From the University of Toronto:
Search for life on exoplanets more difficult than thought
A new study from the University of Toronto Scarborough suggests the search for life on planets outside our solar system may be more difficult than previously thought.
The study, authored by a team of international researchers led by UTSC Assistant Professor Hanno Rein from the Department of Physical and Environmental Science, finds the method used to detect biosignatures on such planets, known as exoplanets, can produce a false positive result.
The presence of multiple chemicals such as methane and oxygen in an exoplanet’s atmosphere is considered an example of a biosignature, or evidence of past or present life. Rein’s team discovered that a lifeless planet with a lifeless moon can mimic the same results as a planet with a biosignature.
“You wouldn’t be able to distinguish between them because they are so far away that you would see both in one spectrum,” says Rein.
The resolution needed to properly identify a genuine biosignature from a false positive would be impossible to obtain even with telescopes available in the foreseeable future, says Rein.
“A telescope would need to be unrealistically large, something one hundred metres in size and it would have to be built in space,” he says. “This telescope does not exist, and there are no plans to build one any time soon.”
Current methods can estimate the size and temperature of an exoplanet planet in order to determine whether liquid water could exist on the planet’s surface, believed to be one of the criteria for a planet hosting the right conditions for life.
While many researchers use modeling to imagine the atmosphere of these planets, they still aren’t able to make conclusive observations, says Rein. “We can’t get an idea of what the atmosphere is actually like, not with the methods we have at our disposal.”
There are 1,774 confirmed exoplanets known to exist, but there could be more than 100 billion planets in the Milky Way Galaxy alone. Despite the results, Rein is optimistic the search for life on planets outside our own is possible if done the right way.
“We should make sure we are looking at the right objects,” he says, adding that the search for life within our solar system should remain a priority. He points to the recent discovery of a liquid ocean on Enceladus, one of Saturn’s larger moons, as a prime example.
“As for exoplanets we want to broaden the search and study planets around stars that are cooler and fainter than our own Sun. One example is the recently discovered planet Kepler-186f, which is orbiting an M-dwarf star,” says Rein.
Rein says locating a planet in a habitable zone while being able to obtain a good resolution to model the atmosphere will help determine what’s on the planet.
“There are plenty of reasons to be optimistic that we will find hints of extraterrestrial life within the next few decades, just maybe not on an Earth-like planet around a Sun-like star.”
http://www.pnas.org/content/early/2014/04/23/1401816111
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I think it’s simpler than that: ET is hiding in the deep ocean.
Whether it be CAGW or ET, when someone says ‘its worse than we thought’ what does the statement tell us? It tells us that the person making the statement was wrong previously. That new evidence shows that they were wrong.
And what does experience teach us about people that were wrong in the past? That they are more likely than not to be wrong in the present and wrong in the future. That their track record shows that you cannot rely on them to be correct.
So, when someone tells me it ‘its worse than we thought’, it tells me that based on their past track record they are likely to be wrong.
Most likely there is no ET in the visible universe at all (see the Fermi paradox). The only open question is whether the Great Filter is located in our past or future. In the latter case our prospects are bleak indeed.
However, I bet the actual bottleneck is at Robin Hanson‘s point 2. “Reproductive something (e.g. RNA)”, that is, abiogenesis.
Anyway, it is exciting to know we are at the verge of true experimental theology, is it not?
God is the lord of hosts so know problem with alien life out their the host of heaven.
beng says:
April 30, 2014 at 6:22 am
We already have radar-resistant aircraft. Any purported aliens could completely evade radar. If they were detected, it would be by their choice….
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every liter of sea water has thousands if not millions of bacteria and viruses. and there are a whole lot of liters in the oceans. these viruses and bacteria routinely exchange genetic material, creating new life forms. a similar process takes place above and below the oceans.
so far, these life forms have evaded detection by radar. they cross our borders with impunity. for all we know they arrived on earth, frozen in comets from a long distant past, and thawed out on arrival. they may still be arriving today. when you look in the mirror, you may be looking at ET.
when we talk about life we think of plants and animals. instead, consider that life is simply a self-replicating chemical process. once it gets going, it will spread. we are the evidence.
