Discussion Kepler Mission, Finding Lots of Uncolonizable Planets

[Admiral_Ritt]

The Kepler mission puts on a optimistic face, on some really disapointing data.

By Now we should have confirmed Earth Sized Worlds in K type Suns,
within the Habitable Zone. (it's too early for G stars like the Sun.)

Kepler keeps finding compact Solar Systems. This was Never Expected.
A gas giant migration here or there sure, but a whole Mini solar systems
contained within the equivalent orbit of VENUS??

I remember Clearly over a decade ago, when the Earth based planet hunters began to make finds.
Strange distributions were found. Only a few with
our Jovian Orbital distribution. Their Explanation was that their methods
of detection had a bias towards close orbit Jovians. Little did they know.

I wonder if the Kepler team is more than a little stressed about finding even
ONE planet within 20% of earth's size and within the habitable zone of a
K or G type Star. ( it would be the Crown Jewel find of the program)

As I read from another article by an astronomer, If Kepler Finds NOT ONE
Earth Like Planet, in the Habitable Zone, if would mean that earth like planets
are EXTREMELY rare. Something on order of 1/500 solar systems.

Now there are a lot stars out there, but practically speaking only G & K stars
should be considered a colonization target. That's only 10% of stars in our
galaxy. so were are at 1/5000, distribution.

Oh, I forgot, the star chosen for colonization target must be YOUNGER than
Our SUN but not too young. so cut the 1/5000 by 1/3 to 1/15000.

Well Space is big You say: Try this the closest Earth Like world that we would like to colonize is likely to be 300-350 LY away.

I certainly didn't expect that to be case, and if we find Zero Earth analogues
is sure would explain the Fermi Paradox, and why we are here undisturbed (apparently)

 

[garyw]

Also the data is only part of the story. You can easily have a planet outside of the godilocks zone and it would be habitable if their is sufficent CO2 in the atmosphere to offset the distance from the zone.

Finally, even if a suspected habitable world was found without 10 l.y. it would still be uncolonizable because for us to get there today would require engineering that is only on paper and timescales that would make the ship a generational ship.

 

[Tommy]

Finally, even if a suspected habitable world was found without 10 l.y. it would still be uncolonizable because for us to get there today would require engineering that is only on paper and timescales that would make the ship a generational ship.

I'll add that generation ships aren't really a viable colonization method anyway. The only people who would sign up for that are the truly desperate (which implies unskilled, and you need people with useful skills required for a colony) or religious extremists. Either way, I'm not sure you could round up enough qualified applicants to create a sustainable gene pool. I suppose that in some dark, dystopian future "colony ships" might be used to rid the planet of "excess" population - but there wouldn't be any real expectation that the colony would survive.

The only realistic way we could ever colonize another solar system would be if we pull FTL out of a hat. You've got to at least send a probe first - make sure that the planet is actually habitable - check for harmful viruses and bacteria, etc, before you send people on a one way trip.

Without any idea how FTL would work, there's no way to know what kind of realistic range could be involved - 500 LY might turn out to be next door - or 100 LY out of reach.

 

[jedidia]

I really don't think finding "colonizable planets" is a priority right now. We won't have anything to colonise it with for centuries to come, if ever.

Sure, it would be exciting to find something in the habitable zone, but currently, it's just exciting to see our knowledge on planetary sciences increase. We finally have a sample size bigger than one to study the formation of solar systems.

Oh, I forgot, the star chosen for colonization target must be YOUNGER than
Our SUN but not too young.

:lol:

seriously, I don't think people will plan billions of years ahead... also, it's possible to find a habitable planet around a smaller star which would have a considerably longer lifetime. Apart from that, any succesful civilisation taking root on a planet now would exploit its resources faster than the star lasts, so that really isn't a primary concern.

is sure would explain the Fermi Paradox, and why we are here undisturbed (apparently)

The Fermi paradox is sufficiently explained by that FTL travel is impossible. It only becomes an issue if FTL travel is a possibility, and then distances of a few hundred lightyears won't really matter on galactic timescales.

but there wouldn't be any real expectation that the colony would survive.

