The universe is a strange place by its very
nature. Mysterious questions abound over dark matter,
dark energy, how it all came to be and so on. But at the same time, as our astronomical
instrumentation has improved, in modern times we have been able to study the universe in
unprecedented detail. As that process has unfolded, the universe
has rewarded us with both understanding, but also new mysteries, many of which have not
been solved. In the course of making this channel, I’ve
run across and covered many such astronomical mysteries, some of them now solved, some of
them not. But there has always been a core group that
offer possibilities so weird, that they continue to baffle scientists to this day. So here are 10 Unsettling Astronomical Incidents
and Phenomena. Number 10 The Nature of Pulsars When pulsars were first discovered in the
1960’s the possibility that they were alien beacons had to be seriously considered after
it was shown that they were not a product of earth interference. They were, after all, highly unnatural looking
pulses of electromagnetic radiation that repeated with such regularity that some of them rivaled
the accuracy of atomic clocks. In the years since, we’ve learned that they
are just an unusual case of nature emitting a regular signal by way of a rapidly rotating
neutron star. This would seemingly lay the idea of alien
involvement with pulsars to rest. Except, it actually doesn’t. In 2017, Clement Vidal authored a paper that
reopened the question of an alien technological origin for pulars, or at least a certain class
of them that could have been natural objects tweaked by aliens for communications. He pointed out that there were five reasons
that aliens were originally taken off the table as an explanation. The first was the truly titanic amounts of
energy involved, it seemed unlikely to some that a civilization would use that kind of
energy. Trouble is, we’ve never seen an alien civilization
and really have no idea what they would be capable of energy wise, and we do still talk
about galaxy spanning Kardashev type III civilizations that would command far more energy than a
pulsar. The other four reasons are equally problematic. One was that they are not unique. In other words, how likely would it be that
two seperate civilizations would broadcast the same way at similar frequencies. Well, our earth civilizations do that, and
SETI does spend a lot of time looking for aliens at the frequency 1420 Mhz because there
are inherent scientific advantages to do so that alien scientists would also know about. Perhaps that could be the case with pulsars. Another reason was that pulsars generally
do not emanate from planetary systems, but who says aliens have to stick to a planet? Also, they are not narrowband, kicking out
broadband transmissions wastes energy and technology generally sticks to narrowband
as a result. But if pulsars started out as natural objects,
that are being tweaked for communications by exocivilizations, then broadband may just
be a natural leftover artifact. But the fifth argument is the most solid. We have perfectly good natural explanations
for pulsars that fit the bill. There really isn’t a reason or need to evoke
aliens when something appears explained and natural. But that doesn’t eliminate the pesky possibility
that pulsars could be tweaked by an exocivilization as a natural carrier for communications and
that, maybe, we should look for that, especially in light that some of them are extremely accurate
in their pulses, to the point that they could be used for something like a navigational
beacon. That near absolute regularity present in some
pulsars does still look a bit odd, decades after they were first detected. Number 9 Fast Radio Bursts This particular phenomenon is a relatively
new one, having only been discovered in 2007. They come as a very quick bursts of radio
waves that arrive in such a way that scientists know that while extremely powerful, they must
come from very small sources that are very likely outside our galaxy, limiting what could
be causing them. Further limiting what they might be is that
at least one has been seen to repeat, seemingly ruling out any sort of cataclysmic event,
such as a black hole merger. Most hypotheses currently on the table involve
neutron stars or magnetars in some sort of odd situation, but it’s also hypothetically
possible that they could be of alien origin. In 2017, Manasvi Lingham and Abraham Loeb
released a paper, link below, explaining that it’s possible that the origin of at least
some of them could be leakage from alien light sails, because the frequencies at which FRBs
are detected happen to also be optimum frequencies for use with light sails. More, given that the FRBs have been shown
to originate from very small sources, they point out that the emitter for a light sail
would need to be about twice the diameter of Earth, well within the constraints on what
could be producing FRBs. Number 8 The Dyson Sphere Candidates Sometimes ideas within the realm of futurism
can be so speculative that, if realized, are probably going to prove impractical. One such concept is the Dyson Sphere, though
it should more accurately be called a Stapledon Sphere, after the sci fi author that envisioned
them in the 1930’s, as opposed to Dyson’s actual vision of a swarm of energy collectors. To actually encase a star within a solid shell
would be a megastructure undertaking of truly titanic proportions that would involve things
like completely disassembling planets for raw materials. And, it’s not entirely clear how such a
thing would be engineered, constructed and maintained. Surprisingly however, out of all the hypothetical
alien megastructures that we have yet envisioned, the Dyson Sphere remains the only one for
which we have detected candidates, though they probably aren’t very good ones and
are likely really due to natural phenomena. The detections stem from a search of infrared
