Deep Impact Spectral Analysis Results, carbonates and amino acid precursors Options

[Guest_paulanderson_*]

This is the first source I've come across for this, an interview with Carey Michael Lisse, member of the Deep Impact Science Team and Principal Investigator for the Chandra X-Ray and Spitzer telescope Deep Impact spectrometer results:

http://www.earthfiles.com/news/news.cfm?ID...ategory=Science

Interesting results, including 50% + water ice, limestone-like carbonates and amino acid precursors, just presented at the 9th International Asteroids, Comets and Meteors Conference in Brazil.

[Bob Shaw]

This is the first source I've come across for this, an interview with Carey Michael Lisse, member of the Deep Impact Science Team and Principal Investigator for the Chandra X-Ray and Spitzer telescope Deep Impact spectrometer results:

http://www.earthfiles.com/news/news.cfm?ID...ategory=Science

Interesting results, including 50% + water ice, limestone-like carbonates and amino acid precursors, just presented at the 9th International Asteroids, Comets and Meteors Conference in Brazil.

Paul:

Some of the other articles are, er, 'interesting'. Let's hope the Deep Impact reportage is accurate!

NB, the Carbonates were explicitly described as being the result of a long, cold, watery process - nothing biological there, chaps!

Bob Shaw

[Guest_Richard Trigaux_*]

Paul:

Some of the other articles are, er, 'interesting'. Let's hope the Deep Impact reportage is accurate!

NB, the Carbonates were explicitly described as being the result of a long, cold, watery process - nothing biological there, chaps!

Bob Shaw

The very first data showed hot water. At least 50% of Comet Tempel I is water ice. The spectra also showed carbon dioxide and some yet unidentified organic material like graphite or carbon black. And Spitzer spectral data showed some surprises such as precursors to the aminos in amino acids. Those are hydrogen cyanide and methyl cyanide. Surprisingly, Deep Impact spectra also show carbonate - think limestone; and polycyclic aromatic hydrocarbons (PAHs) - think carbon Bucky Balls and nanotubes. I asked Dr. Lisse about his conclusions so far.

Nobody seriously hoped that their would be life on comets! But the fact is that we are now sure that they contain massive amounts of life precursors. That makes a ground for the theories as what comets may bring organic materials on planets, and even be the main or sole source of it.

There are arguments from looking at Hale-Bopp that the oceans can be no more than 30% to 40% comet-derived.

On the other hand, life precursors could also form on planets themselves, and anyway it is not sure that the complex chemicals brought by a comet may survive the impact. They may rather be burned by the heat or scattered in space. Only simple chemicals like water, cyanides, carbon and carbon oxydes would remain.

So the theory of comets providing organic matter is now possible, but not exclusive of others. For instance on Earth (and also Venus and Mars) there was an massive outgasing of mantellic carbon dioxyd (still going on on Earth) which certainly provided most of the today organic matter.

[Guest_RGClark_*]

Paul:

Some of the other articles are, er, 'interesting'. Let's hope the Deep Impact reportage is accurate!

NB, the Carbonates were explicitly described as being the result of a long, cold, watery process - nothing biological there, chaps!

Bob Shaw

But the key fact is that carbonates require liquid water to form. On Earth everywhere we find liquid water we find life.


Bob Clark

[Guest_RGClark_*]

On the other hand, life precursors could also form on planets themselves, and anyway it is not sure that the complex chemicals brought by a comet may survive the impact. They may rather be burned by the heat or scattered in space. Only simple chemicals like water, cyanides, carbon and carbon oxydes would remain.

So the theory of comets providing organic matter is now possible, but not exclusive of others. For instance on Earth (and also Venus and Mars) there was an massive outgasing of mantellic carbon dioxyd (still going on on Earth) which certainly provided most of the today organic matter.

I wouldn't d say "nobody" believed it. That's the main tenet of the theory of Panspermia. Note that there doesn't have to be current life on comets, just past life.
Note also that if this life only existed on comets early in the solar systems history, complex biological molecules may have decayed after millions or billions of years.



