A topic about outer-space and everything in it, from little green men to big spirally galaxies

The Planet Next Door: Astronomers Find Earth-Like Planet Orbiting in the Habitable Zone of the Star Closest to Us

Artist's impression of the view from Proxima b

Well this is big news. In recent years there has been much excitement every time a new 'Earth-like' exoplanet has been discovered by astronomers (exoplanets are planets orbiting other stars). However, with many of those discoveries being very distant, making exact measurements difficult, there has been much speculation as to how Earth-like, and how habitable, those planets really are.

But today (after a few embargo breaks last week), astronomers have announced the discovery of perhaps the ideal 'Earth-like' exoplanet candidate, orbiting the star Proxima Centauri (one of the three stars that make up the 'left pointer' of the 'Southern Cross' constellation):

There’s a new standard in town, and its name is Proxima b. This planet has just about everything we’d want in Earth 2.0: It’s just a speck bigger, with only about 30 percent more mass than Earth (or slightly higher, depending on its orbital geometry); it’s almost certainly a genuine rocky planet; and it orbits smack in its star’s habitable zone.

The best part, though, is that Proxima, the planet’s star, is right next door, just 4.3 light-years away (130 times closer than Kepler 186f), the single closest star to our sun. Astronomers across the globe are drooling. We’ll be able to take actual pictures of it, to search for clues of life, within a decade.

Let's be clear about why astronomers are so excited, by ticking the relevant boxes:

  • Very close to Earth size.
  • Orbiting in its star's 'habitable' zone (the 'Goldilocks' zone...not too hot, not too cold)
  • Orbiting the star closest to Earth

The 'actual pictures' the article above is describing would be from an Earth-based telescope - the European Extremely Large Telescope, currently under construction in Chile. But given the third point above - Proxima b is 'just' 4 light years away - and the fact that the Starshot project financed by Russian billlionaire Yuri Milner (as part of his 'Breakthrough Initiatives') was already aiming to send a space probe to Alpha Centauri in coming decades, there is the possibility we could have an actual robot visiting the planet within some readers' lifetimes. For continued updates on this idea, I recommend keeping an eye on the excellent Centauri Dreams website.

On a skeptical note, however, we should also remember that - for all our excitement about Earth-like planets beyond our Solar System - we actually have two very Earth-like planets right beside us. One, Mars, appears to be devoid of life, and would require significant engineering for humans to live there. The other, Venus - as this Discovery article notes - "would surely be hailed as the most Earthlike exoplanet known" if we found it orbiting another star:

It is just 5% smaller in radius and 15% smaller in mass. It is almost the exact same age as our planet, and gets its warmth from an identical star. The only thing that’s a bit off is that it orbits a bit closer to its star than Earth does, so it receives nearly twice as much radiation. On the other, it also reflects away a lot of that radiation. Its theoretical (equilibrium) temperature is just below freezing, so with a little natural greenhouse warming it would be quite an inviting place.

Instead, Venus is "a profound enigma". While all the variables tell us it should be a hospitable place for life (and at one time, scientists have found, it may well have been), in the present day it is "more like hell on almost-Earth".

Understanding why that is–why our planet went right while Venus went terribly wrong–is crucial for finding out whether habitable planets are common or rare throughout the universe.

So, while we should be genuinely excited about this new discovery, we should also be wary when reading headlines like this (otherwise excellent) piece at The Atlantic: "An Epochal Discovery: A Habitable Planet Orbits Our Neighboring Star". Proxima b is in the 'habitable zone'...but it remains to be seen whether it is actually habitable.

Links:

Questions Remain For "Aliens" 'Round Tabby's Star

Recently Jason T. Wright, the man who sparked a hurricane of clickbait headlines by suggesting KIC 8462852 would be an 'outstanding SETI target', gave a highly informative talk on artifact SETI, megastructures, and Tabby's Star.

Artifact SETI involves the search for artificial phenomena, like Dyson spheres and Niven rings, to narrow down targets for communication SETI to eavesdrop on extraterrestrials. The biggest clue for finding these artifacts is the waste heat given off during their creation and use. In addition to laying out the history of SETI in this vein, Jason tackles the problems with the megastructure hypothesis and why he's all but abandoned circumstellar explanations for something stranger.

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Tabby's Star: Is It Beginning To Look A Lot Like Aliens?

