Besides the infamous War of the Worlds hoax that people actually thought was a bona fide radio broadcast -- never mind Roswell and the onslaught of government conspiracy theories that followed -- there have been a myriad of times actual scientists thought unusual signals from space were some attempt by intelligent life trying to make contact with us Earthlings (or at least trying to get around in their starships). But were they?
Science tends to err on the side of natural phenomena, which is what some of the signals eventually turned out to be. This is space -- there is a chance that naturally occurring oddities could be exponentially weirder than anything someone could dream up in a science fiction novel. However, when even Stephen Hawking insists there must be intelligent life somewhere, you get to wondering.
Blast off into World Space Party 2017 and explore these nine far-out occurrences, some of which remain unsolved ... and theorize for yourself.
You should expect strange things to show up when you study celestial objects as hyper-energetic as quasars. Such was the case of quasar-obsessed grad student Jocelyn Bell Burnell in 1967, when a certain phenomenon still unclassified by science gave rise to the belief that aliens were desperately trying to get in touch with us from the far reaches of space. Suspiciously precise pulses of energy were what Burnell believed to be signals zapped to Earth by intelligent life somewhere out there in the cosmos. Were they being emitted by some sort of extraterrestrial transmitters? She labeled them LGM-1, aka "Little Green Men," but E.T. never phoned home.
Later studies revealed the anomaly to be eerily-timed bursts of electromagnetic radiation issuing from incredibly dense, magnetized neutron stars that rotated ridiculously fast and 'pulsed' a flash across Earth with every rotation. Astronomers later named these "pulsating stars," aka — you guessed it — pulsars.
2. The endlessly debated landscape of Mars
Is there life on Mars (or was there ever)? While we still can't answer David Bowie's question with absolute certainty, one turn-of-the century astronomer thought he had way before glam rock was in vogue. Percival Lowell was positive that "that Mars is inhabited by beings of some sort or other we may consider as certain as it is uncertain what these beings may be," as he declared in 1906. What spawned his theory were the canals on the Martian surface, which he imagined to be the result of intelligent beings irrigating crops on the notoriously dry Red Planet. Keep in mind this guy was one of the most famous astronomers of that era.
Lowell might have been the most influential, but not the first, vintage scientist to spot these canals through the lens of his telescope. His contemporary Giovanni Schiaparelli observed the canals but didn't bother with the possibility of Martians.
3. Mysterious microwave bursts
Imagine you were an astronomer detecting strange signals that were actually coming from something so mundane, it was almost unbelievable. This is exactly what happened at the Parkes Observatory in Australia. Deep-space signals were coming from somewhere way too close — meaning, whatever (or whoever) was emitting them must have been skulking around the observatory. The brief high-energy bursts baffled scientists. It probably didn't help that these 'perytons,' or seemingly cosmic radio signals that are actually coming from Earth, shared their name with a freakish mythological creature that was supposed to be half-bird, half-stag.
Ancient lore aside, it couldn't have been more shocking when they were traced to the cafeteria. The perpetrators weren't aliens or flying deer: they were humans opening the door of the microwave oven before the timer buzzed and the magnetron inside had the chance to completely shut off, releasing radio waves. Leftover pizza just got extraterrestrial status.
4. The SETI Institute signal
When a strange signal described as "millions of times more spectrally compact than a TV broadcast" was picked up by the new 140-foot antenna at the National Radio Astronomy Observatory and zapped to the SETI (Search for Extra-Terrestrial Intelligence) Institute's California headquarters, it seemed surreal. The narrow-band emission, a type with zero bandwidth that exists at only one frequency (think the opposite of broadband), is made almost exclusively by transmitters. There was a chance these could have been alien transmitters. Awake through the night and running on nerves and caffeine, SETI scientists felt they were on the edge of an unprecedented discovery.
Anxiety skyrocketed when they confirmed that the strange signal was not being influenced by any random human radio interference. It was consistently being beamed from the same place in the sky, which meant it had to be aliens ... if you consider one of NASA's solar research satellites to be an extraterrestrial. Sigh.
