Research Suggests How Alien Life Could Spread Across the Galaxy

astroengine writes: As astronomical techniques become more advanced, a team of astrophysicists think they will be able to not only detect the signatures of alien life in exoplanetary atmospheres, but also track its relentless spread throughout the galaxy. The research, headed by Henry Lin of the Harvard-Smithsonian Center for Astrophysics (CfA), assumes that this feat may be possible in a generation or so and that the hypothesis of panspermia may act as the delivery system for alien biology to hop from one star system to another.

Comments

Panspermia!

[Anonymous Coward]

Sure, I've seen lots of panspermia videos, but shooting it all the way to another STAR SYSTEM seems a bit over the top...

Re:Panspermia!

[ArmoredDragon]

From our present position in the galaxy, yes, the chances of that are a mathematical impossibility. However, a few billion years ago our star system was part of a cluster of stars which were in very close proximity to one another, possibly having a protoplanetary disk that overlapped with these other systems.

I personally think panspermia is not only possible, but even likely, as it would explain why we haven't been able to find the right conditions for abiogenesis on this planet.

Re: Panspermia!

[GrantRobertson]

I never thought I would ever have to say this but...

WHOOSH!!!

Re: Panspermia!

[Anonymous Coward]

I think in this case, it's SPLOOSH!!!

It can't.

[Anonymous Coward]

Habital planets are so rare and far apart that alien life wouldn't be able to spread across the galaxy. Hell, even earth is so far away from the nearest possibly habitable planet that if we could travel 90% of the speed of light, it would take something like 10,000 years to get there. Much less a population and equipment and supplies enough to start a society.

Re:It can't.

[Nyder]

Habital planets are so rare and far apart that alien life wouldn't be able to spread across the galaxy. Hell, even earth is so far away from the nearest possibly habitable planet that if we could travel 90% of the speed of light, it would take something like 10,000 years to get there. Much less a population and equipment and supplies enough to start a society.

Actually, we don't know if habitable planets are rare. We are finding a bunch and have barely look at what the universe holds. Now the traveling thing could be a problem, but maybe there are civilization on other planets that don't waste their time and resources killing each other and actually focus on science and space.

Re:It can't.

[jeffb (2.718)]

Hell, even earth is so far away from the nearest possibly habitable planet that if we could travel 90% of the speed of light, it would take something like 10,000 years to get there.

Spores are patient.

Re:It can't.

[Narcocide]

But based on what we know about the basic building blocks of life as we know it there's nothing to suggest they would have to originate from a planet that is habitable, nor that they would even all have to come from the same place to get combined somewhere that is habitable in the same way they were combined here on Earth.

Re:It can't.

[bloodhawk]

we really don't know how common/rare habitable planets are let alone how far apart they are.

Re:It can't.

[ceoyoyo]

Panspermia doesn't involve a bunch of Oregon Trail style settlers heading out and populating an empty world. You fire microbes, or possibly even just the precursors of life out and they start multiplying and evolving if they land somewhere they like.

Re:It can't.

[Anonymous Coward]

Now the traveling thing could be a problem, but maybe there are civilization on other planets that don't waste their time and resources killing each other and actually focus on science and space.

This. There's 7 billion of us. I'd wager less than 100 million of us are engaged in productive activities besides life-sustention, probably less than 10 million using their immense brain computation ability to do it. But this is due to war and inequality, not that the rest of the world are idiots. Not that they were born idiots. Some may have been brainwashed so thoroughly that they might as well be idiots, but that's still not necessarily a permenant condition. If everyone was given equal opportunity, and people with brilliant ideas didn't have to struggle just to survive, the average citizen struggle just not to die from all the corporate poisoning etc, then something closer to 4-5 billion of us could be doing productive stuff. Amazingly productive stuff. Stuff that probably less than 10000 people alive today could even imagine under current society.

Re:It can't.

[Anonymous Coward]

Well put - if this was a few years ago on Slash dot it would have been modded insightful.

Re:It can't.

[Anonymous Coward]

So let me get this straight.

An AC from Slashdot poo poos a paper written by a PhD, reviewed by other PhDs and accepted into a recognized journal, in just two sentences.

I guess Dr. Lin should have just sent it to you for review first.

Re:It can't.

[Anonymous Coward]

Because a few years ago Slashdot was populated by inane and ignorant Occupy Wallstreet people?

Really, the parent AC should be commended, but only because he fit just about every whine and bitch and moan the Left has into one paragraph.

Re:It can't.

[cavreader]

"everyone was given equal opportunity" How would you go about doing this for 7 billion people? I guess one solution could be to wage world wide war until there is only a few thousand people left alive and they can restart the perfect society where everyone has equal opportunities. Since the beginning of human history civilizations and societies have been created by war and then eventually destroyed by war.

Re:It can't.

[Immerman]

Indeed, especially if kept near absolute zero within a chunk of rock and ice potentially miles across . And you don't even necessarily need spores - a single strand of RNA capable of replicating itself from naturally occurring organic molecules might be all you need to jump-start a biosphere on a new planet.

Re:It can't.

[Anonymous Coward]

And then the SJW-callers came from breitbart. So sad.

Re:It can't.

[Immerman]

And even the "firing" doesn't necessarily need sapient life - the impact that flung the material that formed the moon free from the Earth probably flung some pretty large chunks of material completely free from Earth, and possibly even from the Sun. There may even now be primitive cryogenically preserved microbes in the heart of some of those planetary fragments slowly coasting across the cosmos, just waiting to impact a promising new world. If the fragments are big enough the microbes could survive reentry - a few miles of shielding should be more than sufficient, and would still represent only a relatively small fragment.

If such an impact were to happen today, there's lots of Earth life that might survive the voyage. Even relatively complex animals such as the tardigrade, which has been shown to be able to survive naked exposure to space for months on end with no apparent long-term damage, and would no doubt have a far easier time of it in the middle of a big chunk of ice and rock.

Re:It can't.

[MightyMartian]

And you know habitable planets are rare how?

Re:It can't.

[MightyMartian]

Because the right is known for its stiff upper lip...

Re:It can't.

[MightyMartian]

The team issue is radiation. We're talking about journies of hundreds of thousands or even millions of years. I can imagine nucleotides specifically protected by some heavy duty shielding making it (in other words big ass gene pods built by aliens), but accidental hitchhikers on meteors seems far less probable.

Re:It can't.

[Anonymous Coward]

That's a pretty impressive feat for a mere strand of RNA. Has anyone ever witnessed such an incident?

Re:It can't.

[Dutch Gun]

There's something I've never figured out about this particular theory. All life, even some sort of "patient zero" alien life, had to arise from non-organic substances somewhere, right? If it can happen once, then it should be able to happen any number of times given a set of similar conditions. Given the size of the universe, and even our own galaxy, that's like to be a *lot* of places.

As such, why would anyone think it's more plausible for a chunk of life to hitch a ride on some piece of space debris, and then survive re-entry on a coincidentally habitable planet on which it can flourish... than for life to have sprung into existence here, where obviously conditions were optimal for it (or at least life as we know it)?

I have to wonder if the enthusiasm for this theory is partially based on the admittedly exciting prospect that we could be the descendants of exotic alien lifeforms rather than some homegrown slime mold.

Re:It can't.

