Looking for Life in Light 140
Gearoid_Murphy writes "Earth-like planets around distant stars may be too far away to be reached by spacecraft but scientists could still investigate whether they harbour life.
Telescope technologies are being developed that will probe the very faint light from these objects for tell-tale signs of biology.
These are the same "life markers" known to be present in light reflected off the Earth - so-called "earthshine"."
Earthshine? Pah. (Score:5, Funny)
Re:Earthshine? Pah. (Score:2)
Re:Earthshine? Pah. (Score:1)
Re:Earthshine? Pah. (Score:1)
Me.
Although Unitrode will probably come in and squash that theory. :-)
Re:Earthshine? Pah. (Score:2, Funny)
I apologize. Sir.
I just realized that maybe you were interested in a excachange of cash for my "slashpot" userid.
Now oridinarilry, I'd turn you down Iraq style. But. Since I'm an unemployed tech worker who
has only been receiving head hunter calls from god damn indian fucks that don't event speak a
word of fucking english....
I'll be happy to sell you my stoner pun slashdot ID that goes all the way back to the beginning baby.
Let the bidding begin here.
Richest hacker gets her.
post your bids belo
Re:Earthshine? Pah. (Score:1, Offtopic)
I was just wondering because your name was so perfect and your UID so low.
No offense meant.
P.S. We'll both get modded down for this exchange, especially so early in the thread; but, whatever, we're drunk.
good times.
Re:Earthshine? Pah. (Score:2)
All I have is some tall boys of mickeys.
Re:Earthshine? Pah. (Score:2, Insightful)
Re:Earthshine? Pah. (Score:2)
Well, $2 after the last two Mickeys.
Re:Earthshine? Pah. (Score:2)
Low UID implies being a certain age. After a while you get tired of just getting pissed on cheap stuff. Once you develop a taste for liquor (or wine or good beer) you begin to realize that a $40 bottle of scotch can be more bang for the buck than cheap macro-brew if you are looking for overall enjoyment rather than just getting drunk.
I am somewhere in between: I thoroughly enjoy my 15yr bottles of The Glenlivet and The Macallan (not so much a fan of Glenfi
Comment removed (Score:5, Funny)
By the sound of it, they will be using optics (Score:4, Interesting)
Telescope technologies are being developed that will probe the very faint light from these objects for tell-tale signs of biology.
I am guessing that they are talking about optical observations, since it appears to be an extra-atmospheric telescope they are designing. However, at those distances, how can they discern the difference between the shine from a planet and the light given off by the star(s) near the planet? I would think that we observe the earthshine from small enough distances that we can see it in spite of the Sun. I am curious how this would work for distant bodies.
Re:By the sound of it, they will be using optics (Score:3, Insightful)
PS: funny part is, if they see our earthshine from the same distance, we humans wouldn't even exist. Talk about being stealthy :)
Seeing the past (Score:1)
Re:Seeing the past (Score:3, Funny)
Oh, I come here for the witty conversation.
Re:Seeing the past (Score:1)
As to his legendary (miraculous even) efficiency in catering arrangements and the question of whether he was a threat to the vinicultural industry, that's a different matter.
Re:Seeing the past (Score:1)
Not necessarily a threat. Actually, there was a marketing opportunity there, if the competition'd had enough sense to see it:
“Pick up some skins of Sea of Galilee® today. Our wine was never water!”
Re:Seeing the past (Score:2)
Re:By the sound of it, they will be using optics (Score:3, Insightful)
Seriously though, it seems to me that we always have this idiotic need to find ORGANIC life. Perhaps it might not be light emitting or light modifying. Perhaps they're not even "corporeal" or light necessitating. Perhaps they'd find Pluto's cold more hospitable than the wet juicy nature of our own ball of mud. Everyone always thinks in their own paradigm. Why not think outside the box that someone always dema
Re:By the sound of it, they will be using optics (Score:1)
Unless it's a hyperintelligent shade of blue, that is.