Bob Clark

[volcanopele]

But the key fact is that carbonates require liquid water to form. On Earth everywhere we find liquid water we find life.
  Bob Clark

On EARTH, everywhere we find liquid water we find life. Comet Tempel 1 is nothing like earth and one should be very careful comparing grapes to pumpkins.

[Guest_paulanderson_*]

Paul:

Some of the other articles are, er, 'interesting'. Let's hope the Deep Impact reportage is accurate!

NB, the Carbonates were explicitly described as being the result of a long, cold, watery process - nothing biological there, chaps!

Bob Shaw

Yes, I know, but I do think it is accurate as the quotes are from Mr. Lisse himself and I did hear the broadcast interview itself that this report is based on (Coast to Coast AM) where he is stating these results. I would just say the theory is that the carbonates are the result of a longer, colder process, but this will be debated for some time to come, I am sure...!

Paul

[Guest_Myran_*]

RGClark said; I wouldn't d say "nobody" believed it. That's the main tenet of the theory of Panspermia.

Somehow I just waited for someone to dig up poor old Arrhenius, but he wrote about his theory at a time when nothing was known about cosmic radiation and the charged particles of the solar wind. Precursors of life - yes! Our Suns T-tauri phase most likely cooked up one interesting stew of organic chemistry, but that would have happened in exposed places where they the same time were most exposed at to ultraviolet light (and you scientists can make a much better list than me about cosmic radiation etc than me.) So I view the chanse for life to develop on comets to be infinitesimal.

[Guest_BruceMoomaw_*]

It should be kept in mind that many of the carbonaceous asteroids had large amounts of WARM liquid water in their interiors, mixed with large amounts of complex organic biological precursors, for tens of millions of years -- much longer than the total liquid-water exposure time of the interior of any comet -- but show no sign of evolving life. As Chris Chyba says, that's one indication that the evolution of life may not be as easy and inevitable as is widely assumed nowadays, and it certainly speaks strongly against cometary life.

[deglr6328]

Ughhh I didn't even know that first link's association to THAT radio show until I got halfway down the page! Eeewwwwww, I feel all dirty now.

[Guest_BruceMoomaw_*]

Now, how can you say that? The item on the mystery of large numbers of "mutilated, bloodless kangaroos" being found in Australia was fascinating. If there's a pack of vampire kangaroos hopping around in the Outback, wouldn't YOU like to know about it before camping there?

Meanwhile, Hawaii's Jeffrey Bell tells me he's very skeptical of the carbonate detection, because carbonates aren't being found in the cometary dust particles collected by U-2s from Earth's stratosphere. Question: could vaporized carbonates have been formed on the spot in the very high-temperature gases produced by the Impactor's impact, out of the carbonaceous-chondrite dust and CO2 in the comet? Indeed, could both carbonates and the detected CO2 have been formed out of a quick reaction between the chondrite dust and the oxygen released by the high-temperature breakdown of water ice? (He also tells me that "Linda Moulton Howe... is a regular on the Art Bell show and has a long history of zany pseudoscientific beliefs. Back in the 1980s she pretty much created the modern myth of cattle mutilations by UFOs and/or black helicopters." However, I don't see any obvious BS in her quotes from Lisse, and Paul Anderson tells us he heard Lisse saying the same things in person.)

[Guest_Richard Trigaux_*]

Carbonates does not necessary need liquid water to form. They can also form in volcanoes, and there are several instances of carbnate lavas, in Africa and even in Europe. Carbonate lavas may form from phase separations in magmatic chambers, being not mixible with silicate lavas. I must confess I do not really understant how carbonates may sustain such high temperatures: when you heat limestone, it does not melt, instead it decomposes and form lime and carbon dioxid. Maybe carbonatite lavas are mixtures which melt at about 400-500° without decomposing.

And when we look at Temple II it really looks like a complex body exhibiting layers and varied structures. So it may be a part of a much larger body where many chemical reactions were possible. It may happen that even the coldest bodies in the Kuyper belt or Oort belt may have experienced ennough heat during their accretion to have liquid water inside. BruceMoomaw also have arguments to have some caution about carbonates.

