Life on moon rather than planet

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Main Question or Discussion Point

why planethunters and astrobiologists are concentrating on finding life on earth like planet with an orbit around host star rather than on jupiterlike planets moon

i was browsing through the essentials of complex life to evolve on a planet. i am sure you all pretty much know that.

plate tectonics,
reasonable gravity (1/2 earth to 10 earth masses)
massive magnetic field
big moon to stabilize planets tilt
certain degree of vulcanism
habitable zone
water
etc.

i was adding up probabilities for thease occations to happen on earthlike planet. and found out that this is very higly improbable.
for e.g. for earthsize planet to have a big moon is almost imposible. it really involves two planet crash. wich means two planets have to form in same orbit. witch is close to impossible.
to have a massive magnetic field is also very impossible for small planets.


if a planet is a moon to a jupiter. its much much easier. - probable.

you dont have to have your own magnetic field - solar winds are deflected by host planets magnetic field.
host planet does not let its moon tilt go wild.
it is cracking the planets core allowing vulcanism and plate tectonics to accure on much smaller objects than earth - sustaining rich atmosphere
it is protecting against asteroids and comets.

we have no reason to believe that jupiterlike planets will not have many big moons like it is here
we see that facelocking threat is not an often case in solar system moons
we know that gas gigants often drift inwords after planet formation and mey find its orbit near habitable zone.

if we could put our gas giants in habitable zone i have at least 2 moons airing for life - europa and titan, maybe titania... but it could be more than that

it is easy to detect jupiterlike planets. wich means we know exact points where to concentrate our efforts in order to find the moons rather than looking for planets everywhere
 

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  • #2
Vanadium 50
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why planethunters and astrobiologists are concentrating on finding life on earth like planet with an orbit around host star rather than on jupiterlike planets moon
They aren't. But planet hunters can only see extrasolar planets, not moons.
 
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They aren't. But planet hunters can only see extrasolar planets, not moons.
and not just any planets, they have to be relatively large compared to their star. basically, we're only seeing the "jupiters" of other stars.
 
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keppler mission (loounched march 2009) wich is the most expensive and promising planethunting device... is built to detect earthlike planets in an area as big as two constilations.

it is not explicitly pointed to known jupiters in habitable zone.

1. so i guess we are concentrating on planets rather than moons
2. yes we can detect earthsize objects (data is flowing in ever day)
 
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keppler mission (loounched march 2009) wich is the most expensive and promising planethunting device... is built to detect earthlike planets in an area as big as two constilations.
interesting. I wasn't aware of that.
 
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keppler mission (loounched march 2009) wich is the most expensive and promising planethunting device... is built to detect earthlike planets in an area as big as two constilations.

it is not explicitly pointed to known jupiters in habitable zone.

1. so i guess we are concentrating on planets rather than moons
2. yes we can detect earthsize objects (data is flowing in ever day)
Kepler works by measuring a dip in the brightness of a star as a planet passes in front of it. This is not very conducive to detecting moons circling a gas giant.
 
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Kepler works by measuring a dip in the brightness of a star as a planet passes in front of it. This is not very conducive to detecting moons circling a gas giant.
Yes that is what I am saying.
It is built so that it can detect planets not moons.

which in my opinion is incorrect.

I dont know how a moondetecting instrument should work...probably the same way - measuring the dip in solar radiation (light) of a star made by host planet and see if that dip is not linear and has some periodical fluctuations. if the instrument would zoom in any known jupiterlike planet in any constellation, whenever it or the host star is eclipsing. then the data could maybe reveal something

but anyhow the idea stays, living on moon is far more easier - in onther words - probable - in other words moons ought to be more frequently inhabited than planets.

http://upload.wikimedia.org/wikipedia/commons/c/cc/Exoplanet_Period-Mass_Scatter.png
this graph shows that there are a lot of known jupiters in habitable zone

we are all the time complaining that we keep finding only jupiters, but i believe - that is just what we need.
 
  • #8
DaveC426913
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Yes that is what I am saying.
It is built so that it can detect planets not moons.

which in my opinion is incorrect.
Simply put: we are doing the absolute best we can. Planet detection is right at the very limits of our technology. Anything we see is a bonus.


Wait another ten years, till planet detection is as common as dirt, then we'll start getting picky about what kinds we want to concentrate on.
 
  • #9
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The variation in light between a large planet eclipsing a star is very, very small. And it would be very^5 smaller for a moon eclipsing a star. You would have to know the orbit of the planet, and be able to look at the star just before and just after the planet eclipses the star in order to detect a variation in light output.

Heck the variation in light output is small for binary stars!
 
  • #10
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I find this very, very, very hard to believe. Do you have any evidence for your claim?
 
  • #11
DaveC426913
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Your arguments are way too Earth-centric, and flawed even at that.

One example:
My logic ?
Intelligent life like us needs EYES
No they don't.

Dolphins are intelligent yet they live in an environment that is relatively opaque to visible light beyond a few dozen feet. They do quite well with sonar. Scorpions locate prey using vibrations through the ground. And, of course, bats...

You are looking at the whole scenario backwards. Life does not get to choose the planet it evolves on. It's not like life is going to say to itself "hm, this atmosphere is opaque, I guess I won't bother evolving beyond the bacterial stage."


If life got a start on a planet with an atmo that's opaque to visible light, it would just make do.
 
  • #12
DaveC426913
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....like us

perhaps i should of said " a naturally evolved technologically advanced species...like us"
What is not naturally evolved about dolphins, scorpions or bats?

OK, now you're talking about technologically advanced. You're changing the goal posts.

many times easier for a biped with two free arms and opposing thumbs , stero vision and hearing to build spaceships..than an octopus
On what do you base this?

im not earth centric....the laws of physics and evolution tell us that our body shape is the easy way...thus these economic & efficient forms will be dominant numerically
On what do you base this?


TESLACOILZAP, you are simply saying stuff that makes sense to you and claiming it as obvious or inevitable. This is not how science works.
 
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  • #13
DaveC426913
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Imagine a telescope 100 times the power of hubble. Now imagine 100 of these in deep space orbit. The task of detecting & filtering light passing through the atmosphere of a moon 1000 light years away quite doable.
Yes we all have good imaginations. What does 'imagination' have to do with 'doable'?


This is a rhetorical question. You are not answering a question asked, you are off on a philosophical tangent.
 

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