Jim Clarke ,
“If you believe God is the creator of life on Earth and no other place, then why did he go through the trouble of creating an additional 40,000,000,000,000,000,000,000 stars and a likely similar number of planets besides our sun and this planet Earth?”
But which was the easy one? 40,000,000,000,000,000,000,000 stars working according to simple and predictable equations – or us having this discussion?
Jorgen F. Ask him.
As an engineer the best methodology to find something out is “ask someone that knows the answer”.
“””””…..Phil. says:
April 30, 2014 at 4:42 am
george e. smith says:
April 29, 2014 at 11:49 pm
There’s not a shred of evidence, that intelligence enhances survival. It’s just another gimmick Mother nature is giving a shot to prove itself.
So the dinosaurs survived for 140 million years, just by being big and mean and ugly.
But the little ones with feathers outlasted the big mean ones. :-)……”””””
Well If I’m not mistaken, so did the horseshoe crabs !
Come to think of it; there are far more species on earth that look like lobsters, than there are, that look like humans; and they look back to see what’s chasing them.
The far more intelligent humans, look forward where they are going; but in their infinite wisdom, they grant right of way, to the car that is driving through the parking lot (forward), with a driver who can see where (s)he is going; rather than the driver who is trying to back hiser small fuel efficient, compact car out of a parking space between two big SUVs, that have semi opaque windows.
Moreover, all cars are required to have white backup SIGNALLING lights (they are able to ILLUMINATE nothing, in daylight hours); but nobody, is required to heed those signals, coming from a vehicle whose driver can see nothing coming at himer from the side !
Yes intelligence has great survival properties.
Safeprayer! The name of his game is not asking – let alone demanding 🙂
Israel Anderson (@israelanderson) says:
April 29, 2014 at 4:24 pm
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The problem with war is that it takes too sides to make peace.
When one side wants war, the other side has two choices, submission or fight back.
What we actually learn from all this space exploration of what lies say 500 light years away always seems a bit of a mystery to this simple minded Englishman…when the search for a Boeing 777 in the Indian Ocean reveals that we know almost nothing about the beds of all the oceans which cover three quarters of our own world. There must be enormous riches down there which just might be more easily recoverable than from somewhere which would take us hundreds of years to get there…if we could travel at the speed of light……
The article as quoted makes no sense at all. It says that a lifeless planet, having no chemical signatures of life, might also have a lifeless moon, but because we see them both in a single blur, we detect the chemical signature of life. Huh? No, 0 + 0 does not equal 1, even under Common Core.
As for telescopes to distinguish the two objects, there are already plans for a thirty meter telescope. The two ten meter Keck telescopes have been combined into an interferometer with a much larger effective resolution. In any case, astronomers manage to tease out a lot of information from spectrometry and photometry without being able to resolve the planet from the star at all, never mind separating the planet from a hypothetical moon.
“Neil says:
April 29, 2014 at 6:47 pm
This is precisely why I do not believe evolution. The whole reason for looking for et is to prove evolution.”
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There’s no need to “prove” evolution, since it is an observable fact.
“And before anyone jumps down my throat, please explain, without using faith based statements, or we think, believe, feel, the theory is, etc., explain how life started here to begin with, oh and without saying God started the whole lot rolling then stood back.”
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“We” have observed evolutionary processes operating all the time around us, & the results of past evolution. No need for faith, as is the case with your denial of reality.
You make the common mistake of conflating evolution, the origin of new life forms & sometimes preservation of older ones, with abiogenesis, the origin of life.
“Oh and if anyone comes up with the “you must be a flat earther” your comment will be ignored.”
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You are figuratively a flat earther, since you’re denying demonstrable reality. You’re just afraid to look & think for yourself. If for a moment you chose to do so instead of basing your conclusions upon “belief” you’d soon see that evolutionary processes like natural selection, to cite but one, cannot help but operate. They result from reproduction, one of the traits of life.
