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Looking For Earth-Like Exoplanets

Soulskill posted more than 5 years ago | from the dust-motes-orbiting-a-yottawatt-light-bulb dept.

Space 73

Discover Magazine is running a story detailing the search for planets like Earth orbiting other stars. While we've been able to locate a few "super earths" so far, none of them really compare in size or the potential for habitability with our own world. Fortunately, advances in data analysis and new space-based telescopes — such as Kepler, the James Webb Space Telescope, and the already-launched CoRoT (PDF) — have some astronomers predicting we'll find such an exoplanet by 2010, and a habitable one by 2012. Earth-based telescopes are also in the hunt, though the article notes, "even if a habitable Earth-like world is found first from the ground, it will most likely take a space observatory to search for the chemical signals that tell us what we really want to know: Is anything living out there? If the planet is one that can be observed transiting, it just might be possible to provide a hint of an answer in the next few years."

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73 comments

nice idea... (1)

Adolf Hitroll (562418) | more than 5 years ago | (#25338833)

But even without a planet we could send all of these friggin' Amuritan into space... good riddance!

Re:nice idea... (1)

Gerafix (1028986) | more than 5 years ago | (#25338877)

You mean Amarantin? They already have (had) spaceflight capabilities. Unfortunately for them they activated the Wolf Device near the neutron star close to their homeworld and got their civilization destroyed...

Re:nice idea... (0)

Anonymous Coward | more than 5 years ago | (#25338899)

Heh, thought about the same thing when reading GP's post :)

Alastair Reynolds FTW!

Re:nice idea... (1)

ZarathustraDK (1291688) | more than 5 years ago | (#25339417)

You mean Amarantin?

You mean American?

Re:nice idea... (1)

ratinox (582104) | more than 5 years ago | (#25340877)

No, he means Amarantin, and anyway, ultimately it's the Greenfly that we have to worry about ;/

Welcome friends! (0)

Anonymous Coward | more than 5 years ago | (#25338875)

I for one, will welcome our new earth-like alien overlords.

Wow... An article about planets that isn't... (4, Insightful)

Devout_IPUite (1284636) | more than 5 years ago | (#25338909)

Obsessed with the fact we haven't observed something we can't yet detect... This must be some sort of mis-post.

Re:Wow... An article about planets that isn't... (2, Insightful)

sortius_nod (1080919) | more than 5 years ago | (#25339029)

This just seems like old news to me... I remember reading a post about 3 or 4 months ago about us finding "earth like" planets but outside the bounds of what we understand can substantiate life. Maybe it was on new scientist, but I swear I've seen almost the same tag line on a slashdot article.

This just reads like Discovery documentary - a lot of "meaningful"* questions, no real substance.

*by meaningful I mean trying to come across as meaningful, but either rhetorical or just plain obvious.

Re:Wow... An article about planets that isn't... (2, Interesting)

Original Replica (908688) | more than 5 years ago | (#25340515)

us finding "earth like" planets but outside the bounds of what we understand can substantiate life.

There definitely needs to be some refinement of what qualifies as "earth like". I would consider Mars to be a the extreme outer edge of "earth like". Some of the more extreme bacteria and lichen from earth might be able to survive, maybe. I wonder what the parameters for "earth like" should be. Maybe: 0.4G to 1.4G gravity range, a temperature range between 180K and 335K, atmospheric pressure of 1kPa to 110kPa. What else would need to be included for a meaningful "earth like" definition?

Re:Wow... An article about planets that isn't... (3, Funny)

John Hasler (414242) | more than 5 years ago | (#25340975)

Why such a low upper limit on gravity? Lichen don't care what they weigh.

Re:Wow... An article about planets that isn't... (2, Interesting)

Original Replica (908688) | more than 5 years ago | (#25342415)

I thinking about your question I realized that my conception of "Earth like" carries an implication that the planet could be usefully colonized by humans. I think much beyond 1.2G it would be terribly difficult to get anything done. I could probably get up out of a chair and walk across a room at 2G but I certainly couldn't build anything substantial. Yes I know I first qualified "earth like" with lichen habitability but would there be any point in seeding a 3G planet with lichen, knowing that humans could never go there? The more I think about what "earth like" implies to me, the stricter my definition becomes. However to say a planet is like Earth, inspires a lot of excitement and hope, so it needs to used sparingly and only when appropriate.

Re:Wow... An article about planets that isn't... (1)

Devout_IPUite (1284636) | more than 5 years ago | (#25511371)

There are people who weigh 300 pounds and they function. I'm sure I could learn to function at that weight too.

Re:Wow... An article about planets that isn't... (3, Interesting)

arminw (717974) | more than 5 years ago | (#25341291)

... I wonder what the parameters for "earth like" should be....