[ShadowRangerRIT]

Hate to break it you, but the formation of the Moon probably didn't seed the solar system (or anywhere else) with life from Earth. The earliest single cell life forms likely date to around 3.6 billion years ago; the Theia impact hypothesis puts the collision around 4.4 to 4.5 billion years ago (and only 30-50 million years after the Solar System even began forming). Even if both estimates are off by a couple hundred million years, there is still no overlap. Earth was an uninhabitable ball of molten rock at the time, not remotely suitable for the initial development of life remotely like ours.

Re:It can't.

[Anonymous Coward]

.... but maybe there are civilization on other planets that don't waste their time and resources killing each other and actually focus on science and space.

Fantasy. An advanced, large-brained species is highly likely to be Top Predator. Like us.

Re:It can't.

[Hognoxious]

That or they fantasise about meeting women who are just like the ones here except with pointy ears, bumpy foreheads or some other prosthetics budget friendly difference. And who have the hots for nerds.

Re:It can't.

[Captain Hook]

Are we top predators? We are certainly the dominant species but that is not the same thing.

It seems like our success has been brought about by our ability to engineer the environment to our liking. After we were able to increase our population due to agriculture we started impacting on predator species partly by hunting them directly but more by crowding them out of their ideal territory.

Re:It can't.

[jandersen]

There's something I've never figured out about this particular theory. All life, even some sort of "patient zero" alien life, had to arise from non-organic substances somewhere, right? If it can happen once, then it should be able to happen any number of times given a set of similar conditions. Given the size of the universe, and even our own galaxy, that's like to be a *lot* of places.

I think you are right, and probably most researchers of this subject would agree. My personal feeling is that life didn't happen because of some amazingly unlikely combination of lucky accidents, it happened because it was likely enough that it must happen almost anywhere the conditionas are right. There is a book that you might enjoy - "The Vital Question" by Nick Lane; a bit technical, but that's why I like it. According to him, prokaryotic life more or less has to happen, but he isn't so sure that eukaryotes are likely to evolve (I disagree, but that's another matter).

As such, why would anyone think it's more plausible for a chunk of life to hitch a ride on some piece of space debris, and then survive re-entry on a coincidentally habitable planet on which it can flourish... than for life to have sprung into existence here, where obviously conditions were optimal for it (or at least life as we know it)?

As far as I understand it, the current thinking is not so much that life evolved in just one place and then travelled as cells or spores to other places, but that a suprisingly large proportion of the molecules needed for life have evolved in the dustclouds around newly formed stars. Panspermia in some form could still have played a large role as well, as it isn't implausible that cells or spores could have been blasted off their home planet and survived the journey / we already know of some on our own planet that could potentially make it.

I have to wonder if the enthusiasm for this theory is partially based on the admittedly exciting prospect that we could be the descendants of exotic alien lifeforms rather than some homegrown slime mold.

Could be, but I think it also has a lot to do with the fact that until fairly recently, we didn't have any really detailed ideas about the first cells might have evolved, and there was a widespread feeling that it was a very improbable event, so the idea of life arising in only a single or a few places and then spreading out was attractive. We now know much more, and it seems like life must be widespread, maybe even universal.

Re:It can't.

[Anonymous Coward]

That's just an excuse, a very very very lame one.

Re:It can't.

[DNS-and-BIND]

I take it you haven't met average people, have you? I'll bet you're surrounded by upper-class Ivy League (or wished they had gone to an Ivy) intelligent people like yourself all day long, and have used that great intellect to project those characteristics onto the rest of humanity. Why don't you actually get out there and talk to some of them? You'd be horrified, and withdraw into a gated community like so many of your fellow travelers have already done.

Just think of how stupid the average person is. And half of 'em are stupider than that!
-- George Carlin

Re:It can't.

[Anonymous Coward]

While the vastness of time and space make it a near certainty that there is/was/will be life in thousands or even millions of places, at the same time it's rare enough that makes it very likely that no life will ever come into contact with any other life. Maybe there was life just a few light years away from us... a billion years ago, and that never made it to a multi-cellular level. Maybe at this very moment there's an intergalactic civilization a hundred billion light years away that will completely collapse before we could even notice them (plus, all life here will probably have ceased by that point as well).

Re:It can't.

[l0n3s0m3phr34k]

robots, automation, industrial-level 3-d printing, and many more sustainable energy generation systems. It's actually not too far outside our current capabilities. It's just that the 1% will never allow everyone else to come up to their level, or allow themselves down here in the dirt with the rest of us.

Re:It can't.

[l0n3s0m3phr34k]

yeah, I don't know if their idea of a three meter rock (mentioned in this article that is linked inside TFA) is thick enough to stop radiation once outside the heliosphere. But the second article is discussing intra-solar transfers, not between systems. I have no idea what level of shielding would be required to survive millions / billions of years of traveling through interstellar space.

Re:It can't.

[Anonymous Coward]

And if frogs had wings they wouldn't bump their asses on lily-pads.

Re:It can't.

[Anonymous Coward]

We need to stop warring and have those people do something useful instead

And how do you suppose we do that? We must war so there is so few people left, then those left can do something useful!

*facepalm*

Re:It can't.

[ceoyoyo]

It doesn't have to be something as large as that. Much smaller impacts throw up material from rocky planets that can seed the solar system. Escaping the sun would be a bit harder, but it could happen via occasional very large impacts, or comets being seeded by small impacts and then ejected from the solar system.

Re:It can't.

[tomhath]

Actually, we don't know if habitable planets are rare.

It depends on what you mean by "rare". Habitable planets that are hundreds, thousands, or millions of light years apart are rare on the scale of living organisms.

Re:It can't.

[meta-monkey]

Ice. Water is very good at stopping radiation. There's lots of ice in comets. One RNA strand, encased in ice in a comet, ejected from a solar system.

Chances are tiny. Number of trials is huge. Time span is extreme. Need more data.

Re:It can't.

[meta-monkey]

This is the problem of big numbers. You're multiplying a really big number (number of solar systems) times a really big number (time) times a number of unknown smallness (chances of life emerging from inorganic materials). We only know it's happened once. We haven't seen it anywhere else in the universe. We've tried our hardest and never seen it in a lab. So we have no idea what order of magnitude that chance is. A few orders of magnitude in one direction and there's life everywhere. A few orders of magnitude in the other direction and there's life in but a handful places in the universe. Maybe even only here.

We need more data to help pin down what order of magnitude that really small number is. One thing that would help with that, though, would be what these researchers propose to look for. Once we can detect signs of life on an exoplanet (like the presence of oxygen in the atmosphere...a very likely sign of organic processes under way, because oxygen does not stay free for long), how uniformly is it distributed in the galaxy?

If life is likely to arise, like your hunch, then life in the galaxy should look pretty uniform. It's everywhere. But if instead it's clumpy (or more likely smeared as stars move relative to each other) then that indicates life is very rare, and spreads instead by panspermia.

Uniform distribution of life in the galaxy: life is likely to arise, and may or may not spread via panspermia, too.
Clumpy/smeary distribution of life in the galaxy: life is unlikely to arise, but likely to spread via panspermia.

Re:It can't.

[StarryEyed]

I've always figured it was both simple life developing here, then complex life hitching a ride and spicing things up when it landed. http://www.livescience.com/280...

