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8.8 Billion Earth-Like Planets In Milky Way

Foster Zygote

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Foster Zygote
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A recent study published in the Proceedings of the National Academy of Sciences of the United States of America journal, conducted with data gathered from the Kepler telescope, suggests that there are at least 8.8 billion planets in our galaxy which are about the same mass as Earth, and orbit single stars similar to ours at a distance where surface water would exist in a liquid state.

How freaking cool is that?
 
Roboramma said:
Freaking cool.
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It's way cool... 'till you realise just how far away they are and realise dreams of colonising them and having a viable DR scenario for the destruction of earth remains way beyond us.

The distances are incredible, awe-inspiring and just a tad depressing...

Still cool though.
 
It also give us a place to look for tell-tale signs of massive infrastructure, FLT "contrails", signals.
Once we put up an interferometric telescope we might even start finding them and cataloging.
 
Future generations of telescopes should be able to make spectroscopic analyses of the atmospheres of many of these worlds. Imagine if we found a planet with a substantial atmosphere with a considerable amount of oxygen.
 
Ethan Thane Athen said:
It's way cool... 'till you realise just how far away they are and realise dreams of colonising them and having a viable DR scenario for the destruction of earth remains way beyond us.

The distances are incredible, awe-inspiring and just a tad depressing...

Still cool though.
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True. But just image how far beyond us, back in the 19th Century, was the ability to send humans to the moon and send a robotic explorer to the surface of Titan a billion miles away.

It won't be like Star Trek, but we may be sending humans on one way colonization trips some time within the next millennium. First, I'm sure, we'll be sending our trusty robots ahead to scout out the lay of the land. Human civilization will, in many respects, shift to a time scale that seems paralyzingly slow to us today.
 
Foster Zygote said:
A recent study published in the Proceedings of the National Academy of Sciences of the United States of America journal, conducted with data gathered from the Kepler telescope, suggests that there are at least 8.8 billion planets in our galaxy which are about the same mass as Earth, and orbit single stars similar to ours at a distance where surface water would exist in a liquid state.

How freaking cool is that?
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Very.

At least some of those must have (or had) life.
 
Dr. Keith said:
Wow, God really likes to hedge his bets.
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I was just wondering if there is a Jesus for every single planet, or is there just one Jesus for all of the planets.

If he hangs out on each planet for around 30 years that would be over 100 Billion years! No wonder he hasn't been back.
 
Well, let's just play with some numbers for a minute, for amusement.

Say for argument's sake that one in a hundred actually had water. One in a hundred of those had a large and close moon to keep the climate stable. One in a hundred of those had massive planets "outside" them to mop-up incoming asteroids and the like with their gravity. One in a hundred of those had an atmosphere. And one in a hundred of those had an ozone layer and a magnetic core to protect any occupants from solar wind. How many would that leave habitable by us?

.01 x .01 x .01 x .01 x .01 x 8.8 billion = .88 of a planet, or, say, just Earth.

Mike
 
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MikeG said:
Well, let's just play with some numbers for a minute, for amusement.

Say for argument's sake that one in a hundred actually had water. One in a hundred of those had a large and close moon to keep the climate stable. One in a hundred of those had massive planets "outside" them to mop-up incoming asteroids and the like with their gravity. One in a hundred of those had an atmosphere. And one in a hundred of those had an ozone layer and a magnetic core to protect any occupants from solar wind. How many would that leave habitable by us?

.01 x .01 x .01 x .01 x .01 x 8.8 billion = .88 of a planet, or, say, just Earth.

Mike
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So does this mean God must exist?
 
wrs said:
So does this mean God must exist?
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Yes, unless you multiply by the number of galaxies in the universe.

But then if you divide by the likelihood that hebrew is developed it may prove that we don't exist. Barbie was right, math is hard.
 
Water is really common. Just about all of them will have water.
The moon's another story, that's a really rare event.
Gas giants are incredibly common.
Atmosphere depends on size, magnetic core depends on same. Earth-size is listed in the description.
Ozone layer is created by life.

Does this change your numbers?
 
