If we find a habitable extrasolar planet, what would we do?

[grokme]

Also, how fast are deep space ojbects moving in relation to the speed of light?

 

[Shpaget]

The quickest way to get a response,...

:shock:
Where did this come from?
Why would you assume they were more technologically advanced than us? Even If they are, maybe they're using completely different kind of technology not compatible with our own, or maybe they're so advanced that they consider our tech obsolete.
Even if they do get and manage to record our signal, there is no way they could decipher it. First they would need to figure out the concept, than modulation, than coding. And even if they do manage to do all and end up with perfectly accurately received words, how the hell are they supposed to understand such a complex message? It's ridiculous.
There are much simpler ways of establishing first contact via radio signals.

Let's say they have received the signal via microwave (I believe is our fastest type of communication)

Why would it be any faster than any other wavelength?

Since it's already out there in space, and it's already moving at a good clip, and since it is something that has been in space for billions of years and is likely to "travel well", seems like we could leverage it somehow.

It doesn't work like that. You can't extract speed out of an asteroid.

Are there any stars that are set to approach Sol close enough to be less than a light year?

Not in near future.

Also, if you rendezvous with a deep space object that is moving towards a distant star, and just parked yourself on it for the ride, would that work?

Same with as asteroids. You first need to catch it (more speed than it already has) than decelerate to land on it... Just wasting precious fuel.

Lastly, what types of studies could we do of said habitable planet in the future from a distance? I understand we might be able to discern some features, but what kind of things will we be looking at.

Do you by features mean mountains and oceans?

Also, how fast are deep space ojbects moving in relation to the speed of light?

0 c

 

[grokme]

Since it's already out there in space, and it's already moving at a good clip, and since it is something that has been in space for billions of years and is likely to "travel well", seems like we could leverage it somehow.

It doesn't work like that. You can't extract speed out of an asteroid.

Yes, I didn't say anytihing about "extracting" speed from an asteroid.

Are there any stars that are set to approach Sol close enough to be less than a light year?

Not in near future.

I kind of assumed long term when I asked the question.

Also, if you rendezvous with a deep space object that is moving towards a distant star, and just parked yourself on it for the ride, would that work?

Same with as asteroids. You first need to catch it (more speed than it already has) than decelerate to land on it... Just wasting precious fuel.

Maybe so, considering that if you're up to the same speed you can just continue at that speed.

Lastly, what types of studies could we do of said habitable planet in the future from a distance? I understand we might be able to discern some features, but what kind of things will we be looking at.

Do you by features mean mountains and oceans?

Well, actually I was asking what we would be studying.

Also, how fast are deep space ojbects moving in relation to the speed of light?

0 c

I'm assuming it would be greater than 0 since it wouldn't be moving at all at zero. Do you mean some tiny fraction of 1?

 

[Shpaget]

I kind of assumed long term when I asked the question.

I meant near future in universe terms, not in human.

Yes, I didn't say anytihing about "extracting" speed from an asteroid.

But you are talking of it assisting you in traversing space distances quickly.

I'm assuming it would be greater than 0 since it wouldn't be moving at all at zero. Do you mean some tiny fraction of 1?

The only way to measure the speed of something is by comparing it to the speed of something else. Since you can't find anything that stands still you yourself become a reference point, no matter how fast you are moving, and you call your motion, whatever it may be, standing still.
If you take some space object as a reference point, it becomes stationary.

Relative speeds between deep space objects vary, but it doesn't matter.
Even if you could find something traveling at a significant portion of c (not likely), you wouldn't be able do do anything with it. Like I said more than once, you first need to catch (be faster than it so you can land on it) it to hitch a ride, and if you are able to catch it , you don't need it. You can go all by yourself.

Also you should consider that there are no objects in Solar system that are going to leave it. No asteroid, no comet, no meteoroid has enough speed to leave it.

 

[robnissen]

I agree with everything you have written except this:

Also you should consider that there are no objects in Solar system that are going to leave it. No asteroid, no comet, no meteoroid has enough speed to leave it.