Do you mean by that the conditions necessary to develop intelligent life, such as the SETI project is looking for? Assuming that the laws of physics are the same everywhere in the universe, the molecular binding energies for living things would dictate the temperature range. For practical purposes this would mean the temperature range in which water remains liquid at least some of the time. This would require a stable orbit around a star the output of which does not fluctuate too much. Orbital mechanics show that such a star must not have a neighbor closer than about 3.8 ly. By that specification alone, about one half of all stars in the universe are disqualified from having such a planet because they are too close to each other.

Really big stars are also disqualified because their output varies too much in order for intelligent life to develop or exist. If a star is too small, a potential planet must be placed too close in order to get enough heat. Any such close in planets all are unlikely to freely rotate, thereby having one side always facing the star. That would mean the dark side would get extremely cold. Assuming there was a viable atmosphere, it would circulate violently between the day and night side.

Living processes involve large complex molecular structures which only the element carbon allows. Therefore, any physical life must be based on the chemistry involving carbon. Of course, there may be nonphysical life, but that is not what we are talking about here.

Re:Wow... An article about planets that isn't... (0)

Anonymous Coward | more than 5 years ago | (#25341637)

Life can be based off of any atom with a valence higher than 2. Just because we haven't observed non-carbon-based life in action doesn't mean that it doesn't exist.

[citation needed] (1)

SL Baur (19540) | more than 5 years ago | (#25342585)

Life can be based off of any atom with a valence higher than 2.

References, please. Silicon, valence 4, same as Carbon is a natural possibility, but I've never read anything seriously suggesting another base element.

Re:Wow... An article about planets that isn't... (1)

Mal-2 (675116) | more than 5 years ago | (#25341925)

Still, why is it assumed that life has to develop on a planet by current definitions? We're looking at Enceladus as a possible habitable body in our own solar system, and all the gas giant planets have satellites aplenty. Why should another solar system have "naked" gas giants? I think it is more reasonable to assume that gas giants gather satellites, and that some of them will be fairly large.

Also, we have a situation here that we have yet to find elsewhere -- the stability of a "double planet" system. We have yet to find anything like our own Earth-Moon system in this or any other solar system. Life has benefited greatly from the stabilizing influence of a large, close satellite and also by the tides it creates, but this appears to be a fairly uncommon situation. A satellite stabilized by proximity to a gas giant is much more likely by comparison. We should be looking for gas giants in the habitable zone or slightly outside it (tidal heating and residual heat from the planet can make up the shortfall), and when we have the technology to look for them we should scour such systems for habitable satellites, not just planets.

I'm not advocating abandoning the search for earthlike exoplanets, only saying that such worlds are only a small fraction of the potentially habitable bodies out there.

Mal-2

Re:Wow... An article about planets that isn't... (1)

John Hasler (414242) | more than 5 years ago | (#25342337)

> Still, why is it assumed that life has to develop on a planet by current definitions?

I don't believe it is so assumed, but planets are easier to find than satellites of gas giants.

Re:Wow... An article about planets that isn't... (1)

arminw (717974) | more than 5 years ago | (#25343461)

....why is it assumed that life has to develop on a planet by current definitions...

It does not really matter what you call the environment where life may exist or develop. It could be a spaceship such as Hollywood's death Star. The point is, that the environmental requirements for physical life are quite narrow. Even a single cell is far more complicated than a large city. On the atomic and molecular level, the process of life is extremely complicated and intricate. More complex systems generally have stricter environmental requirements than simpler ones.

Isn't it interesting, to contemplate the large amount of human effort that is expended to answer the question: "Are we alone in this great big huge universe?" The hoped for and yet also feared answer to this question apparently is a resounding "no"! We do not like the idea of being "home alone", but also fear that some alien life form coming here might have us for lunch. How is this question related to the questions of origin and purpose? Is the the fact that all humans are incurably religious also related to these questions?

If someone did come and visit us, someone from far beyond our own galaxy, how would such a living being convince us that he/she/it really did come here from a distant universe, or even more far out, some other universe? Would a few Star Trek like demonstrations of advanced technology do the trick to convince us? Is sufficiently advanced technology truly indistinguishable from the supernatural? How would such a visit have played out centuries ago, before our own modern technological age began? Is it possible or even probable that such a visit has already taken place in the history of humanity?

Re:Wow... An article about planets that isn't... (1)

RockDoctor (15477) | more than 5 years ago | (#25393109)

Is the the fact that all humans are incurably religious also related to these questions?

ALL humans are INCURABLY religious? That's a big claim. For a start I know of at least one human who's been cured of the religious delusions inserted into his head in childhood. So that disposes of your "all" claim, and your incurable claim simultaneously.
But more realistically, surely most humans have been and will be cured of their religious delusions in the few seconds between their heart stopping and their brain succumbing to hypoxia.

Re:Wow... An article about planets that isn't... (1)

arminw (717974) | more than 5 years ago | (#25401255)

....For a start I know of at least one human who's been cured of the religious delusions....

I assume you are mean yourself here? Well I got news for you! Everybody, even atheists have a world view, life philosophy if you will. You BELIEVE far more things than you KNOW.

