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New Paper Explores The Prospects For Life Around M-Class Stars (arxiv.org)
Long-time Slashdot reader RockDoctor summarizes the significance of a new paper describing "The Habitability of Planets Orbiting M-Dwarf Stars":
Although Star Trek had a minor smattering of "M-class planets" -- a designation that tells one nothing of substance -- "M-class star" is a much more meaningful designation of color, with two size classes, the dwarfs and the red giants... an M-dwarf of 1/10 the mass of the Sun will burn for around 1000 times the time that the Sun does... Therefore, if humanity ever meets an alien species, the odds of them coming from an M-dwarf [system] are already high. If humanity ever meets an alien species that has been around a billion years longer than us and has technology we can't even dream of, then the odds of it coming from an M-dwarf are overwhelmingly high.
This new paper offers "a comprehensive picture of the current knowledge of M-dwarf planet occurrence and habitability," pointing out that most of these stars are apparently orbited by planets packed closely together, with "a paucity of Jupiter-mass planets and the presence of multiple rocky planets." And more importantly, roughly a third of those rocky planets are orbiting in a "habitable zone" -- far enough away from their stars to support liquid water.
This new paper offers "a comprehensive picture of the current knowledge of M-dwarf planet occurrence and habitability," pointing out that most of these stars are apparently orbited by planets packed closely together, with "a paucity of Jupiter-mass planets and the presence of multiple rocky planets." And more importantly, roughly a third of those rocky planets are orbiting in a "habitable zone" -- far enough away from their stars to support liquid water.
I can't help but think that an M-dwarf system would have a much narrower orbital Goldilocks zone, which would *reduce* the odds of having a habitable planet in that orbital belt.
Another problem is that the habitable zone is so close to an M-type star that most of the planets there are probably tidally locked. The sunward side would be hot, while the night side would be frigid, unless there are some possible atmospheric circulation mechanisms that I'm not aware of.
"Although Star Trek had a minor smattering of "M-class planets" -- a designation that tells one nothing of substance ..."
Wrong. If you have an M-class planet, you should at least be able to find Roddenberries there.
#DeleteChrome
setup your home as a "safe zone" (outside lights/cams decently setup landscaping ect) and work in your neighborhood to increase the peace (heck if you want to be snarky setup a little office hut with doughnuts and coffee). Instead of griping work to fix things.
100K folks will come to a protest but 100 folks won't come to a work day
Never. It is essential that we are pitted against each other so that we won't think to go after the 1%.
heard this 1 year back and they then disclaimed it due to the fact for life it would have to be so close to the star that the radiation would bath most worlds and too far out = too cold.....
nice try and rehashing crap
Although Star Trek had a minor smattering of "M-class planets" -- a designation that tells one nothing of substance
Then why did you bring it up?
And actually, in universe it tells you plenty. It tells you humans and most of the other bipedial humanoid life-forms which smatter the galaxy can survive on the surface and breathe the atmosphere. It also tells you it's likely to be littered with polystyrene rocks or to look a lot like parts of California.
systemd is Roko's Basilisk.
Well, not being able to directly detect something doesn't equate to it not being there. The much larger issue is even if we could directly image something like unexpected lights on the dark side of a planet, and we had some supporting evidence that this may indicate a civilization, we still would have to expend a ridiculous amount of resources just to attempt to send some sort of signal to them, and even more to send a probe. Then we would have to wait for whatever to get there, then wait for a response that may never come.
Basically, it would be a huge expenditure for very little chance of results.
It's particularly interesting as M-dwarfs last a LONG time (10 trillion years) so if life exists around them, the expectation time for life is shifted way into the future - see http://phys.org/news/2016-08-e...
Humanity could never meet an alien civilization. We cannot travel even a significant fraction of the speed of light. And due to Physics we never will be able to. Sorry, but that is reality.
Or is there a reset point. When the technology enables them to destroy themselves, at which point it just just a matter of time. Maybe thousands of years, but not billions.
And the intelligence is unlikely to be biological. How long will it be before humanity is replaced by computers. Not within 100 years, but it is hard to see it not happening within 1,000 years.
http://www.computersthink.com/
Fucking idiot doesn't know that Star Trek never used M-Class Planet. Letter class was and is assigned to Stars, with our sun being a "G" Class. Earth is a Class-M planet (Man) for human habital as we don't live on stars and of course, this didn't gauranty that there wasn't something to kill you on the world as all the red shirts discovered in various ways though we never saw anything that was a virus that crossed species boundaries - a few were covered in Enterprise and DS9 but none in ToS.