You claim to have studied & understood evolutionary theory, but clearly that’s not the case.
Jorgen F: For methodology check Isaiah 58v4ff
milodonharlani: you have observed the amazing ability of genetics to solve problems and to provide adaptability through varying existing variables. Genetics as a problem solving mechanism is mathematically optimal at searching an n-variate solution space for possible, though not optimal solutions.
The paradox that genetics being an optimal process does not find optimal solutions. In other words, we can conclude that Genetics itself is designed to do what you observe.
Berényi Péter says:
April 30, 2014 at 6:59 am
IMO abiogenesis isn’t a bottleneck. It may happen all the time & indeed could be inevitable in our universe. If, as accumulating research suggests, it could routinely occur in ice or on some other common substrate as a catalyst for complex, self-organizing organic chemistry, then microbial life might be common in this & other galaxies. Or not. Which is why looking for ET life is IMO an endeavor worth pursuing.
What could however be vanishing rare even if microbes aren’t is complex, multicellular life, let alone large organisms capable of rational thought, like many vertebrate & some invertebrate animals on earth.
An emerging school of thought on life as an example of a class of self-organizing physical phenomena:
http://www.simonsfoundation.org/quanta/20140122-a-new-physics-theory-of-life/
safeprayer says:
April 30, 2014 at 10:09 am
Genetics isn’t designed; it is enabled by chemistry. You could argue that we live in a universe the rules of which allow the organic chemistry behind genetics. But there are other, competing explanations for that fact besides the God hypothesis, which I grant cannot be ruled out in the present state of scientific knowledge.
“A telescope would need to be unrealistically large, something one hundred metres in size and it would have to be built in space”
Long baseline interferometry?
“The study, authored by a team of international researchers led by UTSC Assistant Professor Hanno Rein from the Department of Physical and Environmental Science, finds the method used to detect biosignatures on such planets, known as exoplanets, can produce a false positive result.”
But he proceeds to make the case for “locating a planet in a habitable zone while being able to obtain a good resolution to model the atmosphere will help determine what’s on the planet.”
What is a “model of an atmosphere”? Is this the most powerful tool ever discovered, whose results lay the foundation of the great new era in science? Or is a “model of an atmosphere” a simple scientific diagram which the reader is never allowed to see, and can never utilize because of the prohibitive costs of super computers?
“Rein says locating a planet in a habitable zone while being able to obtain a good resolution to model the atmosphere will help determine what’s on the planet.”
Why don’t they just use the GCMs? Anything that can be used by progressive scientists to wager billions of livelihoods and economies on must be certain enough to declare the existence ET.
What is extraterrestrial is the lip service these experts give to the possibility of a “false positive.” It is a very exciting sighting!
george e. smith says:
April 29, 2014 at 4:42 pm
…
So far as I know, life on earth began some 4.5 billion years ago, and I’ve seen no evidence of it ever beginning again anywhere in the universe, including on earth.
Somewhat later probably. The planet itself is only about 4.5 BY old as best geology can estimate. As regards evidence of extraterrestrial life, that relies largely on what we consider “evidence.” There are reasonable grounds for arguing that Viking may well have detected life of some form on Mars in one test, while the other tests that accompanied the Viking lander might well have yielded false negatives. Part of the reason for the false negatives would be our assumptions regarding what “life” must consist of and how its chemistry must work. Even the possibly-positive test made some assumptions about the nature of life that are not fully justifiable. As far as the present discussion goes, it is reasonable to lean toward a Type II error, but once we start sending samples home, the weight of caution should lean the other way because the evidence is equivocal rather than firmly negative. In addition, we also have the curious bodies – possible fossils – found in ALH 84001. The results again are equivocal rather than negative. My reading of the debate suggests that the greater weight of support may lean toward genuine fossils rather than a previously unknown mineral habit.
