Are we human because we look at the stars, or do we look at the stars because we're human?

But do the stars look back?

Reddit user autonova3 asked:

What's the most terrifying message that could be received in a radio signal from a distant star?

Here are some of the best speculations.

A distress call.

Then later, another one, this time from a closer star.

Then a third, closer still.

OR

One distress call, but this one specifically addressed to Earth's spacefaring nations.

I can't decide which has more terrifying implications.

Instructions to build something we don't understand that ends up making life impossible on Earth and then transmits the same instructions to yet another unsuspecting planetary system.

Literally anything because just knowing they speak English would be pretty terrifying.

This question reminds me of the scene from Contact where the first confirmed radio signal from another star is Adolf Hitler giving a speech.

A top concern is that the aliens think, "you're our kind of people."

"Leave the planet, now. We tried to deflect it but missed. Sorry"

(translated from octopus) Are you there octopodes? Sorry for the delay but your weapons and space suits should be available now. Please exterminate land animals and enslave some of the humans we like their sexy hands

"Why haven't you been doing maintenance on your sun? It's going to burn out in another year unless you-"

Oh... we forgot about you. End simulation.

Jupiter is actually a very small planet, with an enormous atmosphere made up of trillions of spooky ghosts.

####

"Cease radio contact immediately, or they will hear you."

"The last episode of How I Met Your Mother has just reached us".

BALLISTIC MISSILE THREAT INBOUND TO HAWAII. SEEK IMMEDIATE SHELTER. THIS IS NOT A DRILL

Nothing, absolute silence

Despite overwhelming evidence that the other star has intelligent lifeform with advanced technology

Do you listen to ants before you step on them?

People of Earth, your attention please. This is Prostetnic Vogon Jeltz of the Galactic Hyperspace Planning Council. As you will no doubt be aware, the plans for development of the outlying regions of the Galaxy require the building of a hyperspatial express route through your star system, and regrettably your planet is one of those scheduled for demolition. The process will take slightly less that two of your Earth minutes. Thank you."

Dear Human:

I have been requested by the Zuxleyon National Tetroleuminium X67 Company to contact you for assistance in resolving a matter. The Zuxleyon National Company has recently concluded a large number of contracts for exploration in the region. The contracts have immediately produced moneys equaling 40,000,000 credits. The Zuxleyon Company is desirous of exploration in other parts of the Galaxy, however, because of certain regulations of the Zuxleyon Government, it is unable to move these funds to another region.

You assistance is requested as a non-Zuxleyon inhabitant to assist the Zuxleyon Company, and also the Central Storage Bunker of Zuxleyon , in moving these funds out of Zuxley. If the funds can be transferred to your name, in your account, then you can forward the funds as directed by the Zuxleyon Company. In exchange for your accommodating services, the Zuxleyron Company would agree to allow you to retain 10%, or 4 million Earth Credits of this amount.

However, to be a legitimate transferee of these moneys according to Zuxleyon law, you must presently be a depositor of at least $100,000 Earth credits in a Zuxleyon Bunker which is regulated by the Central Bunker of Zuxleyon .

Time is of the essence in this matter; very quickly the Zuxleyon Government will realize that the Central Bunker is maintaining this amount on deposit, and attempt to levy certain depository taxes on it.

Yours truly,

Prince Alyusi Islassis Bypton VII

We made a mistake. That is the simple, undeniable truth of the matter, however painful it might be. The flaw was not in our Observatories, for those machines were as perfect as we could make, and they showed us only the unfiltered light of truth. The flaw was not in the Predictor, for it is a device of pure, infallible logic, turning raw data into meaningful information without the taint of emotion or bias. No, the flaw was within us, the Orchestrators of this disaster, the sentients who thought themselves beyond such failings. We are responsible.

It began a short while ago, as these things are measured, less than 66 Deeli ago, though I suspect our systems of measure will mean very little by the time anyone receives this transmission. We detected faint radio signals from a blossoming intelligence 214 Deelis outward from the Galactic Core, as photons travel. At first crude and unstructured, these leaking broadcasts quickly grew in complexity and strength, as did the messages they carried. Through our Observatories we watched a world of strife and violence, populated by a barbaric race of short-lived, fast breeding vermin. They were brutal and uncultured things which stabbed and shot and burned each other with no regard for life or purpose. Even their concepts of Art spoke of conflict and pain. They divided themselves according to some bizarre cultural patterns and set their every industry to cause of death.

