could we see how aliens mine asteroids?
Whenever skeptics talk about the probability of an alien invasion, we often like to point out that attacking very distant worlds is totally unnecessary thanks to asteroid belts, which contain countless tons of resources of virtually every sort and won’t require an armada to subdue before extraction can begin. But, wonders a duo of astrophysicists, wouldn’t a civilization so big and technologically advanced that it absolutely needs to mine an entire asteroid belt to fuel its explosive growth on a massive scale also leave astronomically noticeable clues as to what it was doing? In effect, could we point our telescopes to a debris cloud around a star and detecting various anomalies such as an odd lack of certain materials, strange heat signatures, and dust clouds within dust clouds, gather enough evidence of alien asteroid mining in full swing? It’s an interesting idea and it may actually help us find places where to find other intelligent life nearby, however, it does come with a catch, one which the authors readily acknowledge. Our hypothetical aliens would have to consume resources on cosmic scales, devouring asteroid after asteroid at a dizzying rate, no easy task for anything that may be out there.
Tracking down an alien species by watching it mine its home asteroid belt carries a lot of advantages over an occasional peek at their home planet intended to figure out whether it may have oxygen in its atmosphere or a trace of liquid water on its surface. We’ll already know three very important things about them. We’ll know that they exist. We’ll know that they’re intelligent and have the technology required to leave their planet. And finally, we’ll know that they’ve built a vast civilization which requires a lot of resources to keep going. Just one simple set of observations could yield answers to many questions we’d otherwise have about them, and raise many, many others which we’re forced to relegate to the realm of highly speculative philosophical ruminations today. However, we can only really detect the debris clouds they would be mining with instruments just not sensitive enough to pick up a small scale operation. Any conclusive evidence would have to come from anomalies that cover a significant percentage of the debris cloud, pointing to an incredibly vast and advanced society which is likely to be quite old when compared to us, and in need of more resources than it would take to supply all our energy and material needs for millions of years. Such a civilization would be very rare and very hard to track down unless we get lucky and just manage to stumble across one in our backyard.
Should we find such a species though, we would very likely see significant reductions in heavy metals that we expect could be used for superconductors, high-end electronics, and in smelting sophisticated alloys while a debris cloud of far more common materials would be ejected and discarded. Though this would only happen if the species in question decided to employ massive mining machinery on asteroids instead of finding other solutions to extraction or refinement, such as nanoparticles which sink into the innards of asteroids and bring back large clumps of iridium, gold, platinum, palladium, iron, nickel, and copper. Such mining from the inside out would be completely undetectable to astronomers because it would leave the surfaces of asteroids pretty much the same until they’re completely tapped out and abandoned. Only very old mining missions would ever show up, and even then, they would be rather inconclusive until we start seeing patterns in mineral depletion which are very difficult to explain by any other means than targeted extraction. Considering that there are likely to be thousands upon thousands of asteroids in your typical debris belt, the species in question has to keep on mining for many millennia to make a dent significant for us to notice from Earth, which means that again, a species like that would be very rare, an exception rather than the norm, and very difficult to find.
See: Forgan, D., et al. (2011). Extrasolar Asteroid Mining as Forensic Evidence for ETI arXiv: 1103.5369v1
[ story tip by Dr. Ian O'Neill ]
Of course, the worse thing would be to see half the sky full of mined out solar systems, the other half pristine. And us in the middle…
People write/talk about how our civilisation would react to proof of alien intelligence. (My answer is a big “Meh” from 90% of humanity unless they were shooting at us.) But they mean “contact”, I’ve wondered about the effect over time of proof of an alien intelligence beyond our comprehension, without contact. (Example, there are “Ring galaxies”, where the type I stars are all in a ring around the type II core. Looks cool, almost artificial.) It made me think, suppose we found an undeniable example of galactic scale engineering, say half a billion light years away. No sign that They can reach us, no “signal”, just evidence of Big Intelligence. We can’t learn anything, we can’t talk to them, they aren’t a threat to us. But they are beyond comprehension… How would people react over generations with that knowledge?
“How would people react over generations with that knowledge?”
My guess? They would worship such aliens as deities or use it as proof that there is a deity out there and it’s their deity giving them a sign that the end is near. So basically, a lot like we have now only with a real object to fuel the religious debates.
If you were an alien looking to harvest stuff for your alien overlords would you choose Earth to invade? My guess is we’re probably the last place in the galaxy you would choose. For the following reason:
1. Our gravity makes it painful to get stuff off the planet. It takes a lot of energy to lift a kilo of anything into space.
2. Humans are extremely mean-spirited, suspicious, unfriendly, and prone to random and unprovoked violence. We can’t even get along with each other let alone some strange being with seven legs and four arms. Furthermore, we take pleasure in hurting things – suffering is a kind of sport to us.
3. Humans are clever critters and can figure out complex systems and machinery. Accidentally lose one of yer purple plasma gob smackers – we’ll find it, figure it out and use it against you.
4. Human beings are incubators of biologic and toxic agents. We literally spew bio-infection every time we breathe. Not to mention all of the toxins we excrete like mercury, arsenic, lithium – even salt. Humans are a mobile infection factory. Bring us aboard you space craft and the only way to get rid of the infection is to plunge the craft into the center of the sun. And even that is a maybe ..
5. Human like radioactive stuff. We dig it up and then make it more radioactive. After that we let it sit in open pools of radioactive water.
6. Our God doesn’t believe in you, therefore you do not exist. And if you exist then we must make you unexist to please our deity.
7. Your civilization will be seen as an untapped marketing resource. Soon you will be inundated with product placement, reoccurring revenue models and advertising events. Your offspring will be turned into zombies crying for the new Galactic Happy Meal.
8. We would never leave you alone. Constant communication – 24/7 information – we would demand you entertain us. Appearances on Letterman, Leno and the Daily Show would be required.
9. Humans love to lie. You could never trust anything we ever told you. Also, we would tell lies about one alien to another alien. It wouldn’t be long before our lies caused the Great Galactic War.
10. Even if you got rid of all the humans, there would still be all of our stuff left behind. It wouldn’t take long before that stuff became such a distraction that no work got done at all. Just a whole bunch of aliens trying to figure out how to get to the next level of Angry Birds.