data from the IRAS satellite done by scientists at FermiLab. The idea is that Dyson Spheres absorbing energy
from their star would re-emit that energy in the infrared in a specific, detectable
way. They found 17 candidates that fit, though
they were very ambiguous and probably have natural explanations, though efforts to figure
out what they are are ongoing, and another project to search for them using the GAIA
spacecraft has already yielded a further two eyebrow raisers, TYC 7169-1532-1 and TYC 6111-1162-1
though again they are really ambiguous. Nothing definitive, but in coming years if
civilizations do indeed encase their stars in Dyson Spheres, it seems likely we’ll
spot it. Number 7 The Phantom Planet Unlike most of the phenomena on this list,
this one could well be explained within the next few years, as several groups of scientists
are actively looking for it. The motion of objects in the outer solar system
is peculiar, as though they were disturbed by a large object in the outer solar system. In fact, yet another object showing orbital
peculiarities consistent with this was found recently, bolstering the case that another
planet exists in this solar system much further out than the orbit of Neptune. One possibility is that it’s the solar system’s
missing super earth. Our star system is unusual because we lack
a super earth, seemingly one of the more common types of planets in the Milky Way. This hypothetical planet may have formed closer
into the solar system, but might have been pushed out early in the solar system’s history. Another possibility is that it may not be
from this solar system at all, and may be a captured object the sun acquired at some
point in its history, in which case it would truly be an alien interloper in our star system,
and would offer a chance at studying an actual former exoplanet that formed somewhere else. While it’s not universally accepted that
Planet 9 must be out there, there is also an arguement that the data is skewed and it
may not exist at all, whatever the case, as hints of this phantom planet’s existence
continue to surface, it seems very possible that within a few years we may well have another
known planet to explore. Number 6 TYC 8241 2652 This entry is truly bizarre because not only
is there no ready explanation for it having happened, but also no ready explanation for
how fast it happened. In 1983 the star TYC 8241 2652 was observed
in the infra-red to have a debris disk. That in itself is nothing unusual, dust disks
are a normal part of planetary formation, and indeed earth itself formed from one. And over time, a very long time in geologic
terms, these disks tend to clear out as stable planetary systems develop. When TYC 8241 2652 was observed in 2010, the
dust disk had completely disappeared, not in millions of years, but in the time since
a previous observation in 2008. Whatever caused the dust’s disappearance
did it under two years. Numerous natural explanations were suggested
for just how that could happen, only to fall flat and the cause for the disappearance remains
a mystery, and has been seen in no other star system with debris disks since. Number 5 234 Detections of Something Strange Occasionally, a scientific paper will come
out that’s seemingly worthy of attention and then instantly go into obscurity. That’s essentially what happened with a
paper by Ermanno Borra and E. Trottier in 2016. It related to an earlier paper by Borra where
he predicted that certain types of pulses could be produced by current technology and
be detected a thousand light years away, and vice versa. Borra then searched existing data for anything
that might look like those kinds of signals. He found 234 of them. Now, the media at the time sensationalized
the story and in some cases badly reported it as though aliens had been found. This was not the case, and the scientists
themselves made no claims that this was an actual detection of alien civilizations, merely
that that was a possibility and that further follow-up work should be done. And that’s where it sits today, but one
thing still stands out. Nearly all of the detections where coming
from stars of spectral types believed to be suitable for life. 1220-91-1
Number 4 The Wow! Signal This bizarre signal in some ways gets even
more bizarre as time goes on simply because an alien origin for it cannot be ruled out,
even though the signal was detected over four decades ago. In 1977 (check) astronomer Jerry Ehman using
the Big Ear radio telescope at the Ohio State University picked up a signal. This signal was noteworthy for several reasons. The first is that it was very close to 1420
Megahertz, which is the frequency at which hydrogen, the most common element in the universe,
emits radio waves. This frequency is of note to SETI scientists,
in fact it’s set aside and not broadcasted on specifically for this reason, because any
alien civilization that possesses science and radio transmitters would know of this
frequency. As a result, it might be a universal frequency
to broadcast a contact signal. The second is that the Wow! Signal was strong. Very strong, which is why Dr. Ehman famously
wrote wow on the printout. The third strange thing about this signal
is that it was narrowband, which is in itself very odd. Nature tends to emit radio signals broadband,
whereas technology tends towards narrowband. Another odd aspect of Wow is the fact that
it was a very brief signal, it was there and then it was not. That seems counterintuitive for a contact
signal, and it’s never been picked up since, despite plenty of attempts to do so. Perhaps the strangest aspect of Wow though
is that it keeps defying explanation. It’s never been shown to have been earth
interference, or a glitch in the equipment that picked it up. To this day, potential explanations continue
to be put on the table, only to be shot down. This happened most recently with the hypothesis
that Wow! might have been due to emissions originating from comets, and this was widely