And before you know it, they fall through a time distortion a million years into the past and populate earth... :lol:

 

[Urwumpe]

I am pretty sure, FTL will one day be possible. I see nothing in the world of physics, that means that it has to be ultimatively impossible to overcome the speed of light. The problem is just: How.

Any such discovery would be just a first step...I wish we would have a X-Prize for the experimental proof that FTL is possible.

 

[Admiral_Ritt]

FTL I woulnd't count on it.

I think we can put an upper limit on max practical speeds for a
colony ship. I think 40% of C, is about right.

With such a large invesment in the colony ship, if you run into
a marble sized object at that speed, you can say Vapourized Investment.
However, with radars to detect your more dangerous rocks, and 40% C
(instead of 50%C), you will have time to correct course a few tenths of
meters which is all you need. (time need for radar wave round trip), or maybe
blast them into dust.

I think we need biological breakthroughs, longer lifespan, 120 years seems
reasonable and some kind of hibernation tech, 19 years of sleep and 1 year
of wakefulness. So to arrive at a new world some 300 LY, you will need
37.5 years of a lifetime of 120.

P.S. I read novels where promising planets are prepped for colonization by
sending bioseeding ships to initiate an Oxygen atmosphere. Since it would
be a robotic mission and all you are carrying are blue-green algae, THIS ship
can be propelled to speeds closer to C, with a series of these ships you
could arrive at a world that has had 500 years of time to Oxygenate the
atmosphere, not a lot but atleast it could be harnessed easily.

 

[boogabooga]

I don't know, I've found the Kepler mission rather fascinating and exciting. When I was in grade school, we were taught that the sun was the ONLY star that even had planets. The existence of exo-planets was mere speculation and science fiction.

We did find Kepler-22b, a "super earth" in the habitable zone of a G type star. What law says that a host for life has to be within 20% of the size of earth? Only for humans, perhaps.

That said, I'm not sure that finding "colonization targets" was the goal of Kepler, even while we have Mars and Titan (for when the sun expands) in our own solar system yet.

 

[jedidia]

even while we have Mars and Titan (for when the sun expands) in our own solar system yet.

Even Mars will get swollowed wen the sun expands... :shifty:

 

[boogabooga]

Mars for now, Titan when the sun expands...

 

[Loru]

Even Mars will get swollowed wen the sun expands... :shifty:

Well - that's not determined yet actually. From what I've read and watched scientists still are not sure if it expands to 1 AU in radius or more.

 

[Unstung]

Kepler stares into the same area of the sky, it cannot only look at G and K stars. The majority of stars are red dwarfs and they have extremely long lifetimes, so life has more time to arise before those stars fade. I remember reading that it's possible a tidally locked planet's atmosphere can distribute heat effectively between the day and night sides. Also, because a red dwarf produces a greater proportion of infrared radiation, the 'Goldilocks Zone' could be extended.

Even Mars will get swollowed wen the sun expands... :shifty:

I never heard of the scenario where the sun engulfs Mars. The worst-case scenario I'm familiar with is the sun consuming Earth, but the planet's semi-major axis should increase as the sun loses mass and its diameter grows. Nonetheless, Earth will become too warm long before the sun expands into a red giant.

 

[Admiral_Ritt]

Red Dwarves, sure abudant, but aren't these the stars that
have titanic flares with regular frequency. Tide locking is the least of the problems.
I think life could exist there, buried under tons of rock or water.

One more thing a colonizable world needs to have is magnetic field.
you need rotation and a liquid iron core to get that. Unfotunately
Kepler cant's tell us about that aspect of new planets found.

