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

[bdewoody]

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 that a large generation ship capable of duplicating most of the conditions found on earth would be the only way to go. A large cylinder spinning so the colonists would walk around on the inside surface of the outer shell would seem to be the ideal shape. 10,000 people is probably a good number but I think only a few hundred would need to be scientists. Most of the rest would be ordinary people doing the same ordinary work they do here on earth. And like others said the second and third and so on generations would have no choice.

 

[Shpaget]

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.

As I said many times in some other thread, to catch an asteroid you first need to land on it, and to do that you need to have more speed than it. If you have that much speed (which you paid for with big bucks), you can just continue without the asteroid. Landing on it would just waste speed since you need to spend a lot of fuel to slow down so you don't crash. That fuel could be used to increase the speed even more if there wasn't an asteroid in the picture.
And than you need to correct it's course...
Gravity assists work only if you have a large planet in the right place at the right time. Chances that you will also have a suitable asteroid at the right place at the right time are even slimmer. Chances of those two happening at the same time are astronomical (get the pun? :lol: ).

Slowing down is the easy part, gravity assists can be used for that too.

errr... no.
Aerobraking is pretty sensitive maneuver. You fly to high - you don't accomplish anything, or even get more speed. You fly too low, you burn up faster than you can say "Oh my god, we are all going to burn in the atmosphere of that alien planet, it is pretty though, with all those colors and twinkling lights. You think there might be a civilization down there?".

It would also require incredibly accurate calculations. Just a minor error can get a large one over the distance of light years. There are also unpredictable differences in interstellar medium which could cause unexpected drag that would also slow down the ship.
Not to mention that you first need to find a planet around a distant star suitable for aerobraking and plot it's orbit very precisely for the period of hundreds of years.

 

[EarthlingX]

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.

As I said many times in some other thread, to catch an asteroid you first need to land on it, and to do that you need to have more speed than it. If you have that much speed (which you paid for with big bucks), you can just continue without the asteroid. Landing on it would just waste speed since you need to spend a lot of fuel to slow down so you don't crash. That fuel could be used to increase the speed even more if there wasn't an asteroid in the picture.
And than you need to correct it's course...
Gravity assists work only if you have a large planet in the right place at the right time. Chances that you will also have a suitable asteroid at the right place at the right time are even slimmer. Chances of those two happening at the same time are astronomical (get the pun? :lol: ).

You can look at asteroid as a source for fuel/mass, and as you said, there's plenty of it

As to the gravity assist, how about a star ? Massive enough ?

 

[Shpaget]

You can look at asteroid as a source for fuel/mass, and as you said, there's plenty of it

And very little of which you can actually use considering our current technologies.
Asteroids happen to have only small number of different materials, so if you're going to use it's material for fuel, it would have to be a volatile rich (B-type) asteroid which are pretty rare.

As to the gravity assist, how about a star ? Massive enough ?

Which star?
The Sun or the one at the end of the journey?
The Sun won't work (no angular momentum regarding the solar system).

Are you proposing aerobraking using the atmosphere of a star? You do know it's hot there? The expression "snowflake's chance in hell" comes to my mind, especially if you use the above mentioned B-type asteroid.

 

[JohnniG]

While it would be one of the greatest discoveries in the history of makind, I think there is really only one acceptable answer to your question. The planet must be left alone. Humans have a planet already, but we haven't been too responsible with ours till recently. I don't think it would be right for humans to play any sort of role in the evolution of another world. That is their chance to live. We have too many issues of our own to start worrying about how to destroy the next planet.

That's a pretty interesting opinion on this.

 

[BenS1985]

What would happen if we find a habitable extraspolar planet?

We would invest in many new telescopes

In all seriousness, that is our only option for quite some time. There isn't enough funding to warrant anything more than looking at a habitable world. Furthermore, if there *was* a desire to actually go there, we would want to invest heavily in understanding how to get there, and what the world is actually like - to ensure we're not taking a trip to a secretly poisonous world filled with 10 foot tall blue people ;-)

How long did we contemplate going to the moon before actually traveling to it? Much in the same way, finding a second earth would fill our imagination for decades, and generations to come. This would be a good thing. It would spur on research and attitudes toward reaching out to new destinations.

