One big unknown: Did life ever take root on Mars? And if so, is that planet home to living organisms today? So far, the life-on-Mars card has not played out. Rover scientists have seen nothing they regard as needing a biological explanation.

here he says no life on mars

McKay said it is now clear water flowed across Mars. A lot of water, in fact. Furthermore, there may still be water spurting out onto the planet at certain times. "The same pendulum may be swinging back toward life," he said. "We’ll wait and see. These are exciting times."

here he mentions the possibility of life on mars. His probably restricted the definition of life to carbon based life forms that need water to survive.

Mars has all the conditions for life: water, energy, and organic substances, McKay pointed out.
...
In addition to that, from the meteorites, we think there’s evidence that, in fact, there was microbial life on Mars," McKay said.

very interesting, how would scientists know that the meteorites actually came from mars. I am intrigued.

So far, the Mars rovers have found no obvious fossils big enough to be clearly observed and credible.

It seems Mckay is just being hopeful, maybe to attract media attention. The more publicity shows that progress is being made. After all if there was extraterrestrial life out there it would show that we are not alone in the universe.

There is fear within the Mars research community, McKay continued, that a negative result would essentially kill the program. "I don’t think that’s the case at all."

A negative result, we don't even know what we're looking for??? Seems odd that the robots weren't equiped with the design specifications to search for life.

I think the most interesting prt of the article was this.

The Mars rovers represent an incredibly successful mission, McKay said. Moreover, they seemingly have "uncovered" a major find. He points to pictures taken by the rovers that show areas of the martian surface disturbed by the retraction of landing airbags.

Patches of surface "acted as a cohesive blanket of some sort" when the airbags pulled back, McKay explains. "It wrinkled…and pulled along rocks with it. It didn’t simply crack apart like a dried-up crust."

Why the soil reacted in such a manner remains obscure, McKay admits. "But one possibility is that this is the fossilized remains of a biological mat of some sort," he speculated. The mat would be made up of bacterial parts and pieces.

Its interesting that we may have already seen proof of life on mars and simply didnt have the tools to recognise t.

He points to pictures taken by the rovers that show areas of the martian surface disturbed by the retraction of landing airbags.

Patches of surface "acted as a cohesive blanket of some sort" when the airbags pulled back, McKay explains. "It wrinkled…and pulled along rocks with it. It didn’t simply crack apart like a dried-up crust."

Interesting, what does that have to do with fossils or life on mars?

He is hypothesising that it may be the fossil of a "microbial mat" a very early form of life.

If there IS life on Mars.... What would NASA or anyone else do besides just look at it?

I am sure that if they got their hands on some...well, it opens up a lot of possibilities.

Originally posted by websurfer
Seems odd that the robots weren't equiped with the design specifications to search for life.

That's exactly what I thought when I read that. You would think they could spend an extra couple of million and add some sensors to aid in the search. NASA really puzzles me sometimes.