Red dwarf stars might be best places to discover alien life

Aug 12, 2014
Red dwarf stars could also be hosts for life. Pictured is an artist’s conception of this star type with, in the foreground, a planet with two moons. Credit: D. Aguilar/Harvard-Smithsonian Center for Astrophysics

Red dwarfs are the most common type of star in the universe, and nearly every one of these stars may have a planet located in its habitable zone where life has the best chance of existing, a new study concludes.

This discovery may increase the chances that could exist elsewhere in the cosmos, researchers say. They detailed their findings in the International Journal of Astrobiology.

Red dwarfs, also known as M dwarf stars, are up to 50 times dimmer than the Sun and are just 10 to 20 percent as massive. They make up to 70 percent of the stars in the universe.

The fact that are so common has made scientists wonder if they might be the best places to discover alien life. Astronomers are discovering more and more around red dwarfs, and recent findings from NASA's Kepler space observatory reveal that at least half of these stars host rocky planets that are one-half to four times the mass of Earth. All in all, planets about the size of Earth seem plentiful in the universe, as do other worlds that are smaller than most gas giants, on the order of Neptune (which is 17 times the mass of Earth). Why such worlds are abundant is a mystery.

A leading theory in planetary formation suggests that as embryonic planets develop in the disks of gas and dust surrounding newborn stars, these nascent planets migrate inward as the matter in these proto-planetary disks erodes their orbits. However, migration models suggest Neptune-size planets should be rarer than they actually are.

Instead, some researchers have suggested these relatively low-mass planets may assemble in situ—that is, they are born and stay in much the same places around their stars their entire lives, with little to no migration toward or away from their stars. Study author Brad Hansen, an astrophysicist at the University of California at Los Angeles, used computer models of in situ to see how often red dwarfs might develop Earth-sized worlds, and where these planets might orbit around the stars.

In his computer simulations, Hansen modeled red dwarfs half the mass of the Sun, with proto-planetary disks extending from 0.05 AU to 1 AU (one astronomical unit is the average distance from the Sun to the Earth) from the stars. The disks contained an amount of gas and dust equal to six times the mass of Earth. He then looked at how many planets developed after 10 million years.

Of particular interest to Hansen were the so-called of these stars, the areas where planets are potentially warm enough to sustain liquid water—and potentially life—on their surfaces. Red dwarfs are relatively cold stars, which means their habitable zones are closer than Mercury is to the Sun—just 0.1 to 0.2 (AU.

Hansen found most of the resulting planetary systems comprise between four and six surviving planets inside 0.5 AU, although the largest number went as high as 10. In addition, the red dwarfs usually possessed one or two planets within their habitable zones, which extended from 0.23 to 0.44 AU.

"A high frequency of potentially habitable planets makes it more likely that we could actually find one that is habitable," Hansen said.

Moreover, Hansen also found that planets in the habitable zones of red dwarf could accumulate significant amounts of water. In fact, each could possess roughly 25 times more water than Earth has as a whole. All in all, he noted these results "broadly support the notion that are plentiful around M dwarfs in the solar neighborhood."

Explore further: Red dwarf planets face hostile space weather within habitable zone

More information: International Journal of Astrobiology, journals.cambridge.org/action/… Id=S1473550414000159

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Modernmystic
2 / 5 (8) Aug 12, 2014
This is wishful research. Red Dwarfs are horrible places to look for complex life, for reasons we've known for decades. Move on to something that actually makes sense please.

High variability, tidal lock, luminosity, etc etc etc....

The ONLY thing they have going for them is abundance, but this is like saying you might find a good wife in a mental institution of women....
Modernmystic
1.6 / 5 (7) Aug 12, 2014
In fact, each could possess roughly 25 times more water than Earth has as a whole.


And this is a GOOD thing? Any ideal what that does to greenhouse concerns? Atmospheric pressures? The fact that there will be NO land whatsoever....

Do these people THINK....it's like a creationist seeing his world view slip away and he's desperately grasping at straws that actually make his position worse because he's not thinking about what he's actually saying or he's clueless.

