movement of space animals

Question

Animals on planets are so 20th century - let's herd us some space animals!

In this story I have the need to move a herd of pesky space animals. They like Suns for their juicy solar energy and hydrogen, have stumbled into our solar system and are in no hurry to leave.

This causes some problems, I'll come up with those later on, the point is that my guys will want to move the herd about.

So:

• How would an animal in space evolve with an ability to move rapidly? What, specifically, would be the bodily apparatus for movement?

• How would we go about herding them?

• They move at about an eighth to a half of the speed of light, can be a bit less or a bit more (I'll change this if it turns out to be problematic, please let me know. Do mind that they have a long way to go between solar systems).

• The movement must be sustained for quite a long time (dozens of years, between stars), so particle ejection (Jet?) based movement is less preferable to say, some form of gravity manipulation, because I don't want my space animals to get stranded in the great void with an empty particle/fuel tank, without the ability to refill it.

• They're solid animals, not gas/plasma based like in some sci-fi stories
• Their size has to be larger than a small space craft (can't nudge them about, or capture them easily)
• They're not aggressive but will defend themselves if they feel threatened
• I don't care much about shape, though exotic ones will be nicer for the story (see: How do I prevent my turtle from collapsing under its own gravity? )
• EDIT2: The life span of the animals and their evolution span can be long, really long. I'm thinking a couple of thousand of years for life, and the evolution can take billions of years. But you may suggest other spans as needed.

EDIT: Ok, I found this: Could life form in outer space? but I don't feel that it covers the speed and supposed energy requirement of my space critters. Also, it seems to lack a hard science discussion about evolution (see the comments by @Peter Masiar). I'd like to get a plausible, sizeable, rapid-moving animal that will eventually damage the sun or humanity's requirements of the sun (it's a futuristic thing so we might have a Dyson sphere that could be ruined or something like that. Suggestions into the manner of the disruption that the animal will cause are welcome, especially if they have to do with the animal's requirements for movement).

Yippie ki-yay, space cowboys

Answer 1

I'd take a moment first to outline the limitations I see with spacefaring creatures. It's hard to see any kind of mechanism that would allow this kind of evolution purely in space, just on the basis of the harshness of the environment. I see the chance of some planetoid, maybe collapsing or cracking apart, with some species surviving the apocalyptic events and as their world decays and gravity and atmosphere slowly dissipate, the pressure to adapt remains and pushes the flora and fauna to gravityless and atmosphereless space. As this kind of changes would be more of the rapid and world-ending type, small species with short spans between generations would be my choice. From this, the simple fact that space is empty and big, the organisms would benefit greatly from the longer lifespans, meaning slower and larger. But as the change from small to large would happen in space, most likely any limbs designed to bear their weight would be gone.

I'm pretty sure any "realistic" means of movement go out the window with the requirement of such speeds, so I'll just give my ideas here, even though they won't match this requirement.

1. Movement

Magnetic propulsion of various sorts.

Currently available(realistic in that sense) include Ion thrusters, Magnetoplasmadynamic thrusters and their variants. Usually operated by pushing some form of fuel, after ionization, through an exhaust. Siphoning hydrogen off stars would be a good way to get some plasma going, though the amounts for any realistic propulsion required would be quite massive(and getting massive faster than the creature itself). And don't even think about going fast with this option. It's good for efficiency, but speeds are abysmal.

From the outer-space life topic linked, the Solar sails type of creature could pretty well fit into this type of movement as well, diving close to the sun for a gulp of gaseous plasma and then flying away with sails. In large enough numbers(someone better with numbers has to do the calculations) they could basically speed up the life-cycle of Sol, consuming the hydrogen and rapidly shifting our sun to the end of its life as a red giant.

"Spitballing"

Clam-like accretion of a ball of space debris and accumulated dust from their travel across the void. This movement isn't very precise, nor very efficient at going exactly at a destination. Asteroid belts and planetary rings might be alluring to these creatures for just propulsion purposes. This type of movement would also act in pretty much a end-all solution for the animals needs: Capture ice for things like breathing(!!) and nutrition, use up the minerals and whatever you can't use, you'll store up and use later on as you spitball your way across the universe.

