M dwarf star planets likely sterile? What a load of horse feathers

Earth got it's original and second atmosphere obliterated twice. third times the charm? it seems planets shed thier atmosphere as casually as a model changes clothes. what does this mean for m dwarf planets?

www.spacedaily.com...

Take that you "m dwarf planets have to be dry" types:

phys.org...

yup. geochemistry babe. it's the other other other white meat.


And this article has some relation to tidally locked planets as might be found in the life zone of M dwarf stars. the right conditions can prevent the boil freeze double whammy

phys.org...

originally posted by: stormbringer1701
Take that you "m dwarf planets have to be dry" types:

phys.org...

yup. geochemistry babe. it's the other other other white meat.


And this article has some relation to tidally locked planets as might be found in the life zone of M dwarf stars. the right conditions can prevent the boil freeze double whammy

phys.org...

Ah, beat me to it!

For me, the jury is out. Until we have a good survey of nearby M-Dwarf planet's atmospheres we won't be able to say for certain.

I would not be shocked if we find quite a few covered in shallow seas of water.

But I also would not be shocked if all we came across were arid desert planets.

I suspect the truth will lay in the middle of those, planets with water vapor and a density that indicates that at least part of the the planet is liquid water.

Bring on TESS, bring on JWST!

Many learned people on here.

As we have "White" light on our planet and our visible light covers the spectrum, we also have occasions of Red and orange light (Sunrise/Sunset) that changes the colours we visibly see.

Would these "Red" visible light stars have a corresponding light on their planets, which means they do not have a full spectrum like us White light creatures, and presumably for "Growth", what "colours" would life be on those planets?
Would everything be red or black? Would White exist (I guess not).
Would that be why the grey ET have large black filters on their eyes while on the Earth, because of our harsh white light? (ie Sunglasses)

Perhaps we are unique in the Galaxy, as we live near a mid size white Star, not a more prevalent Red or dark yellow small star?
Perhaps Earth life is also more "Watery" than some other Life forms near these smaller stars...we are 80% H2O.
No wonder they are studying us?? .

well k type and even m dwarfs do not put out monochromatic light. it's just that the mix of light frequencies are different and skewed to the red portion and infrared portion of the spectrum. we actually have plants that adapted to micro climates on earth like cave entrances, narrow box canyons and so forth that have altered to thrive on red and infrared. so even some unmodified earth life could thrive in such places.

originally posted by: JadeStar

originally posted by: stormbringer1701
Take that you "m dwarf planets have to be dry" types:

phys.org...

yup. geochemistry babe. it's the other other other white meat.


And this article has some relation to tidally locked planets as might be found in the life zone of M dwarf stars. the right conditions can prevent the boil freeze double whammy

phys.org...

Ah, beat me to it!

For me, the jury is out. Until we have a good survey of nearby M-Dwarf planet's atmospheres we won't be able to say for certain.

I would not be shocked if we find quite a few covered in shallow seas of water.

But I also would not be shocked if all we came across were arid desert planets.

I suspect the truth will lay in the middle of those, planets with water vapor and a density that indicates that at least part of the the planet is liquid water.

Bring on TESS, bring on JWST!

you said in the next few years the separation of ACa and ACb will increase so that two teams are planning close study to see if there are more planets there. do you know if any time will be devoted to A Proxima?

we need someone to survey the nearest m dwarfs and brown dwarfs because they are 90 percent of the local star population and have a huge statistical probability to have planets and large statistical for planets in the life zone. They are 90 percent of the stars that we might send a probe to because of proximity. reds have been shown to have planets about 9 light years away plus a dusty disk. additionally because they are dim it should be easier to spot terrestrial class planets around then compared to the blazing overwhelming shine of brighter stars.

we need to look at A Proxima, Barnard's Star, Wolf 359, and so on for every red within 20 light years or so.

another article on m dwarf red dwarfs. basically they say what i said earlier about refilling habitable zone planets with water and also about looking further out on younger stars for even more targets for searching for life:

www.spacedaily.com...

originally posted by: stormbringer1701
when you ask them stuff could you ask about the recent discovery of water at the mantle core boundary that is a bout 400 percent or so of the water we thought earth had.

I always try to keep my promises and yesterday I received answers to your questions.

The recent discovery of more water at the core-mantle boundary is interesting and almost certainly has astrobiological implications.

First what we know:

The water is locked up in Ringwoodite minerals which form from olivine under very high pressures and temperatures. The pressures and temperatures present in the mantle's transition zone allow this.

The discovery is consistent with models geologists have had for some years.

Most of the surface water we have now came from degassing of molten rock, the original rock ingredients of Earth.

What we don't know:

How much water is still inside the Earth today relative to the surface?

How do different sized terrestrial type planets retain this subsurface water? Composition matters. Planets higher in carbon will be drier. Planets higher in silica like Earth will be wetter.

i mean it may have implications about water retention given the pressure and temperature there.

Agreed. It is unclear if much water would be in the original material habitable zone M-Dwarfs would form in due to the reasons outlined above.

However.... An intriguing possibility may exist for planets which form just beyond the initial frost line and above about 1.3 Earth radii. The internal pressures keep such water locked up during that early phase of the star which burns off surface water but if such a planet has a sufficient atmosphere water from the interior may degass over time as the atmosphere contracts and atmospheric pressure rises.

