Almost saying the forbidden word
Now, twice during NASA’s news conference, scientists danced very close to this line. They had the word on their minds, it seems, and they were determined not to pronounce it. Instead, they talked around it.
With what looked to me with a gleam in his eye, project scientist Stephen Squyres gave some background about the mineralogy in the crater that Opportunity had done its exploring of the bedrock layers.
"What kind of rocks preserve signs of ancient life?” he mused. “Minerals that precipitated from water. They can trap the evidence for that." And the minerals at Opportunity's site are exactly such minerals, the results indicate.
MIT’s Dr. John Grotzinger, in response to a question, cautioned that even on Earth, fossils were very rare in ancient rocks. But he too mentioned off-hand that "these minerals [provide] ideal candidates to be time capsules, to preserve something that was there."
“If there are fossils, though,” he continued, “in order to be recognized as such they'll have to meet ‘the Knoll criterion.’” This is named after Andrew Knoll, an expert on fossilized Earth bacteria who is on the mission science team. He is the author of “Life on a Young Planet.”
Morton explains: “The Knoll criterion is that anything being put forward as a fossil must not only look like something that was once alive -- it must also not look like anything that can be made by non-biological means.”
And so far, on Mars, we’ve obviously just scratched the surface on the non-biological surprises that the planet has to offer. So however much we may be tempted by exotic shapes, we aren’t justified in classifying them with what on Earth we can prove were formed by living things.
Originally posted by WestPoint23
why would it be hard to find fossils on mars here on earth if we look at river beads or where once ocean floors had been we find a lot of fossils and aren't these the places that the rovers are looking at on mars.