I dont feel strongly about the 'Life on Mars' issue- I would like to see proof of life on a planet other than Earth... It would raise fascinating questions.

I am not qualified to really evaluate the methane issue, I dont have the data or the experience... however, I think I can raise some valid questions...

1) Do we really know enough to rule out natural chemical reactions on the surface of that alien planet- Carbon and hydrogen are there as is ionizing radiation... could those ingredients mix in a way to produce methane at low levels?

2) Volcanism could be the culprit, I guess, If we really find 'hot spots' for methane you could attribute them to localized outgassing from remnant volcanism, or to localized biological activity... (how would we know what was the cause? Localized concentrations of methane would be hard to attribute to one source over the other)

3) There are other possible sources, do we know what the natural, non biological influx of methane is in the form of 'snowballs' impacting mars?

Maybe these questions have been addressed- but they would just be the first questions I asked...

From what I have seen and know, these results are suggestive but not conclusive- this seems to be the way it is with Mars, as is the premature leaking of info before it is published.

My own opinion is that it is quite possible that life in a primative form once existed on Mars... how possible is pointless to debate since we have only one data point- Earth...
I do believe that IF there was life once on mars then it almost certainly there now. can you imagine a disaster capable of wiping out all life on earth? I cant.... short of our sun going Nova...

Microbes are living off of rock kilometers down here on earth... It would be hard to kill them off.

This is suggestive and very interesting, but not YET conclusive- I look forward to reading the article...

I have NEVER argued that there never was or is not now life on mars... I have argued that if there is then it is simple and not widespread....