Water vapor itself is a greenhouse gas so this process might warm such borderline planets to the point where liquid water could eventual exist on its surface as the star M-Dwarf cools from its initial early phase thus extending the habitable zone outward slightly.

We'll have to wait and see. Once we have a nice collection of spectra from nearby planets around M-Dwarfs we'll better know how dry these planets are.

also please ask them what effects the extreme longevity of red dwarfs would have. some of these things might just be first generation stars. they really can live that long. during that time a lot of stuff can happen. its like comparing the stuff an infant has seen to the stuff a centurnarian has seen.

Great point. I asked this and they said it has an effect on planets which migrate inward. Some of those frozen worlds over a gigayear (billion year) time scale could perhaps migrate inward thus warming them up from their initial frozen genesis. Our understanding of planetary migration is in its infancy but we should know a lot more about the likelihood of this in the next 10 years.

Also life on M-Dwarf planets such as Kapteyn b have had a LOT more time for life to evolve than the Earth has so they may represent prime targets for SETI experiments and they already are prime targets to search for biomarkers with next generation telescopes like the TMT, ELT and of course the James Webb Space Telescope.

i know the arguments they made but something about them just doesn't make sense. i cannot help but think it's over simplified.

Well its more complicated than they portrayed in the articles you read which provide a kind of summary of the research. There may be more on all of this at the AAS meeting next month. Stay tuned!

it might be more than just inward migration. i am sure they didn't want to go into excessive detail because they wanted to be brief but...

they seem to have missed an additional thing that can happen to long lived stars since they are travelling around all throughout their life time and so are molecular clouds, dust clouds, interstellar debris fields like the OORT clouds of all the other stars, even galactic traffic accidents where galaxies merge or eat other galaxies. with a potential lifespan as big as that of the universe at large those little unassuming red dwarf star systems have plenty of time to get late bombardments.

did you know virtually all of earth's accessible/mineable gold is from late bombardment by asteroids? The original supply of earth's gold sank into the core while earth was yet molten from forming. Very little of earth's original heavy stuff ever got free of the core to make it back up to where we can reach it. the stuff is so dense and heavy it just sank out of reach along with most of earth's initial supply of heavier than average elements.

a reply to: stormbringer1701
not to be funny but isn't sol classified as a yellow orange dwarf star?

originally posted by: proteus33
a reply to: stormbringer1701
not to be funny but isn't sol classified as a yellow orange dwarf star?

yes; i think. but Sol has sufficient mass for it's internal structure to be different from smaller stars. what this means is it's fusion process will run out before it has even used 3 percent of its available fuel. (put another way if Sol had complete mixing it would not go off main sequence for approx 100 billion years.) The internal structure and convection will not move the fuel from its outer layers to where the fusion occurs in the interior.

but smaller stars have simple convection and other processes that will ensure every bit of fuel it has will get used before the star dies. red dwarfs can live for longer than the projected life of the rest of the universe.

On earth when your fire dies down you move incompletely burned wood to where the dying flame is and the fire gets new life. small stars are like that. Bigger stars are not.

Leconte and his team reached their conclusions via a three-dimensional climate model they developed to predict the effect of a given planet's atmosphere on the speed of its rotation, which results in changes to its climate," said Leconte. "Atmosphere is a key factor affecting a planet's spin, the impact of which can be of enough significance to overcome synchronous rotation and put a planet in a day-night cycle."

Read more at: phys.org...

How's them horesefeathers?

more proof of horsefeathers!

phys.org...

that bad attitude of m dwarf stars when young may convert mini-neptunes into rocky earth like planets.

All depends on migration like i said Nice to see UW's program in the news again though

Necroing because this is the same sort of reasoning applied to another class of star system

phys.org...

Tau Ceti has planets with possibly two in the life zone. this article starts of by saying one of them probably isn't in the life zone and the other has only been in the life zone for 1 billion years so there is likely no chance of intelligent life or civilization.

Yeah but if you want to colonize a garden planet, -that is impossible to ethically do if there are already intelligent occupants. So in my view that makes Tau Ceti more attractive; not less.

Finding beings like us is not the only reason to go out there and it is unlikely that that is even the best reason to go out there.

originally posted by: stormbringer1701
Necroing because this is the same sort of reasoning applied to another class of star system

phys.org...

Tau Ceti has planets with possibly two in the life zone. this article starts of by saying one of them probably isn't in the life zone and the other has only been in the life zone for 1 billion years so there is likely no chance of intelligent life or civilization.

Yeah but if you want to colonize a garden planet, -that is impossible to ethically do if there are already intelligent occupants. So in my view that makes Tau Ceti more attractive; not less.

Finding beings like us is not the only reason to go out there and it is unlikely that that is even the best reason to go out there.

It's not about that...

It's about being able to detect biosignatures in the atmosphere.

Tau Ceti f will have only been habitable for a billion years but it took Earth 2 billion years for life to become detectable.

Of course we're going to assume that life on a SuperEarth would take as long to develop and become detectable as life did on Earth.

In my opinion we should, and probably still will look for biosignatures on Tau Ceti f and maybe even Tau Ceti e but there are probably other nearby targets of opportunity which will look a lot better.

We still don't know about them but TESS should reveal some starting in 2017.

indeed. speaking of which:

phys.org...