reported in the press as a case closed explanation. What they didn’t report as widely is that
the comet hypothesis was shot down by the scientific community very quickly. If comets emitted that strongly at the hydrogen
line, radio astronomers would have noticed that by now and it should be easily observable. It’s not. So, to this day, the Wow signal remains unexplained. Number 3 Strange Signals While the Wow! Signal is the most famous of the unexplained
odd radio signals SETI astronomers have picked up, it is not unique. Other examples include a signal picked up
just once, and did not repeat, from the direction of the star TYC 1220-91-1. What’s notable about this signal is that
it appeared to originate from a nearby star that’s very similar to our sun, and potentially
habitable. It was also at a magic frequency mathematically
related to the 1420 megahertz hydrogen line. It was also narrowband, and was observed for
a full ten seconds. But most noteworthy was that the signal was
so strong, about ten times stronger than Wow!. But, since the signal didn’t repeat and
couldn’t be verified, it can’t ever be determined if it was simply earth interference. Other unverifiable signals include a 2015
signal from the star HD 164595, another very sun-like star, but this time with a verified
planet in orbit around it. But it never repeated, and it happened to
be in a military band, and it seems likely that there are satellites downlinking from
orbit that scientists may not be aware of. And then there was the signal SHGb02+14a,
which was weird even for a signal plausibly of alien origin. Firstly, unlike most, this signal repeated,
having been initially observed three different times. And, it was at the 1420 Megahertz frequency,
initially. But then it would drift. More, there didn’t seem to be any corresponding
star system to where the signal was coming from. And it was very weak, and if it originated
on a planet, that planet would have to have been rotating 40 times faster than earth. Number 2 KIC 8462852 Tabby’s Star In 2015 a star was found in the massive amount
of data collected by the Kepler spacecraft that was behaving like no other star previously
seen. It would experience dips in brightness of
up to 22 percent suggesting that something extremely massive was passing in front of
the star. Initially, it was uncertain as to what this
could be. A cloud of dust wasn’t a good fit because
star systems that have dust discs tend to emit infrared radiation brightly. No such radiation was found at KIC 8462852. The star’s main investigator, Dr. Tabetha
Boyajian, suggested that it could be cold comets blocking the light. But on further investigation, it was found
that the number of comets needed to produce the effect would have been implausible, hundreds
of thousands of them. More, another study found that exocomet signatures
in the Kepler light curve don’t fit what’s going at Tabby’s star. Given that natural explanation after natural
explanation were falling flat with this star, the idea that gigantic alien megastructures
could be blocking the light was starting to be considered. Now, even that doesn’t fit as later researched
showed that whatever was blocking the light, at least with the most recent dips measured
from the ground here on earth, was not opaque, and that dust in some bizarre juxtaposition
around the star was the cause. But there’s still the question of the missing
infra-red. To date, no one yet knows exactly what’s
going on at KIC 8462852. Number 1 Pryzybylski’s Star At the time when the KIC 8462852 story was
a media hit, it was often called the strangest star in the universe. And while it certainly was strange, this final
star on our list gives it a run for its money. The star is called Pryzybylski’s star after
the Polish-American astronomer that first studied it. The star is what’s known as a peculiar star,
a class of stars that are chemically unusual in some way when compared to other stars. But even then, this star stands apart because
it contains elements that really shouldn’t be there and are more at home in a laboratory
on earth than in nature. And it’s not just a handful of odd elements,
it’s a lot of them, in sufficient quantities to be detectable at great distance in the
star’s spectrum. Elements like praseodymium, ytterbium, technetium
and prometheum are present, the last only discovered through the activities of the Manhattan
project. Certainly odd, but stars can have odd elements
in them. But there’s more, the star is also anomalously
low in iron and nickel, abundant elements in the universe, but perhaps strangest of
all are the very short-lived actinide elements higher on the periodic table than uranium. Quite a few of these are present, and it’s
just weird, but one in particular raises an eyebrow. Plutonium. Plutonium is thought to be produced only in
minute quantities in nature, and only under specific circumstances. For this star to have it in abundance is a
mystery, though hypotheses have been put forth that you might be able to get to elements
higher than uranium if the star were bombarded by a neutron star, or some unknown nuclear
process within the star is creating them. But it’s worth mentioning that in 1966 Carl
Sagan and Iosef Shklovski hypothesized in their book “Intelligent Life in the Universe”
that one way for an alien civilization to announce its presence to others would be to
add plutonium to its star. Thanks for listening! I am futurist and science fiction author John
Michael Godier currently planning Halloween episodes for both channels, this one and Event
Horizon, like to that channel below. Halloween is my favorite holiday, and I’ve
been busily filling my house with dried ears of corn and various carved gourds as is the
custom here and be sure to check out my books at your favorite online book retailer and
subscribe to my channel for regular, in-depth explorations into the interesting, weird and
unknown aspects of this amazing universe in which we live.
