[X] My Assistant

[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.