(...will be cured of their religious delusions in the few seconds between their heart stopping and their brain succumbing to hypoxia...)

That shows your faith right there! You don't KNOW that this is so, but simply BELIEVE that as part of your world view. You have not experienced death yet, so how CAN you so confidently make such a claim? You may believe that is true and that's OK. According to the most widely distributed book on the planet, the Holy Bible, we read in Hebrews 9:27 -- And as it is appointed to men once to die, but after this the judgment"

Even you have no argument about the first part of that sentence. as surely as death will come to you, just as surely you will stand in judgment before your Maker.

Even if you confine "religion" to a belief in the supernatural, you still cannot tell sufficiently advanced technology from the miraculous. If you claim you can tell, would you share with me and maybe other readers how you accomplish that feat? There is not now and there has never been *any* culture or civilization that does NOT give religion a central place in their lives.

Re:Wow... An article about planets that isn't... (1)

RockDoctor (15477) | more than 5 years ago | (#25392893)

Really big stars are also disqualified because their output varies too much in order for intelligent life to develop or exist.

I agree that stability of energy output (on a moderate timescale - thousands of years or longer) is a desirable. But really big stars have a more serious limitation - duration.
The evidence from fossils is that it took between a half billion and a billion years for the first lifeforms to evolve on Earth ; developing intelligent life took another several billions, though that might conceivably be shortened.
A big star with a lifetime of less than a couple of billion years isn't a likely candidate for intelligent life.
Wikipedia gives this [wikipedia.org] relationship for stellar mass versus lifetime :
Main sequence lifetime (Tms) ~= 10^10 * [M(sol)/M(star)]^2.5
So for a couple of billion year lifetime, (2*10^9), I make that stars of less than 1.9 times the mass of the sun. We can safely ignore the non-main sequence part of a star's lifetime ; things are going to be getting pretty difficult for any developing intelligences, and they've a few millennia to develop interstellar travel, or at least interplanetary travel.

Re:Wow... An article about planets that isn't... (1)

thrillseeker (518224) | more than 5 years ago | (#25339235)

when you can send me, Yeoman Rand, and a six pack of beer, give me a call ...

Take some time (1, Informative)

Anonymous Coward | more than 5 years ago | (#25339015)

To travel to such a planet will take a ship of multiple generations. We haven't even remotely touched the Oort cloud with the 30 years (quite fast) traveling Voyager 1.
So ... take your time. People just don't grasp how far this really is.

Re:Take some time (0)

Anonymous Coward | more than 5 years ago | (#25339137)

To give you an idea: Voyager 1 is 15 lighthours away, after 30 years of traveling, and close to breakdown. Now imagine 15 lightyears (this is where Gliese 876 is).

Super Earths??? (3, Funny)

owlnation (858981) | more than 5 years ago | (#25339045)

...we've discovered the planet Krypton?

Re:Super Earths??? (1)

heptapod (243146) | more than 5 years ago | (#25339163)

Super Earths last all summer long.

The future is 2012 (3, Funny)

MR.Mic (937158) | more than 5 years ago | (#25339095)

From what I understand from all the latest the tech news on /., we are going to have a super-awesome sci-fi future world in 2012.

Re:The future is 2012 (2, Funny)

pushing-robot (1037830) | more than 5 years ago | (#25339285)

Yes. It will be like a whole new world.

Re:The future is 2012 (1)

Gerafix (1028986) | more than 5 years ago | (#25339305)

I think it is going to be a Brave New World.

The psychological limit of awesomeness, really (2, Insightful)

Moraelin (679338) | more than 5 years ago | (#25341379)

Well, it seems to me that it's just a matter of perspective. We don't really see absolute values, we see deltas, and the baseline is the present.

Think of, say, dollars. Just saying "in year X you'll earn Y dollars a month" is only saying anything as a comparison. Whether it's in absolute dollar values, or "how much can I buy with it", the comparison only says much compared to your current lot in life. A 1960 standard of living would be luxury for someone from 1912 (think even just having antibiotics for a change), but would be a step back for you from 2008.

Or think of CPU MHz / Gigaflops / Gigabytes / whatever computer metric. "You'll have a computer with a 4 MHz CPU and 48 kilobytes RAM and a CRT" would have sounded like an awesome supercomputer in 1960 (they eventually landed on the moon with a weaker computer than that!) Have it in your home, all yours? Man, that would have sounded so unbelievably cool. Just think of what you'd do with all that raw computer power. But few people would even consider it a usable computer nowadays in 2008.

And I will postulate a _hypothesis_ that there must be a psychological "X times better than today" threshold, which drives those predictions. I don't know what that X might be. But there's a point where the "meh, who cares" factor of, say, predicting something 10% better next month, starts being the "that's awesome" of, say, predicting something 10 times better in 5 years.

E.g., think back when Moore's Law still worked that way, and you had, say, a 100 MHz Pentium. Predicting that you'll have 133 MHz in a few months, is uninteresting. Predicting you'll have a whole 1 GHz of CPU power in 5 years, now that would have gotten your attention.

