Life.

[Sayonara]

The chances of this object getting here is the same as any other "seed" planet I would think , as the "seed" needs to grow when stimulated by a chemical reaction .

I'm not sure I follow.

[Verusamore]

Ok ,sorry if you misunderstood me I didn't bother to check about what I wrote,I feel silly ,

 

the miniscule chances of it actually getting here and not going to any of (literally) countless other destinations

If there are various objects in space flying around & one being an asteroid,then the chance of that hitting a planet is the same as any other planet .

 

It was just luck that Earth already provided the chemicals to support further potential life to grow when this event unfolded .

 

the time needed for life to arise on its body of origin, I think the idea that life was seeded here by one impact (or a shower of impacts) is even less likely than life simply arising here to begin with.

Life began here some time when major changes were occuring on Earth or and our Solar System .

I would agree to the impact theory also or else it may have been some evolution involved as the influence of the Sun and the effects on the Solar System changed ( which I think is possible that life could have arised here )

[us.2u]

It maybe or may not be luck life grew here by impact or natural earth resources but whether it did or not we're still just one of many planets in space. What I am convinced of though is we're not "alone" I would like to personally believe any constellation that can support a planet with the rudimenary ingredients i.e. heat oxygen water e.t.c. or whatever life needs to survive will occur & evolvement will be a natural phenonema, I think to try & believe we're the only ones is outrageous

[Verusamore]

What about the size & mass of a central star like our sun ?

 

That would play a supporting factor on whether life exists on those planets wouldn't it ?

 

Do you think if another system of planets existed that it would have also a sun which is able to balance and sustain life ?

[Sayonara]

If there are various objects in space flying around & one being an asteroid,then the chance of that hitting a planet is the same as any other planet.

My point was pretty much exactly that, but you are seeing it from the point of view of Earth's chances of being hit as being "just as good" as any other body. I'm not disputing that at all - Earth is nothing special in floating rock terms. What I am saying is that the chances of Earth being hit by life-bearing extrasolar masses are infinitesimal, just as they are for any other planetary body in any other large star system.

 

If an object somewhere in the universe is suddenly accelerated, the chances of it arriving in our solar system are somewhat remote.

 

Assume it does, however: the chances of it then avoiding Jupiter's gravity well, the sun, the asteroid belt, the Kuiper belts, or just shooting straight out of the system again, and instead hitting Earth, are also somewhat remote.

 

The chances of any extrasolar object that makes it to Earth just happening to be from a body that supported life or prelife, or carrying organic compounds that could trigger life, any and all of which are required to have survived a trip of millions of years duration through goodness knows what harsh conditions, are also pretty slim.

 

Put that all together with the added requirement that this must all take place within a window of around 6 billion years (at the most), and it doesn't seem very likely at all.

 

 

It was just luck that Earth already provided the chemicals to support further potential life to grow when this event unfolded

That's not actually based on anything. You are embellishing supposition with speculation.

[Verusamore]

It was just luck that Earth already provided the chemicals to support further potential life to grow when this event unfolded

 

Ok it may not be luck but the same chances as to finding other life in outer space .

 

"That's not actually based on anything."

 

I made that ground based on ;

" As the Earth formed out of rocky snowballs it grew hot and probably melted. One theory is that early in its history a large object hit the Earth, which threw out a shower of rocks .These collected together to form the Moon. If it is true this would certainly have made the Earth melt.."

http://www.historyoftheuniverse.com/earthori.html

 

Anyone know of other possible 'rocky snowballs' ?

 

with my relevance to premise ;

chemicals to support further potential life to grow when this event unfolded

 

If other planets consist of other chemicals / gases that which on Earth do not give equal to our conditions then I say that we out of all were the most likely planet being able to support life than the rest.

[Sayonara]

I'm going to go back to "I'm not sure I follow", because this is not looking very consistent.

