Sorry about that Nick.

That's really bizarre. The link works straight from Google News but not from here. They must be filtering.

PASADENA, Calif. - The rover Opportunity took its first roll on martian soil Saturday, and scientists offered the most tantalizing evidence so far that the landing site once lay in liquid water.

While ice still exists near the poles, most of Mars is devoid of water, liquid or frozen. But some scientists believe Mars was warm and wet early in its history and may have possessed an environment where life could have arisen. The $820 million mission of Opportunity and its twin, Spirit, is to look for signs of liquid water in Mars' distant past.

At a news conference Saturday at NASA's Jet Propulsion Laboratory, Dr. Philip Christensen, a professor of geological sciences at Arizona State University, confirmed that an instrument aboard Opportunity had detected the iron oxide hematite in the pebbles and gravel that dot the landing site.

Furthermore, Christensen, the lead scientist for the instrument, said, "I think the preliminary evidence is consistent with hematite forming at low temperatures in chemical reactions with water."

The instrument, called the minithermal emission spectrometer, looks at infrared light radiated from rock and soil. Certain minerals, including hematite, emit a distinctive mix of infrared light.

Hematite that forms at low temperatures from sediments at the bottom of a lake or sea has a noticeably different infrared signature from hematite that forms out of hot lava without water. Christensen said that infrared data argued against lava.

Hematite is what drew scientists to this location, the flat plains of Meridiani Planum, near the equator. From orbit, the Mars Odyssey spacecraft spotted a deposit of hematite the size of Oklahoma blanketing the area, but it could not tell whether the hematite was in the soil or the rocks or elsewhere. Opportunity was sent to investigate, and researchers hope to learn not only where the hematite is, but also its origin.

Already, the infrared instrument has provided some clues.

While the pebbles and gravel contain hematite, the fine reddish soil below does not. The exposed, light-colored bedrock 20 feet from Opportunity is also free of hematite. Christensen said the pebbles must have come from a rock layer, not yet seen, above the light-colored bedrock that had eroded away into pebbles.

"It's got to be there somewhere, and if we're lucky, we'll find it," Christensen said.

Scientists will soon have a better look.

At 4:50 a.m. Saturday, Opportunity made its first drive, rolling 10 feet off the front of its lander, its six wheels then digging into the dirt. It will sit there for the next few days, conducting experiments on the soil beneath it, before moving on to the bedrock.

Scientists have no idea what the bedrock is made of.

"All I can say at the moment is what it's not," Christensen said. The instrument readings showed no hematite, no quartz, no carbonates.

A suite of instruments that Opportunity will press against the rocks should tell more about the minerals there. For instance, if scientists find goethite -- essentially hematite with trapped water -- that would strengthen the argument for water in the past.

"Or perhaps we'll actually *learn* something about Mars if we stop trying to shoe-horn it into our preconceptions ? :-)"

You're asking WAY too much there...preconceptions are as second nature as breathing. To suspend our expectations and insert a blank sheet makes us all uncomfortable. Like visiting a friend's house for the first time - we plug in what we know of our friend and imagine the decor we will see. Imagining empty rooms is unthinkable.

As for my WAG...I thought it would be a fun exercise to paint out a non-greenhouse solution to the loss of any preconceived ancient oceans. Of course if the oceans were never there to begin with, that would make it much easier to explain their disappearance. ;-)

That leaves Hellas Basin still posing somewhat of an enigma.

SDAI-Tech1