So depending on which curve you are, and assuming it looks like infinite exponential growth ahead, the future (worth predicting) will always be Y years ahead. As in, "in Y years it'll be X times better than today." If you have the same X you aim for, the future will always be Y years ahead.

But... (-1, Offtopic)

Anonymous Coward | more than 5 years ago | (#25339111)

Will these planets have oil? If so how do we extract it and ship it back here?

Re:But... (3, Funny)

name*censored* (884880) | more than 5 years ago | (#25339471)

Increase the rotational speed of the planet so much that the centripetal force counteracts gravity. Then, with giant nets, catch the oil as it floats up from the surface. Then, pump it through a hose and squirt it back to a giant funnel sitting outside earth. I mean, our only other alternative is NON-fossil based fuels, and that's just CRAZY!

Without Earth-Class Embezzlers +1, PatRIOTic (-1, Offtopic)

Anonymous Coward | more than 5 years ago | (#25339223)

I just hope these exoplanets don't have criminals [whitehouse.org] who can defraud U.S. $ 1 trillion from the U.S. Treasury.

Regards,
Kilgore Trout

Ummm... (1)

Vu1turEMaN (1270774) | more than 5 years ago | (#25339227)

Who said that the planets have to be Earth-like to find life on them? I would rather find life on a planet that would have a hard time breathing in out atmosphere than one that could take it over for their parking garage.

Re:Ummm... (1)

Gavagai80 (1275204) | more than 5 years ago | (#25339309)

Most aliens prefer parking garages that take fewer years to reach.

Chance of choosing a suitable star system (1)

Man Eating Duck (534479) | more than 5 years ago | (#25339569)

If we observe a random star sustem which seems like it could have earthlike planets, it seems to me that observing a transition is unlikely.

Suppose that earth was the only planet revolving around the sun; the chance of observing a transition from some large distance is approximately:

(diameter of sun / diameter of earth) 109

(2 au / diameter of earth) 73686 earth diameters.

The chance of the orbit being oriented correctly seems to be 0.00147986287 [google.com] .

I suppose you could increase the chances by choosing larger stars, but it is still a very long shot. From reading TA it seems that they are indeed hunting for "eclipses" from a planet passing directly in from of it's star, causing dips in a star's luminosity.

Which of my assumptions are wrong? :)

Re:Chance of choosing a suitable star system (1)

Man Eating Duck (534479) | more than 5 years ago | (#25339655)

Ah, dammit. Did'nt read the article properly...
It seems they will be observing up to 12 000 systems at once:

The spacecraft's 27-centimeter (10.6-inch) telescope monitors up to 12,000 sunlike stars at once. Getting a big sample is crucial because only one in a hundred of those stars that do have planets will be oriented so that the passage of the planet in front of the star is visible from Earth.

Those scientists think of everything. Still, they say that one in a hundred will be orientated properly, but according to my calculations above it will still be about only one in about 675 [google.com] .
Even if one accounts for more planets per star their orbits will probably be oriented in approximately the same plane.
Again, this is probably still wrong, but I'd be grateful if someone could explain why.

Re:Chance of choosing a suitable star system (0)

Anonymous Coward | more than 5 years ago | (#25341031)

There's a strong tendency for planetary discs to form on a plane very close to the galactic plane. Some will be eccentric, many in fact, but there is a skew towards finding solar systems with an ecliptic similar in orientation to ours.

Re:Chance of choosing a suitable star system (1)

Man Eating Duck (534479) | more than 5 years ago | (#25343935)

Of course. Shame on me for not picking up that one. Thanks!

Re:Chance of choosing a suitable star system (1)

ceoyoyo (59147) | more than 5 years ago | (#25340361)

The looking at one star part. Fortunately there are LOTS of stars to look at.

High resolution images possible in near future? (1)

mattr (78516) | more than 5 years ago | (#25339801)

It will be nice when we find an oxygen planet but still we will only know it as a small blue dot I expect. Anybody have ideas for what kind of telescope could actually take detailed pictures - perhaps enough to even see cities - of exoplanets?

Say 50 light years. I wonder is it possible to run an interferometer across spacecraft far apart in the solar system? The separation is I suppose a matter of trigonometry and optics. Then the question of what do we need to do it and when?

Re:High resolution images possible in near future? (4, Interesting)

ceoyoyo (59147) | more than 5 years ago | (#25340691)

It's harder than that. I assume by "see" you mean two-dimensional visible or near-visible light images. To produce images like that you have to be able to move each telescope in your interferometer (or have lots of them), in two dimensions. The big radio interferometers put the radio telescopes on train tracks. Some proposals for space interferometers put one on each end of a tether, spin them, then winch them closer and farther apart to trace out a spiral.

The other problem with crazy long baseline interferometry is that you need to transmit the received signal (including phase) between the individual elements. For radio that's not too bad because you can actually detect and record the phase, for low enough frequencies. For optical it's much harder.