They terrified us, but we were older and wiser and so very far away, so we did not fret. Then we watched them split the atom and breach the heavens within the breadth of one of their single, short generations, and we began to worry. When they began actively transmitting messages and greetings into space, we felt fear and horror. Their transmissions promised peace and camaraderie to any who were listening, but we had watched them for too long to buy into such transparent deceptions. They knew we were out here, and they were coming for us.

The Orchestrators consulted the Predictor, and the output was dire. They would multiply and grow and flood out of their home system like some uncountable tide of Devourer worms, consuming all that lay in their path. It might take 68 Deelis, but they would destroy us if left unchecked. With aching carapaces we decided to act, and sealed our fate.

The Gift of Mercy was 84 strides long with a mouth 2/4 that in diameter, filled with many 44 weights of machinery, fuel, and ballast. It would push itself up to 2/8th of light speed with its onboard fuel, and then begin to consume interstellar Primary Element 2/2 to feed its unlimited acceleration. It would be traveling at nearly light speed when it hit. They would never see it coming. Its launch was a day of mourning, celebration, and reflection. The horror of the act we had committed weighted heavily upon us all; the necessity of our crime did little to comfort us.

The Gift had barely cleared the outer cometary halo when the mistake was realized, but it was too late. The Gift could not be caught, could not be recalled or diverted from its path. The architects and work crews, horrified at the awful power of the thing upon which they labored, had quietly self-terminated in droves, walking unshielded into radiation zones, neglecting proper null pressure safety or simple ceasing their nutrient consumption until their metabolic functions stopped. The appalling cost in lives had forced the Ochestrators to streamline the Gift's design and construction. There had been no time for the design or implementation of anything beyond the simple, massive engines and the stabilizing systems. We could only watch in shame and horror as the light of genocide faded into infrared against the distant void.

They grew, and they changed, in a handful of lifetimes they abolished war, abandoned their violent tendencies and turned themselves to the grand purposes of life and Art. We watched them remake first themselves, and then their world. Their frail, soft bodies gave way to gleaming metals and plastics, they unified their people through an omnipresent communications grid and produced Art of such power and emotion, the likes of which the Galaxy has never seen before. Or again, because of us.

They converted their home world into a paradise (by their standards) and many 106s of them poured out into the surrounding system with a rapidity and vigor that we could only envy. With bodies built to survive every environment from the day lit surface of their innermost world, to the atmosphere of their largest gas giant and the cold void in-between, they set out to sculpt their system into something beautiful. At first we thought them simple miners, stripping the rocky planets and moons for vital resources, but then we began to see the purpose to their constructions, the artworks carved into every surface, and traced across the system in glittering lights and dancing fusion trails. And still, our terrible Gift approached.

They had less than 22 Deeli to see it, following so closely on the tail of its own light. In that time, oh so brief even by their fleeting lives, more than 1010 sentients prepared for death. Lovers exchanged last words, separated by worlds and the tyranny of light speed. Their planet side engineers worked frantically to build sufficient transmission infrastructure to upload the countless masses with the necessary neural modifications, while those above dumped lifetimes of music and literature from their databanks to make room for passengers. Those lacking the required hardware or the time to acquire it consigned themselves to death, lashed out in fear and pain, or simply went about their lives as best they could under the circumstances.

The Gift arrived suddenly, the light of its impact visible in our skies, shining bright and cruel even to the unaugmented ocular receptor. We watched and we wept for our victims, dead so many Deelis before the light of their doom had even reached us. Many 64s of those who had been directly or even tangentially involved in the creation of the Gift sealed their spiracles with paste as a final penance for the small roles they had played in this atrocity. The light dimmed, the dust cleared, and our Observatories refocused upon the place where their shining blue world had once hung in the void, and found only dust and the pale gleam of an orphaned moon, wrapped in a thin, burning wisp of atmosphere that had once belonged to its parent.