Silly Green Monkey said:
.......Atmosphere depends on size, magnetic core depends on same.......
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Now hold on one cotton pick'n second.......:)

Atmosphere depends on size, does it? How come a close neighbour of ours, Mars, has a tiny, tiny atmosphere compared with us, despite being of comparable size? And I am pretty sure that having a magnetic core depends on having a lump of molten iron in the middle of the planet, and is nothing whatsoever to do with size.
 
MikeG said:
Now hold on one cotton pick'n second.......:)

Atmosphere depends on size, does it?
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No, at least not exclusively.

How come a close neighbour of ours, Mars, has a tiny, tiny atmosphere compared with us, despite being of comparable size?
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Mars has ~0.1 earth mass so it is not comparable to the earth. Despite this Titan has ~0.025 earth mass yet happens to have an atmosphere that's thicker than the earths.
 
Very cool, and yet ... We're the middle children. We were born too late to explore this world, and too early to explore all of these. :o

McHrozni
 
Arcade22 said:
......Mars has ~0.1 earth mass so it is not comparable to the earth.........
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Within one order of magnitude is very comparable, in the terms of the extremely loose discussion we were having, in my view. It makes my point for me.
 
wrs said:
seeking a motivation for result attained with the speculative numbers.
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I do have a motivation, indeed. It is to introduce an element of "hang-on-a-minute" to the excitement about so many planets potentially having life. Just to get people to stop and think. It is very easy to say "8.8 billion......there MUST be life on some of them", but actually, there are multiple reasons why there may not be, even on planets perfectly suited to harbouring life. It would be wonderful if there was, of course, but that sort of wishful thinking leads people to belief in all sorts of things from the Loch Ness monster through magic to fairies and god unless constrained by an element of "hang-on-a-minute".

Other than that, I have no axe to grind.......and certainly no religious perspective on any of this.
 
MikeG said:
Mars, has a tiny, tiny atmosphere compared with us, despite being of comparable size?
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Mars is only half the diameter of earth.


And I am pretty sure that having a magnetic core depends on having a lump of molten iron in the middle of the planet, and is nothing whatsoever to do with size.
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It has everything to do with size. If a planet is too small it will cool much faster and thus its molten interior will solidify. No molten interior, no magnet field. Mars has a huge volcano so it must have had a molten interior, but not any more. It cooled rapidly due to its small size.

Steve S
 
MikeG said:
Well, let's just play with some numbers for a minute, for amusement.

Say for argument's sake that one in a hundred actually had water.
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Which makes a stupid argument. Hydrogen is the most common element in the universe, and oxygen is the third most common. Consequently water is the most common chemical compound. If a planet is at the right distance from its sun to have liquid water at all, it almost certainly will have liquid water.
One in a hundred of those had a large and close moon to keep the climate stable.
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Jury is still out on how important large and close moon is. Mars does not have one, yet its climate does not vary wildly. From what I read in Icarus without Moon, Earth's axial tilt would vary from 0 to almost 90 degrees -- on the timescale of tens of millions of years. Plenty of time for life to adapt.
One in a hundred of those had massive planets "outside" them to mop-up incoming asteroids and the like with their gravity.
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Considering the number of giant planets already known, you are just being a troll.
One in a hundred of those had an atmosphere.
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Why would it NOT have an atmosphere if it is large enough to hold onto it? Once again, look at most common elements. Hydrogen, oxygen, carbon and nitrogen are all there. At the very least a planet will have a CO2 atmosphere.
And one in a hundred of those had an ozone layer and a magnetic core to protect any occupants from solar wind.
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Granted, a planet will not have ozone layer until it has free oxygen, which means photosynthesis, which means already fairly advanced life. So here you have a point.
How many would that leave habitable by us?

.01 x .01 x .01 x .01 x .01 x 8.8 billion = .88 of a planet, or, say, just Earth.

Mike
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Sorry, but your calculation is junk.
 