[Ophiolite]

Sayonara you don't need to have a life bearing 'object' arrive from another planet. Life, or at least precursors more advanced than polypetides are pre-assebled by natural chemistry througout the vastness of interstellar gas clouds, so when one of these clouds condenses to form a planetary system the planets are literally deluged not only with prebiotic material, but quite probably primitive life as well. The Earth, is the only one (probably) where conditions remain tolerable for 4 billion years so that we are still here. Yes, this is a minority view, but it is a soundly based alternative. Please stop knocking

[Ophiolite]

Damn. hit the wrong key before I finished and it wont let me edit.

Last sentence is incomplete. It should read

"Please stop knocking panspermia until you have studied it a litlle more rigorously."

[TimeTraveler]

I tend to think that the compounds for life have always been on Earth, I am sure there were many conditrions in early Earth that prevented life from taking off earlier (impacts, temperture variations, mixtures finding each other, ect), but eventually it all came together and formed. I believe Mars and Venus were both similar to Earth in the early part of the formation, but due to temperature, life was never able to form on venus and its water was evaporated into space, and mars well it had flowing water at one point, but it seems that we have found some very interesting things about the tilt of Mars' axis that may explain what happened there. Needless to say it was very cold and did not come together (at least not for any long period, long enough to progress the evolution beyond the basic stages.

 

Things do not have to come together exactly like our solar systems but a terrestrial planet would need similar conditions I think to form and evolve life. I would think Jupiter played a role in attracting debri that may have hindered the development also.

[Sayonara]

Damn. hit the wrong key before I finished and it wont let me edit.

Last sentence is incomplete. It should read

"Please stop knocking panspermia until you have studied it a litlle more rigorously."

I am not knocking panspermia (which' date=' I am fairly certain, [u']does[/u] require the arrival on Earth of biotic matter - there is no life or precursor that would survive planetary condensation), I am knocking the idea of exogenesis from a point extrasolar source.

 

I have no opinion either way on panspermia, for the record. Directed panspermia is - in fact - a good way to get around the infinitesimal odds problem.

[Bettina]

When trying to imagine the chances of a life bearing comet connecting with earth, don't forget that the planets, etc, were much closer together than they are now, and there was a lot more junk flying around.

 

Bettina

[Sayonara]

I wasn't simply considering the chances of a life-bearing comet connecting with earth.

 

I was comparing the chances of a life-bearing body of extrasolar origin connecting with Earth, to the chances of a solar body hitting Earth or life simply arising here in the first place.

 

I really don't see what is so difficult for everyone to understand with that.

 

Regardless, you all need to consider that all three scenarios require life precursors to (a) originate somewhere, and (b) be on Earth. Therefore precursors originating on Earth is by default the most likely scenario, as one of the probability-mediated requirements is already fulfilled (i.e. getting here).

 

The order of likelihood goes like this:

 

- Originated here on Earth: Likely (well, probability=1 actually but we'll leave that for now),

 

- Originated in this system: Less likely,

 

- Originated somewhere else: Highly unlikely.

[coquina]

I just found this site which gives a concise overview of astronomy.

 

http://csep10.phys.utk.edu/astr161/lect/

 

While it doesn't directly talk about the origin of life it does explain the formation of the solar system.

 

As to the "pan spermia" idea - comets are thought to have originated within the solar system - quote from this site:

http://zebu.uoregon.edu/~js/glossary/oort_cloud.html

 

Oort Cloud :

Comets also are cosmic debris, probably planetesimals that originally resided in the vicinity of the orbits of Uranus and Neptune rather than in the warmer regions of the asteroid belt. Thus, the nuclei of comets are icy balls of frozen water, methane, and ammonia, mixed with small pieces of rock and dust, rather than the largely volatile-free stones and irons that typify asteroids. In the most popular theory, icy planetesimals in the primitive solar nebula that wandered close to Uranus or Neptune but not close enough to be captured by them were flung to great distances from the Sun, some to be lost from the solar system while others populated what was to become a great cloud of cometary bodies, perhaps 10 trillion in number. Such a cloud was first hypothesized by the Dutch astronomer Jan Hendrik Oort.

