Freethought & Rationalism Archive

LiveFreeOrDie · 04-06-2002, 04:44 AM

I saw the following article on CNN that suggests there may be chlorophyll on Mars:

<a href="http://www.cnn.com/2002/TECH/space/04/05/mars.green/index.html" target="_blank">http://www.cnn.com/2002/TECH/space/04/05/mars.green/index.html</A>

If this speculation indeed turns out to be true, what are the implications for evolution and more importantly for abiogenesis?

lpetrich · 04-06-2002, 08:16 AM

I'd be surprised if this finding holds up; I don't see what's so special about Earth chlorophyll. Many Earth plantlike organisms use additional ones called carotenoids and phycobilins, and I'm sure that some extraterrestrial plantlike organism may use something other than chlorophyll.

<a href="http://www.ucmp.berkeley.edu/glossary/gloss3/pigments.html" target="_blank">http://www.ucmp.berkeley.edu/glossary/gloss3/pigments.html</a>

Valentine Pontifex · 04-07-2002, 07:45 PM

The first thing to notice is that the researchers work for what is becoming an increasingly disreputable source for life in space claims: NASA. NASA as of late has been really pushing anything that could even be the slightest hint of extra-terrestrial life no matter how flimsy. Its motivation for this is clear: the desire to promote its programs and obtain more money. I am really sorry to say this, because if I were made supreme dictator the money for planetary probes would go up astronomically. I support more space missions and research, not the low standards NASA is stooping to got try get there.

I found the abstract <a href="http://www.astrobiology.com/asc2002/abstract.html?ascid=371" target="_blank">here</a>:

Quote:

The Superpan, an image product from the Pathfinder lander camera, is a multispectral panorama of the Pathfinder landing site acquired in 15 wavelengths in the spectral range 440 - 1100 nm. We have performed an automated search of the Superpan image cubes for the spectral signature associated with chlorophyll. First, images were calibrated to radiance values and then the multispectral images were co-registered to subpixel accuracy. An automated pixel-to-pixel search was performed on a 3-filter set of images (530 nm, 670 nm, 980 nm) to identify pixels where the following condition was met: 530 nm > 670 nm, and 980nm > 670 nm. Thus, we searched for the spectral signature associated with red light absorption by chlorophyll. When this case was met by the search routine, we plotted a full spectrum for the involved pixels and carefully examined the images. The condition was met for small areas in six image cases. All of these cases occur in near field images, where resolution is highest. Four of the cases occur on the spacecraft and appear to be associated with spacecraft structure. Two intriguing cases occur in small areas on the ground near the spacecraft.

Judging from this abstract it was worse than I imagined. This would have considered laughable if trying to find x molecule not associated with life. I would seem to me that they should "find" chlorophyll from this procedure purely by chance. There needs to be some sort of control procedure here and it does not sound like they have done so. And 15 wavelengths does not make a spectra, at least not a spectra detailed enough to identify chlorophyll. There just has to be who knows how many compounds or mixtures of compounds that would like similiar the chlorophyll looking at only 15 wavelengths.

LiveFreeOrDie · 04-08-2002, 05:13 AM

Did you have to go and spoil my fun?

I thought this might make an interesting "what-if" discussion, but I guess I was mistaken. Oh well...

Oolon Colluphid · 04-08-2002, 06:29 AM

Quote:

Originally posted by LordValentine:
<strong>
NASA as of late has been really pushing anything that could even be the slightest hint of extra-terrestrial life no matter how flimsy. Its motivation for this is clear: the desire to promote its programs and obtain more money. </strong>

Sorry, off-topic, but it makes one wonder why they bother, since the evidence from UFOs is pretty unequivocal: we're being visited by extraterrestrials...

IOW, surely one of the most obvious arguments against such visitations is the fact that NASA -- who'd surely know about it if true -- have to scrape around so apparently desperately for signs of extraterrestrial life to keep the funds coming in.

Oolon

Oolon

Dr.GH · 04-08-2002, 10:10 AM

NASA's money tap is also IMO the source of the renewed interest in "panspermia" notions appearing recently in the lit'.

04-06-2002, 04:44 AM	#1
LiveFreeOrDie Junior Member Join Date: May 2001 Location: Milwaukee, WI, USA Posts: 77	Chlorophyll on Mars? I saw the following article on CNN that suggests there may be chlorophyll on Mars: <a href="http://www.cnn.com/2002/TECH/space/04/05/mars.green/index.html" target="_blank">http://www.cnn.com/2002/TECH/space/04/05/mars.green/index.html</A> If this speculation indeed turns out to be true, what are the implications for evolution and more importantly for abiogenesis?

Thread Tools	Search this Thread
Show Printable Version	Search this Thread: Advanced Search

04-06-2002, 08:16 AM	#2
lpetrich Contributor Join Date: Jul 2000 Location: Lebanon, OR, USA Posts: 16,829	I'd be surprised if this finding holds up; I don't see what's so special about Earth chlorophyll. Many Earth plantlike organisms use additional ones called carotenoids and phycobilins, and I'm sure that some extraterrestrial plantlike organism may use something other than chlorophyll. <a href="http://www.ucmp.berkeley.edu/glossary/gloss3/pigments.html" target="_blank">http://www.ucmp.berkeley.edu/glossary/gloss3/pigments.html</a>

04-08-2002, 05:13 AM	#4
LiveFreeOrDie Junior Member Join Date: May 2001 Location: Milwaukee, WI, USA Posts: 77	Did you have to go and spoil my fun? I thought this might make an interesting "what-if" discussion, but I guess I was mistaken. Oh well...

04-08-2002, 10:10 AM	#6
Dr.GH Veteran Member Join Date: Jul 2001 Location: Dana Point, Ca, USA Posts: 2,115	NASA's money tap is also IMO the source of the renewed interest in "panspermia" notions appearing recently in the lit'.

Freethought & Rationalism Archive

The archives are read only.