I think for those saying that interstellar travel is unlikely are not having faith in the development of technology, or the business of space travel. 100 years ago, our only methods of travel were by slow boats and horse-drawn buggies. Yes, there were new technologies such as planes and cars, but there was not a large amount of money spent on such projects which is a mirror of where we are now, albeit on a larger scale.

Likewise, we haven't spent much money, time, or resources on traveling in our local system. All the efforts have been up to cheap governments, which hasn't spurred strong growth in the industry. Although its something far more for the space business side of things, I think that we'll see incredible growth in space-based industries over the next 100 years if governments allow it. With such developments will come ways of traveling faster. On May 20th and 21st, Charles Lindbergh took ~33 hours to cross the ocean in a risky flight. That trip cut the amount of time down by weeks. Likewise, in 60 years, we could then travel the ocean in passenger planes in under 10hrs thanks to the development of commercial crafts.

Much in the same way, we'll see our engines, and our transport ships grow in size and stature. I can only imagine what travel will be like when I am 60 years older (24 now) and hopefully coherent enough to understand what is going on in the space industry. We will find reasons to mine Eros, a need to draw fuel from Saturn, and the enjoyment of swimming underneath Europa - all of which brings investment into space. Nevertheless, our technology will continue to grow to the point that a trip to the habitable world will drop from centuries, if not millenia, to a matter of decades or a singular decade (depending on where the planet is). At that point, we'll launch the Nina, Pinta and Santa Maria 2 and embark on a new series of voyages that were thought implausible by this generation. I don't think anyone should be a naysayer when it comes to traveling to another habitable planet, as we should know it is just a matter of time before we find it.

Unfortunately though, I know almost certainly that I won't see the launch of such a mission in my lifetime.

 

[duluthdave]

As I said many times in some other thread, to catch an asteroid you first need to land on it, and to do that you need to have more speed than it. If you have that much speed (which you paid for with big bucks), you can just continue without the asteroid.

Okay, obviously you're right about that. But what does it have to do with the reason I gave for using an asteroid? The advantage to using an asteroid is size, not speed. As I said before, once you've landed on the asteroid, you can begin to mine it for raw materials to supply the ship. Old mining tunnels can be turned into additional living space, essentially increasing the size of the ship. So for the price of launching a smaller ship, you can end up with a larger one. Or to put it another way, using an asteroid would decrease the size of the ship you'd have to launch and accelerate to the asteroid's speed in the first place.

Slowing down is the easy part, gravity assists can be used for that too.

errr... no.

Um, are you saying gravity assists can't be used to slow a spacecraft? If so, you may want to brush up on your orbital mechanics. The links I gave MeteorWayne yesterday could be a good place to start.

Not to mention that you first need to find a planet around a distant star suitable for aerobraking and plot it's orbit very precisely for the period of hundreds of years.

Well, the discussion is about going to a habitable planet, so that would give at least one with a suitable atmosphere. And yes, you'd need to know it's orbit very precisely. But I'm not sure where you get the idea that would take hundreds of years.

 

[Shpaget]

Um, are you saying gravity assists can't be used to slow a spacecraft? If so, you may want to brush up on your orbital mechanics. The links I gave MeteorWayne yesterday could be a good place to start.

I was saying it's not easy, not that it is physics forbid it.
Let me repeat myself "Aerobraking is pretty sensitive maneuver. You fly to high - you don't accomplish anything, or even get more speed. You fly too low, you burn up".

you'd need to know it's orbit very precisely. But I'm not sure where you get the idea that would take hundreds of years.

You misunderstood me. I didn't mean it would take hundreds of years to plot the course but you would need to plot it for the next couple of hundred of years, since that kind of trip, even to the nearest stars, would take that long, if not tens of thousands of years.