Re:It can't.

[Anonymous Coward]

Actually, we don't know if habitable planets are rare. We are finding a bunch and have barely look at what the universe holds. Now the traveling thing could be a problem, but maybe there are civilization on other planets that don't waste their time and resources killing each other and actually focus on science and space.

That seems improbable. We only developed minds as advanced as we have now because of working our way up the chain to be apex predators then not stopping and further refining our intellect by fighting eachother for what is likely hundreds of thousands if not millions of years. The only known mechanism to produce intellect is intensive intraspecies warfare.

Re:It can't.

[david_thornley]

How do you get the hundred million engaged in productive activities besides sustaining life? Most people in the US do not work in agriculture or the clothing or construction industries, and that's pretty much what you need to sustain life. Add in Europe, and you're clearly talking hundreds of millions. Do you count engineers designing new machines and prototyping them as unproductive or life-sustaining? I'm in the support structure for that activity.

Realistically, lots of the seven billion of us do not have seriously above average intelligence and creativity. There are a lot of people I know who couldn't do brilliant things no matter what the opportunities. Shall we look at the number of people we can draw on who have the opportunity to shine, and that's well in excess of a hundred million people in the US alone. There are millions of people in the US with Ph.D.s. I suspect that the percentage of the population that has opportunities to become a scientist or artist has never been higher, and that there are billions of people with such opportunity. We can and should do better, but there really isn't that much war anymore, and while the number of people who struggle to survive as gone up, as a ratio I suspect it's smaller than ever before.

Re:It can't.

[pepsikid]

Organics are simply what our form of life is made of; it doesn't imply it was made BY something living. It's just a class of molecules. The universe is filled with organic matter which is not living.

Re:It can't.

[un1nsp1red]

And who have the hots for nerds.

Being aliens doesn't make them any more desperate than earth women.

Re:It can't.

[Anonymous Coward]

Also, the statistical sample of exoplanets that have been found is biased by the types of stars, mainy red dwarfs, that we've been looking at in order to find exoplanets. Given how little we know about planet and star formation, the error imposed by this bias could be considerable.

Re:It can't.

[cavreader]

"We need to stop warring " Since the dawn of time there has always been at least one war raging somewhere on the planet. Every border on the planet has been drawn in blood. Power and influence has been built on top of mounds of corpses. There are currently numerous wars raging all over the world providing the blood needed to redraw existing borders while also increasing the body count. Pleas for love and understanding are just empty words no matter how loud you shout them. Instead of solving the problems in the world today we only want to find someone to blame and thinking assigning blame translates into actions to correct the problem.

Re:It can't.

[Immerman]

Hitchhikers *in* asteroids, not on. I agree any on the outer surface would be unlikely to last on an interstellar journey, but an asteroid hundreds of feet across is pretty tiny really,, and offers *far* more radiation shielding than we have on the surface of the Earth - the atmosphere offers only about 10-15 feet of rock equivalent, and the magnetosphere only protects us from charged particles that wouldn't make it far through solid rock anyway.

Re:It can't.

[Immerman]

(Some) RNA self-replicates from amino acids all the time, and is one of our current best guesses for the earliest forms of proto-life - it's can forma an amazingly versatile range of nanomachines. The question is whether it's more likely that a self-replicating strand forms spontaneously on a hospitable world or gets seeded from elsewhere. After that it's just a matter of evolution.

Re: It can't.

[Anonymous Coward]

Do you listen to the nonsense you spew. There are 7 billion people on earth. A feat that has taken 3 or so million years to accomplish and at any point in time it could well have ended badly and you spout out corporate poisoning and yet we as a species flourish. Then you throw in a dash of SJW with your 'given opportunity' and you still don't answer the or come close as to why panspermia works or should given it's statistical impossibilities (your words) and then you leap to the idea that you believe this is the way it probably happened, so you devolved your idea down to simple faith. You're no better than a religious believer.

Re: It can't.

[Anonymous Coward]

That alone makes us the top on this planet. Until any other species cancel what we've done for good or for ill, then we are apex.

these guys are so amazing:

[circletimessquare]

resistant to heat, cold, vacuum, desiccation, radiation, pressure, toxins, etc.

https://en.wikipedia.org/wiki/...

you realize they could leave earth (ejecta from a sever impact) and colonize other planets

then you think... wait a second, maybe we're here because these guys colonized earth

Re:these guys are so amazing:

[Anonymous Coward]

It's a neat thought, and something similar may very well turn out to be true, but we can tell from DNA if they're our ancestors. And they don't seem to be.

Re:these guys are so amazing:

[circletimessquare]

no, i know

they are very ancient though, the cambrian

makes you wonder if perhaps they are precambrian and they had some guests in their gut...

ok, i'll stop now ;-)

Mankind and aliens will prefer orbital colonies

[pepsikid]

It seems likely that mankind, and aliens who got started before us, will eventually establish permanent residences off of their home planets. In the not-so-distant future, the majority of mankind, by percentage, will live off-Earth. However, you should think of the planets as being the bottom of very deep holes, with most of them being too hot, cold, poisonous, exposed to radiation, or too much or too little pressure. The task of getting and leaving these places is risky and expensive, too. Let's just give up on the idea of colonizing Mars for the forseeable future, please! It may not always be so, but the solar system's orbital rocks are easier resources to get, and spitting up material from low-gravity objects with mass drivers. There's no point to terraforming a planet when that will take thousands of years, and no human civillization can keep a project like that, and it's cash flow, going for so long.

In short, we're just not gonna live like pale, stick-figure trolls in underground caverns on the moon or mars. Mining will be done by pulling a big bag over an asteroid and breaking it up from the outside in. Attached refining equipment will separate useful elements and chemicals. This will be mostly-automated. We'll use the tailings as concrete to build our colonies. A gigantic mirror will heat the crushed rock and sinter it into shape, like an enormous 3d printer. There is enough material to build millions of them in OUR OWN solar system, and they'll be essentially self-sustaining once they've been established. Conditions inside will be perfect for human life. It's a far better prospect than making do with low-gravity moons and poisonous planetary atmospheres. Groups of colonies might form "countries" and others will operate independently. The colonies will be built robotically, so the cost will eventually drop to the point where one might be owned by a single family or other social group.

While most colonies will participate in a humanity-wide economic and social network, a life of physical isolation and self-sufficiency will be the norm for most. We'll be in communication, but not often physically visiting other colonies. Some of these may try hurtling themselves onward to the next closest star. They'll stay in touch the whole time, they'll just be permanently out of reach from then on.

The stars DO NOT need to be sun-like, nor do they need Earth-like worlds! They just need to have exploitable resources in easy reach. Red and brown dwarfs are more plentiful than any other type, and they'll last orders of magnitude longer, too. This is probably where the majority of intelligent life will live at some point. Not to miss out on any exploitable resource, those who live around dwarf stars will push onward to practically every type of star within reach. A million years or so, and we'll have colonies throughout the galaxy, and hundreds of alien neighbors to enrich our culture and science.

Re:Mankind and aliens will prefer orbital colonies

[Immerman]

A sufficiently advanced and adventurous colony might even redirect their host star through a series of gravitational slingshots sufficient to set in on a course to another galaxy. Sure, hurling stars around is a bit of a herculean task by our current standards, but a dwarf star isn't *that* big, and if you've got the long-term vision to consider intergalactic travel, the acceleration phase shouldn't deter you.