Just because an M-type dwarf will burn for 1000 times longer than our sun doesn't necessarily mean that any civilization in orbit around an M-type star is already older than we are.
I thought that meant survivable to all lifeforms not wearing a red shirt.
It seems to me that it is a safe bet that the known limitations of Physics will never be overcome, to such an extent that we will be able to dominate the galaxy. I.e. FTL travel doesn't seem like it will ever be more than science fiction. Many phenomena are governed by a dipole curve, where things start slowly, then hit a tipping point where they rapidly accelerate until they reach a new level of stability. You see this in economics, in Physics / Chemistry, in the evolution of new species, etc.
Why are we alone then? If alien civilizations had arisen 1 billion years before ours, and developed technology beyond our dreams, wouldn't they at least leave a trail of some kind?
Something to consider is that radioactivity decreases with the age of the universe. There is a certain probability that a % of an element will be a radioactive isotope when such elements are created. Less and less heavy elements are being created as the universe ages, and existing ones decay. This means that life will arise more easily.
http://www.fourmilab.ch/docume...
...the development of life of a level that supports advanced intelligence probably needs a certain level of energy intensity across the spectrum in order to develop and that an M-class star doesn't provide that, meaning they would stall at a fairly low level of life and remain there.
E Proelio Veritas.
You're wrong. Arguably. First, obviously, we need to agree (or disagree, but if you disagree then I've nothing more to say to you) on a definition of life - at least in broad terms. It is generally assumed that "life" means "life as we know it" which means carbon based, using liquid water as its reaction medium. So, given that definition we already can constrain where life will not exist - say the photosphere of a G class star or the core of a Gas Giant. You're also wrong about your "no evidence" non-sense. The fact that we are alive is evidence for life elsewhere. I could be (but ain't gonna be) generous and assume you meant "good, solid, specific evidence". I'll also mention that there's (or was when I studied it decades ago) scholarly consensus that we don't know what "Jesus"'s actual name was, a trivial point. If you'd agree that the Scientific method requires prediction, in order to test/challenge/prove a hypothesis, then claiming that a paper such as the one here, is absolutely "scientific". Your understanding of what is and is not "scientific" seems to be very stunted and ill-informed. So, bottom-line:
1. No evidence? Wrong. We are evidence, especially taken with the enormous number of exo-planets we've discovered in the last 2 decades. Consider the opposite: that no exo-planets had been discovered despite decades of looking for them. That would clearly be a problem for the "life on Earth is unique" people.
2. Know nothing? Wrong. We know life (as we know it) requires the existence of liquid water, which in turn requires a planet (or satellite) with certain characteristics and without any (globally) lethal characteristics.
3.Little information. Well I shouldn't argue that. On the other hand, compared with the information we had 20 years ago, we have a huge amount of information, plus the fact that our understanding of our own Solar System has improved and is continuing to improve. We are better and better able to constrain the planetary conditions necessary for life-as-we-know-it to exist. But of your 3 points, this is by far the most accurate. Our models have failed us pretty dramatically in recent years. I see little reason to trust them. Never-the-less, either you start somewhere and improve by "playing the game" (aka "the scientific method") or you don't ever start - and join some religious cult of "true believers". A lot of mathematicians would be surprised to learn that something has to exist to be studied. That's just not true - most of the structures they study do not have any physical existence. But this seems to be (again) a matter of definition. Our theories have two uses: to explain the past (and present) and to predict the future. In this sense, using theory to attempt to characterize the location of "habitable zones" is perfectly good science - under the presumption that better observational techniques will allow us to begin to test such predictions.
Man did I screw up that post. No exo-planets would support (not be a problem for) the life is unique to Earth people. And I made some other silly typographical errors. Sorry.
Does this suggest (however lightly) that perhaps we (humanity) should be looking not to M-class stars but to K-class stars for more intelligent lifeforms and more advanced civilizations?
E Proelio Veritas.
OBAFGKM.
E Proelio Veritas.
I was under impression that Jupiter-size planets are useful in in star systems where you hope to get life. They catch a lot of space debris (up to moon size), preventing some (most?) of it with colliding with rocky, life-bearing planets. Avoiding serious extinction events or even blowing up entire atmosphere looks like healthy thing for fragile, growing life.
Here we read about 'planetary systems characterized by a paucity of Jupiter-mass planets', but there is no mention of space guard role they fulfill. Is it overrated or we just don't know enough about their importance to put it into scientific paper?