Orange dwarfs are MUCH more hospitable to life...maybe more than our own sun...

http://en.wikiped..._systems
AnthonyAmerica
1 / 5 (2) Aug 12, 2014
Like the evolution of Hu-mans, discovering fire.
When it comes to the universe we just about discovered fire;
To think we are the only life in the universe is total nonsense;
We won't be around in a few hundred years from now; I would like to believe we continue to venture outward into the trillions of secrets the universe holds.
Torbjorn_Larsson_OM
5 / 5 (5) Aug 12, 2014
Nice! But recent migration models converge on much the same results I think, providing the migration is rapid enough.

@ModernMystic:

"This is wishful research. Red Dwarfs are horrible places to look for complex life, for reasons we've known for decades. Move on to something that actually makes sense please.

High variability, tidal lock, luminosity, etc etc etc....".

The kind response is that your comment is wishful opinion. No such "horrible" circumstances are known to exist.

Tidal lock:

- While Venus is nearly locked, Mercury isn't. Turns out half the time, resonances appears.

- Even better, tidal lock means inherently little for climate. When modeled, water clouds mitigate uneven irradiance.

- And of course a denser atmosphere does too, as shown by Venus. It just moves habitability towards more massive, volatile rich planets - those we see.

[tbctd]
Torbjorn_Larsson_OM
5 / 5 (5) Aug 12, 2014
[ctd]

Variability:

- 10 % of M stars are inherently calm. That is more stars than there are G stars like the Sun.

- Binaries calm their partners. There are as many binary M stars as singlets. And most have habitable planets.

- M stars are most unruly as young. Provided the atmosphere lasts, life can survive. That is another reason to want massive planets and denser atmospheres.

Luminosity:

- M stars radiate at energies that fits the opsins and IR edge chlorophylls better than the Sun does.

etc etc etc...

What we want to do is to look. Conveniently and unfortunately for the worth of your opinion, these stars are the ones that are most frequent and so closest, and easiest to characterize planet atmospheres on. So (to sum up) this is likely where we will find Life 2.0, cyanobacteria equivalents with oxygenating photosynthesis. (Which can grow simple multicellulars, and lead up to eukaryote like endosymbiosis.)
Andrew Palfreyman
5 / 5 (3) Aug 12, 2014
Tidal lock isn't a fatal condition. Another thing going for red dwarves is their extreme longevity. This implies that, were a civilisation to successfully evolve in such a system, it could be around for a very long time. Indeed, were we searching for the oldest such in our own galaxy, red dwarf systems may well be the best bet. Theoretically, the oldest could have a 9 billion year head start on us. Not too shabby.
Psilly_T
5 / 5 (1) Aug 12, 2014
i gota agree with some of the others torb. There have been more than a few phys.org articles, recently, explaining the harsh environment red dwarfs would actually have. It's true that not all planets will be tidally locked(around dwarfs), but wouldn't or couldn't a large majority? What about the massive gigantic magnetic power of these dwarfs and the proximity of the habitable zone? In another article on PO it explained how this could pretty much fry most habitable planets around dwarf stars( i don't remember exactly but it was bad for the planet). They are definitely more abundant, and easier to find more planets around them, but based on the articles i've read on this site this type of environment is extremely harsh. Not saying there couldn't be any life there, but there has got to be better places to look whose habitable zones would be more nurturing.
yaridanjo
3 / 5 (2) Aug 14, 2014
On Proxima Centauri:
The Cenos extra-terrestrial aliens landed near HANDS when he was 2 ONES years old. Cenos beings have two arms, two legs and (slightly pointed) heads as do humans and wear grey suits with helmets. They are bigger than humans, maybe 8.0 to 8.5 feet tall. They have many little hearts all over permitting more strength and they are about 5 times stronger than a normal human. Their lungs function as our kidneys to expel waste. They are a carbon based life form with many big pores on their skin. They have no serious diseases or illness and live until they are about 120 years.They eat tasteless pills. They no longer sleep.

Humans, on the other hand, are the retards of the Universe.
Modernmystic
1 / 5 (2) Aug 15, 2014


- While Venus is nearly locked, Mercury isn't. Turns out half the time, resonances appears.