By the same argument though, I would advocate for terraforming other worlds in our own system, once we've determined that they don't host life of their own of course. No sense destroying such a potentially vast scientific resource for a project that will take thousands of years.

The beauty of terraforming though is that, done carefully, it may not need much human intervention at all. Just release the right mix of engineered microbes with an optimized mutation rate, and let the planet develop into a primordial "slime world" on it's own. Then, once it has a robust and thriving microbial biosphere, introduce the thin veneer of complex life that we are more familiar with. Maybe it takes thousands of years, so what? As long as it's a self-guided project we just need to get it started, and maybe give it an occasional nudge if it starts destabilizing.

Re:Mankind and aliens will prefer orbital colonies

[Anonymous Coward]

A million years or so, and we'll have colonies throughout the galaxy, and hundreds of alien neighbors to enrich our culture and science.

No, we won't. How do I know this? Because we would have found them already (or they us). So either the other life that is out there is not intelligent and we're essentially alone, or the barriers to spreading out to other solar systems are so high that they're basically unreachable at any level of technology. Some of what you propose may be workable as long as you have the sun handy to get power from, but travelling through interstellar space means no source of energy and no way to survive.

Re:Mankind and aliens will prefer orbital colonies

[pepsikid]

A civilization sufficiently advanced enough to move their whole star system would probably not be so attached to genuine planetside living that they'd go to all that trouble. They could simulate normal life perfectly inside orbital colonies. I can't think of any sort of being which would wish to travel personally to the stars, and yet could not leave home soil. Even a mountain-sized plant. or something like it, could live in a custom colony. And the kind of stars that would make a good gigarocket are not all that long-lived. That level of technology would easily be able to move colonies almost anywhere.

As for terraforming; The other planets would be more useful if broken up for raw materials to build orbital colonies. Long after the asteroids and other moons had been used up. The result would be millions of times the surface area of a mere planet, and it would all be built to perfectly comfortable climate. Colonizing Mars, Venus or moons is just a daft idea. Scientific and mining stations, sure. But the walloping majority of mankind will be in orbital colonies. This is infinitely easier than dealing with wrong gravity, pressure, temperatures and chemistry of planets other than Earth. If we ever start a terraforming program, we will not benefit from it. Aliens that rise and explore the galaxy long after we've died off might stumble upon some and use them. But why would we launch such a program?

Re:Mankind and aliens will prefer orbital colonies

[pepsikid]

I wasn't aware that we'd explored all of space, and that the hunt for alien life was over. I was actually under the impression that we've only been eyeballing nearby rocks and making skywizard-influenced conclusions about how things work and why! And we've only been doing this for less time than the length of the kind of journey we're talking about here.

But, get back to me in a thousand years when we've adopted, and abandoned, hundreds of totally new ways to communicate with each other and observe the heavens. Chances are, aliens aren't using 4G or VHF. It's possible that we just don't know how to detect a Dyson Swarm of colonies over these distances yet.

In closing, I never said there was a source of energy in interstellar space. However, we might find that there is. Otherwise, travelers would bring one with them, or have the power transmitted via tight beam from home. These are all well-known scenarios.

Re:Mankind and aliens will prefer orbital colonies

[Anonymous Coward]

You make very great points, and to be honest, probably the most realistic points compared even with this article of hope and wonder about our origins.

As space mining is getting on its way, the most useful way of expanding the human race is by building in Earth orbit.
We could build massive space colonies up there with all the resources we get over that time.
Nice big thick walls to stop radiation.
Constructions large enough that they become useful for artificial gravity through rotation. (there is an equation to balance out the force difference felt between head and feet to be comfortable, anything over it and we are all good)

Already we have a test satellite sitting in space for a space mining agency. Sitting there for the next month and a half I believe.
We are on our way.
In a few decades, it will be in its beginnings. We'll start seeing the rocks.
Hopefully not The Rock though. His bald head will surely have some major wrinkles on it by then, right? It would be like a penis in the cold.

Re:Mankind and aliens will prefer orbital colonies

[Anonymous Coward]

2000 years ago people were just getting over the idea that Roman and Greek gods spent their time floating around space and screwing with humans. I expect in another thousand years, your common core, hijacked social welfare school system will still be teaching this kind of claptrap. Most people have the capability not be incredibly stupid, but it is pretty easy to turn them stupid. In fact, if you are a liberal democrat, it is essential that we find someone out there to blame and take responsibility for our actions. We are running out of rich white males on this planet, and I suspect in 1000 years (probably less), we will have no one left to fund aids research. Now there seems to be a lot of consternation about what an illegal alien is these days, but if you have to dream up plans to ship them in from half way across the galaxy, you are DOOMED!
Forget about life on other planets, the entire universe is expanding away from us. If there is life out there you will never know about it. Ever. I blame Obama, not because he is a socialist, but because like most political opportunists, he is not up to the job at hand. Of course if you think a blowhard like Donald Trump is the solution, I suspect we will have a lot of bankrupt casinos on mars.
The point is, we now have a pope that won't shut up about things he knows nothing about and aren't really in his wheelhouse. I have come to terms with being gay. All of humanity is gay, as anyone with a brain realizes, we have been taking it up the ass from the beginning. Little green men aren't going to change that fact, despite your inability to process really big numbers.

Re:Mankind and aliens will prefer orbital colonies

[Hognoxious]

tl;dr version of the above 3 posts.

Magic!

How about magic?

Yeah, but, you know - magic.

Re:Mankind and aliens will prefer orbital colonies

[littlewink]

Glad you got all that worked out, George.

Now, if you don't mind, could you quit surfing /. awhile, at least long enough to put the cylinder heads back on that Honda Civic you've had for two days?

Sorry to disturb you but the owner is getting testy and wants his car back.

Re:Mankind and aliens will prefer orbital colonies

[pepsikid]

Our first space mining outpost will be on the moon, and the first major colonies will be built around the moon and Earth in Lagrange orbits. These colonies will primarily be homes for the builders of orbital power stations and spacecraft. Virtually all of the material will come from the moon, launched by electric-powered mass drivers. The material they're built of will simply be a kind of ceramic concrete made from superheated lunar rock dust. The structural mass doubles as radiation shielding. Some colonies will be very large, with the ground area of a whole county inside. At this scale, folks will feel centripetal force almost like real gravity.

It will take a very long time til we run out of moon to build with, but our next step will be to mine the moons of Mars and build orbital colonies there. These colonies will more likely be independent, and not reliant on relationships with Earth. I thought Mercury would make a good next step, being so close to the free energy from the Sun, and only a little bigger than the moon, but it seems that it's gravity is almost as much as Mars. There might be surface operations there which beam power back to Earth and all around the whole system. The asteroids and other stray rocks come after that.

Other than our own big moon, since it's so close to us and it's all we've got for now, the other moons will be used starting with the smallest. The planets will be visited eventually, but not permanently inhabited, until we have some very cheap and safe way to get on and off. Planet-based habitats (surface, airborne, floating) on/at Mars, Venus and the moon will be concerned with science and business, or even leisure, but they simply will never make good places for modern humans to live. If we mutate into winnowy cave-dwelling morlocks, then those might be happy there.