Well yes, tide locked planets are not likely to have a strong magnetic field,
comparable to the Earth's

I don't know if there is a standing theory of planetary rotation for rocky
planets. Is a rotation of 18-28 hours expected from a rocky world, or is it
just chance? Now THAT would put a damper on colonization efforts.

 

[sorindafabico]

We can't even reach Mars (manned) and Proxima (unmanned). Let's develop interstellar flight before talk about interstellar colonization...

 

[Admiral_Ritt]

Maybe A moon

Unfortunately, I don't think Kepler is capable of detecting the moons
of planets discovered so far. But with future missions the technology
will exist to follow up on the Kepler discoveries.

A moon will necesarily be tide locked to the planet it orbits.
the only type that might be made habitable is one whose surface
is mostly ocean, even more than the earth. A moon with 85% equatorial
spanning ocean would do nicely. For colonization of the landmasses you
would have to settle on the drier colder regions, as there would be
powerfull rains constantly generated by the evaporation and the Windpatterns moving
air from darkside to dayside.
Such a world would neccessarily need to have active plate tectonics
because landmasses would tend to weather faster than on earth.

CALADAN? anyone.

 

[Hartmann]

Could be possible that there are a lot of giant planets with habitable exo moons. despite it´s tidal locked could have a reasonable day night cycle while orbit his planet ans stay protected by the giant planet magnetic field.

Also the tidal forces and gravity can help to the moon to have tectonic activity and be able to renove it´s atmosphere.

When the sun turns into a red giant, Titan can be a good place to stay and there is a lot of water in saturn to make an ocean in titan with water ice

 

[Keatah]

If moons around gas giants have habitable conditions; what about the radiation? I understand that Jupiter has a lot of radiation going on. So much that special shielding is required for spacecraft that conduct Jovian operations. And Juno's solar panel life in the radiation soaked environment is the limiting factor in how long the mission lasts.

So, how would that effect life trying to evolve on a "jovian" moon?

 

[RisingFury]

If moons around gas giants have habitable conditions; what about the radiation? I understand that Jupiter has a lot of radiation going on. So much that special shielding is required for spacecraft that conduct Jovian operations. And Juno's solar panel life in the radiation soaked environment is the limiting factor in how long the mission lasts.

So, how would that effect life trying to evolve on a "jovian" moon?

It's shielded under 20 km of ice, if it's there.

 

[Admiral_Ritt]

Yes Jupiter does a stong Magnetic field and rather deadly radiation belts
I was thinking more in vein of Neptune whose magnetic field is
2.5 -3 times of earth, while jupiter's is gargantuan .
the Belts are deadly to the moon's atmosphere as it
allows easier escape of lighter elements.

So No, I don't expect large Jovian planets to have habitable moons,
or even atmosphere's left, if they're too close.
And Moons too far away from the jovian are a problem too with tide locking,
the planet gains too much heat in day side and looses too much in the dark side,
creating a world of titanic Storms, that would weather any land masses to
shallows and sand bars, in no time at all geologically speaking

 

[Admiral_Ritt]

BAD NEWS

Damn it to hell, all these worlds are USELESS for colonization. Not even
Close.....LOOK.

http://scitechdaily.com/kepler-data-used-to-identify-41-new-transiting-planets/

Once again, terestrials and super earths's are in too close.
As I mentioned before, If Kepler can find No terrestrials within a sun's
bio-zone, that will be a tremendous hint that Life with Organic chemicals
is not favored by the rules of planetary formation.

I am sure that certain folks will blow their tops (Read Anti-Humanist),
when some planetary astronomer postulates that the formation of the solar
system was a special case, and the norm is sterile hostile worlds.

I think I know the answer to how special it was.

When the Sun was born it must have passed within the proximity of
very large star of size close to a Type 'O' Star. This star happened
to have a short life maybe 3-6 million Years. It detonated close to
our solar system sending a shock wave through our proto-planetary disk
It cleared our solar system of alot of the fluff. Result, less orbital debris
due to this clearing with the result that:

1) protoplanets finished clearing their neibhood sooner, and were thefore
smaller than they should have been. (No longer Super Terrestrial or small
Neptune)

2) Stopped Inward migration of the terrestrial planets that did form.


