, public speaker, science evangelizer, and author of Death from the Skies!  


So here's the scoop. There are reports of a loud blast coming from the sky in San Diego, around 9:00 a.m. on April 4. They're described as being like sonic booms, but there were no meteors reported, no explosions from a nearby marine base, no airplanes seen. What could have caused them?

On April 7, three days later, similar booms were heard in Mississippi. There are other reports from Alaska, Alabama, and other states, too.

Now, if I were faced with this situation, there are a lot of things I would suspect. There are air bases not too far from San Diego, for example, with some hotshot pilots. A low-flying plane might be missed, and it's doubtful if it would be reported by the military. And Mississippi? There are several air bases in that area as well. Coincidence, maybe. The reporter does say the FAA said there were no transsonic planes in the area at that time.

Could it be a meteor? That's possible. In broad daylight, a meteor coming in from the direction of the Sun might be hard to spot, even if it were pretty big. It depends on how big the area affected was. I tried mapping some of the locations listed in the article, but they were too vague to get a good line on. The article discusses it with an astronomer, who said a meteor is unlikely. I'd agree, but it's not impossible. And it is pretty unlikely it's been meteors causing all of these booms all over the place (unless crop circles know something we don't).

But in a long list of things this might be, where do you think I would put UFOs?

If you said last, then yeah, that's about right. Why resort to something for which there is zero evidence when there is plenty of evidence for more mundane things?

But for once, a UFO expert is in agreement! The article quotes Peter Davenport of the Seattle-based National UFO Reporting Center, who, when asked if these boom were caused by a UFO, replied, "Probably not."

Wow, I thought to myself when reading this. Logic, reason? Many people who believe in UFOs are relatively sane folks, but some of the more vocal proponents you hear from are, um, well, nutbags. I've heard Davenport on the occasional radio program, and he appears very earnest, and in many cases he does seem to be keeping a level head. I haven't heard him very often, so I can't make too much of a judgement.

The problem here is, in the article Davenport kept talking:

"UFOs almost never generate sonic booms or shock waves," he added. "They accelerate so rapidly that they leave a vacuum in the sky, much the way lightning does."

There are at least two silly things in his statement. One is the assumption that we know anything at all about UFOs, given the scant (read: zero) physical evidence for them. The best he can say is, with the anecdotal evidence we have gathered, alleged UFOs almost never make any noise. But ascribing a physical cause to that is asking for trouble...

... which is what he brought on himself. My favorite part of that quotation has to be his comparing them to lightning, saying this is why they are silent.

Lightning does create a vacuum in the sky, as he implies. It's because lightning is very hot, and creates a sudden expansion of the air. This compresses the air violently, supersonically. This creates a shock wave. That makes... oh, what's the word?

Oh yeah. Thunder. Lightning makes thunder! And that's really kinda loud, don't you think?

So hey, maybe a UFO did make these booms! Of course, you can be pedantic and say it was a UFO, because whatever it was, it was unidentified.

But pedantry is very tiring, and I would have to sigh and say you know what I mean.

Anyway, no, before you ask, I don't know what's causing these booms, but then I only read a newspaper article about them. I'd love to know what's going on (especially if they are meteors) but I'm a bit busy these days. If there are any follow-up stories, BABloggers, please let me know. Link 'em in the comments here. Maybe we can get some more clues.

Tip o' the flying saucer beret to the approximately eight billion people who sent me email about this newsletter article. Also, the image up top links to a fantastic CGI site for Gerry Anderson TV show stuff. If you're not familiar with his show, then what can I say? You're too young.'