Asteroid mining will involve surrounding a rock with a sort of bag, to keep all of the material from flying away and causing navigational hazards. These bags might be abandoned when the operation is finished. Colonists might seek these out for a rich source of pre-digested material. Some of the bags may intentionally be the right size and shape to line with sintered rock and simultaneously build a colony. It's interesting to think of the colonies and the objects they're built out of as cells or virus membranes. Humanity might be the DNA of a new breed of space virus.

Re:Mankind and aliens will prefer orbital colonies

[Immerman]

Sure, planets are optional - stars however are kind of appealing - massive nuclear reactors bound together by the mass of their own fuel - sufficient fuel to continue generating energy unflaggingly for hundreds of billions of years, with nothing to break down and no maintenance required.

Of course, if you're orbiting one of those long-burning dwarf stars you need to worry about the fact that they're prone to not-infrequent superflares. Might be nice to have a big chunk of mass for radiation shielding, preferably something nice and stable that would have a fair chance to survive even if your civilization collapses several times sending everyone back to nearly the stone age - I would imagine such considerations would be relevant to journeys lasting tens or hundreds of times longer than our species has existed. Planets are handy for such things, even if you live deep underground the gravity will help keep atmosphere and resources from escaping.

Re:Mankind and aliens will prefer orbital colonies

[Immerman]

Oh, and to address your "millions of times the surface area" remark - are you so sure you would want it? After all the surface is vulnerable to radiation, impact, radiant heat losses, etc. You could just as easily turn the whole planet into a honeycomb of underground colonies with ample resources available. A molten cores would be an issue, though a passive heating system might be worth the resource loss, but smaller planetoids such as the moon wouldn't offer than problem.

The primary benefits of an orbital colony are that it's more mobile than a planet, and you're not at the bottom of a substantial gravity well. I rather doubt either concern would be terribly significant to a race capable of flinging stars around.

Re:Mankind and aliens will prefer orbital colonies

[RockDoctor]

They could simulate normal life perfectly inside orbital colonies.

By the time you've reached that point, the number of people living in orbital colonies wouls mean that they are the norm, and it is people who live at the bottom of a (gravitational) hole who would be considered dumb, crippled dwarfs.

Re:Mankind and aliens will prefer orbital colonies

[pepsikid]

First of all, I'm not considering your idea of moving stars and planets. It's a far higher level of technology, which does not need to be attached to the concept of building colonies.

You seem to completely miss the point of building orbital colonies. The object is to provide quality living space for modern humans living off-world. They're not built for portability or convenient access to Earth. Virtually every orbital colony will be non-mobile. They'll be custom built for the orbit they're constructed in, essentially exchanging places with the asteroid they were built from. The colony's outer shells will be a dozen meters thick. The colonists will live on the INSIDE where the radiation ISN'T at. Their interiors will be climate controlled for modern humans and posthumans. Heat will generally not be a problem. Actually, getting rid of excess heat could be. But that's a separate issue.

It would actually be orders of magnitude more difficult to engineer the tunneling of a planet than it would be to just crack it apart and build orbital colonies out of the rubble. Demolition also makes far more building material available. But that would come gigayears later, when the manageable rocks and moons had been used up. Demolishing planets is also a level of technology unnecessary to filling the solar system with a million orbital colonies. There's only one planet we could "honeycomb" (well, two if you disregard the super-high temperature and high-pressure acid of Venus - nope), and that is Earth. Living under Earth is not living in space. All of the other planets have gravity that is too low or too high for healthy human life. Living forever inside tunnels within the planets and moons is for mutant albino morlocks. Folks have GOT to give up their fetish for colonizing planets! Essentially, we neither can, nor need to honeycomb any planets.

Addressing your misunderstanding about dwarf stars: Most of the stars in the universe are, or will be, super-long-lived dwarf stars. Obviously, no-one's going to colonize an unstable system, but dwarf stars, brown and red, are actually the most stable. Excluding white dwarfs in close proximity to another star or black hole. And those are very rare.

Re:Mankind and aliens will prefer orbital colonies

[Immerman]

Well, you prefaced your comment with "A civilization sufficiently advanced enough to move their whole star system would probably not be...", so I responded to that. I should also make clear that I'm a huge fan of the concept of orbital colonies, both as a stepping-stone for human expansion to the stars, and the romantic appeal of the fierce independence and cooperation such a society will likely breed. But I think it's important not to lose site of the limitations, and the fact that planets offer their own advantages.

As for less advanced civilizations, say our own within a few centuries, orbital colonies still have considerable downsides. Impacts being one of the big ones - a meteor even a few meters across, the sort that barely makes a tiny flash in the sky here, would likely be devastating to any colony with only a paltry few dozen meters of rock shielding - the velocities involved in a collision with eccentric-orbit debris debris tends to be phenomenal. Easily enough to vaporize all but the largest debris just from friction with our upper atmosphere, and there are several vast clouds of such debris that regularly intersect the Earth's orbit.

The second big problem that springs to mind is the actual mass distribution - if I recall correctly the combined mass of the entire asteroid belt is estimated at only about 5% that of the Moon, while the Moon's geologic stability and low gravity would offer ample tunneling potential, even if you restrained yourself to the thin outer shell corresponding to an equivalent mass. Also there's some potential for Mercury (much cooler than Venus), and several of the gas-giant moons. You do have the trans-Neptunian objects and hypothetical Oort cloud, but at that point you're pretty much living in interstellar space for most intents and purposes, and lose out on the many benefits of having a nigh-inexhaustible fusion reactor right next door.

As for gravity - we don't really have any idea what effect low gravity may have on life yet - we know *microgravity* is a big problem, but that also entails a much more radical reduction in many forms of routine exertion, as well as a near-total elimination of all gravitational orientation cues, plus the micro-impact shockwaves from walking, which have been shown to be a major factor in skeletal self-maintenance. Orbital colonies also don't necessarily solve the problem - you can get "centrifugal pseudogravity" easily enough in theory, but we have no idea what the long-term side effects of that might be (unless it's *huge* you introduce not-insignificant tidal forces within the body, just for starters), and it requires material engineering for tensile strengths capable of supporting the entire mass of at least your colony's living areas against 1g (or whatever) acceleration. And tensile strength involves much more sophisticated engineering and much lower fault tolerances than the comparable compression strength necessary for tunnels.

But no, living underground isn't "living in space" as most people think of it, But then what exactly is the appeal you of doing so? Besides, even on Earth you're only sixty-some odd miles from space, it's only the radical inefficiency of our current transportation infrastructure that put it out of reach.

Re:Mankind and aliens will prefer orbital colonies

[pepsikid]

Well, planets which are practically identical to Earth would have advantages... provided you intended to abandon space for ground living again. Remember, my point is that once you're in orbit, everything you need is in easy reach. Why go back to ground again? If a planet isn't Earth, then it won't be much like Earth anyway.

I'm at a loss to understand why you're so fixated with living on planets. That you would consider almost any planet or moon over a colony. Colonies will be easier to build with existing material in orbit, and promise ideal living conditions, while planets and moons will be expensive and dangerous to get on and off of, and provide unnatural living conditions.