 

[duluthdave]

I was saying it's not easy, not that it is physics forbid it.
Let me repeat myself "Aerobraking is pretty sensitive maneuver. You fly to high - you don't accomplish anything, or even get more speed. You fly too low, you burn up".

You're right, aerobraking is a sensitive maneuver. It was a poor choice of words on my part to call it easy. When talking about something like travelling to an extrasolar planet, there really isn't any step in the process that should be called easy. My apologies for misunderstanding you about plotting the planet's orbit. I should have known that's what you meant.

 

[BossFan]

I think it would be awesome to find out what's it like, but on the other hand.....

 

[brandbll]

I would selfishly be interested in what we could learn about that planet in my lifetime. So I would want to see money spent on bigger and better instruments to study it from afar rather than on missions that I would never see the results of.

I'd have to agree with centsworth. Studying the planet from afar is our best bet right off the bat anyways. I'd hope we would immediately begin on Hubble Telescope on steroids. And when i say Hubble Telescope on steroids, i mean chalk full of them. I'd say we should build a telescope and place it in whatever orbit we have to and soley focus it on said planet, maybe let it work on finding others but 99% of it's focus should be on that planet. If it helped to put this thing in Mars orbit then do that. We are a long ways away from even worrying about getting to this place, so we might as well study this planet until we can get there.

 

[EarthlingX]

Kepler is loose, and busy :
Kepler continues to collect science data

If anyone wants to start placing bets, here is a short list of the nearest stars :
http://en.wikipedia.org/wiki/List_of_nearest_stars

and a picture from An Atlas of The Universe:

to get a better picture :roll: ...

There is a star, Ross 248, rushing toward us with 80 km/s, it's still at comfy 10 light years away, and well, no real worry for the next 30 000 years or so, when it gets to about 3 ly distance.

How long would it take to get there ?
You might get some answers here:
Relativity Calculator

 

[pyoko]

Leave it alone and work on physics and science to see if FTL is possible. If it were a matter of "saving the human race", trying to get to the planet with current technology is still moot. Space stations etc would make much more sense.

P.S. The ducks are restless.

 

[High_Evolutionary]

While it would be one of the greatest discoveries in the history of makind, I think there is really only one acceptable answer to your question. The planet must be left alone. Humans have a planet already, but we haven't been too responsible with ours till recently. I don't think it would be right for humans to play any sort of role in the evolution of another world. That is their chance to live. We have too many issues of our own to start worrying about how to destroy the next planet.

It may not have do with playing a role in the evolution of another world. Imagine this, your starship and it's crew has just ended it's long mission(depending on the tech when launched)and is at the end of it's abilility to nourish it's crew. Risking starvation or some other life ending scenario(use our imaginations)survival of the crew would most likely mean relocating to the planet surface for food, materials etc. So need for one's own survival will always out way the possibile tainting of an evolution process on this new found planet(moon).

 

[JeffreyNYA]

I think for those saying that interstellar travel is unlikely are not having faith in the development of technology, or the business of space travel. 100 years ago, our only methods of travel were by slow boats and horse-drawn buggies. Yes, there were new technologies such as planes and cars, but there was not a large amount of money spent on such projects which is a mirror of where we are now, albeit on a larger scale.

Likewise, we haven't spent much money, time, or resources on traveling in our local system. All the efforts have been up to cheap governments, which hasn't spurred strong growth in the industry. Although its something far more for the space business side of things, I think that we'll see incredible growth in space-based industries over the next 100 years if governments allow it. With such developments will come ways of traveling faster. On May 20th and 21st, Charles Lindbergh took ~33 hours to cross the ocean in a risky flight. That trip cut the amount of time down by weeks. Likewise, in 60 years, we could then travel the ocean in passenger planes in under 10hrs thanks to the development of commercial crafts

Now one here has lost faith in our technology and what we can do now or in the future. But the comparison you made is a bit off. To compare interstellar space travel and colonization to sailboats or even airplanes is a bit off. We may be more accurate to say that were are at the learning how to use a stick as a tool stage of interstellar colonization.