One again DAMN it really does look like the closest reasonable Earth
twin is probably 500-1,000 Ly Away.

Hmm, Mars, Callisto, Ganymede, Titan. Our badlands worlds are begining
to look like paradise in comparison to most planets out there.

 

[T.Neo]

Maybe I'm missing something, but isn't the transit method biased toward larger planet candidates with short period orbits? Perhaps less so than the radial velocity method, but still...

but practically speaking only G & K stars should be considered a colonization target.

Why? Some M stars are flare stars, but if I recall correctly, not all are. There are publications on the reaction of planetary atmospheres to the sorts of flares thought to be associated with M stars.

You can easily have a planet outside of the godilocks zone and it would be habitable if their is sufficent CO2 in the atmosphere to offset the distance from the zone.

Wouldn't that planet be inside the habitable zone, and simply demand that the habitable zone be redefined?

I would imagine things would be more limited for humans than alien organisms- such a 'habitable' planet may have a very high partial pressure of CO2, which would cause hypercapnia in an unprotected human.

check for harmful viruses and bacteria, etc

Alien viruses likely wouldn't be harmful to humans for the same reason plant viruses aren't; viruses co-evolve very specifically with their hosts and jump the species barrier only between related organisms. It should also be noted that the diversity of bacteria on Earth alone is truely staggering, and our immune systems seem to cope with most of the organisms that are just 'lying around'.

It only becomes an issue if FTL travel is a possibility, and then distances of a few hundred lightyears won't really matter on galactic timescales.

There are discussions involving the Fermi paradox without FTL travel; STL colonisation, if uniform and constant, could 'conquer' the galaxy in far less than its total age. That said, there is still a very large abundance of explanations for the fermi paradox.

Unfotunately Kepler cant's tell us about that aspect of new planets found.

Kepler can tell us density. From that we should be able to surmise the presence of an iron core. Rotation is an unknown, but rotation rate should be possible to determine via orbital parameters if a body is tidally locked.

Whether the core is liquid depends on the age of the planet and the amount of heat within the core. Internal heating depends on mass and density (primordial heat from planetary formation, as well as heating from radioisotopes), and age can be determined by the age of the system.

Well yes, tide locked planets are not likely to have a strong magnetic field, comparable to the Earth's

Are there any publications that give figures for the strength of planetary magnetic fields at different rotation rates?

I don't know if there is a standing theory of planetary rotation for rocky
planets. Is a rotation of 18-28 hours expected from a rocky world, or is it
just chance? Now THAT would put a damper on colonization efforts.

Putting tidal forces aside, rotation rate is determined by whatever large impact occured last.

A moon will necesarily be tide locked to the planet it orbits.
the only type that might be made habitable is one whose surface
is mostly ocean, even more than the earth. A moon with 85% equatorial
spanning ocean would do nicely. For colonization of the landmasses you
would have to settle on the drier colder regions, as there would be
powerfull rains constantly generated by the evaporation and the Windpatterns moving
air from darkside to dayside.
Such a world would neccessarily need to have active plate tectonics
because landmasses would tend to weather faster than on earth.

Those are some interesting statements regarding climatic patterns on habitable moons. How did you come to these conclusions on the matter?

So No, I don't expect large Jovian planets to have habitable moons,
or even atmosphere's left, if they're too close.

Do we have figures on what rate the radiation belts of jovian planets in a star's HZ would erode the atmosphere of a habitable moon? What variables can affect the forces involved?

creating a world of titanic Storms, that would weather any land masses to
shallows and sand bars, in no time at all geologically speaking

Do we have any studies on windspeeds for planets at various rotation rates and how these weather patterns would affect geology?