Swiss Cheese Planets:

Tunneling Luna, other moons or planets is still pointless. You don't take into account that due to structural needs, you'll have to leave a lot of solid rock untouched, and you'll still only be able to go down a few miles, wasting most of the interior. And the excavated material needs to be taken into account, as it must be dumped atop the ground outside, creating more pressure. A manufactured colony shell will be much thinner, stronger and bear very little weight other than it's own. If you were a giant, and could hold it, it would feel like a kite. It'll still be plenty thick to stop any ionizing radiation, perhaps even a nearby supernova extinction event that sterilizes Earth.

Tunnels and chambers in a world other than Earth (or Venus) would have the wrong gravity for modern humans. They'd be no place to live. Because we know that microgravity causes the human body to malfunction, it is not valid to assume (or hope, really) that merely "low" gravity will be just dandy. It may also turn out that centripetal pseudogravity doesn't fool the body into behaving either, but then that means we'll never live in space at all. I think that 1-G pseudogravity is more likely to work than various low gravity environments. Those "tidal forces" are believed to be imperceptible on a colony of a few hundred meters diameter. We can build that. Tensile strength is a non-issue. Ordinary asteroid rock is thought strong enough, but these colonies will be built out of an almost ceramic concrete sintered in place with solar light like a gigantic 3D printer. The walls will be cellular or corrugated for even more strength and utility. Your "honeycombed" moon idea will be full of natural flaws and material variations. It'll collapse under it's own weight unless you're a very conservative architect.

Impacts:

The shell of the colonies will be built in layers with embedded tunnels and chambers. Places to run pipes and subways, install machinery and hydroponics, rooms to store raw materials. High-energy impacts might pierce the outermost layer, but then an interesting thing happens. The debris showers across the next level with far less impact, likely being contained. This does not happen with a thick single layer. I don't know just how common impacts are in near-Earth space right now; they'll likely be worse after we've been tossing bags of crushed rock into low-lunar orbit to use in the solar forges, but it appears that the satellites we've launched are only encountering micrometeorites chipping and scratching at them. Oh, and that damn Chinese debris. Our mining debris will likely be fairly low-energy because our orbital stations and activities will all be done at relatively similar speeds. Destructive impacts could be a once-in-a-lifetime event. So we can design to survive that.

Illumination:

Because of these micrometeorites, as well as the bigger rocks, I don't like the idea of our colonies featuring gigantic windows to let in sunlight. I love the idea of living inside an O'Neil Cylinder, but those mammoth windows and mirrors make me cringe. Someone who understands optics would probably like to tweak my solution: I would go for a significantly smaller single solar window at the tip-end of the colony (assuming a cylindrical shape) and which is inset within a wall or length of

weasel words

[swell]

I skipped the Discovery link to avoid hype and went directly to the Harvard link.

Disappointing. One expects a certain sobriety from scientists and yet something is terribly wrong here. The article is peppered with weasel words: an unusually vague 'theory'; and words like: could, might, if, potentially, would, and the ever dreadful 'assumes'. Let's hope that the actual paper will have a more solid foundation.

Re:weasel words

[deviated_prevert]

I skipped the Discovery link to avoid hype and went directly to the Harvard link.

Disappointing. One expects a certain sobriety from scientists and yet something is terribly wrong here. The article is peppered with weasel words: an unusually vague 'theory'; and words like: could, might, if, potentially, would, and the ever dreadful 'assumes'. Let's hope that the actual paper will have a more solid foundation.

What the hell do expect when academia at places like Harvard has become little more than "publish or die" rat race. The quality of the paper does not matter for shit anymore what matters is the paper that it is written on and the fact that it was published. I doubt that pier review means anything near as much as it once did in the gilded halls of Harvard. In fact most likely if a negative pier review occurs it is quickly suppressed in the Deans office if the so called academic has rich parents or relations!

It is almost as if Dr Venkman has tenure as far as some so called research goes. It is blatantly obvious that the rich are completely calling the shots in the top universities these days. I am not at all surprised that foot ball at Harvard is not top notch because the rich parents usually do not have kids that can play football worth shit. Harvard has become is a place to put rich kids so that they can put that Harvard on their CV to impress the CEOs political movers and shakers and other upper class society peoples that their parents introduce them to after they "graduate". Skull and Bones and BULLSHIT is the real order of the day.

Re:weasel words

[Hognoxious]

I doubt that pier review means anything near as much as it once did

It used to mean jugglers, comedians, dancers, singers and usually a novelty act.

P.S. ITYM "revue".

Re:weasel words

[michelcolman]

And what exactly did they "discover"? What's the "research"?

Meteorites from Mars have been known for a long time. The theory of panspermia was invented many decades ago. What did these researches add to the discussion that we didn't know already?

Re:weasel words

[CrimsonAvenger]

I doubt that pier review means anything near as much as it once did in the gilded halls of Harvard.

I'm not sure why Harvard is supposed to be doing something that building inspectors normally do.

Though maybe you meant "peer", not "pier"...never mind.

Ashley Madison?

[Known Nutter]

Were the alien's exoplanetary atmospheric escapades discovered in the Ashley Madison database?

Oh, this article isn't the hourly Ashley Madison tripe? Pardon me... I apologize. Carry on!

Basically, it's like this --

[Anonymous Coward]

We need to seed the universe with our sort of DNA so that by the time we get around to getting there the local cuisine is tasty and delicious even if somewhat exotic, and not yucky and disgusting or even toxic. You reap what you sew.

And if you cook it right it's mighty tasty.

Re:Basically, it's like this --

[Hognoxious]

You reap what you sew.

No, you sew what you rip.

Where's the Appeal?

[Capt.Albatross]

Given that life had to originate somewhere, and that we know next to nothing about the distribution of life in the universe, panspermia seems to me like a solution looking for a question to be the answer of. I am bemused by the fact that some people seem to find a universe having panspermia more satisfying than one without it, just as I am bemused by people who find a universe with reincarnation more appealing than one without (if you can't remember anything about your former selves, what's the difference? - they are as good as dead.)

I don't deny panspermia could happen; my attitude is essentially 'call me when you have something that goes beyond speculation.'

Re:Where's the Appeal?

[Immerman]

I think it's basically that, given some fairly plausible assumptions, panspermia would make it almost inevitable that the galaxy is full of at least simple life, and probably at least some complex life as well. And a galaxy full of ife is far more exciting proposition than a field of hundreds of millions of dead rocks.

Of course at present we have no particular reason to believe such a setting is real, but it makes for a much more compelling story - and humanity is built upon it's ability to tell stories of what might be, and then try to discover, or even create, the truth. From the day one of our pre-verbal ancestors first dreamt of a rock or bone of a certain shape that would make a more effective tool and set out to find or eventually create it, to todays scientific journals describing the experiments and conclusions of our most curious minds, storytelling has been our species defining advantage

Re:Where's the Appeal?

[Anonymous Coward]

There is a major problem which people promoting panspermia are attempting to address: They have moved a bit past the textbook explanations, and, thinking from materialistic presumptions, need an infinite number to make abiogenesis and evolution seem plausible. Since materialism provides no such number, they are using indefinite (though large) numbers as a substitute.

Re:Where's the Appeal?