IIRC there was a comet in the 70s that appeared to have sufficient velocity to escape from the solar system. And it appears that there may be occasionally extra-solar system comets that pass through the solar system. But your general point is correct. Even if we could land on these inter-steller comets it would do us no good because 1) we have to match their speed to land, thus we get no speed increase; and 2) even these interstellar wanderers are only traveling in the order of magnitude of 100s KM/sec. To travel interstellar distances in any reasonable amount of time would requirse speed around 30,000 KM/sec. (.1c)

 

[mithridates]

Oh good, my favourite subject. Here are my thoughts on what will happen when we find an extrasolar planet that resembles our own.

First of all, it will change everything. The universe we know of up to now has consisted of a single inhabitable planet, and thousands of other bodies that humans can't possibly live on without some pretty impressive technology to keep them alive. No atmosphere, thin atmosphere, too cold, too hot, no solid surface, what have you. I know we're used to the idea of an extrasolar Earth being discovered one day but to everyone else it will be an earthshaking discovery.

Interstellar travel right now is pretty much meaningless, since even if we are talking about the closest destination there is (Alpha Centauri) and we assume that we can almost reach velocities approaching the speed of light (which we can't), it would still take at least a decade to reach. But that's to one solar system. Now compare that to simply building a better telescope. That takes somewhere close to a decade, is a bazillion times cheaper, and allows us to observe not just that one system but every other system with greater detail as well. So the easiest way to find out about a new planet we've discovered that resembles ours is to simply build better and better telescopes.

I don't think we'll end up sending people to other solar systems until we have the ability to send them within about 20 years or so, simply because anything greater than that and 1) the people sent there will be old by the time they arrive, and more importantly 2) technological progress makes it very likely that we'll develop something even better while they're on the way. If we sent a group of people off to Alpha Centauri for example on a long long 70-year journey for example, chances are we'll develop something on the way that will simply be able to pass them by while they're still making their slow way there. That would be depressing.

 

[JeffreyNYA]

Honestly I think the only way we will ever get any distance outside our solar system is with something other than ships. While its been shown that Wormholes are possible we have no idea how to create one or if anything of any mass would be able to be sent through it if we could. But it is really the only way theoretically that we are going to be able to get anywhere within any lifetime.

Now being a fan of the novel Pandora's star, I may be just indulging my scifi side a bit much with this post, but in the coming centuries if we were able to prove and engineer a solution to wormholes it would be possible to open up the universe to us. Until then we are stuck here.

Large colony ships will almost all fail. just to many things to go wrong in space and not enough resources to available.

 

[eburacum45]

Several problems here;

first what do we mean by 'habitable'? If we mean 'with an oxygen atmosphere' then there must already be life present, since high levels of oxygen do not occur in the atmospheres of lifeless planets. If there is life there we will not be able to tell if the proteins and other organic chemistry of the life forms are compatible with Earth-life. I suspect that in most cases the lifeforms will be at the very least inedible, and most likely poisonous or otherwise dangerous to colonists.

Even if we find a planet with life which is exactly compatible with Earth-life would we have the right to affect the natural evolution of that world by introducing Earth species such as humans? Unless we can foresee the future evolution of such a planet I am not sure that we would have that right.

As far as getting ther goes, some methods might get us there in the long run. Daedalus type ships (which rely on an external fusion pulse, rather than a contained fusion reaction) are one option, but ther are many others.

 

[bdewoody]

Several problems here;

first what do we mean by 'habitable'? If we mean 'with an oxygen atmosphere' then there must already be life present, since high levels of oxygen do not occur in the atmospheres of lifeless planets. If there is life there we will not be able to tell if the proteins and other organic chemistry of the life forms are compatible with Earth-life. I suspect that in most cases the lifeforms will be at the very least inedible, and most likely poisonous or otherwise dangerous to colonists.

Even if we find a planet with life which is exactly compatible with Earth-life would we have the right to affect the natural evolution of that world by introducing Earth species such as humans? Unless we can foresee the future evolution of such a planet I am not sure that we would have that right.