A threat from clams sounds pretty silly unless there's some caveats made. They'd probably have to be large enough to swallow space stations. Perhaps the waste they spit for movement is durable enough to endure re-entry heating. That way if these creatures gather en masse to our solar system, we could see an increase in 'asteroids' hitting earth(they'd have to slow down when entering our solar system, so there'd be an initial chunk from interstellar travel, possible disruptions in the Oort cloud etc.) causing all sorts of havoc.

2. How to herd these creatures

First option is just a net. Carbon nanotubes or some other good tensile strength wire, woven to a net. As there are some advances already in that area, should be pretty manageable in the futuristic space zoo too. This would also work with the 'spitballers', as long as they're rid of huge chunks prior to capture. A dyson sphere would of course create a frozen and radiation free solar system, which would make the whole system undesirable for the thruster types and they'd leave or starve just by completing one around our sun.

Currently realistic options out of the way, there's always force-fields or tractor-beams. Any propulsion or solar sale kind of creature only needs the tiniest of tugs to counter their extremely slow acceleration, meaning they'd be easy to control with just some kind of radar mounted turning tractor-beam that assesses if any one of them is trying to accelerate away from their designated area and pulls it back. Force fields is just the go-to for material-free cage.

Answer 2

Within currently known space and science you have only two real choices here - solar sails and propulsion jets. There is lots of other "maybe" stuff like gravity manipulation, reactionless drives, etc but absolutely none of them are currently even known to be possible.

Neither of those will let them get up to any significant fraction of C without an external boost so you may need to revisit that part of the concept. (I've seen figures of 4,300 years being used for how long it would take for an interstellar solar sail unboosted to cross from one star to another).

Most likely the creatures would have a combination of the two, jets for close maneuvering and personal defense used when they must and solar sails for primary propulsion since they do not require reaction mass.

The creatures could have a life cycle where they arrive in a star system and find a ring or asteroid belt. That they then seed with spores that use the raw materials to grow more of themselves. Once the younglings are fledged they start to gather close to the star, forming themselves together into an enormous lens. Finally as the last stage some of them move into the beam of light from the laser and use that to accelerate themselves out of the star system and across interstellar space.

Once they get too far from the star they enter hibernation, woken up when they approach the next system. Deceleration at the target star can be achieved in a number of ways, none of them simple. See this discussion here:

http://www.centauri-dreams.org/?p=28653

The good news though is that this gives you your hazard as well, this giant beam of energy concentrated from the sun and lasered out into space. That's a very deadly thing to have under the control of animal level intelligence beings acting as some sort of hive. Especially as they start building more and more of them and sending themselves out to more and more nearby stars.

Answer 3

Perhaps they are engineered vonNeumann machines that have gone feral. They were engineered to gather raw resources, produce goods and perform services, and maintain homeostasis ans reproduce.

Those that reproduce and don't do the original purpose will have a competitive advantage. But they start to interact and form a biosystem.

Code of the Lifemaker is obviously due to a damaged tech system. The origin is left open for Camelot 30K. I envision a complete replacement of purpose with evolved traits: they do become wild animals with little in common with the original genesis beyond the low-level metabolism toolkit.

An explicit creation gets around the issue of how such a thing would come to exist and shortcut the time scale needed for evolution.

Maybe many intelligent species have come and gone and their only lasting role is to add to the diversity of permanent galactic life. Over a time span of millions of years they mix and spread and encounter remains of planetary life that reached the point of technology and space-fairing, and incorporates the stuff it finds.

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Machines assembled using self-growing nanotechnology will be more like living things we are used to. Rather than a factory making an engine casing out of metal or composites, it would grow it featuring an internal circulatory system and nanobots that incrementally take-up and re-pave the advanced composite structure from within. In us those are called osteoblasts and make bones.