Radiation and relativistic shrapnel had wiped out much of the inner system, and continent sized chunks of molten rock carried screaming ghosts outward at interstellar escape velocities, damned to wander the great void for an eternity. The damage was apocalyptic, but not complete, from the shadows of the outer worlds, tiny points of light emerged, thousands of fusion trails of single ships and world ships and everything in between, many 106s of survivors in flesh and steel and memory banks, ready to rebuild. For a few moments we felt relief, even joy, and we were filled with the hope that their culture and Art would survive the terrible blow we had dealt them. Then came the message, tightly focused at our star, transmitted simultaneously by hundreds of their ships.

"We know you are out there, and we are coming for you."

A stray super giant black hole will be moving through your region of space soon, and you should begin evacuating to at least 300 light-years distance.

36,400,000. That is the expected number of intelligent civilizations in our galaxy, according to Drake's famous equation. For the last 78 years, we had been broadcasting everything about us -- our radio, our television, our history, our greatest discoveries -- to the rest of the galaxy. We had been shouting our existence at the top of our lungs to the rest of the universe, wondering if we were alone. 36 million civilizations, yet in almost a century of listening, we hadn't heard a thing. We were alone.

That was, until about 5 minutes ago.

The transmission came on every transcendental multiple of hydrogen's frequency that were listening to. Transcendental harmonics -- things like hydrogen's frequency times pi -- don't appear in nature, so I knew it had to be artificial. The signal pulsed on and off very quickly with incredibly uniform amplitudes; my initial reaction was that this was some sort of binary transmission. I measured 1679 pulses in the one minute that the transmission was active. After that, the silence resumed.

The numbers didn't make any sense at first. They just seemed to be a random jumble of noise. But the pulses were so perfectly uniform, and on a frequency that was always so silent; they had to come from an artificial source. I looked over the transmission again, and my heart skipped a beat. 1679 -- that was the exact length of the Arecibo message sent out 40 years ago. I excitedly started arranging the bits in the original 73x23 rectangle. I didn't get more than halfway through before my hopes were confirmed. This was the exact same message. The numbers in binary, from 1 to 10. The atomic numbers of the elements that make up life. The formulas for our DNA nucleotides. Someone had been listening to us, and wanted us to know they were there.

Then it came to me -- this original message was transmitted only 40 years ago. This means that life must be at most 20 lightyears away. A civilization within talking distance? This would revolutionize every field I have ever worked in -- astrophysics, astrobiology, astro-

The signal is beeping again.

This time, it is slow. Deliberate, even. It lasts just under 5 minutes, with a new bit coming in once per second. Though the computers are of course recording it, I start writing them down. 0. 1. 0. 1. 0. 1. 0. 0... I knew immediately this wasn't the same message as before. My mind races through the possibilities of what this could be. The transmission ends, having transmitted 248 bits. Surely this is too small for a meaningful message. What great message to another civilization can you possibly send with only 248 bits of information? On a computer, the only files that small would be limited to...

Text.

Was it possible? Were they really sending a message to us in our own language? Come to think of it, it's not that out of the question -- we had been transmitting pretty much every language on earth for the last 70 years... I begin to decipher with the first encoding scheme I could think of -- ASCII. 0. 1. 0. 1. 0. 1. 0. 0. That's B... 0. 1. 1 0. 0. 1. 0. 1. E...

As I finish piecing together the message, my stomach sinks like an anchor. The words before me answer everything.

"BE QUIET OR THEY WILL HEAR YOU"

"It has been reported that some victims of torture, during the act, would retreat into a fantasy world from which they could not wake up. In this catatonic state, the victim lived in a world just like their normal one, except they weren't being tortured. The only way that they realized they needed to wake up was a note they found in their fantasy world. It would tell them about their condition, and tell them to wake up. Even then, it would often take months until they were ready to discard their fantasy world and please wake up."

Signals which appear to come from another population of humans, in modern English, yet from impossibly far away and long ago in time. Advertisements, music, sounds of Earthly animals, not even intentionally sent to us, yet including a lot of distress calls and fear too. From several different locations in space, or even worse, every direction. There'd be no way to explain how the universe could possibly work for that to be true, but there'd obviously be something utterly different going on behind the scenes.