Plus you have the problem that interferometers have great resolution but poor light gathering capability. They can't see things that aren't bright.

A back of the envelope calculation (which might be wrong) shows that a 50 km city at 50 light years would be about 2 x 10^-5 miliarcseconds. To get that kind of resolving power in the middle of the visible spectrum you'd need a telescope about 6000 kilometres across. That's not too insane. You might be able to pull it off with an array of a hundred or so reasonably sized space telescopes all orbiting around a L point somewhere. If you could collect enough light, and distinguish between the city light, the non-city planetary light and the star, of course.

Re:High resolution images possible in near future? (1)

John Hasler (414242) | more than 5 years ago | (#25340945)

> It's harder than that. I assume by "see" you mean two-dimensional visible or
> near-visible light images. To produce images like that you have to be able to move each
> telescope in your interferometer (or have lots of them), in two dimensions.

You can produce useful "images" that are not free of ambiguity, though. For example, you might be able to show that features in a certain size range (i.e., continents or clouds) exist without being able to produce pictures of them.

> The other problem with crazy long baseline interferometry is that you need to transmit
> the received signal (including phase) between the individual elements. For radio that's
> not too bad because you can actually detect and record the phase, for low enough
> frequencies.

Radio frequency images are possible and useful.

Re:High resolution images possible in near future? (1)

ceoyoyo (59147) | more than 5 years ago | (#25340977)

Certainly, but the original poster wanted images of cities. 1D lines, though very useful, don't really catch the attention of people who want to see something like this [nasa.gov] .

Ditto with radio images. Extremely useful, but probably not what the poster was hoping for.

Re:High resolution images possible in near future? (0)

Anonymous Coward | more than 5 years ago | (#25341241)

What about something with a more limited resolution range ie,

this? [imageshack.us]

Same basic parameters apply obviously, but an image of something like this with just a few brown&green smudges of continents would be remarkable.

Re:High resolution images possible in near future? (1)

ceoyoyo (59147) | more than 5 years ago | (#25341325)

If you make a pixel 1000 km, which gives you about eight across the disk of an Earth size planet, you get a resolution of about 0.0004 mas, needing an aperture of about 300 km. With a nice desert you could potentially do that on the surface, although you might still want to build a space interferometer instead.

Re:High resolution images possible in near future? (1)

Mandrel (765308) | more than 5 years ago | (#25342679)

A back of the envelope calculation (which might be wrong) shows that a 50 km city at 50 light years would be about 2 x 10^-5 miliarcseconds. To get that kind of resolving power in the middle of the visible spectrum you'd need a telescope about 6000 kilometres across. That's not too insane.

Even with a telescope that's big enough and perfect enough to not be limited by diffraction or aberration, would there be so few photons that the required integration time would mean that it'd only be able to image detail on slowly-rotating planets?

Re:High resolution images possible in near future? (1)

ceoyoyo (59147) | more than 5 years ago | (#25342843)

It depends on how much light collecting area you have. That is the problem with interferometers, all right - they can have the resolving capability of a gigantic telescope, but they don't have the light collecting capability.

Still, you should be able to build some monstrous mirrors in space. The biggest problem with building gigantic telescopes on Earth is that gravity tries to warp them, so bigger mirrors have to be much stronger. If your 6000 km interferometer was composed of 100 m space telescopes, you'd probably have a decent shot at it.

Maybe someone with more time on their hands can figure out what the luminosity of a decent sized city is, and how big a light collecting area you'd need to detect it in a decent amount of integration time.

On the other hand, if you can figure out the rotation time of the planet, you can image it for as long as you want, taking breaks while the face you're interested in is facing away.

Re:High resolution images possible in near future? (1)

Mandrel (765308) | more than 5 years ago | (#25343169)

On the other hand, if you can figure out the rotation time of the planet, you can image it for as long as you want, taking breaks while the face you're interested in is facing away.

Ah, good point. You'd just have to take (exo-)daily samples.

Does either the inter-stellar atmosphere or gravity waves eventually impose resolution limits?

Re:High resolution images possible in near future? (1)

ceoyoyo (59147) | more than 5 years ago | (#25343251)

Probably. Over 50 light years unless you happen to pick a really bad direction you're probably okay trying to image a planet. I don't think gravity waves would be a problem. Unless you really took things to extremes.

Incidentally, optical interferometry gives you some immunity to blurring from the Earth's atmosphere too.

Re:High resolution images possible in near future? (1)

Mandrel (765308) | more than 5 years ago | (#25344315)

OK, thanks.

It looks like we could therefore use SETI to spread through the galaxy at near c:

  1. Build a massive array of spaced-based telescopes.
  2. Detect a civilisation.
  3. Communicate AI technology.
  4. If get reply, transmit scientist.
  5. Repeat.

If there's no suitable civilisation to leap through you'd have to shoot massive numbers of self-constructing nanotech AI particles in the desired direction, hoping that some impact solid bodies.

