[TheCrusader]

"Ammonia is not a stable molecule in the Martian atmosphere. If it was not replenished in some way, it would only last a few hours before it vanished."

Right. It could also mean that the Martians are mass-producing Windex at a low inter-galactical price.

This whole 'life-on-Mars' hypothesis is based on the scientists' hope to prove their pet theory. Without being educated in science I can still say with absolute certainty that today's scientific 'facts' very often become tomorrow's follies when they learn more. If you research with an open mind you'll let your findings simply lead you to where they will. If you're goal is trying to prove that there is/was life on Mars then you'll hang on to whatever straw you can find, and allowing the detection of amonia to make you conclude there's life on Mars is just that, grasping at straws.

I wish them all good luck on their Martian hunt.

[jennyp]

This whole 'life-on-Mars' hypothesis is based on the scientists' hope to prove their pet theory.

And the problem is...?

Without being educated in science I can still say with absolute certainty...

Ah. As I suspected.

[RadioAstronomer]

This whole 'life-on-Mars' hypothesis is based on the scientists' hope to prove their pet theory.

What "pet theory" is that? Do you know what it takes for a theory to become a theory in science? Hint, it's not just some WAG.