 

 

If this hypothesis is correct, and comets did originate within the outer reaches of the solar system, but were flung into the Oort Cloud, it doesn't seem that they would already contain life.

 

The fact that they are mainly frozen water, methane and ammonia might mean that they brought the materials that could form life to earth.

 

That - together with the fact that the earth is tectonically active, and has a molten core and volcanic activity, which provides a heat source, leads me to believe that live originated here on earth.

 

That is not to say that life could not have originated independantly within other stellar systems.

[Sayonara]

That is not to say that life could not have originated independantly within other stellar systems.

Or even within this system.

[Guest dracul89]

I recently watched a report that was actually diiferent then pan spermia recent studies have shown the the earth is nightly subjected to new bacteria from space yes this means we are all E.T's I think there maybe a reference on http://www.pbs.org I think it was nova I was watching essentially they collected sample from the upper atomsphere that had living organisms in it. so this suggest live does not evolve on earth but in space.

[Sayonara]

No, that suggests a really poorly-devised study.

[Guest dracul89]

well it is already been proven that microbes can survive extreme cold and extreme heat massive pressures that would kill us and they don't need oxygen

[Bettina]

The order of likelihood goes like this:

 

- Originated here on Earth: Likely (well, probability=1 actually but we'll leave that for now),

 

- Originated in this system: Less likely,

 

- Originated somewhere else: Highly unlikely.

 

 

Sayonara, I enjoy reading your posts and I don't disagree with you at all except the part where you say highly unlikely. I don't think that life just started here. I'm a tough sell, and I read a lot so my mind is open and still developing. When I read more, I'm going to come back and chalenge that last line......

 

Bettina

[Sayonara]

I apologise, that was an ambiguous line. It should have read:

 

- Originated somewhere else and started life off here: Highly unlikely.

 

The second line should also have that additional bit for accuracy. I am quite sure life is probably common in the universe.

[TimeTraveler]

Straying slightly off-topic, how would gravity effect the origins of life forming? Could life develop in zero gravity? It's been documented life can live in zero gravity but can it form there?

[MOTP]

I haven't read more than the first post, so I may be repeating what someone else has said.

 

Life can be defined as a complicated chemical reaction where chemicals are created to bind other chemicals together in an organized, repeating pattern. This pattern can also be shifted in the environment to adapt to the environment, ie keep a pattern going longer. Life must draw on outside resources because energy is always lost.

 

Thus, it makes sense that if life has to survive, it must be able to "be aware" of its external environment. Intelligence, of course, comes from higher levels of awareness.

 

It's curious to note that biologists will tell you that chemistry is the "structure of life", whereas chemists will tell you that biology is a coincidental consequence of atoms interacting.

 

There are more than 100 elements, and a ridiculous number of possible compounds. What we have witnessed, DNA, amino acids and the rest are a remote possibility that itself has many different possibilities.

 

If life exists elsewhere, we must bypass our rules of thumb, and instead look at the overall chemical picture. In this way it is possible that all of terrestrial life itself is a unified species.

[us.2u]

I guess we should experiment with "caterpillars" they can survive in over -200 farenheit; which is amazing so my guess is, they could probably survive zero gravitity too, but that's sheer optimisim...

[Sayonara]

There are more than 100 elements' date=' and a ridiculous number of possible compounds. What we have witnessed, DNA, amino acids and the rest are a remote possibility that itself has many different possibilities.

 

If life exists elsewhere, we must bypass our rules of thumb, and instead look at the overall chemical picture. In this way it is possible that all of terrestrial life itself is a unified species.[/quote']

As JaKiri just bellowed in another thread, "carbon can make more compounds than all the other elements together".

[us.2u]

Well Sayonara I think that's more than likely that we're all reelated one way or another especially if we are of this solar system then we all obviously depend on light for life which our sun delivers I think Sayonara you are 100% correct....