Re:High resolution images possible in near future? (1)

ceoyoyo (59147) | more than 5 years ago | (#25351299)

There's a novel, actually a series I think. Unfortunately I can't remember the title. But one day our civilization finds an alien artifact floating out at the gravitational focus of the sun. That's where the sun's gravity focuses light rays, like a giant lens. When we go out to find out what this thing is, it turns out it's a transporter. It dematerializes you and transmits you (and the speed of light, using the sun as a giant lens, to another star where you're rematerialized. Some aliens seeded these things throughout the galaxy as the ultimate mass transport system.

Re:High resolution images possible in near future? (1)

Mandrel (765308) | more than 5 years ago | (#25392069)

Thanks, I wasn't familiar with such solar focus points. It looks like they're about 14 times farther from the Sun than Pluto. That's one tough sentinel.

In terms of our present understanding of Physics, such a transporter's more in the fantasy realm. AI envoys are more realistic.

Because there is likely to be such a small gap between a civilisation able to receive radio signals from space, and one able to run a properly described AI sim, one wouldn't have to transmit any info about how to construct a simulator computer, only the mind itself.

Would we care if one was captured and "tortured"?

Re:High resolution images possible in near future? (1)

Mandrel (765308) | more than 5 years ago | (#25344363)

Whoops, that'd be c/2, unless the computer blueprint and the scientist binary were transmitted at the same time.

I'm trying to think of protocols that would assure the aliens that we did not have an evil intent, and to prevent empowering aliens who had evil intent.

Re:High resolution images possible in near future? (1)

mattr (78516) | more than 5 years ago | (#25344719)

Thank you *very* much for your hard work and excellent replies. Though of course visible light at even higher resolution than the Earth by night pic of the day, I wouldn't disparage radio or other spectra especially if they provide higher resolution.

Unfortunately I do not have enough technical background to understand interferometers well yet. If you can indeed store the phase information (interference pattern?) of each telescope for combining in what I think is called a nulling interferometer at a later point in time, then perhaps there is an easy solution. Out own planet is a spaceship and a ground based or orbital telescope could trace out quite a long distance in even a day, let alone a year.

Put it this way. that a new add-on to the Hubble Space Telescope could store wave information for 60 seconds. Maybe it is radio telescope with existing tools, maybe there is a wierd Bose-Einstein condensate or something else slowing down the light. The http://www.windows.ucar.edu/tour/link=/kids_space/earth_galore.html [slashdot.org] is 29.8 km/s, so if wave information can be stored for 1 minute then we could have a 1788 km baseline (well shorter since it's the chord). Or, perhaps just storing the information for 10 seconds would allow the telescope to take a 10 second exposure and then combine with the previous exposure, continuing this every 10 seconds for as long as desired.

Is the above concept physically possible or is there fatal misunderstanding in what is involved? If so then incremental advances in physical sciences / telecommunications may give us supertelescopes.

Re:High resolution images possible in near future? (1)

ceoyoyo (59147) | more than 5 years ago | (#25351431)

For interferometry you need two or more observations made at the same time, from different locations. You then arrange for those signals to interfere. Basically, optical interference is a Fourier transform, so you can then read off the Fourier coefficients by examining the interference pattern. You need to move your observing stations (or have more than two) in order to measure more than one Fourier coefficient. Once you've got enough, you can inverse Fourier transform to get your image.

With radio astronomy, due to some clever techniques, you can take the information from each observing station and record it, then compare them later. That's the magic of Very Long Baseline Interferometry. As far as I know, nobody has done that with anything higher frequency than radio. For higher frequencies you have to let the two signals interfere directly, which limits how far apart you can put your telescopes. It's a moderately ambitious high school science fair project to build a visible light interferometer with a separation of a few feet though.

The problem with taking a measurement now and another with the Earth on the other side of it's orbit is that you can't get the simultaneous measurements you need. If you put a satellite at that L-point though, you could definitely do it. There are some radio telescopes in orbit already that are being used in combination with ground stations to make VLBI arrays with effective apertures larger than the planet: http://www.gb.nrao.edu/ovlbi/OVLBI.html [nrao.edu]

Re:High resolution images possible in near future? (1)

adavies42 (746183) | more than 5 years ago | (#25349935)

Whatever happened to the idea of a gravity-based telescope? The lens formed by the Sun has a "focal sphere" starting about twenty times the orbital radius of Neptune out; I imagine if we sent it straight there instead of making it visit everything on the way, we could get a satellite there in a decade or two. What would its resolving power be?

Re:High resolution images possible in near future? (2, Interesting)

ceoyoyo (59147) | more than 5 years ago | (#25351553)

A telescope at the Sun's gravity focus.

http://www.centauri-dreams.org/?p=785 [centauri-dreams.org]
(the comments contain some interesting information as well.