As far as getting ther goes, some methods might get us there in the long run. Daedalus type ships (which rely on an external fusion pulse, rather than a contained fusion reaction) are one option, but ther are many others.

How do you know that our going there isn't part of another world's natural development?

 

[neilsox]

Unless there is some secret much more advanced technology, we can't do much about a possibly habitable planet 4 light years away, so I agree, it is mostly a pure science type thing. The difficulty increases rapidly for greater distances.
We can send a message, perhaps even a big bluff as The_unknown suggested, but we have no reason to think the ET there understand English or will understand a message of any kind.
Possibly habitable does not necessarily mean intelligent civilization. Mars is possibly habitable, but likely has no life more advanced than microbes far below the surface.
By 2020 humans may have a practical way to change the direction of asteroids by a few seconds of arc, but that is almost none. Changing the direction of comets in the Oort cloud by a few seconds of arc can redirect the comet in the inner solar system by millions of miles. With present technology it takes almost a century travel time to reach the Oort cloud. I think it is unfortunate that some famous author long ago suggested that an asteroid can make a good counter weight for a space elevator, as that is a completely unworkable idea for the rest of this century, but we could have a working space elevator by 2031. We only need a few tons of counterweight for a space elevator optimised to send pay loads though out the inner solar system. Neil

 

[Solifugae]

It's hard to accelerate mass close to light speed to cross the distances to a habitable planet. What if we reduced the mass of the craft to the extent that it was actually a micro-craft?

Exceeding light speed is not possible, but it should be possible in the future centuries for AI to achieve the human level, and also for us to minaturize that to an extent, cutting down on weight. We could have a probe that weighed just several grams speeding its way to the next star. Although that depends on how much we could weight down and still have viable propulsion. Also, with AI, you have less need for tolerable accelerations.

 

[Shpaget]

It's hard to accelerate mass close to light speed to cross the distances to a habitable planet. What if we reduced the mass of the craft to the extent that it was actually a micro-craft?

Unless you don't plan on stopping or slowing down once you reach your destination, you still have insanely huge amounts of fuel to haul around.

 

[duluthdave]

Would we just continue to perfect our technologies for imaging and studying the planet from this great distance? Would this be an impetus for someone to try an interstellar manned mission, perhaps using a generational type transport?

I like that question, and my answer would be both. It seems to me our first response would be to keep working on our technologies for studying the planet from a distance. That's the only method that would give results within our lifetime. But I'd like to think it would also inspire using a generational transport to send a manned mission. The idea you mentioned about using an asteroid is a good one. A generational transport would benefit from being attached to an asteroid for the trip, and could make the launching of such a mission much simpler.

 

[Shpaget]

A generational transport would benefit from being attached to an asteroid for the trip, and could make the launching of such a mission much simpler.

How (on both parts of quoted text)?


The problem I see with generation ships is that the original crew would likely be handpicked mostly from scientific community and would be composed of highly educated and capable (preferably in more than one area) individuals covering all fields of today's sciences.
Such ship would require a very large crew, my estimation is no less than 10 000 if the goal is to colonize another world (gene pool). While the Earth population could surely supply such a number, if 10 000 first class scientists suddenly disappeared from Earth it would leave consequences on our future researches.
The other thing is that even though these people would probably be very interested in the mission, chances are that their children will not share their enthusiasm and would feel they are being forced to do something they never wanted to be involved with, especially when they learn what their parents left behind.

If the trip takes only two generations, the mission might even succeed, but with every new generation, the number of people interested in sticking to the original plan will fall.

 

[MeteorWayne]

Would we just continue to perfect our technologies for imaging and studying the planet from this great distance? Would this be an impetus for someone to try an interstellar manned mission, perhaps using a generational type transport?

I like that question, and my answer would be both. It seems to me our first response would be to keep working on our technologies for studying the planet from a distance. That's the only method that would give results within our lifetime. But I'd like to think it would also inspire using a generational transport to send a manned mission. The idea you mentioned about using an asteroid is a good one. A generational transport would benefit from being attached to an asteroid for the trip, and could make the launching of such a mission much simpler.