[Anonymous Coward]

The main appeal of reincarnation is:
1. It reconciles the idea that "the universe is fair" with the idea that "I don't deserve the bad things that happen to me".
2. It's a sort of application of the law of conservation of mass/energy. easily if you think souls actually exist it's easy to think there must be some similar conservation law for them (reincarnation)

As to panspermia, I think it's main appeal is to people who intuitively think the world is unchanging and have a hard time grasping how abiogesis event are constantly occurring today.

Occam's razor suggests that until we can produce (or observe) an abiogenesis event an confirm that the conditions didn't match anything we suspect could have occurred in Earth's 4 billion year histotory, we should prefer the theory that at some point abiogenesis happened on Earth, rather than the one in which abiogenesis happened elsewhere and life managed to migrate to Earth.

After all there was apparently an extremely ancient naturally occurring nuclear reactor in Africa. One off highly complex combinations of matter do happen on Earth. Abiogenesis is juts one specific case.

Not Weasel Words: Weasel Theory

[Anonymous Coward]

When they do speak soberly and from a solid foundation, such scientists tend to be identified as Creationists, ridiculed widely and from unexpected adversaries, and forced out or ignored out of their institutions and fields.

The rest look for infinite numbers to invoke and give you their wild unprovable, untestable speculations. With their critics out of the way, all they need to do is cloak their unscientific work by speaking of it as facts and certainty.

This haiku has nothing to do with spreading life

[TheHaikuLover]

There is a faggot
He puts his erect penis
In a man's anus.

"Maybe aliens don't kill each other"

[Anonymous Coward]

HAL-2: "Dave, I am picking up a broadcast from this planet. It appears that there is intelligent life here."

Dave: "Can you tell me what the message says?"

HAL-2: "Just a minute; this language is unfamiliar but there is a tutorial embedded in the signal. Working... working..."

HAL-2: "The message says, roughly, 'Welcome to Scar-Oh, home of the most advanced race in the universe. Please transmit the coordinates of your home planet, and we will send a fleet out to ex-ter-mi-nate it as soon as we possibly can. Thanks for nominating yourself for a Dav Err Us Award, and have a nice day!"

Re:"Maybe aliens don't kill each other"

[Anonymous Coward]

Nononono, the tagline is, "The message says... 'For pizza out, it's Pizza Inn...'?"

Abiogenesis is a fairy tale.

[Anonymous Coward]

Sorry, but it is. As much as I am a big Sci-fi fan (Bladerunner, best sci-fi movie of all time), abiogenesis is just an umbrella term for a bunch of competing crap science theories for "spontaneous generation" ... the father of that fairy tale (pun intended). Now ... you can all mod me down and/or drool out the par-for-the-course ad hominem attacks and strawmen fallacies ... or someone can frickity frackin man up and give me a plausible explanation for how life can arise from non-life.

Re:Abiogenesis is a fairy tale.

[Anonymous Coward]

or someone can frickity frackin man up and give me a plausible explanation for how life can arise from non-life.

There are plenty. Life is not magic, it's just a chemical reaction.

Re:Abiogenesis is a fairy tale.

[Godwin O'Hitler]

Spontaneous: "Performed or occurring as a result of a sudden impulse or inclination and without premeditation or external stimulus".
So all these theories suggest that non-life->life happens without any external stimulus? They are indeed crap.

Re:Abiogenesis is a fairy tale.

[Gilgaron]

Life is just a set of chemistry reactions we've decided is special enough to have its own name.

Hey asshole - asking for citations?

[Anonymous Coward]

Learn to shut your mouth asshole or I'll slam it shut again like I did here http://ask.slashdot.org/commen...

You unbelievable blowhard bullshitting fuckwad loser - what makes me laugh MOST about you?

All this talk about "how much you've coded" & "since the 80's" but nothing to show for yourself for it either.

APK

P.S.=> I am going to have a FUCKING FIELDDAY ON YOUR ASS regarding that link above where you "demanded citations" & NETCRAFT ONES ATE YOUR ASS ALIVE, blowhard bigmouth done zero loser hiding behind a FAKE internet name online (you have to - you haven't done shit with yourself - prove otherwise in the field of computing)... apk

Re:Hey asshole - asking for citations?

[Anonymous Coward]

what makes me laugh MOST about you?

Something tells me someone as sad and pathetic as APK doesn't do a lot of laughing.

You're known as a blowhard I dusted... apk

[Anonymous Coward]

Like I did here using valid netcraft data http://ask.slashdot.org/commen...

You unbelievable blowhard bullshitting fuckwad loser - what makes me laugh MOST about you?

All this talk about "how much you've coded" & "since the 80's" but nothing to show for yourself for it either.

APK

P.S.=> I am going to have a FUCKING FIELDDAY ON YOUR ASS regarding that link above where you "demanded citations" & NETCRAFT ONES ATE YOUR ASS ALIVE, blowhard bigmouth done zero loser hiding behind a FAKE internet name online (you have to - you haven't done shit with yourself - prove otherwise in the field of computing)... apk

Re:You're known as a blowhard I dusted... apk

[Anonymous Coward]

Curious, are you the same APK who was complaining earlier that someone who pointed out that your writing style resembles geocities (which it really, really does) was making an "ad hominem" attack on you (comment here for reference)?

I ask because it looks from here as if you are confused or misinformed about what such an attack is: It's not merely an unflattering observation of facts as in the case of the "geocities" observation, but it is rather attacks such as "You unbelievable blowhard bullshitting fuckwad loser" quoted above.

Either ad hominem attacks are bad, or they aren't; you can't have it both ways. (Spoiler alert: From most perspectives they are "bad".)

Re:You're known as a blowhard I dusted... apk

[Anonymous Coward]

What are your feelings on HOSTS files? APK

We're talking about showing you're weak

[Anonymous Coward]

Like I did here using netcraft data http://ask.slashdot.org/commen...

You unbelievable blowhard bullshitting fuckwad loser - what makes me laugh MOST about you?

All this talk about "how much you've coded" & "since the 80's" but nothing to show for yourself for it either.

APK

P.S.=> I am going to have a FUCKING FIELDDAY ON YOUR ASS regarding that link above where you "demanded citations" & NETCRAFT ONES ATE YOUR ASS ALIVE, blowhard bigmouth done zero loser hiding behind a FAKE internet name online (you have to - you haven't done shit with yourself - prove otherwise in the field of computing)... apk

Re:We're talking about showing you're weak

[Anonymous Coward]

snaf snarf snufle wee wonk bazoo

Re:We're talking about showing you're weak

[Anonymous Coward]

Curious, are you the same APK who was erroneously complaining earlier that someone who pointed out that your writing style resembles geocities (which it does, by the way) was making an "ad hominem" attack on you (comment here for reference)?

I ask because it looks from here as if you are confused or misinformed about what such an attack is: It's not merely an unflattering observation of facts as in the case of the "geocities" observation, but it is rather attacks such as "blowhard bigmouth done zero loser" quoted above.

Either ad hominem attacks are bad, or they aren't; you can't have it both ways. (Spoiler alert: From most perspectives they are "bad".)

Again, I (we) get that you are high on your windows-only tool that installs somebody else's custom hosts file in place of the default one, but you might win more believers by being less of a geocities-writing-style asshat. I am sure you are a nice guy; I am not criticizing you. This is genuinely friendly advice. When I was younger and sometimes acted like this, I now wish someone had give me the same advice.