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The mystery surrounding Tabby's Star just ratched up another notch. Or down, considering the data outlined in Benjamin Montet and Joshua Simon's latest submission to the arXiv, "KIC 8462852 Faded Throughout The Kepler Mission". Everyone's favorite "megastructure" star continues to confound mainstream astronomers and the taboo of last resort, aliens, is still on the table.

Montet and Simon discovered KIC 8462852, a.k.a. Tabby's Star, dimmed by 2.5% over the course of Kepler's mission to survey the heavens for alien planets. The data lends support to Bradley Schafer's conclusion [1] that Tabby's Star steadily dimmed from 1890 to 1989. What everyone and their telescope are getting excited about is the rate of dimming has been increasing according to the Kepler data.

If the rate of dimming increases, this could be the product of self-replicating machines or von Neumann devices tasked to build this putative alien megastructure. When I looked at Montet and Simon's graphs, I had an insight on how they could suggest the possibility of self-replicating machines or aliens. Rather than charting the curve of the dimming light, but the 'growth' of material or machines causing the dimming, the a graph would show a sigmoid curve. In biology, sigmoid curves illustrate population growth [2, 3] through three phases of transitional and exponential growth before reaching a plateau. In this context transitional growth may be the dust of "construction crews" tearing apart an object for raw materials, followed by exponential growth as another segment of the megastructure is created, before plateauing as the 'bots travel to the next planetary or cometary resource a mere handful of astronomical units away.

The prospect of aliens, despite my speculation, remains unfalsifiable for now. But Montet and Simon do a handy job outlining the unlikely natural explanations most sane scientists would embrace. Astronomers have observed polar star spots on F-type stars like KIC 8462852, but those F-type stars are cooler and smaller in contrast. Also polar spots can't explain the short-term dips previously observed by Tabetha Boyajian, et al.. Some of the proposed transit events under suspicion for the star's dimming are even less likely.

For an optically thick transiting object, the 2.5% transit depth indicates a minimum radius of 0.15R* (Boyajian et al. 2016 estimate a radius of 1.58 R☉ for KIC 8462852). If the transiting body is in a Keplerian orbit, the extremely slow ingress time and long transit duration place it at the implausibly large distance of ~10 PC, with a transit possibility of ~10-9.

Fingers are crossed that the Tabby's Star observing campaign with the Las Cumbres Observatory Global Telescope Network, currently underway after the successful Kickstarter, will capture one of the mysterious long transits. Should the cause is a solid object, like a megastructure, then the dimming of KIC 8462852's light would be achromatic. On the other hand if the culprit is dust and/or gas, then the starlight would redden.

Maybe in a year we'll know for certain if the alien hypothesis is still worth consideration. Perhaps some science fiction-types will find inspiration around Tabby's Star for another big dumb object to fit the mystery. In either case, our interesting times are becoming more interesting by the moment.

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  1. KIC 8462852 Faded at an Average Rate of 0.165+-0.013 Magnitudes Per Century From 1890 To 1989 - https://arxiv.org/abs/1601.03256
  2. Populations - http://ibguides.com/biology/notes/popula...
  3. Explain the sigmoid population growth curve - http://ibbiology.wikifoundry.com/page/Ex...

Special Effects Legend Douglas Trumbull Talks About How He Has Created a System for Capturing UFOs

Close Encounters of the Third Kind

If you were to survey sci-fi geeks for a list of their favourite movies, there's a fairly good chance that somewhere near the top of that list you'd find Bladerunner, 2001: A Space Odyssey, and Close Encounters of the Third Kind. So it's easy to understand the legendary status of Douglas Trumbull within sci-fi geekdom, given he helped design the visual effects on all three of those seminal films.

When Jacques Vallee ran a crowd-funding campaign last year to create a collector's edition of Wonders in the Sky, his book with Chris Aubeck about historical sightings of UFOs, I was surprised to learn that Trumbull was one of the backers of the project. As it turns out though, Trumbull has been interested in the UFO phenomenon for some time now (in retrospect, it's probably not that surprising, given two of the three films above are specifically about humans making contact with an alien intelligence).

In a video interview posted by Open Minds (embedded below), Trumbull describes his interest in 'scientific ufology', and how he thinks he could help the effort with his own skills and network, by designing a 'UFO capture' system he calls UFOTOG:

When I started making inroads into MUFON and the UFO community, I found that there were a number of very highly-placed and credible people, like Jacques Vallee, like air-traffic controllers, like doctors, like scientists, who took the whole thing very seriously - mixed in with a lot of people who were into auras, and spirituality, and other kinds of things that were more hearsay than science. And I didn't like that part of it, I've never liked the hearsay part of it, I didn't like people telling their stories, even though many of them are tremendously compelling and heartbreaking - abduction stories in particular. I said well, you can't prove any of that, there's no evidence, there's nothing to do.