5. KIC 8462852
1,480 light years away in the constellation Cygnus is an advanced alien civilization in an enormous satellite.
Kepler, the space observatory which has detected thousands of exoplanets via occultation -- the brightening and dimming of a star as its orbiting objects periodically pass in front of it -- observed erratic flickering in KIC 8462852. It was something never seen by Kepler before, and suggested that whatever was occulting this star was accounting for these irregular intervals. Astronomers figured the star was possibly being orbited by wildly varying masses of debris that could be anything from asteroid fragments to comets.
But they didn't stop there. More unlikely theories suggested extraterrestrials orbiting it in a Dyson sphere, an impressive infrastructure of mirrors and solar panels generating up to one trillion times the energy used on Earth. While the existence of this extraterrestrial marvel hasn't been proven, it hasn't been disproved, either — so stay tuned.
6. Simultaneous stars
It’s bizarre enough when two or more stars pulse at the same time, but try 234 of them. That was what wowed astrophysicists Ermanno Borra and Eric Trottier when they detected so many simultaneous signals in the Milky Way. They theorized these were extraterrestrial intelligence (ETI) signals because they believed it was just so unlikely there was any other way a coincidence of such astronomical proportions could occur.
The skepticism was strong with this one. It seemed equally abnormal that 234 different intelligent alien societies would beam that many signals to Earth with such impeccable choreography. Borra and Trottier's paper was nearly rejected from Publications of the Astronomical Society of the Pacific at the recommendation of several other scientists who found it impossible to view as anything but a far-out theory. Even the SETI institute shook its head. While the stars definitely warrant future investigations, aliens remain a distant possibility.
7. HD164595 b
You know you're going to get an alien theory when the first person to analyze an odd signal is — what else — a science fiction author. Paul Glister, who blogs about space exploration and extraterrestrials on his site Centauri Dreams, learned about a signal from this potentially habitable planet after scientists brought it to light in a presentation. When Glister received the data from another scientist as attention-getting blog fodder, he took these findings several steps further by hinting at the chance that the signal could be transmitted by aliens.
Apparently these aliens give new meaning to "intelligent life." He theorized the signal's strength indicated its origin in a civilization so much more advanced than us Earthlings, they have enough brains to channel their star's energy into inventions we haven't even yet imagined.
Then again, it might just be a satellite or a stellar flare or terrestrial interference. Cue SETI investigation.
8. The Wow signal
What astronomer and SETI community member Jerry Ehman discovered in 1977 triggered a collective 'wow' from the scientific community. When Ehman was sorting through microwave frequency data from the Big Ear Radio Telescope one night, he came across a signal from the constellation Sagittarius involving an unusual sequence of numbers that looked anything but random. What he was looking at was an unexplained spike in the signal's strength that barely lasted for more than a minute before vanishing into nothingness.
Nothing like it ever materialized again.
Sure, it could have been space junk or rogue objects or some random false alarm from Earth, but that's probably the last thing on your mind when you think you've discovered aliens. The fact that no other telescopes observed it only magnified the mystery. The signal got its unofficially official name when the excited Ehman famously circled it in red and wrote "Wow!"
9. Fast Radio Bursts (FRBs)
When scientists actually publish a paper on something in space that has no natural explanation, then it's definitely aliens, right? Astrophysicists Mansavi Lingam and Abraham Loeb insist that rapid radio pulses issuing from some extragalactic source (not to be confused with pulsars) are actually transmitter beams that power alien starships to infinity and beyond. These supposedly originate outside the ship and fuel it from afar.
Even rocket science seems to support their theory, because the possibility of reducing spacecraft mass by separating the fuel from the craft itself is starting to look less and less like sci-fi.
Not that everything which doesn't go against the laws of physics necessarily exists. FRBs could be emissions from magnetars or exotic black holes that are the corpses of stars which collapse under their own gravity. So if cosmic radio waves don't propel extraterrestrial space travel, they could be coming from something just as weird.