I doubt you realize the energy required to place an asteroid on a path out of the solar system. So far we have sent 5 spacecraft on such trajectories, with a total mass of a few hundred kg. An asteroid is many billions of times more massive and will therefore require many billions of times more energy.

 

[JeffreyNYA]

A generational transport would benefit from being attached to an asteroid for the trip, and could make the launching of such a mission much simpler.

How (on both parts of quoted text)?


The problem I see with generation ships is that the original crew would likely be handpicked mostly from scientific community and would be composed of highly educated and capable (preferably in more than one area) individuals covering all fields of today's sciences.
Such ship would require a very large crew, my estimation is no less than 10 000 if the goal is to colonize another world (gene pool). While the Earth population could surely supply such a number, if 10 000 first class scientists suddenly disappeared from Earth it would leave consequences on our future researches.
The other thing is that even though these people would probably be very interested in the mission, chances are that their children will not share their enthusiasm and would feel they are being forced to do something they never wanted to be involved with, especially when they learn what their parents left behind.

If the trip takes only two generations, the mission might even succeed, but with every new generation, the number of people interested in sticking to the original plan will fall.

I agree with you on most everything other than the kids having something forced on them. The kids most likely would have no other point of view. This would be there life and they would live it as such, the same as say the Amish or any other group that we could probably come up with.

However, the other issue with generational ships is that one disaster could kill the mission. It could be internal or external. With this many people there is always going to be the human nature issue to deal with. the fact that people will separate and groups will form and power struggle will happen. No way around it really. When on a planet, people can move. On a ship like this, its not possible. There will be problems. And actually I think there would need to be at lest 3 or 4 of these things sent to the same destination maybe 6 months apart, or 2 at a time, just to increase the probability of success. All in all I do not think people in general are ready for such grand programs. Now if you could somehow magically land 10K people on another planet in a week, well then that is an all together different story.

 

[duluthdave]

I doubt you realize the energy required to place an asteroid on a path out of the solar system. So far we have sent 5 spacecraft on such trajectories, with a total mass of a few hundred kg. An asteroid is many billions of times more massive and will therefore require many billions of times more energy.

The energy sending those 5 spacecraft out of the solar system came from gravity assists by the planets they visited along the way. If they had relied solely on the energy supplied at launch, they'd have gotten about as far as Jupiter before falling back into orbit around the sun. The limiting factor in the size of those spacecraft isn't the planets' ability to send them out of the solar system, it's our ability to launch something from Earth's surface and get it to those planets in the first place. That would be the advantage of an asteroid - they're already in space and occasionally pass near large planets. If we found a suitable asteroid a sufficient amount of time before such a pass, it would require only a tiny adjustment in the asteroid's path to set it up for a gravity assist (or more likely a series of gravity assists) that would send it out of the solar system. Granted, even making a tiny adjustment in the path of an asteroid would itself be very difficult. But as for supplying the "billions of times more energy", I think the angular momentum of Jupiter would be up to the task.

 

[MeteorWayne]

That's not really true. Most of the velocity for the 5 craft came from the initial launch; the planets were used primarily to change direction, not add speed, though in some cases it did do so to a limited extent.

 

[JeffreyNYA]

Once you find this Asteroid then what? How are you going to Hollow it out? How are you going to make it habitable? How are you going to add propulsion system to it to slow down or change course? How are you going to generate water and air and grow food. How are you going to store Radioactive material for the engines? You will need a whole lot of it to power a 100 to 200+ year trip.

Leaving propulsion out of it, the engineering of this project would be greater probably that most other projects humans have ever completed combined. We simply do not have the resources or will to take on a project like this in any foreseeable future. Hate to spoil it, but its just not going to happen. Actually I think it would be easier to just piece something together in orbit over 250 years then try to make a large asteroid home. At least we have some idea how to do it and its always close to home.

 

[duluthdave]

Such ship would require a very large crew, my estimation is no less than 10 000 if the goal is to colonize another world (gene pool).