I started asking those people, has anybody ever mounted a scientific endeavour, a privately funded scientific endeavour, to quantify what a UFO is made up of, and how fast does it go, and how high does it fly, and where does it come from, and is it changing state from plasma energy to aluminum or whatever? And the answer was no, no-one had ever done that. And I said, well, I'm going to make that my mission, because that sounds like fun to me, 'cause I'm a geek.

So that was the beginning of UFOTOG, to try and spend at least some part of my hobby time going down that path, like an amateur astronomer.

UFOTOG - the name is a contraction of 'UFO photography' - is a UFO video tracking and capture system that came about when Trumbull considered how his own skill-set could best be put to use in seeking answers to the UFO mystery: "I had access to these high-end cameras, access to engineers who build motion-control systems that we use for movies that could be adapted to tracking systems and things like that."

Interestingly, even with his legendary status, Trumbull soon discovered how heretical the idea of scientifically researching the UFO phenomenon can be. "That's when I started finding out that talking about science fiction is fine," he notes, while "talking about actually capturing UFOs is not fine...it's actually antagonistically greeted." Trumbull even tried pitching the idea to 'reality TV' producers, but "couldn't get any traction at all...and I've got a really good resume."

In the video, Trumbull also discusses his work on 2001, why he turned down Star Wars but worked on Close Encounters, and how he created a science fiction movie about UFOs as a cover for his effort to photograph UFOs - even designing the story "so that if we actually got real photography, we could put that into the movie and suddenly the movie would become non-fiction".

The Culture Next Door: Tabby's Star Remains Strange... And Unique

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Also known by its designation KIC 8462852, Tabby's Star continues to perplex astronomers and mainstream science bloggers.

News broke in September 2015 after citizen scientists noted the abrupt, non-periodic dimming of this distant F-type star. F-type stars are like our sun, but bigger and hotter. Hard line skeptics dismissed the phenomenon as comets, but evidence has yet to emerge supporting this hypothesis. Currently astronomers and cosmologists can't imagine how ~648,000 giant comets could coordinate their orbits to dim a star over the last hundred years.

Bradley Schaefer of Louisiana State University combed through Harvard's archive of astronomical plates from the last century, finding there's been a steady dimming of Tabby's Star. Faced with a deepening mystery Michael Hippke, self-proclaimed (and cringey) "gentleman scientist", and Vanderbilt University doctoral student Michael Lund earnestly tried, and failed, to disprove Schaefer's discovery. There's nothing wrong with the Kepler observatory that first imaged KIC 8462852, nor Harvard's plates, and Schafer's methodology is watertight.

Spicing up the story is Penn State's Jason Wright, suggesting the dimming's cause might be an alien megastructure like a Dyson swarm or sphere. The invocation of aliens by straightlaced scientists without outright dismissal by their peers means more money from ad impressions, and angry flame wars in comment sections around the web. Also aliens?

To puzzle out this anomaly, the only sensible course of action is to continue surveying the sky, and reviewing past data for other stars with similar characteristics. Should one be found, astronomers can study it, compare it, then begin narrowing down the suspects behind the strangeness 1,480 light years away from us.

This search might take longer than hoped. Daryll LaCourse, profligate Kepler data miner, announced to the internet how Tabby's Star is unique.

The Kepler spacecraft is now observing a series of new ecliptic fields (K2) and has accumulated observations of ~165,000 additional targets. Continued visual inspection of these public data has failed to recover an analog to KIC 8462852. Lack of such a detection suggests that the aperiodic dimming indeed represents a rare astrophysical phenomenon, regardless of the true root cause mechanism involved.

For now Homo sapiens should content themselves with Tabetha Boyajian's successful Kickstarter to continuously monitor her star, and see how deep the rabbit hole goes.

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Video from Juno Space Probe Shows Moons Orbiting Jupiter

I will never get tired of space probe images. Four centuries after Galileo gazed through his crude telescope and saw Jupiter being circled by a number of its own moons (thus dealing a serious blow to the Ptolemaic, Earth-centric view of the cosmos), NASA's Juno probe captured the higher-fidelity view above of the Galilean satellites orbiting the giant planet as it approached its own orbit.