That being said. In all honesty we maybe 1 or 2 major technological discoveries away from being able to realistically design such a mission. But no one knows when the next Einstein will come along with such a discovery. It may be tomorrow or it may be the year 2632. We just have no idea.

 

[Gravity_Ray]

If we were to find an extrasolar planet that was habitable, let's say within a couple hundred light years away, what would our next steps be? Tell us your vision of how events would unfold.

Would we attempt to send an unmanned mission there? It would take at the least a few hundred to thousands of years to get any results back, and then what would we do, the usual soil samples, spectrum readings, etc...? 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? Is an interstellar mission, either manned or unmanned, just so far fetched that we would never attempt it?

I think the word 'habitable' is the problem for me. Something that is habitable for a silicon based life will be very different from habitable for a carbon based life. But let’s just say habitable in a sense of a goldilocks distance from its sun were water is wet and available. Well that will be a game changer in my opinion. It will change the way we humans look at ourselves and our place in the universe. Maybe for the better, and maybe for the worse. The rest with the generational ships and FTL is fun to think about but wont impact what is going on. But I think it will give us an idea of how often it’s possible for habitable planets (for us anyway) to exist in the universe. If habitable then denotes is there life there and the question of 'are we alone in the universe' will shock our psyche to a point that will change us for sure.

 

[JeffreyNYA]

If we were to find an extrasolar planet that was habitable, let's say within a couple hundred light years away, what would our next steps be? Tell us your vision of how events would unfold.

Would we attempt to send an unmanned mission there? It would take at the least a few hundred to thousands of years to get any results back, and then what would we do, the usual soil samples, spectrum readings, etc...? 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? Is an interstellar mission, either manned or unmanned, just so far fetched that we would never attempt it?

I think the word 'habitable' is the problem for me. Something that is habitable for a silicon based life will be very different from habitable for a carbon based life. But let’s just say habitable in a sense of a goldilocks distance from its sun were water is wet and available. Well that will be a game changer in my opinion. It will change the way we humans look at ourselves and our place in the universe. Maybe for the better, and maybe for the worse. The rest with the generational ships and FTL is fun to think about but wont impact what is going on. But I think it will give us an idea of how often it’s possible for habitable planets (for us anyway) to exist in the universe. If habitable then denotes is there life there and the question of 'are we alone in the universe' will shock our psyche to a point that will change us for sure.

Unless ET shows up in a ship on the lawn of the white house, I doubt any shocking of the phyche will happen. Frankly I think we are to desensitized with all the TV and Sci-Fi shows and so many other things. Finding a fossil or bacteria on another planet would be 2 to 3 days in the news and it would be done for mainstream people. Sure you will have the highly religious people that may good goofy about it and of course scientist will be excited. But as far as it making a serious dent in how fast space is explored or even colonized is a long shot.

In order to get off earth and colonize we need a few things to things to happen. First we need the drive from everyone. That drive is not there and will not be there for sometime. We will need a amazing discovery of some kind. Underground lakes on Mars teaming with life may do it. But still may not be enough to excite the general population. I threat to earth that is verifiable by all would surly get things moving in some direction. Nothing motivates like the survival instinct. And actual single from an alien source that can be translated into something we can understand and prove that it can only be from a intelligent source, but of course it would need to be right in our back yard or it will be out of the news in no time.

I would love nothing more than to see the spread of humans throughout and the advances of technology that will be needed. It would be a great time to be alive. But it will not happen in this generation I am guessing and probably not in the few to come. Maybe my daughter of 3 will see something like this by the time she hits retirement. I can only hope. Maybe we should focus on serious life extension.

 

[EarthlingX]

There is a possibility of planets around the nearest stars:
Nearest star's wobbles could reveal Earth's twin

Another Earth may be orbiting the star next door, and we could detect its presence within a few years, a new study argues. A telescope trained permanently on Alpha Centauri should be able to pick up the slight stellar wobbles induced by a small, rocky, Earth-like planet.