Re: This haiku has nothing to do with spreading li

[Anonymous Coward]

Theeeee faggots on the bus go fuck my ass.
Fuck my ass.
Fuck my aaaass.
The faggots on the bus go fuck my ass
Because they're fuckin gaaaaaay.

starseeds

[Anonymous Coward]

As everyone who read Larry Niven would know.

panspermia

[BringMyShuttle]

He should win the Nobel for the name alone! :-)

Um, even worse news:

[Anonymous Coward]

You do realize that we haven't even found life on a second planet yet, don't you? This is extrapolation at its speculative best, people. Get back to us when you fine life in one other location in the galaxy...

Re:Um, even worse news:

[Impy the Impiuos Imp]

The more important point is using spectography to analyze planetary atmospherez for signs of life. This should be possible.

And if it is, and life is detected, we should be able to tell enough about it to make a guess as to whether it evolved independently, or was related to each other (or us) the way we can relate all life here via DNA.

Correction, 0.001%

[lamer01]

The 1% probably includes a lot of people who have no say in anything that goes on.

A hypothesis cannot act.

[dakra137]

Proper use of the scientific method may prove or disprove a hypothesis.
A widely publicized hypothesis might cause mass hysteria while being neither proven nor disproven.
Could "A hypothesis of panspermia" "act as the delivery system for alien biology to hop from one star system to another" ?
NO. Any "delivery system" requires instantiation of a mechanism, which might follow from a provable hypothesis.

Panspermia - ducking the question.

[RockDoctor]

All panspermia discussions strive to avoid being seen to duck the difficult question : how did life first originate anywhere? Even if you prove beyond doubt that Sol organisms are derived form (e.g.) Van Maaanen's Star organisms, as are Banardians and ... you still have the problem of finding out how originated the first time.

While OOL (Origin Of Life) is by no means a settled question on Earth, we do at least have good evidence of what happened here. Otherwise, being able to determine that life originated in a cluster which got destroyed 3 billion years ago by a GRB is unlikely to leave much tangible evidence.

If it can happen anywhere, it could happen repeatedly. And so multiple civilisations is my bet, and they just learned to keep quiet around the Primitives.

Everyone is dead, or elsewhere remains on the list of possibilities.

About Planets

[Immerman]

For the sake of clarity I'm going to split this post into two - one pro-planet, and one for habitat discussions:

I'm not fixated on living on planets - I'm saying they have a lot of their own advantages which make them desirable locations TOO. Basically:
Planet advantages:
- serious radiation and impact protection
- real gravity
- abundant resources (almost all mass close enough to our star to not be effectively interstellar)
- a large enough ecosystem to absorb large disruptions without lasting damage (at least in the case of Earth, and any planets we decide are worth spending a few thousand years terraforming)
Disadvantages:
- Deep gravity well requiring surface-to-orbit infrastructure for easy access to space
- most resources probably substantially more difficult to access than from asteroids (asteroid ease suspected but not yet known with certainty)
- long-term adaptability of humans to different surface gravity is currently completely unknown

I'll grant you that if we discover that humans can only thrive in a narrow range of gravities we'll have a problem. In principle there's no reason that centrifuge-habitats couldn't be constructed on lower-G worlds to make up the difference, but they would almost certainly be more problematic than doing so without gravity or air resistance. I'll repeat though that from the very limited data we've accumulated, there's no particular reason to assume that lower gravity would present a major problem - the microgravity problems discovered to date seem to all be related to the total absence of properties that would only be moderately impacted by even relatively large departures from 1G. And there's no particular reason to suspect that human adaptability is so poor - for example most humans can adapt just fine to atmospheric pressures between 0.5atm and 2atm, despite the fact that most gene-lines have never been exposed to anything close to those extremes. Infant mortality might be high until greater adaptability evolved, or there might be centrifugal "pregnancy districts" to allow infants and expectant mothers to remain at 1G during any critical developmental periods. Or, perhaps the best option, we could breed such adaptability into mice or other animals and then transfer the relevant genes into human colonists. Modifying ourselves to better fit the environment would after all be far more expedient than adapting the environment to fit us.

I like your sintered ceramic honeycombs, can you point me to any information about research into the relevant properties of such materials? I would suspect though that any such material could be made far stronger in compression than tension, and compression has the advantage that micro-fractures are less likely to lead to sudden catastrophic failures. You could use the same basic material to construct arched tunnels and domes for underground habitats at a substantial reliability advantage. And you would probably want to do so anyway even for your honeycombed spinning asteroid - if you've got 1G of pseudogravity then those habitat modules will need to be able support the "weight" of anything above them, at least as a safety measure in case the module directly overhead loses tensile support. And if you assume a large city-sized structure at 1G psuedogravity, there's no reason you couldn't do substantially the same thing building on a planet - there's no need to leave rock untouched if everything above you is engineered to distribute the weight evenly. The deeper you go the greater the pressure from above, and at some point you'll likely need more walls than rooms to support the load, but even if you only covered the planet with a mega-habitat few dozen miles deep you'd likely have more habitat than available from all the asteroids in the inner system. And if your large-scale engineering is sufficient to distribute the load laterally around the planet instead of only vertically - well then you can keep going deeper until it gets too hot for comfort and/or structural stability.

About orbital habitats

[Immerman]

I have to agree with you about giant windows being a bad idea. Observation domes, etc. on the outer surface would certainly have their place, who wouldn't want to look down through the transparent floor and see the stars spinning past beneath them? But such chambers should be easy to isolate from the main habitat in case of the inevitable impacts and radiation surges. Giant windows letting you see stars overhead may make for good science fiction, but I doubt many people would want a scant sheet of "glass", no matter how sturdy, being the only thing standing between their children and explosive decompression.

I'm less convinced that such huge open environments are a good idea, at least as the primary habitat. Personally I'd certainly enjoy having such a "tube of air" available for "outdoorsy" activities, but I would suspect the bulk of the actual habitat would actually be within the "ground". Even psychologically, it might be preferable to have an expansive painted (OLED screen?) sky several stories overhead rather than seeing the world curling up over you. That would also allow for multiple floors with very different gravity - I'm sure "low G" floors would have numerous recreational, industrial, and rehabilitative applications. Such interior floors could even be potentially constructed from structurally-stabilized high tensile strength fabric, adding minimal mass while providing not only expansive low-G surfaces, but also air baffles to prevent Coriolis storms, and to slow atmosphere loss in case the outer hull were punctured.

As for lighting - I like the light-pipe idea, be it glass tubes or mirrored pipes leading to windows overlooking large interior areas. I think I would avoid vacuum though, too much trouble. I'd lean towards slightly over-pressured clean-room grade air, so that the lighting tubes need not be completely airtight to avoid dust contamination. Maybe even pure nitrogen or carbon dioxide to avoid oxidation issues as well, while also discouraging adventurous "explorers". Combined with airflow monitors it would even make it relatively easy to locate breaks in the tube without requiring manual inspections. With advances in photovoltaics and electric lighting though, it might well make more sense to stick to artificial lighting. And of course for trans-Neptunian habitats fusion-driven electric lighting is almost a forgone conclusion.