MikeG said:
Now hold on one cotton pick'n second.......:)

Atmosphere depends on size, does it? How come a close neighbour of ours, Mars, has a tiny, tiny atmosphere compared with us, despite being of comparable size?
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Mars is only 0.1 Earth's mass and has 0.38 surface gravity. Enough for air to escape.
And I am pretty sure that having a magnetic core depends on having a lump of molten iron in the middle of the planet, and is nothing whatsoever to do with size.
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The larger is the planet, the longer that lump stays molten because its heat content increases as cube of size, but the heat loss into space increases as square of size. Mars used to have a molten core -- it almost certainly had cooled down, hence lost magnetic field.

Basically, Mars is not "of comparable size" to Earth. It is much too small.

[Edited] I just looked at the article linked in OP. The researchers defined "Earth-size" as between 1 and 2 Earth radius. So Mars is entirely outside these 8.8 billion.
 
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kedo1981 said:
It also give us a place to look for tell-tale signs of massive infrastructure, FLT "contrails", signals.
Once we put up an interferometric telescope we might even start finding them and cataloging.
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.
Doesn't FTL increase the mass a LOT?
Just look for moving gravitational variations among the planets/stars.. and track those back to the source.
Easy.
 
OnlyTellsTruths said:
I was just wondering if there is a Jesus for every single planet, or is there just one Jesus for all of the planets.
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Scholars and theologists have pondered that question for centuries. I don't know what the current consensus is, nor what is the Catholic Church's official position.

The question itself goes waaay back. Already in 1277 the Aristotelian doctrine of there necessarily being only one world was condemned and plurality of worlds became accepted doctrine in the Catholic Church. From plurality of worlds there's only a small step to speculate about the possibility of alien life, and also the meaning of sin, incarnation of Logos, and redemption of Christ in that context.

Through centuries many positions and arguments have been presented. For example Guillaume de Vaurouillon (c. 1392 – 1463) argued that as aliens had not sinned like Adam, they would not need redemption by Christ, and in case of there being other sinful worlds the single death would cover those too: “As to the question whether Christ by dying on this earth could redeem the inhabitants of another world, I answer that he was able to do this not only for our world but for infinite worlds. But it would not be fitting for him to go to another world to die again”

OnlyTellsTruths said:
If he hangs out on each planet for around 30 years that would be over 100 Billion years! No wonder he hasn't been back.
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Guillaume would probably agree and say that indeed that would not be fitting.

But what if there were not only plurality of worlds but also plurality of Christs: one incarnation of Logos for each world in need of Redemption? Or what if there were Christs for every world whether they have sinned or not, and on those worlds that don't need Redemption he doesn't need to die but gets to chill around happily ever after? Through centuries arguments have been presented for those scenarios also. But as said, I have no idea what the current consensus may be - yet I think that if an alien civilazation is ever met someone will propose sending missionaries to save them.
 
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MikeG said:
I do have a motivation, indeed. It is to introduce an element of "hang-on-a-minute" to the excitement about so many planets potentially having life. Just to get people to stop and think. It is very easy to say "8.8 billion......there MUST be life on some of them", but actually, there are multiple reasons why there may not be, even on planets perfectly suited to harbouring life.
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That's a laudable goal, but your arguments are ridiculous. Much more plausible factor which may greatly decrease the number of habitable planets in the galaxy is too much atmosphere -- it is entirely possible that most of these Earth-size planets are similar to Venus rather than Earth. As I said, water is the most common chemical compound in existence, but carbon dioxide is also up there. We are lucky to have as little of it as we do.
 
MikeG said:
Well, let's just play with some numbers for a minute, for amusement.

Say for argument's sake that one in a hundred actually had water. One in a hundred of those had a large and close moon to keep the climate stable. One in a hundred of those had massive planets "outside" them to mop-up incoming asteroids and the like with their gravity. One in a hundred of those had an atmosphere. And one in a hundred of those had an ozone layer and a magnetic core to protect any occupants from solar wind. How many would that leave habitable by us?

.01 x .01 x .01 x .01 x .01 x 8.8 billion = .88 of a planet, or, say, just Earth.