"If our understanding of terrestrial planet formation is at all correct, then there should definitely be terrestrial planets orbiting both members of the Alpha Centauri binary pair," team member Greg Laughlin of UCSC told New Scientist.

What's more, any such planets might boast the conditions thought to be necessary to support life. In the team's simulations of planet formation around the smaller star, Alpha Centauri B, an Earth-like world often coalesced in or near the star's habitable zone, where liquid water could exist on the planet's surface.

Not all astronomers are convinced by the simulations that Alpha Centauri should host terrestrial planets. "I tend to be sceptical of planet-formation models," says Sara Seager of MIT in Cambridge, US, who did not take part in the study.

But Seager is impressed with the second part of the paper, demonstrating that these planets should be detectable. "It is tremendously exciting that we can search for an Earth cousin in a habitable zone of a nearby star with current technology," she told New Scientist.

More about it:
What alien worlds orbit our nearest star?
and a link to the paper:
Planetesimal Accretion in Binary Systems: Could Planets Form Around Alpha Centauri B ?
ABSTRACT

Stellar perturbations affect planet-formation in binary systems. Recent studies show that the planet- formation stage of mutual accretion of km-sized planetesimals is most sensitive to binary effects. In this paper, the condition for planetesimal accretion is investigated around  CenB, which is believed to be an ideal candidate for detection of an Earth-like planet in or near its habitable zone(0.5-0.9 AU).
A simplified scaling method is developed to estimate the accretion timescale of the planetesimals embedded in a protoplanetary disk. Twenty-four cases with different binary inclinations(iB=0, 0.1o 1.0o, and 10o), gas densities(0.3,1,and 3 times of the Minimum Mass of Solar Nebula, MMSN hereafter), and with and without gas depletion, are simulated. We find: (1) re-phasing of planetesimals orbits is independent of gas depletion in  CenB, and it is significantly reached at 1 − 2 AU, leading to accretion-favorable conditions after the first  105 yrs, (2)the planetesimal collision timescale at 1-2 AU is estimated as: TB col  (1 + 100iB) × 103 yrs, where 0 < iB < 10o, (3)disks with gas densities of 0.3-1.0 MMSN and inclinations of 1o-10o with respect to the binary orbit, are found to be the favorable conditions in which planetesimals are likely to survive and grow up to planetary embryos, (4)even for the accretion-favorable conditions, accretion is significantly less efficient as compared to the single-star case, and the time taken by accretion of km-sized planetesimals into planetary embryos or cores would be at least several times of TB col, which is probably longer than the timescale of gas depletion in such a close binary system. In other words, our results suggest that formation of Earth-like planets through accretion of km-sized planetesimals is possible in  CenB, while formation of gaseous giant planets is not favorable.

From the conclusions:

In summary, although planetesimal accretion in CenB is significantly less efficient and slowed-down as
compared to single star systems, it is still possible if gas density is 0.3-1.0 MMSN and binary inclination is
1o < iB < 10o. These accretion favorable conditions, in fact, are typical values for initial gas density(Andrews &
Williams 2005) and binary inclination(Hale 1994, Jensen et al. 2004, Monin et al. 2004, 2006) from current obser-
vations. Our results support recent work by Guedes et al. (2008), which has shown Earth-mass planets can be
formed near the habitable zone(0.5-0.9 AU) of  CenB if the disk is initially composed of lunar-mass planetary-
embryos. The possible accretion zone shown in this paper is roughly between 1-2 AU, which matches well with
their planet formation zone(0.5-2.0 AU, as shown in figures 1 and 2 of Guedes et al. 2008). In addition,
at the time of writing this paper, we note a promising result from Payne et al. (2009) that Earth-like planes
can also form in the habitable zone of  CenB-like bi-nary systems through outward migration from the inner
accretion-unperturbered zone(within  0.7 AU). Therefore, by combining these studies(Guedes et al. 2008;
Payne et al. 2009) and our simulations, it is quite possible that a habitable Earth-like planet may be hidden
around  CenB.