Evidence of life from a comet?

[MillCreek]

http://www.technologyreview.com/view/512381/astrobiologists-find-ancient-fossils-in-fireball-fragments/

Interesting first look at cometary fragments.  Some opinions that evidence of fossilized algae is found inside and cannot be explained by Earth-borne contamination.  It will be interesting to see what conclusions come out of further research.  I wonder if this may actually be the first known evidence of life elsewhere.

[makattak]

http://www.slate.com/blogs/bad_astronomy/2013/03/11/meteorite_life_claims_of_fossils_in_a_meteorite_are_still_wrong.html


His take down is pretty good.

[MillCreek]

I wonder if this will be another ALH 84001 situation.  As far as I recall, there is still no consensus as to if the findings in that meteorite are definitely due to biological activity or are definitely not.

[Tallpine]

I wonder if this will be another ALH 84001 situation.  As far as I recall, there is still no consensus as to if the findings in that meteorite are definitely due to biological activity or are definitely not.

A definite maybe, maybe 

[vaskidmark]

So, if this report is accurate, we are most likely aliens from outer space?

If so, will we have to re-do all the 1950s sci-fi movies?

stay safe.

[AJ Dual]

So, if this report is accurate, we are most likely aliens from outer space?

If so, will we have to re-do all the 1950s sci-fi movies?

stay safe.

It makes a certain sense. Smaller bodies like Mars would have cooled faster and held liquid water sooner than Earth, which would have been molten longer, both due to it's size, then later on from it's impact with Thea which obliterated the Earth once again then made the moon etc.

Meteorite ejecta carrying single cell organisms does the rest.

[Tallpine]

So, if this report is accurate, we are most likely aliens from outer space?

That actually makes as much sense as macro-evolution.

Sort of begs the question of how the aliens got started ...  

I'm guessing that we eventually develop time travel, and send some folks back to be our ancestors  

[Ron]

The wiki article on the Fermi paradox, also touching on the Drake equation and other theories pretty much allows me to dismiss this stuff out of hand.

In the unbelievably unlikely event extraterrestrial life is found I'm thinking it will be clear cut and undeniably alien.  

In the meanwhile I'm a skeptic based on the observed data.

Some folks have more faith in ET(certainty more than faith) than others show in their/our God.

edited for clarification

[AJ Dual]

The wiki article on the Fermi paradox, also touching on the Drake equation and other theories pretty much allows me to dismiss this stuff out of hand.

In the unbelievably unlikely event extraterrestrial life is found I'm thinking it will be clear cut and undeniably alien.  

In the meanwhile I'm a skeptic based on the observed data.

Some folks have more faith in ET(certainty more than faith) than others show in their/our God.

edited for clarification

Eh... amino acids found in comets etc. (no guesswork, this is confirmed) are the same common ones on Earth. And stuff from the Kupier Belt and Oort Cloud does not have much chance of ever having traded with Mars or Earth.

Although there can be variations. There are various "left handed" and "right handed" variations of many complex organic molecules. You could synthesize, or perhaps evolve left-handed DNA and RNA, sugars, various proteins etc. An alien planet where the life used as many left handed molecules as possible, assuming it's not poisonous, and tastes good, it would be the ultimate diet food. 

You could also argue that there's "alien life" on Earth now. There are still some holdover archaea class bacteria that live in the ground to this day that are arsenic based, rather than phosphate. We use the coenzyme Adenosine Triphosphate (ATP) which iin our DNA and other cellular processes, these organisms use similar arsenic compounds. And this is why arsenic is a metabolic poison to us, because it pokes out the phosphorus and screws up those functions...

That's a pretty basic and very early "fork" in the 'ol tree of life.

[Ron]

Big surprise, creatures that consist of elements and compounds exist in a system where we find those elements and compounds  

Just because something is an alternative life form to what we normally find doesn't mean it is alien to earth.

All that really tells us is that life thrives on earth, even life that is different from what we initially assumed about life.

Conjecture and faith, or hope if you will, run rampant in the "scientific" community where it concerns ET.

Turns out scientists don't want to be alone in the universe either ha ha ha

[Tallpine]

I'm a skeptic based on the observed data.

It's a pretty big universe out there. 

[Ron]

It's a pretty big universe out there. 

Keep the faith 

[Tallpine]

Keep the faith 

I don't know if there is intelligent life in outer space, but I can't think of a better place to look 

[makattak]

Since no one seems to have read my link, allow me to quote:

They still haven’t established this rock is even a meteorite at all! They make this claim many times in the paper, but they do so without firm proof. They examined the rock using various methods, but none of them establish the sample as being a meteorite. Quite the opposite, in fact.

And again, let me point out that they didn’t go to an outside lab to substantiate their results. Not their conclusions, just their data. It’s no hardship to chisel off a piece of a rock and send it to a lab for analysis; they did it for themselves, so why not get someone else to do it as well?

So, they find some rocks, they claim (without enough  evidence) that they're meteorites, and they claim (without evidence) they're from a recent meteorite fall. They find diatoms, and they claim (without controlling for contamination) that not only these diatoms came from space, but that meteorites like this seeded Earth with life.

Which is more likely: that, or that they found a rock from Earth that already had diatoms in it? Just like essentially any porous rock you find in a wet area?

...

Their claims are, down to a one, extraordinary, with pretty underwhelming evidence to support them. So the idea that these are ordinary rocks found in wet conditions under no control that have been sitting around a long time and are therefore loaded with diatoms that evolved here on good ol’ planet Earth seems just a tad more likely to me.

In my opinion, Wickramasinghe and his team are not just wrong, they are precisely wrong: Life didn’t crawl from this rock onto the Earth, life crawled into this rock from the Earth.

[HankB]

I think it's silly to discount the possibility of ET life.

But I have yet to see compelling evidence of it. (Although some ancient artifacts do make me go "Hmmmm . . .?  ")

Someone mentioned the Drake equation . . . I like Michael Crichton's critique of it:

"The problem, of course, is that none of the terms can be known, and most cannot even be estimated. The only way to work the equation is to fill in with guesses. As a result, the Drake equation can have any value from "billions and billions" to zero. An expression that can mean anything means nothing. Speaking precisely, the Drake equation is literally meaningless."

[Ron]

Hey Mak! I read your linked article.

Hank, the Wiki article mentions how the Drake equation has been used to both "prove" and "disprove" the idea of life somewhere else in the universe!