Incorrect. This solar system is not analogous to a red dwarf. In those systems tidal lock without resonances are a virtual certainty within the VERY narrow habitable zone. Now a very large planet might escape it, but it would be so massive as to not be a good candidate for life. Let's not leave out tidal heating and the huge abundance of heat this produces. This is a problem for planets which need to be sooooo close to their primary to even have a slight chance of liquid water on their surface (see "tidal Venus").

What you're saying is the same as, "Well here's someone who's pointing a gun at me and saying he's going to shoot...let's look at the bright side and list all the thin possibilities that might occur in which I don't end up dead..."

Some perspective is needed for your rose colored glasses sir :)

(cont)

Modernmystic
1 / 5 (2) Aug 15, 2014
- 10 % of M stars are inherently calm. That is more stars than there are G stars like the Sun.


Well that might be good news, if we hadn't already established that it's highly unlikely for them to be habitable simply due to the orbital mechanics of those systems. Again this isn't a feature, it's a barrier to life formation. Again it's like saying...."I'm going over a cliff in a car, but there's a 10% chance the car won't blow up and kill me even though I'm 99% likely to die from the impact anyway". Variability of younger stars tends to completely blow off the atmospheres of planets in the habitable zone, so by the time the stars "calm down" they are nothing but rock and vacuum.

(cont)
Modernmystic
1 / 5 (2) Aug 15, 2014
- M stars radiate at energies that fits the opsins and IR edge chlorophylls better than the Sun does.


Where do you get this stuff? The spectrum is sooooo narrow compared to our sun or a K type star, and soooo much less energetic that plants would have to be completely black in order to eek out enough absorption to survive...assuming that they survived the tidal heating, tidal lock, and lack of atmosphere....
baudrunner
2.3 / 5 (3) Aug 16, 2014
Now I've been saying that for years. Planets around red dwarfs are the most likely candidates for the emergence of life. The main reason for that is that red dwarfs are the most stable stars in the universe. Gilese 581 is a prime example of a stable red dwarf with quite possibly habitable worlds, whether they be a planet in the Goldilocks zone or a moon circling one of them. Gilese has existed as is for at least 2 billion years longer than Sol, which means that life has had a much larger window of opportunity to evolve than it has had on Earth. That alone lends credence to the idea.

By comparison, our sun is relatively unstable - generating harmful solar eruptions; cyclic manifestation of sun spots which can even affect severity of El Niño.
TheGhostofOtto1923
4 / 5 (4) Aug 16, 2014
The rank amateur says
Red Dwarfs are horrible places to look for complex life, for reasons we've known for decades. Move on to something that actually makes sense please
-While bonafide researchers

"detailed their findings in the International Journal of Astrobiology"

and conclude that

"these results "broadly support the notion that habitable planets are plentiful around M dwarfs in the solar neighborhood."

-Another example of the audacity of the truly stupid. Or hopelessly senile.
High variability, tidal lock, luminosity, etc etc etc....
And what makes YOU think that real scientists dont know about these things? WHY would you possibly assume you know more than they?
The ONLY thing they have going for them is abundance
The article lists more than this. Why dont you try reading it before you dump next time?
TheGhostofOtto1923
3 / 5 (2) Aug 16, 2014
"The International Journal of Astrobiology is the peer-reviewed forum for practitioners in this exciting interdisciplinary field. Coverage includes cosmic prebiotic chemistry, planetary evolution, the search for planetary systems and habitable zones, extremophile biology and experimental simulation of extraterrestrial environments, Mars as an abode of life, life detection in our solar system and beyond, the search for extraterrestrial intelligence, the history of the science of astrobiology, as well as societal and educational aspects of astrobiology. Occasionally an issue of the journal is devoted to the keynote plenary research papers from an international meeting."

-I guess mm is pissed because he isnt on the peer list. Wonder why.
Modernmystic
2.3 / 5 (3) Aug 17, 2014
LOL...yeah it threatens your worldview. I get it Otto. There simply isn't complex life (and perhaps no life at all) around any red dwarf star.

