Is it true that life chain started on earth transfer from a comet

[suntrack2]

May be Due to a comet which was fall on earth through which the life chain was started on earth, at the very first instance. Say for any type of life on earth like insects, human, animals etc. How they appear on earth ! Do you think that there is a duplicate of earth in this universe and that duplicate earth is very old than our earth!.

Or the first "life" was brought here only due to a comet struck on earth, eighter in the form of small and single cell bacterias !, and later that evolved.

what would be the short cut in finding life on another planet!

Or from the unknown destination life process was started. !

[NEOWatcher]

Nobody really knows, and from the general concensus that I hear, life here originated here. But; if panspermia is true, then why is it more likely that life started somewhere else?

My personal opinion is that it is equally likely for life to start on any suitable planet (including ours) which means that adding the complexity of riding on a comet makes it an unlikely scenerio.

[Moose]

There is currently no evidence whatsoever to suggest panspermia is possible, let alone happened. A prerequisite for this hypothesis is evidence of extra-terrestrial life.

[NGCHunter]

There is currently no evidence whatsoever to suggest panspermia is possible, let alone happened. A prerequisite for this hypothesis is evidence of extra-terrestrial life.

Suppose for a moment that in our future missions to mars we discover direct evidence of past or present life on the planet at some level and it seems to resemble life on earth (cell structure, dna, proteins, etc). Would that be suggestive of panspermia or only evidence that life is contagious between habital worlds in the same solar system, if even that?

[Neverfly]

Suppose for a moment that in our future missions to mars we discover direct evidence of past or present life on the planet at some level and it seems to resemble life on earth (cell structure, dna, proteins, etc). Would that be suggestive of panspermia or only evidence that life is contagious between habital worlds in the same solar system, if even that?

Did Viking sneeze?

[KaiYeves]

Well, I've heard that this is one possibility.
Viking was apparently sterilized, but we just found out that even our modern clean rooms are still full of germs, so it's possible that Viking was contaminated.

[eburacum45]

If comets were involved in the origin of life on Earth they didn't bring living organisms in from elsewhere. Comets form by accretion within a solar system, and there is no opportunity for them to acquire life. But perhaps comets did bring in the ingredients for life, not only water but quite possibly a number of other, more complex compounds too.

I wouldn't rule out Lithopanspermia yet, the transfer of living organisms from one planet to another inside rocks. Life may have started on Mars or Venus and been transferred here inside rocks which had been thrown into space following meteoric impacts. Or vice versa. But this doesn't imply that life could have been transferred via comets; any ice thrown into space by an impact would vaporise on route.

Despite Chandra Wickramasinge's enthusiasm for life from comets, I can't see any way of making it work. Comets are too volatile.

[Ronald Brak]

Suppose for a moment that in our future missions to mars we discover direct evidence of past or present life on the planet at some level and it seems to resemble life on earth (cell structure, dna, proteins, etc). Would that be suggestive of panspermia or only evidence that life is contagious between habital worlds in the same solar system, if even that?

Life with a seperate origin from life on earth will be quite different even if it uses DNA. There is now way it be mistaken for earth life if examined carefully.

[Moose]

Would that be suggestive of panspermia or only evidence that life is contagious between habital worlds in the same solar system, if even that?

It wouldn't vindicate panspermia. Not on its own, anyway. But it would make discussions of possible mechanisms a lot less pointless: "What color is a Nargle's eyes, anyway?" Show me a Nargle and we'll look into it.

[A.DIM]

There is currently no evidence whatsoever to suggest panspermia is possible, let alone happened. A prerequisite for this hypothesis is evidence of extra-terrestrial life.

There is plenty of circumstantial evidence which suggests panspermia is possible, yet still nothing can be deduced from the single example of life.

[transreality]

They've been one or two relevant articles lately. One on the baptista family of asteroids which may have been responsible for the end cretaceous extinction (65myr ago), after an asteroid breakup in the asteroid belt 160myr ago.

bapista asteroids kill dinosaurs (http://news.bbc.co.uk/2/hi/science/nature/6980468.stm)

or a recent nakhlites, martian meteorites that were ejected 11 myr from mars.