The resolving power is a bit of slippery subject, because gravity microlensing doesn't work quite like a regular refractive lens. According the the comments, you can basically see anything, no matter how far away (subject to caveats when you start getting insanely far away) as if it were in close orbit around the sun. So the resolution you can obtain really depends on what kind of telescope you put out at the gravity focus. One of the commenters calculated that if we put Hubble out there we could see things about the size of Mercury, at ANY distance. The light collecting ability is also enormous.

There are some problems though. First, you have to get out there. Farther than anything we've ever sent. Also, 550 AU (about 20 Pluto distances) probably won't work, because then the light you're collecting has to skim the surface of the sun. Better would be to go out to about 1000 AU (about 1/200th of the way to Alpha Centauri) so that you're not trying to see through the thick parts of the sun's atmosphere.

Once you get there, you have to be able to accurately record smeared out images while staring into the sun.

Finally, you can really only look at one thing. If you want to look in a different direction, you have to move the probe a LONG way. These would probably be single purpose missions, which means you'd basically have to know exactly what you wanted to look at before you sent out the probe.

We use microlensing caused by other objects all the time though. There's even a project to look for extrasolar planets that happen to be revealed by microlensing events.

Any later and it would be hopeless (1, Redundant)

Khavanon (1253062) | more than 5 years ago | (#25339829)

Just in time for the end of the world. Now all we have to do is invent reversible cryostasis, terraforming, and a starship that could support a significant enough portion of the human population to allow for a decent level of diversity in reproduction and carry enough supplies to sustain them, and Holly, our ship's AI with an IQ of 6,000. Not that there'll be any money anywhere in the world by then...

Re:Any later and it would be hopeless (1)

John Hasler (414242) | more than 5 years ago | (#25340955)

> ...support a significant enough portion of the human population to allow for a decent
> level of diversity in reproduction...

Eggs and sperm can be frozen and revived. AI works.

Re:Any later and it would be hopeless (1)

phedre (1125345) | more than 5 years ago | (#25341691)

> ...support a significant enough portion of the human population to allow for a decent > level of diversity in reproduction...

Eggs and sperm can be frozen and revived. AI works.

Who exactly is going to revive the eggs&sperm? Even if the AI does it, you can't exactly just fertilize a bunch of eggs and hope for the best.

Re:Any later and it would be hopeless (1)

John Hasler (414242) | more than 5 years ago | (#25342369)

AI-> Artificial Insemination, not Artificial Intelligence. As to who is to revive it, the colonists. I just wanted to point out that the effective gene pool of a colony can be much larger than that provided by the colonists on the ship.

Re:Any later and it would be hopeless (1)

Khavanon (1253062) | more than 5 years ago | (#25343445)

But *I* want to live!

And Holly, the lovable, senile, bald AI exists?

Earthlike, Warp Speed, etc (0)

Anonymous Coward | more than 5 years ago | (#25340015)

I know that we are always looking for a "Earthlike" planet and hope that it "supports" life like ours, but it is time to question the laws of physics, math, and overall science truthfully.

I always want to comment on these stories, but feel that my ideas would be ridiculed, but I don't care today. What "we" know as "life" could be supported by an entirely different form of environment than we are.

If the laws of Biology are any indication that organisms can adapt to their environments, then who says that life can't start in a pool of methane? Perhaps a pool of liquid nitrogen? There maybe individuals that are supported entirely by no direct sunlight and pressure 100 times greater than our own.

Fact is we don't know if oxygen is dangerous to some other form of life, that we have yet to come into contact with.

Personally I don't ascribe that water supports every form of life out there. It isn't plausible that water exists every were (or hell anywere else, but earth, I don't buy ice on mars having water it could be so many other things other than H2O) in the universe.

Until we finally develop the technology to actually go to another world, we will never know what actually sustains other forms of life. Math and Science can't fully explain everything all the time, theories are consistantly tested and broken, math equations thrown out.

Re:Earthlike, Warp Speed, etc (1)

arminw (717974) | more than 5 years ago | (#25342249)

...If the laws of Biology are any indication...

Underlying the laws of biology are the laws of physics. In this case, specifically the electronic binding energies of atoms to each other. To have PHYSICAL life forms, requires complex molecular structures, such as proteins. One of the definitions of "life" is the ability to reproduce. This implies some way to record and pass on the structural and functional capabilities, such as DNA. We have evidence that the elements that exist here on Earth are also present in the distant reaches of the universe. It also appears that the basic laws of physics and chemistry are amazingly uniform throughout all of space we can observe.

Of all elements able to form the foundation for large complex molecules, none is better than carbon. Together with hydrogen, oxygen and nitrogen, carbon alone is able to meet the complexity requirement of living chemistry.

The next best is silicon, but its binding energies to other atoms is too high for really complex molecular assemblies. Therefore, the conditions for life, especially intelligent? life like ours could not be too different from what we know. This essentially means a temperature range where water can exist as a liquid. Life chemistry proceeds most effectively between 32 to 42 degrees C. It is no accident that the internal temperature of warm blooded creatures lies in this range.