Perhaps components that work under conditions that can't withstand being fully alive would be formed in another organ, like a shell is grown but not living; then installed when needed.

Ion engines may need parts formed in fab organs and moved into place. But a solar sail is well suited to being living tissue through and through, constantly maintaining itself against wear and damage. Long mooring and control lines may be carbon nanotube that's patrolled by tiny nanobots that constantly crawl its length and rework the material. Raw materials would be carried by more efficient specialized carriers that also use the lines as a freeway, perhaps along the inside of hollow tubes, like a dry blood supply.

The fundamental technology of the original machines would be nanobots that grow through asteroids and commetary bodies like fungus hyphae, digesting it and harvesting raw materials, moving it to concentrated stockpiles. As greedy organisms they would be just like mushrooms, eating bodies where spoors land and producing units that travel to new sources of material. They may be as simple as durable spoors and not need much propulsion within the belt where they are found.

As part of a larger ecosystem, they would play the role of concentrating and providing raw and refined materials for others to use: growing fruit to be taken by other types of creatures.

So there are roles not just for "animals" but all manner of categories some of which are clearly analogous to algae, plants, fungi, plankton, etc.

Asteroid-sized rapidly mobile heterotrophs with active defenses and teeth are the first thing you may notice — space animals. But they're just the top of a food chain. Fungi mines raw material. Plants collect sunlight and form large stable platforms. Microbes specialize in many different metabolisms and live in and around the macro forms where their special features are employed.

Answer 4

How would an animal in space evolve with an ability to move rapidly? What, specifically, would be the bodily apparatus for movement?

This would likely be a combination of things. Inside a solar system using sails to catch the solar wind would be the most energy efficient. However, have some kind of jet/ion propulsion would be useful for faster course corrections or added bursts of speed.

How would we go about herding them?

You would need to have some idea of what they want/need and what they fear. One useful thing would be to build your space ships for herding to have at least a nominal appearance to the animals themselves. If you make your ships larger then depending on the mentality of the animals, you might even be able to 'lead' them, but herding would likely be easier and less likely to get an attack response.

They move at about an eighth to a half of the speed of light, can be a bit less or a bit more (I'll change this if it turns out to be problematic, please let me know. Do mind that they have a long way to go between solar systems).

That is pretty fast. I was looking for information on speed of solar sails, and while they can get things going pretty fast, (fast enough for inter-solar travel) the max estimate I could find under ideal conditions was 1/10 c. So to go much faster than that they will also need a propulsion system, which for interstellar travel will need a decent sized 'fuel tank'.

1/2 the speed of light is FAST, and they become planet killers if they should run into one. To even come close with the least amount of energy expended, would be to dive toward the sun, picking up speed, and 'slingshot' out, furling out the solar sails near the bottom of the swing to help speed up more on the outbound run.

The movement must be sustained for quite a long time (dozens of years, between stars), so particle ejection (Jet?) based movement is less preferable to say, some form of gravity manipulation, because I don't want my space animals to get stranded in the great void with an empty particle/fuel tank, without the ability to refill it.

The nice thing about space is that other than gravity wells you just keep on going at a constant speed in the direction you set. So once the herd has reached cruising speed (what ever that happens to be) they can all go dormant for the trip. They can deploy their sails to start catching solar winds when they approach the destination star to slow them down for entry into the system.

I don't care much about shape, though exotic ones will be nicer for the story (see: How do I prevent my turtle from collapsing under its own gravity? )

The shape could be anything, but being able to open and collapse to catch and 'dive' the solar winds would be useful, maybe like an octopus? Likely they would need to be able to handle impacts from small matter since traveling at relativistic speeds is dangerous for any collision.

The life span of the animals and their evolution span can be long, really long. I'm thinking a couple of thousand of years for life, and the evolution can take billions of years. But you may suggest other spans as needed.

That might be needed just to get a species that can travel between the stars, though if they go dormant during travel it could help increase their lifespans easy.