Re:By the sound of it, they will be using optics (Score:1)
Re:By the sound of it, they will be using optics (Score:3, Insightful)
This is not just a case of assuming everything has to be like us. The reason we look for organic life is the same reason we're made out of carbon and the same reason carbon (organic) chemistry is an entire subject separate from inorganic (non-carbon) chemistry -- carbon is an amazingly versatile element, totally unlike anything else. Sure, it's possible there might be life made of something else, in the same sense
Carbon Life (Score:2)
As an aside, your signature brought to mind the high school I went to. Some silly idea about "self-directed" learning, which actually just meant that the school only had to pay its staff to mark papers and yell at kids who brought slurpees to the study hall, rather than actually teaching anything. The graduation rate was about 20%, most of who
Off topic, but (Score:3, Insightful)
Strange, since it seems to me that its mostly an American thing... our children are lazier than hell. And public school teachers are coerced into standardizing a shitty education, instead of making it engaging, interesting, and possibly controversial (as in the case of history, politics, language, physics? I once had a physics professor who began class by explaining that explosions are really fast burns, and, in fact, that flour, as
Re:Off topic, but (Score:2)
That's not so much "more free time" as kicking kids' asses and making them work in the time they have. And that I totally agree with. The whole idea of "unschooling" is the ultimate expression of laziness. They don't want kids to be challenged, they just want them to do whatever the hell they want so the parents don't have to be parents and be involved.
Re:By the sound of it, they will be using optics (Score:2)
what, like corporations? run for the hills... it's life Jim, but not as we know it...
Re:By the sound of it, they will be using optics (Score:2)
Re:By the sound of it, they will be using optics (Score:1)
Re:By the sound of it, they will be using optics (Score:2)
And wouldn't it be hilarious if we did find alien life forms, and they treated us as idiots on account of our theories of evolution being totally at odds with their metaphysical religious convictions about the origins of life?
There are more things in heaven and earth, Horatio, than are dreamt of in your philosophy.
Re:By the sound of it, they will be using optics (Score:2)
Actually, you bring up an interesting point: Why should the Bible describe everything in the universe? What if it only describes things that are relevant to the main subject--the relationship between humanity and God?
Re:By the sound of it, they will be using optics (Score:2)
Some people, sure.
But do you really think it's "going overboard" when the believers come up with a reasonable explanation for why the Bible doesn't include descriptions of aliens?
Also, why bring the issue up at all? It's not like anybody besides you was talking about the religious angle in the first place. So why the gratuitous jabs?
Re:By the sound of it, they will be using optics (Score:2)
I don't get it.
1903 Called (Score:2)
Re:By the sound of it, they will be using optics (Score:4, Informative)
I haven't studied the specifics, but when I hear about similar ideas, irt usually goes something along the lines of starting by just looking at the star. Based on the spectrum, the star has so much oxygen, so much hydrogen, etc. Then, calculate when the planet passes in front of the star. Then, see how the starlight changes. If there is a spike in the apparent amount of hydrogen indicated by the spectrum of the starlight whenever the planet passes in front, then the planet probably has a lot of hydrogen, and so forth.
Re:By the sound of it, they will be using optics (Score:3, Interesting)
First off, if the planet is partially obscuring the star, most of what we are seeing is the dark side of the planet. So, all we should see is a reduction in the total amount of light from the star, but not much change in the apparent percentage of constituent molecules of the star. Some of the light we are seeing is the star beaming through the planet's atmosphere, which might change the apparent spectrum signature
Re:By the sound of it, they will be using optics (Score:3, Interesting)
When the planet is in front of the star, the total luminosity will increase, but it the star's light that gets beamed through the atmosphere of the planet will show absorption lines of the planet's elements. So, conveniently, that kind of works as a check -- when we see both the planet and the star, we will see extra bands in the spectrum corresponding to the planet's makeup, and when the planet is in front of the star, we should see absorption in those bands. Finally, when the
Re:By the sound of it, they will be using optics (Score:2)
If we would find earth-like reflection one could surmise that this planet would be a good place to look
Re:By the sound of it, they will be using optics (Score:1)
My guess is that they will be looking for chemical signatures in the atmosphere of the planet, via absorption lines. That can tell you, indirectly, about the presence of life. For instance, one of the chemical indicators on the Earth is the presence of methane in an atmosphere containing significant amounts of oxygen. Ordinarily, methane "likes" to combine with oxygen to form water vapor and carbon dioxide. The reaction can go the other way, but it does so much slower. As a result, in a "dead" atmosph
By making some big assumptions (Score:4, Informative)
If you do an spectral anaysis of IR etc reflecting off the earth, you'll get certain signatures for trees, grasslands, sea, coulds cities etc. So if observers see the similar patterns they will assume that the distant planets will have a similar biology, cities,...