There's no need for such a large crew. Frozen embryos or other genetic samples to be cloned later could maintain a sufficient gene pool without that many actual crew members using up all the food and oxygen. Also, that's the point of using an asteroid. It would give the crew a suppy of resources to mine throughout the trip. Old mining tunnels could also provide additional living space, allowing a larger crew. It would ultimately allow a much larger, better supplied spacecraft than could be launched directly from Earth's surface.

If the trip takes only two generations, the mission might even succeed, but with every new generation, the number of people interested in sticking to the original plan will fall.

You make it sound as if they'd have a choice. Maybe they wouldn't be happy about being on such a mission, but it's not as if they could pull the spaceship over and get out and the next rest stop. They'd stick to the original plan simply from a lack of other viable options.

 

[JeffreyNYA]

I doubt you realize the energy required to place an asteroid on a path out of the solar system. So far we have sent 5 spacecraft on such trajectories, with a total mass of a few hundred kg. An asteroid is many billions of times more massive and will therefore require many billions of times more energy.

The energy sending those 5 spacecraft out of the solar system came from gravity assists by the planets they visited along the way. If they had relied solely on the energy supplied at launch, they'd have gotten about as far as Jupiter before falling back into orbit around the sun. The limiting factor in the size of those spacecraft isn't the planets' ability to send them out of the solar system, it's our ability to launch something from Earth's surface and get it to those planets in the first place. That would be the advantage of an asteroid - they're already in space and occasionally pass near large planets. If we found a suitable asteroid a sufficient amount of time before such a pass, it would require only a tiny adjustment in the asteroid's path to set it up for a gravity assist (or more likely a series of gravity assists) that would send it out of the solar system. Granted, even making a tiny adjustment in the path of an asteroid would itself be very difficult. But as for supplying the "billions of times more energy", I think the angular momentum of Jupiter would be up to the task.

Explain how you are going to get it to Jupiter to use it to boost speed or even how you would change the direction of an asteroid orbiting Jupiter enough to make a difference? And once you have done this how in the world are you ever going to course correct? Or are you just going to point and shoot and hope you end up somewhere?

 

[JeffreyNYA]

Such ship would require a very large crew, my estimation is no less than 10 000 if the goal is to colonize another world (gene pool).

There's no need for such a large crew. Frozen embryos or other genetic samples to be cloned later could maintain a sufficient gene pool without that many actual crew members using up all the food and oxygen. Also, that's the point of using an asteroid. It would give the crew a suppy of resources to mine throughout the trip. Old mining tunnels could also provide additional living space, allowing a larger crew. It would ultimately allow a much larger, better supplied spacecraft than could be launched directly from Earth's surface.

If the trip takes only two generations, the mission might even succeed, but with every new generation, the number of people interested in sticking to the original plan will fall.

You make it sound as if they'd have a choice. Maybe they wouldn't be happy about being on such a mission, but it's not as if they could pull the spaceship over and get out and the next rest stop. They'd stick to the original plan simply from a lack of other viable options.

I did not realize that we were so far along in the cloning process that we would be able to create a viable socity out of frozen embryos. Also these frozen embryos can't stay that way forever. Eventually they will be come unusable. It will take many generations of cloning to see if it will be viable. Who knows what errors may occur in the process. You may be in essence killing the mission with this process before you ever launch it.

Living people are the only way to go for any foreseeable future. Sorry, there is no magic tech to fix the issues facing ta project of this nature.

 

[duluthdave]

That's not really true. Most of the velocity for the 5 craft came from the initial launch; the planets were used primarily to change direction, not add speed, though in some cases it did do so to a limited extent.