Conclusion: If there is physical, as opposed to some sort of spirit or mind-life, such life is likely to be not very different in its basis than ours.

Re:Earthlike, Warp Speed, etc (1)

RockDoctor (15477) | more than 5 years ago | (#25393293)

Life chemistry proceeds most effectively between 32 to 42 degrees C. It is no accident that the internal temperature of warm blooded creatures lies in this range.

With the exception of the various extremophiles, which may be the closest remaining organisms to the last common ancestor. They're active up to the 60s, higher for some.

Wow pretty good article; are transits best method? (1)

wisebabo (638845) | more than 5 years ago | (#25340043)

Yes, I know that implies I read TFA. But it was pretty good, I thought it concisely explained that they'll be using transits to look for these exo-planets then hopefully use the Webb space telescope to get an idea of the planet's atmosphere by looking at the spectrum in the infra-red. (That's where Webb is designed to be most sensitive and that's where the star "only" outshines any orbiting earth-like planet by say 10,000:1).

My question is: So does that mean that transit detection has won out over looking for the doppler effect? I thought that there was some advance in making super stable laser "frequency combs" that allowed tiny amounts of stellar radial velocities (like centimeters/sec) to be detected not just the meters/sec that they can do now. This would allow earth-mass objects in earth-like orbits to be detected through stellar "wobbles".

It seems that the doppler detection method would have at least one major advantage, since you don't have to "stare" at the star for months/years on end the telescope doesn't have to be in (deep) space. That implies a really BIG telescope on earth could be used and could visit many targets per night. (On the other hand, having Kepler look at hundreds of thousands of targets simultaneously is pretty darn efficient, Also,observation of transits is not distance dependent). Anyway, maybe it'll be a good way to confirm detection; nothing better than two separate observations using completely different methods, instruments and technology.

You know of course that IF they find a whole bunch of earthlike planets with oxygenated atmospheres they'll be a real desire to try to get better images. Maybe this would be a good use for a REALLY BIG liquid mirror telescope on the far side of the moon! I'm wondering where would it have to be placed in order to cover the same region of the sky as Kepler? I'm wondering if such a telescope could detect any indications of a technological civilization, like fluorocarbons or radionucleotides. How about really big structures (like the great wall of china ;). Also I'm sure that S.E.T.I. will follow up on the list of "earthlike planets" with a targeted radio astronomy listening program. I'm wondering if a dish like Arecibo could detect regular broadcasts or radar that weren't specifically aimed at us over the distances these surveys will be taking place (10K parsecs?). Anyway, exciting things!

Re:Wow pretty good article; are transits best meth (1)

arminw (717974) | more than 5 years ago | (#25342329)

...You know of course that IF they find a whole bunch of earthlike planets...

That is a big IF. Over half of all known stars can never have an earth-like planet for the simple reason that half of all stars are too close to each other. To have a planet with a temperature range suitable for life, its orbit has to be very regular. Another star too close prevents such stable orbits. Other parameters such as the right elements in the proper proportions must also be right, as must be the rotation rate and gravity. The likelihood of all that coming together by sheer chance is exceedingly remote.

Re:Wow pretty good article; are transits best meth (1)

RockDoctor (15477) | more than 5 years ago | (#25393187)

My question is: So does that mean that transit detection has won out over looking for the doppler effect?

Why would they stop using one technique when a different technique is developed which attacks a different question from a different perspective with different constraints to the original technique?
More techniques will be developed for detecting and studying planets in orbit around other stars. But the current techniques will continue to be used until there is nothing more that can be wrung out of them. Which is not in the near future.
For a start, there's not a lot of high quality telescopes in the southern hemisphere, so that's a significant chunk of sky which is under-represented in surveys.

Shouldn't it be Mars-like exoplanets? (0)

Anonymous Coward | more than 5 years ago | (#25340305)

The subject kind of says it all. Any planets we find are likely to be as hospitable as mars, not oxygen rich atmospheres that we could just land on and start living. Not that it won't be cool, but mars-like seems more accurate.

one more eye (1)

drwho (4190) | more than 5 years ago | (#25340539)

..but we need to be like an insect with thousands of eyes, spaced far enough apart. These should be far enough from earth to be able to use interferometry or even triangulation to add data and knowledge about a particular object. It is only with such a system of such sensitivity, precision, and accuracy that we will have the confidence needed to send probes and manned craft beyond this solar system.

We are the bad guys in the sci-fi B movies (1)

viridari (1138635) | more than 5 years ago | (#25341375)

You know all of those movies about aliens from outer space that come to inhabit earth because they have burned out the resources on their own planets?

Yeah, well, we're the aliens.

I'm sure we'll feel justified in displacing whatever inferior species we find out there.

Finding habitual planets (0)

Anonymous Coward | more than 5 years ago | (#25350931)

It's easy and there are many out there availible. Just look for the green trail following the orbit of a planet. Red and blue trails are much harder to live on, though still possible.

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