That does not mean life, as life requires a constant source of energy to evolve, even the simplest living being consume high energy food and release low energy wastes. They need a medium with somewhere an energy source. Living beings are thermal machines (more complex, but the overal working of a food chain is that of a thermal machine) so they cannot exist in a medium in thermal equilibrium such as the hot inside of a newly accreted body. At best they could oxyde reactive chemical items, but this could last only a while, when the appearance of life may require millions of years.

Ughhh I didn't even know that first link's association to THAT radio show until I got halfway down the page! Eeewwwwww, I feel all dirty now.

I did not noticed no more. Personnally I am not closed to such matters as UFOs, crop circles and the like, but I must admit that most of the stuff published in these domains are only rumors and baseless statements. An example is that serious amateurs groups never found any real base or witness for the famous and infamous Roswell story. This was published in a french UFO review "Ovni presence" n° 54, on a study from the Centre for UFO Studies from Chicago, in 1989, and an inquiry by the US General Accounting Office in 1994. But what did you heard in the medias? That there was a movie with a Roswel corpse!! The owner of this movie awowed afterward it was fake, but the dollars he earned with it were not fake. So who is to blame? And who has the more reasons to be angry? The ones who try to search for the truth, whatever it is, who often spent years to inquire on baseless stories.

This was just a side remark, I do not intend to start a discution on these topics. Please start another topic if you are interested to reply.

[paxdan]

I've started a thread over in the commmunity section of the website to deal with hoaxing....

[Bob Shaw]

Bruce:

We don't have Art Bell here, I'm glad to say (yes, I know you *can* find him on the WWW if you want, but he's not corrupted the general public here in the UK in the same way as in the US). The trouble with even quite well-meaning people on the fringe is that they tend to have absolutely zero in the way of judgement, and similarly exhibit an inability to tell fun speculation from hard, established fact. It's always sad to see individuals with creative and enquiring (but often, er, 'unformed') minds having their intellectual processes corrupted. So I was rather wary myself of the original carbonate article, once I saw the company it was keeping...

I blame a lack of good (written) science-fiction in adolescence! Or, in my case, too much!

Bob Shaw

[edstrick]

There's a <deleted>-load about comets we don't know..but there's a lot we do know which gives us pieces of the puzzle.

There has never been a meteor photographed as part of a comet's meteor shower that lasted long enough and penetrated low enough into the atmosphere to have been a rock that could have survived entry. Decades ago, shower meteors were described as "having the mechanical strength of cigarette ash".... which makes loads of sense if they're bits of dessicated <well.. devolatilized> cosmic dust-bunnies.

Small comets like a comet Linear a couple years ago can disintegrate all on their own with nothing left other than dissipating dust clouds big enough for Hubble to see. Clearly, those objects don't have melted-and-refrozen slushball cores.

The parent object of the Kreutz <sp?> Sungrazer comets is believed to have been a monster to have split into so many substantial comets... Bigger than Hale-Bopp which was big.... Maybe it had a core that last rounded the sun in Cro-Magnon time and isn't coming back for another 5000 years, but the pieces it broke up into don't seem to have any more guts than Shoemaker Levy did. Kuiper Belt objects 200.. 500 km across proabaly did heat up inside, but how much is model dependent.. and a big unknown in the model is if any of the short lived radio-isotopes in the early solar system were still around when they accreted.

We have almost no idea how fine the ice grains in comet insides are, below any "rind" or "mantle" heated when a comet is in short period orbits. We have almost no idea of vapor transport within the comet.. barely know how volatile some of the ices are since we don't have any real inventory of the volatiles.... the Deep Impact flash data, and the plume data, both from the spacecraft and remote observations are telling us a lot.

Some of the ices may even be explosive. Take simulated Triton surface ices.. Water/Nitrogen/Methane frosts... Irradiate the mix with charged particles, it turns yellow with new compounds..... and it explodes when heated. There are crackpot therories of exploding asteroid/comet parent planets or ice-moons, with electrolytic chemical products in their interior making them timebombs waiting to go off... The theories overall are crackpot, but bits and pieces of them may well be valid. If we ever do get a cryogenic core sample return from a comet's interior, there's lab safety reasons to be sure it stays cold, besides science-value reasons!