The question comes down to just how “unique” earth is. Since the discovery of nearly 2,000 extrasolar planets, that uniqueness has diminished from “extremely unique” to more than likely “near average.” One of the factors that helps to locate extrasolar planets is that they are either large enough to cause a measurable eccentricity in stellar motion or a detectable occultation when the planet passes between earth and the star. Also, the faster the planet orbits its star, the easier it is to observe a periodicity. More importantly, while occulations will help identify smaller planets whose orbital plane cross the line of sight between the star and earth, the majority of possible orbital planes in the galaxy do not cross that small cone.
We are then required to consider just how likely “life” is, and while it may seem self evident, the available answers are not by any means definitive. Bones might be right: “It’s life Jim, but not as we know it.”
milodonharlani: classic inability to follow basic logic… Genetics is OPTIMAL, yet all known processes, in particular genetics being the best known example, produce non-optimal solutions, apart from ACTUAL DESIGN the product of intelligence.
I will try another one, this logic is a little harder, try and follow along:
ALL processes in the universe result in a net increase in the entropy of the universe, a reduction of the useful energy in the universe. A loose re-statement of what we commonly call the 2nd Law of thermodynamics. Therefore logically there can be no process within the universe that is responsible or explains the starting point of the universe. We can infer that the ultimate source of the universe is a source of energy in an of itself, it is literally all “power” “full”.
and one more: All physical things (matter or energy) are the result of a transformation from something else, therefore whatever came first is not physical.
“””””…..Zeke says:
April 30, 2014 at 11:02 am
“The study, authored by a team of international researchers led by UTSC Assistant Professor Hanno Rein from the Department of Physical and Environmental Science, finds the method used to detect biosignatures on such planets, known as exoplanets, can produce a false positive result.”
But he proceeds to make the case for “locating a planet in a habitable zone while being able to obtain a good resolution to model the atmosphere will help determine what’s on the planet.”…..”””””
So what is a “habitable zone” ??
On any given northern midsummer day, the surface Temperature could be anywhere between +60 deg C, or maybe even + 90 deg . C, and -94 deg. C. Now maybe humans don’t want to live near those extremes, but they certainly do live where the extremes could be between +/- 55 deg. C. No not in the same place.
And we know of things living in places hotter than the boiling point of water, at sea level.
So there is no Goldilocks zone. Life developed on earth under conditions where it could. And it didn’t ask a bunch of post doc fellows, for permission to do so.
Any alien life form (et), that developed, would do so wherever is could. And of course, whatever those conditions were, they would consider to be “the” Goldilocks zone; well they likely wouldn’t even know about Goldilocks and her zones.
Who says DNA, is the only functional path to a system of self replicating (and changing) entities ??
If life develops so easily, why is it that all evidence suggests that on our Goldilocks planet it has only developed once?
Even the most extreme of extremophiles we find can be easily fit into this sequence of life.
Duster says:
April 30, 2014 at 11:48 am
There is definite evidence of life on earth from 3.5 billion years ago, & hints of it from 3.8 Ba. This is so soon after our planet cooled sufficiently to harbor life that it has led some to advocate panspermia, the seeding of earth by microbial spacefarers or at least complex constituents of living things.
Your discussion of Mars is good. However the odds of finding life or evidence of its prior existence on Mars suffered a blow last year, due to rover Curiosity’s inability to detect methane, previously thought to exist in the Martian atmosphere:
http://www.extremetech.com/extreme/167067-nasas-curiosity-detects-no-methane-on-mars-ruling-out-life-on-mars
The now presumably false detection of methane in Mars’ air shows how hard it would be to assess the components of exoplanetary atmospheres.
WetMan says:
April 30, 2014 at 12:02 pm
Twice or thrice can’t be ruled out. The lipid membranes of archaea are different enough from those of bacteria that they may have developed separately, while sharing similar internal metabolic & replicatory chemistry. Not sure that counts as two separate origination events, but having the same processes inside different packaging arguably does. Eukaryote membranes could also have arisen independently, but probably not. In any case, early eukaryotes formed symbiotic relationships with bacteria, the ancestors of our mitochondria & possibly other plastids, plus plants’ chloroplasts.
But more importantly, once life was established here, new colonization or abiogenesis would have been harder for the late-comers.