During it’s final approach to Jupiter, NASA’s Juno spacecraft captured this unique time-lapse movie of the Galilean satellites in motion about the planet. The images were taken 5 days prior to arrival and end when the spacecraft was 3 million miles distant. The innermost moon is volcanic Io; next in line is the ice-crusted ocean world Europa, followed by massive Ganymede, and finally, heavily cratered Callisto.

Imagine the look on Galileo's face if you could go back and show him that video...

Comics Legend Jack Kirby Worried That Our Attempts to Contact Aliens Might Attract a 'Tiger'

Galactus Attack

In recent times, somewhat of a divide has formed in the ranks of scientists involved in the search for extraterrestrial intelligence (SETI). One side is championing the idea of 'Active SETI'; that is, instead of passively searching for signals from elsewhere, as we have been for decades now, this faction wants to start broadcasting our location to the cosmos in case anyone out there is listening as well. The other side thinks this could be a rather bad idea, given the Earth's own history of civilisations being taken over by other, more technologically advanced cultures.

This debate, however, is hardly a recent development. In 1972 and 1973, NASA launched the Pioneer 10 and 11 space probes. Placed aboard each were gold-anodized aluminium plaques - now referred to as the 'Pioneer plaques' - which featured a pictorial message to any extraterrestrial species that might intercept the probes. The plaque imagery depicted a human male and female, as well as a series of lines emanating from a point, intended to act as a guide to our Sun's location in the cosmos (the lines represented the Earth's distance and position from pulsars, allowing aliens to triangulate our position). For even more detail, an illustration showing our position within our Solar System was also included.

The idea for the plaques was championed by 1970s science celebrity and educator Carl Sagan, and it was he, along with SETI pioneer (no pun intended) Frank Drake, who designed the content of the pictogram.

Pioneer Plaque

But not everyone was happy about this decision being made without public consultation. Comics legend Jack Kirby - who just six years previous had created the comic-book character of Galactus, an alien that devoured planets - denounced Sagan's move. Kirby's thoughts were outlined in a response to the Los Angeles Times, which in 1972 had approached a number of artists, including Kirby, asking for their own ideas on what should have been included on the plaque. Kirby made clear that he thought providing a map of our location was a dangerous move, as we can't predict that actions of any alien civilisation that might find it:

I would have included no further information than a rough image of the Earth and its one moon. I see no wisdom in the eagerness to be found and approached by any intelligence with the ability to accomplish it from any sector of space. In the meetings between 'discoverers' and 'discoverees,' history has always given the advantage to the finders. In the case of the Jupiter (Pioneer) plaque, I feel that a tremendous issue was thoughtlessly taken out of the world forum by a few individuals who have marked a clear trail to our door.

My point is, who will come a-knocking - the trader or the tiger?

So what content would Jack Kirby have put on the Pioneer Plaques and sent out into space to represent the Earth? The diagram he provided to the Los Angeles Times is simple, and as promised, has no 'location data' for interested aliens. Instead, it shows idealised illustrations of man and woman, greeting any aliens who might be looking at it simply with a friendly smile and wave. Kirby explained:

It appears to me that man's self image has always spoken far more about him than does his reality-figure. My vision of the plaque would have revealed the exuberant, self-confident super visions with which we've clothed ourselves since time immemorial. The comic strip super-heroes and heroines, in my belief, personify humanity's innate idealism and drive.

Kirby Pioneer Plaque

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Is It Really a Good Idea to Try and Contact Extraterrestrial Species?

Alien attack in the movie Independence Day

While we are all now familiar with SETI - the search for extraterrestrial intelligence, by searching the skies looking for alien broadcasts - in recent years a lesser known aspect to that quest has been generating plenty of debate. A number of researchers - including one of SETI's most well-respected and recognised scientists, Seth Shostak - have been arguing that a comprehensive approach to searching for aliens should include us trying to make contact with them, referred to as both 'Active SETI' and METI (Messaging to ET Intelligence).

But is this really a good idea? Should we be shouting out our location to the cosmos, when we don't know the intentions of any alien intelligences lurking out there? This is one of the major criticisms of Active SETI voiced in a recent paper on arXiv.org, "Reviewing METI: A Critical Analysis of the Arguments".