Mike
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I would be interested to see a response from a knowledgeable astronomer/astrophysicist on these figures. My relatively uninformed reaction is that they are not very good estimates, as follows:
1/100 with water : too low; probably 1/10 or even higher.
1/100 with large moon : too high; probably less than 1/1000
1/100 massive gas giants in bigger orbits : too low probably 1/2
1/100 with atmosphere : too low; probably 1/2
1/100 magnetic core : too low; probably 1/5
As already stated the ozone layer is due to biological activity. I'm not sure how important a large moon would be to the creation and sustenance of life.

So, .1 x .001 x .5 x .5 x .02 x 8.8 billion = 4,400
If a large moon is not necessary, obviously it becomes over 4 million.
 
Mark6 said:
Which makes a stupid argument.
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Mark6 said:
you are just being a troll.
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Mark6 said:
your calculation is junk.
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Mark6 said:
That's a laudable goal, but your arguments are ridiculous.
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Well gee thanks, that's utterly charming.

In fact, my arguments are perfectly good in their context.......it is the plucking numbers out of thin air which obviously aren't. They were never meant to be, of course, as I stated right at the outset:
MikeG said:
Well, let's just play with some numbers for a minute, for amusement.

Say for argument's sake.......
Click to expand...
 
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MikeG said:
Well gee thanks, that's utterly charming.

In fact, my arguments are perfectly good in their context.......it is the plucking numbers out of thin air which obviously aren't. They were never meant to be, of course, as I stated right at the outset.
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My apologies -- I really thought you were being a troll. It is so easy to come up with much more realistic numbers, that your choice of values which are a) blatantly ridiculous and b) conveniently end up with ONE habitable planet in the galaxy, look very much like trolling.
 
Perpetual Student said:
.........I'm not sure how important a large moon would be to the creation and sustenance of life........
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Yeah, probably not that important to life itself, but to us and other complex multi-cellular organisms, it is a critical factor. The moon takes the wobbles out of the earth's orbit and rotation to a great extent, meaning we have a relatively stable climate. This has apparently been critical in allowing evolution to do its thing. The big close moon also produces the tides which create a half-marine-half-land zone, in which the first marine creatures to adapt to life on land were able to undergo the transformation.
 
MikeG said:
Now hold on one cotton pick'n second.......:)

Atmosphere depends on size, does it? How come a close neighbour of ours, Mars, has a tiny, tiny atmosphere compared with us, despite being of comparable size?
Click to expand...

I don't think so

earth-mars-size-comparison.jpg


MikeG said:
And I am pretty sure that having a magnetic core depends on having a lump of molten iron in the middle of the planet, and is nothing whatsoever to do with size.
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Actually you are right, its existence has nothing to do with size, but how long the molten core stays molten, DOES have a lot to do with size, the smaller the (rocky) planet, the smaller the molten core, the more quickly it cools.

Its is thought that Mars once had molten core and a magnetic field, but that the molten core cooled, so the magnetic field disappeared.
 
I read a scifi story about the Earth being visited...
in the winter time.
The visitors used some manner of positional glyphs for their writing.
For instance...
* *



* *
indicated a male.

***
indicated a female.

When they looked up and saw Orion, they left the Earth in a huff.
Too strait-laced to watch the glyph for *********** up in the sky...

* *


***

* *

:)
 
Perpetual Student said:
I would be interested to see a response from a knowledgeable astronomer/astrophysicist on these figures. My relatively uninformed reaction is that they are not very good estimates, as follows:
1/100 with water : too low; probably 1/10 or even higher.
1/100 with large moon : too high; probably less than 1/1000
1/100 massive gas giants in bigger orbits : too low probably 1/2
1/100 with atmosphere : too low; probably 1/2
1/100 magnetic core : too low; probably 1/5
As already stated the ozone layer is due to biological activity. I'm not sure how important a large moon would be to the creation and sustenance of life.

So, .1 x .001 x .5 x .5 x .02 x 8.8 billion = 4,400
If a large moon is not necessary, obviously it becomes over 4 million.
Click to expand...

Thank you, I was thinking similar thoughts.
 
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