I never asserted that "not being able to directly detect something [equates] to it not being there"
What I was pointing out is that for something to be "science" there must be evidence, and while I cited the elements of the oft-slung "Jesus riding a dinosaur on a 6K year old Earth" meme and pointed to there being more "evidence" for THAT, I was pointing out that it was nevertheless a false meme.
First: "evidence" is NOT evidence that something is POSSIBLE, or even proof that required story elements exist. The evidence for the existence of Jesus and of dinosaurs (and yes, we have plenty of evidence for the existence of both) does not automatically become evidence for Jesus riding a dinosaur.
Second: "evidence" is not somebody's guess at the probable chances that something exists. A million scientists can imagine the possibilities of life and chances of civilizations in other galaxies, but NONE of that is "evidence"
All the dreaming and conjecture and educated guesses can be piled up into a mountain of published papers and lectures and web sites and books, but NONE of that is "evidence". It's called "day dreams" and "imagination" and is as scientific as the typical beer-fueled talk in a typical college kids bull session. People who come up with this stuff should be in careers writing science fiction novels, and not wasting everybody's time pretending to be scientists.
Engineering uses numbers.
Science uses data.
Authors of works of fiction use imagination.
No, I'm not, and I weep for science if your opinions are on the rise
You say: It is generally assumed that "life" means "life as we know it" which means carbon based, using liquid water as its reaction medium. So, given that definition we already can constrain where life will not exist
I say: no, I'm more broad-minded and while I'll accept "life as we know it" I'm also willing to accept life that is completely alien to us - in other words I am being MORE generous to the people who imagine life beyond Earth.
you say: The fact that we are alive is evidence for life elsewhere.
I say: No, it's only proof that the forms of life we know of exists HERE. There may be plenty of other forms of life, but this is neither evidence for them, nor of their existence elsewhere.
You say: If you'd agree that the Scientific method requires prediction, in order to test/challenge/prove a hypothesis, then claiming that a paper such as the one here, is absolutely "scientific".
I say: No, science is much more than prediction, which is just one tiny reason among many for my opposition to horoscopes and fortune cookies which also make predictions. Science does not just require some idiot to predict something. It requires some theory and testability etc and some actual evidence.
You say: Your understanding of what is and is not "scientific" seems to be very stunted and ill-informed. So, bottom-line:
I say: Insults by somebody who clearly does not understand even the most basic concept of "evidence" is "stunted and ill-informed"
You say: No evidence? Wrong. We are evidence, especially taken with the enormous number of exo-planets we've discovered in the last 2 decades. Consider the opposite: that no exo-planets had been discovered despite decades of looking for them. That would clearly be a problem for the "life on Earth is unique" people.
I say: Nice try. The existence of planet-sized objects orbiting other stars is just evidence of other planets. That's all it is. It's not evidence one way or the other for life, particularly when all the evidence we have from our own solar system is that no planet here other than Earth has any life. There may well be life on Mars or elsewhere in our solar system, but we have no evidence of it yet
You say: Know nothing? Wrong. We know life (as we know it) requires the existence of liquid water, which in turn requires a planet (or satellite) with certain characteristics and without any (globally) lethal characteristics.
I say: Wrong. We know that SOME life (what we've seen) requires liquid water. So what. We have not seen liquid water on any exoplanet and we've seen water on mars (albeit frozen) but no life there. We also have seen lifeless water on Earth. Water IMPLIES that life as we know it MAY be possible, but is neither evidence for life, nor is its absence evidence for the absence of forms of life we know nothing about.
You say: Little information. Well I shouldn't argue that....
I say: that is wise. We know VERY little of the planets in our own solar system, and a single probe on a slingshot pass by any one of them can generate enough data to completely upend our understanding of an entire WORLD. Just look at all the effort it has taken mankind (over centuries with our actual feet on the ground) to understand life on Earth. We're still learning what we do not know about life here. It's fallacious in the extreme to presume that we know about life on Pluto even though we have just recently flown a probe right past it. That probe provided billions of bytes of information more than what we have for all the exoplanets in the universe COMBINED. Is there life on Pluto? We have no clue. I'm perfectly open to it and I would love to see man set foot on that world and setup a facility and explore that world looking for exotic life forms.... but my hopes that some exotic and fascinating life might be found there or my imagination for what such life might look like is not EVIDENCE.
The whole exercise of things like the "Drake Equ