Of course these are all just assumptions. The scientists hope to make discoveries which they can publish for fame and glory. Luckily for them, they'll probably be dead long before they can be verified by eyeball technology.
Re:By making some big assumptions (Score:2)
If the atmosphere composition is unstable then there must be a mechanism maintaining that stability. One of those is life. The trick will be trying to exclude geological processes.
None of thes
Re:By the sound of it, they will be using optics (Score:2)
There has to be life out there somewhere. But the distances are just so vast that without FTL transport we'll never get to meet them.
Re:By the sound of it, they will be using optics (Score:2)
Yeah, and here I was hoping (from the ambiguous headline) that researchers were actually searching for intelligence patterns in photons.
Fairly recently (a couple months ago; no longer in my posting history), someone on here and I were discussing converting ourselves into energy. If we could determine a way to make interacting photons, then we could beam ourselves at a patch of empty sky and "live forever", since photons do not expe
Re:By the sound of it, they will be using optics (Score:1)
Essentially the same arguments as regular seti, but using optical frequencies as the target "waterhole". This new recent effort is labelled optical-seti, or oseti for short.
Instead of looking for narrowband radio broadcasts, we look for pulses of light that have an extremely short duration. With this kind of communication, you can use a typical earth technology laser in the megawatt output ran
Re:By the sound of it, they will be using optics (Score:3, Informative)
Technically, we use polarization-encoding to split a light beam into two right-angle polarized beams, run them through different color filters, and then recombine them back into a single beam. We then use a fast polarization analyzer to look at each beam independently at speeds close
Re:By the sound of it, they will be using optics (Score:4, Informative)
The project is called Terrestrial Planet Finder (TPF) [wikipedia.org]. I don't know a ton about the details, but I know some guys who were working on it. One of the technologies being investigated (I'm not sure how well this relates to TFA, but it addresses your question directly) is an optical trick called a coronograph [wikipedia.org]. The basic game is to design fancy Fourier optics that put more emphasis on small variations in off-center light. Like I said, not sure of the details, but it actually kind of works.
Details about the optics of TPF (Score:2)
"The basic idea is that under Fourier optics, a wavefront with electric field E that hits a lens with focal length f will produce the Fourier transform of that field E at a distance f from the lens. This location is called the image plane. The location of the lens is called the pupil plane, and the idea is that if you block part of the light at the pupil plane (say with a piece of material in a particular shape,
Re:By the sound of it, they will be using optics (Score:3, Informative)
Re:By the sound of it, they will be using optics (Score:1)
Only their's is higher resolution and we find out their looking at us in our homes in the tub or on the John!
Intergalatic Perverts!
What more reason do you need to build a fleet and wipe them out!!!@!
Only problem is they'd see it and build one of their own to destroy it and then come here to subjugate us for their pe
Pardon me... (Score:4, Funny)
If nothing else, it'll show up on the earth shine and indicate we're inhabited. On the other hand, they probably already know that...
Re:Pardon me... (Score:2)
Re:Pardon me... (Score:1)
Re:Pardon me... (Score:2)
That's not to say that light-free life couldn't evolve independently, ultimately getting it's energy geothermally. Aren't there bacteria that have been found sustaining on geothermal
Earthshine (Score:4, Funny)
Re:Earthshine (Score:1)
...but not life. (Score:1, Informative)
"'This gives you some information on habitability,' said Wesley Traub, chief scientist on the US space agency's (Nasa) Navigator Program..."
Wrong. Only life makes oxygen atmospheres (Score:2)
P.S. Anyone else first learn about this stuff through S
Re:Wrong. Only life makes oxygen atmospheres (Score:2)
Seems primitive. (Score:5, Informative)
How will this help? Radio telescopes can look at the absorbtion spectrum of the planet for the tell-tale lines of water, methane, oxygen (both O2 and O3), and other markers of highly reactive chemicals - especially when they will react with each other. When you have an atmosphere that is chemically violently unstable (as is the case on Earth), it must be being maintained by some process.
That's the first clue, but only the first. The second clue is that "dead" planets will be in equilibrium with their surroundings, but "living" planets will always be in opposition. (Organisms will always create a dynamic equilibrium that suits them, so must always counter any and all natural phenomena that would push the system away from that preferred state. Simple negative feedback.)
Simple radio telescopes can do all this now, no new optical technology need be developed, and no assumptions about the type of life need be made. (All the above assumes is that life can never be inert and that any specific organism cannot function equally under all potential conditions. That's broad enough, although there will probably be exceptions even then.)