The author, John Gertz, points out that in the medical sciences, any proposed experiment must pass ethics review boards. Some experiments are deemed to be too dangerous, or unethical, and are rejected. And yet, "astronomers face no such ethical reviews, since theirs is normally an observational science only", he notes. But "when it comes to METI, which is not observational but manipulative, and on which may hinge the very fate of the world, perhaps they should."

In the paper, Gertz lists and critically evaluates the most common arguments in favour of an Active SETI approach, but finds them wanting:

Whenever one hears a “scientist” assert that ET must be altruistic, or that ET surely knows we are here, or that the closet ET civilization is at least 'x light years' away, ask to see the data set on which they base their conclusions. As of today, no such data set exists. In the absence of any evidence whatsoever, whether one believes that the extraterrestrial civilization we might first encounter will be benign, in the fashion of Spielberg’s Close Encounters of the Third Kind, or ET, or malicious, asin Ridley Scott’s Alien, or robotic, or something else entirely is strictly a matter of one’s personal taste. SETI experiments seek to learn what actually resides or lurks out there in the universe. METI plays Russian roulette without even knowing how many bullets are in the chamber.

It would be wiser to listen for at least decades if not centuries or longer before we initiate intentional interstellar transmissions, and allow all of mankind a voice in that decision. The power of SETI has grown exponentially with Moore’s Law, better instruments, better search strategies, and now thanks to (Russian billionaire) Yui Milner’s visionary investment, meaningful funding. The advances are so profound that it is reasonable to say that the SETI of the next 50 years will be many orders of magnitude more powerful than the SETI of the last 50 years.

[Seth] Shostak, perhaps METI’s most articulate proponent, knows this and has widely predicted that we will achieve Contact within the next two decades. So why can he and his fellow METI-ists not wait at least until then before initiating transmissions?

What do you think? Should we shout out to the cosmos and see if anybody shouts back? Or is it safer not to tempt the fates?

Paper: "Reviewing METI: A Critical Analysis of the Arguments"

(h/t Norman Redington)

Kickstarter: Help Investigate the 'Most Mysterious Star in the Galaxy'

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In October last year, the discovery of strange fluctuations in the light of the star KIC 8462852 (also referred to as "Tabby's Star") led to suggestions that it could be an observation of something that an alien civilization might build (ie. an 'alien megastructure').

Since that time, there's been plenty of debate as to the validity of the observation - but what would be the most help in resolving the mystery is to actually gather more data from observations of the star. And that's exactly what the scientists involved want to do - but that requires telescope time, and that comes at a price.

Enter a new Kickstarter, devoted to the most mysterious star in the galaxy:

The star was discovered with data from the Kepler space telescope, but Kepler has moved on to a different mission and cannot observe it anymore. But for us to understand what is happening -- we need more data and we need your help!

We are using the Kickstarter platform to build community of people interested in working on this mystery with us. What are astronomers doing next? We need more data! Are you wanting to help? To learn? Join us!

This Kickstarter project will secure observing time on a global network of ground-based telescopes so we can catch the star when its brightness dips again. When will the dips occur? What will the dips look like? How long will they last? And last but not least, what is it passing in front of the star to make these dips?

Only with these new data, and the answers to these questions, will we be able to test theories out on what is happening around this star!

Interested? Head on over to the Kickstarter page to find out how you can help out.

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I Know What I Saw: On the 'Unreliability' of UFO Eyewitnesses

I Want to Believe

Over on her blog at National Geographic, science writer Nadia Drake - the daughter of SETI pioneer Frank Drake - has taken Hillary Clinton to task for recent comments made about UFOs. "There’s enough [UFO] stories out there," Clinton remarked during an FM radio show interview, "that I don’t think everybody is just sitting in their kitchen making them up."

Drake notes her disappointment "that influential people are helping fan the flames of conspiracy theories", saying it was "unhelpful and irresponsible for Clinton" to be "teasing the public". Hillary, she says, is wrong to put any stock in eye-witness reports:

Check out the decades of research that have been done on the reliability of witnesses testifying in court. In these situations, our brains often fill in or edit details based on preconceived biases or post-encounter information—and then we subconsciously convince ourselves that our memories are accurate when in fact, they’re not.

This is where Clinton’s reasoning about people sitting in their kitchens making stuff up falls apart. Beliefs are potent. The brain is a powerful tool, and it can lead us to some incredibly wrong recollections and conclusions. And in these situations, assuming there’s safety in numbers is foolish (for more on that topic, start with the Salem witch trials).