If you actually have an argument, other than presenting canned opinions from others...

http://en.wikiped...uthority

....then present it. Otherwise I appreciate your opinion on the matter...oh wait you don't even actually have one of those....never mind.

Otto wouldn't have believed for instance that;

Humans could fly faster than sound

Could fly at all

Could fly in space

time wasn't relative

You couldn't predict a particle's velocity and position (Einstein himself)

or any other of a hundred different things that peer reviewed scientists told him.....
Modernmystic
3 / 5 (2) Aug 17, 2014
Make that time IS relative...

:)
Modernmystic
3 / 5 (2) Aug 17, 2014
There is one point Otto makes that I'll address, it resembles an actual argument...

And what makes YOU think that real scientists dont know about these things?


Because none of it is mentioned in the above article.....or anywhere else....

Show me someone who deals with all the points I've raised and has EVIDENCE (not models), but real physical evidence to the contrary and I'll concede....

And it's absolutely not about them not KNOWING Otto...it's about them being either sloppy, or willfully ignorant, or blatantly twisting known facts in favor of computer models they tweak to support their security in their preconceived notions of what the cosmos SHOULD be rather than what it is.
TheGhostofOtto1923
3.7 / 5 (3) Aug 17, 2014
If you actually have an argument, other than presenting canned opinions from others...
-This is mm's level of regard for the accumulated work of generations of scientists.
Humans could fly faster than sound

Could fly at all

Could fly in space

time wasn't relative
Your OPINIONS are based on outdated research. You haven't bothered to keep up and when researchers such as those cited in the above article present the results of new research you dismiss it rather than change your obsolete OPINIONS.

You will even go so far as to accuse them of
being either sloppy, or willfully ignorant, or blatantly twisting known facts in favor of computer models they tweak
-because you're too fucking ignorant and lazy to be bothered with revising your outdated OPINION.

This is lame by any measure. You have no respect for science or the scientists who do the work necessary to create it. WHAT are you DOING HERE?
TheGhostofOtto1923
3.7 / 5 (3) Aug 17, 2014
none of it is mentioned in the above article.....or anywhere else....

Show me someone who deals with all the points I've raised
I did.

"The International Journal of Astrobiology is the peer-reviewed forum for practitioners in this exciting interdisciplinary field. Coverage includes cosmic prebiotic chemistry, planetary evolution, the search for planetary systems and habitable zones"

-You don't think that people working in this field wouldn't be aware of all the relevant research?? Or that peer review wouldn't reveal any gaps?

You have no understanding of the amount of knowledge needed to earn a degree in science, and to get work as a scientist, or to publish in a peer-reviewed journal.
This is wishful research. Red Dwarfs are horrible places to look for complex life, for reasons we've known for decades
-And you don't realize that this OPINION of yours is based solely on the work of scientists? Science has since discovered new things. They've revised their theories
TheGhostofOtto1923
3 / 5 (2) Aug 17, 2014
-but you're still the same ignorant moron. How come?
Modernmystic
3 / 5 (2) Aug 17, 2014
Sorry Otto, you haven't posted anything that's worth responding to. You're just regurgitating theories. I'm talking about forming an opinion based on the actual observations of orbital mechanics and how we know the sun interacts with various atmospheres with and without magnetic fields etc etc etc...

These people (like Hansen) are tweaking computer models and you're trying to pass it off as being on par with the observational evidence we already have.

Also your "being you" is having a serious flare up, so since your maturity level has once again dropped below something like a two year old child I really don't have the patience to manage you at the moment. Sorry :)

TheGhostofOtto1923
1 / 5 (1) Aug 17, 2014
Sorry Otto, you haven't posted anything that's worth responding to. You're just regurgitating theories. I'm talking about forming an opinion based on the actual observations of orbital mechanics
Ahaahaaaa 'orbital mechanics'. This from the guy who thinks that scientists who get published in "The International Journal of Astrobiology" don't know about
High variability, tidal lock, luminosity, etc etc etc....
I wasn't attempting to debate your various points regarding 'orbital mechanics'. I was pointing out what an asshole you are. And that's not very debatable, is it?