These shed light on the time that life must be expected to remain viable on comets for panspermia to be possible. In the simplest case from a one planet to the next: 10 myr, for something arriving from the asteroid belt 100myr, for something arriving from another star these numbers are going be billions and billions.

These are timescales way above the lifespan of biological species. That means to remain viable the species must be evolving on the comet, out in the frozen darkness, bombarded by cosmic rays, there is no way we can imagine life having any energy for any activity.

Since there is utterly no evidence for biological material, or any processes of life, on any airless body we have visited we should assume that this barrier is insummountable.

[3dknight]

ummmm I'm confused weren't the dinosaurs already dying off because of the separation of Pangea. The asteriod only sped up the process and I think the moon may have put life on this Earth when it first hit us. Moon cannot support life right now but if it could support it for a little time then transfer it to Earth a livable planet this could be possible and animals and insects didn't originate from the same the planet this is my theory. There to different.

[Neverfly]

ummmm I'm confused weren't the dinosaurs already dying off because of the separation of Pangea. The asteriod only sped up the process and I think the moon may have put life on this Earth when it first hit us. Moon cannot support life right now but if it could support it for a little time then transfer it to Earth a livable planet this could be possible and animals and insects didn't originate from the same the planet this is my theory. There to different.
They're too*
According to modern theories, the moon is a PART of Earth that seperated during a collision eons ago.
Animals and insects are indeed different. As are lobsters and crabs from mammals and birds.
Sea cucumbers and squid and octopi are pretty different too:think:
As well as amphipians and reptiles...
I think your theory about the origin of animals vs. insects doesn't hold water...

ETA: Dinosaurs were dying off because of Pangea?!?!
Where did you hear THAT theory?
The seperation of the continents was a very slow and gradual process. Slow enough for evolution to keep up.
In fact, the platetectonics involved is still at work today.:neutral:

[KaiYeves]

ummmm I'm confused weren't the dinosaurs already dying off because of the separation of Pangea.
Many events were occuring at the end of the Cretecious (I know it's spelled wrong) Period- massive volcanic erruptions, evolutions of new plants, climate changes, but the separation had already begun before the C. Period, which was when dinosaurs were at their most vibrant and diverse. The meteor impact theory is supported by layers of material- found in large quantities in asteroids, but uncommon on Earth- in the geological strata from the end of the C. Period.
So I remembered something from all of those dinosaur books I read as a little kid. That doesn't make me wierd or anything, does it?

[Neverfly]

Many events were occuring at the end of the Cretecious (I know it's spelled wrong)
Cretaceous

Period- massive volcanic erruptions, evolutions of new plants, climate changes, but the separation had already begun before the C. Period, which was when dinosaurs were at their most vibrant and diverse. The meteor impact theory is supported by layers of material- found in large quantities in asteroids, but uncommon on Earth- in the geological strata from the end of the C. Period.
Iridium Layer.

So I remembered something from all of those dinosaur books I read as a little kid. That doesn't make me wierd* or anything, does it?

Nope. It's the fact you remember the Ducktails theme song that makes you weird*.

[Neverfly]

KaiYeves, don't hit me!:D

[KaiYeves]

Cretaceous
Thank you. I can't spell big words for beans.

Iridium Layer.
Yup, that's it. But I always try to be nontechnical when explaining something.

KaiYeves, don't hit me!
Don't worry, I consider you a friend.

[danscope]

May be Due to a comet which was fall on earth through which the life chain was started on earth, at the very first instance. Say for any type of life on earth like insects, human, animals etc. How they appear on earth ! Do you think that there is a duplicate of earth in this universe and that duplicate earth is very old than our earth!.

Or the first "life" was brought here only due to a comet struck on earth, eighter in the form of small and single cell bacterias !, and later that evolved.

what would be the short cut in finding life on another planet!

Or from the unknown destination life process was started. !

Hi, Earth most probably got her oceans from impacts with comets.
We have a lot of water. When Earth was a molten orb, it likely did not have
the water.
Best regards, Dan