The planets were used both to add speed and change direction. Here are a couple links you might find useful.

http://www2.jpl.nasa.gov/basics/grav/primer.php
http://en.wikipedia.org/wiki/Gravity_assist

If you don't want to read the whole thing, here's a relevant quote from the JPL site:

"The two Voyager spacecraft provide a classic example. They were launched aboard a Titan-III/Centaur, with destinations of Saturn and beyond. But their launch vehicles could provide only enough energy to get them to Jupiter (halfway out to Saturn). Had Jupiter not been there at the right time, the spacecraft would have reached aphelion near Jupiter's orbital distance (about 5 AU or 750,000,000 km from the Sun). Their perihelion would have been around Earth's orbital distance (1 AU or 150,000,000 km), and they would have remained in that orbit until a planet or something else caused it to change."

Edited to add another link:
http://www2.jpl.nasa.gov/basics/bsf4-1.php
A little over half way down that page is a chart showing Voyager 2's velocity relative to solar system escape velocity. Before reaching Jupiter, it was well below escape velocity. After Jupiter, it was above.

 

[JeffreyNYA]

That's not really true. Most of the velocity for the 5 craft came from the initial launch; the planets were used primarily to change direction, not add speed, though in some cases it did do so to a limited extent.

The planets were used both to add speed and change direction. Here are a couple links you might find useful.

http://www2.jpl.nasa.gov/basics/grav/primer.php
http://en.wikipedia.org/wiki/Gravity_assist

If you don't want to read the whole thing, here's a relevant quote from the JPL site:

"The two Voyager spacecraft provide a classic example. They were launched aboard a Titan-III/Centaur, with destinations of Saturn and beyond. But their launch vehicles could provide only enough energy to get them to Jupiter (halfway out to Saturn). Had Jupiter not been there at the right time, the spacecraft would have reached aphelion near Jupiter's orbital distance (about 5 AU or 750,000,000 km from the Sun). Their perihelion would have been around Earth's orbital distance (1 AU or 150,000,000 km), and they would have remained in that orbit until a planet or something else caused it to change."

Say you somehow get the asteroid to Jupiter and use it to boost speed and change course, then what? You are not a satellite that can just go to deep space and you are done with it. You have a loaded crew that needs to get somewhere. How do you course correct and slow down when getting close to your destination.

 

[duluthdave]

Actually I think it would be easier to just piece something together in orbit over 250 years then try to make a large asteroid home. At least we have some idea how to do it and its always close to home.

Actually that would be the hard way to do it. First you'd have to launch everything into orbit (no small task with current launch systems), then you'd have to boost it out of Earth orbit, and then you'd still probably need a series of gravity assists to get it out of the solar system. Using an asteroid already in space would reduce the mass launched in the first two steps to a small fraction of your way of doing it, and still leave a much larger spacecraft when you're done.

I did not realize that we were so far along in the cloning process that we would be able to create a viable socity out of frozen embryos. Also these frozen embryos can't stay that way forever. Eventually they will be come unusable. It will take many generations of cloning to see if it will be viable. Who knows what errors may occur in the process. You may be in essence killing the mission with this process before you ever launch it.

Living people are the only way to go for any foreseeable future. Sorry, there is no magic tech to fix the issues facing ta project of this nature.

Just to be clear, cloning and using frozen embryos are two different things. Far from being a "magic tech", frozen embryos are commonly used now. Cloning hasn't gotten that far yet, but in the future it may present another option. You may have a point about frozen embryos eventually becoming unusable, the procedure hasn't been around long enough for us to really know what their "shelf life" is. But one way around that problem could be not having the same embryos frozen the whole time. The children born on the spacecraft could come from embryos frozen on Earth while while new embryos taken from the crew are then frozen, and so on. This would still allow the crew to maintain a significantly larger gene pool than their actual population - and that's just with current technology.

How do you course correct and slow down when getting close to your destination.

Slowing down is the easy part, gravity assists can be used for that too. Once the speed has been reduced to an acceptable level, aerobraking can also be used. They're the same techniques used by space probes we've sent to orbit other planets. The speeds may be higher and the masses larger, but the same physics still apply.

As for course corrections, the gravity assists would be used to send the ship out of the solar system on the right course. So only minor adjustments would be needed, and there would be plenty of time to make them. Just do the math. Given the time scales involved, you may be surprised how little force is needed to alter the course of something very massive.