Drake is right, of course, that eye-witness testimony can be flakey, and we should be very cautious in trusting it. However, to swing to the extreme and simply write off the vast number of sightings is also misguided.

Consider, for example, the eye-witness reports a few hundred years ago of an obviously ridiculous 'phenomenon': that rocks fell from the sky. For a very long time these reports of meteorite falls were dismissed as fanciful, or at the very best a confused sighting of some other phenomenon. It wasn't until a confluence of factors around 1800 - ranging from influential publications to bizarre meteor showers - that opinion began to shift towards the belief that rocks did indeed fall from the sky.

One of those incidents was the 'Wold Newton Meteorite' fall in England in 1795, near the home of magistrate Major Edward Topham. Topham was acutely aware of the controversial nature of such incidents at that time, and thus “as a magistrate, I took [the witnesses] accounts upon oath”. Topham had some choice words for those who chose to dismiss these reports. “I mean not to enter into any literary warfare with those sceptics, who think it much easier to doubt every word of this account than to believe such an event could take place,” he remarked. “There is no shorter way of disposing of any thing than to deny or disbelieve it”.

Once the reality of meteorite falls became established, the historian Eusebius Salverte pointed out that scientists' failure to recognise the truth of the matter for so long was borne out of "a predetermination to see nothing, or to deny what we had seen."

And another meteor controversy that ran parallel with the 'rocks from the sky' debate was also often dismissed based simply on the supposed fallibility of eye-witnesses. When a large fireball tore across the sky over England in 1719, a witness reported that it...

...made so strong a light while it was in its greatest extent, that for a moment the Moon, which was above a day past the first quarter, and all the stars, seem'd to disappear by the superiority of this new light; and at that moment one might have read the smallest print by it. While it was throwing itself into this beautiful stream, I thought I heard a noise of hissing, like what is made by the flying of a large rocket in the air, but I heard no other noise.

Others too heard similar noises when the bolide lit the sky that night. But the famous and influential astronomer Edmund Halley (whom Halley’s Comet is named after) was quick to dismiss these claims as “pure fantasy”. Halley’s reasoning was based in hard science: from various ground observations of the bolide’s flight, he had been able to triangulate the height of the fireball. At more than 60 miles distant, Halley noted that it would have been impossible for anybody to hear the fireball at the same time as seeing it: as sound travels at ‘only’ around a fifth of a mile per second, it would have taken some five minutes to hear anything related to the event.

But over the years, people kept reporting this same 'impossible' thing. In 1784 Thomas Blagdon gathered a number of similar reports, but suggested that they might best be explained psychologically, as being the result of “an affrighted imagination”. And yet the reports kept coming. Almost 200 years after Halley's 'debunking', the famous astronomer W.F. Denning would note that "hissing and similar noises…may be dismissed as imaginary…[an] observational illusion… They are either imaginative or due to causes not directly connected with the phenomena observed". In 1932, C.C. Wylie, Professor of Mathematics and Astronomy at the University of Iowa, illustrated once again the dangers of using the words “without doubt” when he wrote that “the explanation [for meteoric sounds] is without doubt psychological”. In fact, even after the turn of the 21st century, I have seen skeptics dismissing these reports as nonsense.

But it turns out that these noises are real, and have even been recorded. Much is still unknown about them, but these 'electrophonic meteors' are now theorised to emit VLF (Very Low Frequency) electromagnetic waves - which travel at the speed of light - and transduce sound in objects near the witness, or perhaps even within their head.

Why did it take more than 200 years - during the great age of science no less - for scientists to recognise that witnesses were reliably reporting the phenomenon, and it was they who were wrong? Firstly, electrophonic meteors were said to exhibit impossible behaviour (instantaneous sounds). Also, they occurred suddenly, without notice, usually to witnesses alone or in small groups, often in remote areas and/or in the middle of the night, who provided the often dismissed 'anecdote' rather than more desired 'evidence'. They were extremely capricious in the manner in which multiple witnesses in the same group might report different sounds (or no sound at all). And for a long time, the fireballs themselves were unidentified objects - without a solid understanding of what they actually were (i.e. rocks falling from the sky), the mechanism behind the production of such anomalous sounds remained a mystery.

Sound familiar?

I'm all for being skeptical of eyewitness reports of UFOs. But let's not be so silly to dismiss them all out of hand without investigating the truly perplexing ones. Otherwise we might be missing out on something very important (and that certainly doesn't have to mean 'alien craft').