The Km array proposed (and the hectare array already built) are just a huge stack of ordinary satellite TV dishes. This could be done by anyone at any time. A mile array would give you 2.5x2.5 pixels ast 100 lightyears - enough to discern if weather patterns exist, though not enough for any long-range forecasts.
Re:Seems primitive. (Score:2)
Nice to meet you.
Re:Seems primitive. (Score:2)
Re:Seems primitive. (Score:1)
Imagine a Beowulf cluster of satellite TV dishes....
Re:Seems primitive. (Resolution v. Lightgathering) (Score:4, Interesting)
So an array of a bunch of teeny TV sattelite dishes wont have as much surface area as a dish a kilometer wide. So yes we could resolve a planet, but it would have to be bright enough to be seen.
Re:Seems primitive. (Resolution v. Lightgathering) (Score:1)
Re:Seems primitive. (Resolution v. Lightgathering) (Score:2)
Well then they would be bright enough to be seen, since there would be much more light gathered
Re:Seems primitive. (Resolution v. Lightgathering) (Score:4, Informative)
In practice, the Square Kilometer Array [skatelescope.org] is intended to have a collecting area close to the physical area of one million square meters - requiring almost no gaps to exist between dishes.
My first calculation would be for dishes with a wider gap, which would give you much greater flexibility on pointing the damn thing, as you can't see through the other dishes. Personally, I consider this to be a much superior design, even though it would cost on the collecting area. Unfortunately, they are the ones being paid, even if I am the one who is right...
By way of comparison, Jodrell Bank Radio Telescope [man.ac.uk] is a paltry 76 meters across, for a total collecting area of 4560 square meters, and that's one of the largest single steerable telescopes out there.
I'm going to guess that a collecting area about nine times that of Jodrell Bank, combined with a resolving ability that is, well, astronomical, you would get a very respectable image of Earth-like planets around other stars. If we accept the SKA group's claims, then you've a collecting area 250 times that of Jodrell Bank.
I first heard the 100LY=1 pixel resolution with SKA from Jill Tarter, head of the SETI Institute [seti.org] at a talk she gave at NASA Langley. From crunching the numbers, I can see nothing that could seriously contradict the claim. Even if you assume my model is the more reasonable implementation, the complete MERLIN [merlin.ac.uk] network that has been detecting jovian planets for some time has only a fraction of that collecting area - probably something like a quarter or a fifth. (Aside from Jodrell Bank, the next-largest radio telescope in the UK is a paltry 32 meters across.)
If we go with SKA's claims, then we're talking about collecting possibly hundreds of times the total radiation, which would definitely be enough to spot even the tiniest of worlds - provided it had some characteristic reflected in the radio spectrum.
(It's also worth bearing in mind that networks such as MERLIN, which are hundreds of kilometers across, are set up for VLBI - very long baseline interferometry. That's fine, when you're talking about gas clouds or stars, but is probably none-too-hot for spotting very fast pulsars or rocky inner planets. On the other hand, a kilometer would let you use regular interferometry, which means these things would show up quite nicely.)
There are three drawbacks to all of this, and I'm surprised none of the posters has commented on them (so far). First, interferometry requires very exact timing of all the delays in the system, or it won't work. Let's go with the SKA estimate and say the dishes are 1 meter apart. Your clock must count an integral number of ticks for every meter the signal travels from the dishes, even after allowing for the natural variation in the data lines varying the speed of the signal. This is some astonishingly serious timekeeping.
The second problem is to keep the signal noise-free. Easy, for a giant single steerable dish - you plunk it in the middle of nowhere and surround it with a huge Faraday cage that only obscures the horizon. When you've a few tens of thousands - or millions - of very small dishes, the problem isn't so easy. The terrestrial radio sources will be far harder to screen out - not just
Re:Seems primitive. (Score:2)
Hmmm. (Thinking) (Score:2)
Your resolving power, however, should be pretty damn amazing at 20 miles diameter. Ok, so what's wanted here is something nice and noisy, where your ability to isolate a region of sky and/or track an object would be of value.
You coul
Why telescopes? (Score:4, Funny)
Re:Why telescopes? (Score:1)
Dead or alive it is or was life, When was the last time you saw a corpse of a bug in the dark?
Besides looking for a bug zapper is a better way of finding out theirs life out their than looking in the dark for life looking for light to zap itself on anyway.
If you ask me it's killing two bugs with one light to go about it this way.
Ok enough with the bug zapper enaligies i got mor
News? (Score:3, Informative)
Re:News? (Score:1)
So maybe it's a slow news day, but maybe some scientists are engaging in public relations.
Re:News? (Score:2)
Re:News? (Score:1)
What's the point? (Score:3, Insightful)
A. attempt to detect life on a planet that is too far away for us to determine if we are correct any time in our lives
B. using a method that has an unknown accuracy
C. despite the fact that we don't even have an idea of the *order of magnitude* of the chances of life out there
What's the point?
Re:What's the point? (Score:4, Insightful)
Re:What's the point? (Score:1)
Re:What's the point? (Score:1)
That's a two pointer!
Re:What's the point? (Score:1)
Greetings Earthlings (Score:3, Funny)
Is communication from Commander Znetab of Zygort Interstellar Death Fleet:
Radio frequency wavefront from your planet is passing through our fleet causing much physical distress. Auditory awfulness of "Wayne Newton" voice recordings we are considering weapon of mass destruction. Is reducing all fleet radio operators to disembodied protoplasmic goo. If not stopping immediately, destruction of your insignificant planet will be accomplished. You have been warned!
Is ending communication.
Isn't this called SETI? (Score:2, Informative)
Re:Isn't this called SETI? (Score:1)
SETI intends to find intelligent life, whereas astrobiologists, although happy to find ANY life, are mostly looking for unintelligent life.
Re:Isn't this called SETI? (Score:1)
Their's plenty of unintelligent life around here as it is without
them trying to find more on other planets.
Re:Isn't this called SETI? (Score:4, Insightful)
TFA is talking about finding planets that have *any* life that can significantly change the atmosphere of a planet. Earth could have been discovered like this probably at least since we've had O2 (regular oxygen gas) and O3 (ozone) in our atmosphere, starting from about 2 billion years (*) ago. Contrast this time with the time we've used radio communications, less than 100 years.
(*) reference:
http://www.globalchange.umich.edu/globalchange1/c
If someone were looking at Earth... (Score:1)
Too far? (Score:2)
It will just take a while to get there. Weapon systems are robust. Of course, we don't know when they detected us so we don't know how much time we have to set up defenses.
Ob. Debbie Boone (Score:1)
You give me hope
To carry on
You light up my days
and fill my nights with song
http://www.romantic-lyrics.com/ly6.shtml [romantic-lyrics.com]
I'm all for it! (Score:1)
Re:Queue xenophobic reactions (Score:1)
Re:Queue xenophobic reactions (Score:1)
Re:Queue xenophobic reactions (Score:1)
Re:This has profound implications (Score:1)
Re:This has profound implications (Score:1)
Re:This has profound implications (Score:1)
Ok, I'll bite (Score:1)
Re:Ok, I'll bite (Score:1)
Re:leaving scientology aside... (Score:3, Interesting)
It seems likely that in the next couple of decades a lot of our brodacast signals on the lower frequencies that can escape the ionosphere will have been turned off in favour of internet based tv/radio, microwave signals from satellites directed at earth and spread-spectrum technologies that are indisti
Re:leaving scientology aside... (Score:1)
Passively in the mechanisms you described, by what I hear commonly referred to as "information leak" in SETI discussion circles.
Active communication however is the classification of those civilizations that will actively broadcast in the hopes of reaching people.
You may ask why would a civilization expend so much money and energy in such a persuit, and this is a valid point ss well. Th
Re:We don't cherish life on EARTH... (Score:2, Insightful)
Very true.
Things that don't work on the small scale, will never work on a large scale. Can't make your family h
Re:Waste of Money (Score:1)
At its current state, the institute is funded entirely from private donations by those who have hope that the discovery of ETI would bring wonderous advances to our society.
If you think its a worthwhile persuit, which I think it is, donate. http://www.seti.org/ [seti.org]
If not, then don't donate. Unlike NASA programs, this one carries your democratic approval of support.
Re:Waste of Money (Score:2)
I could not disagree more.
I think this project is enormously more important than anything else NASA could possibly do in the next decade with that same amount of money. More important than scratching around on the moon, more important than figuring out how to get to Mars, *certainly* more important than futzing around on the ISS.
If this project could determine unequivicably once and for all that there is definitely life on other planets, that would be one of the m