PASADENA, California -- The message from Mars is clear. After decades of collective scrutiny by robotic orbiters and landers, the red planet is a bewildering world still holding tight details as to its warmer and wetter past and conditions active today.

"Were still in for surprises," said Arden Albee, scientific organizer of the conference and planetary scientist, emeritus, at the California Institute of Technology, the lead sponsor of the meeting.

"There is an incredible amount of new data. People are working furiously to understand what they have in hand. And we are just about to get another infusion of surface data," Albee told SPACE.com. Perceptions about Mars history and its current standing are being put to the test, he said.

Albee said the role of water and the possibility of life on Mars remains arguable, just as it has been at earlier conferences.

So too are debates in a trio of research areas: The role of water in the climate of early Mars; todays reservoir and localities of water ice; and enticing evidence for very recent liquid water flowing on the planets surface.

"I think were tantalizing close to getting some answers there," Albee said.

A new twist on the Mars research trail, Albee said, is access to data by a broad community of investigators, from students to professionals of various disciplines.

It used to be that NASAs Jet Propulsion Laboratory (JPL) had all the imaging processing locked up in a division. Thats no longer the case. People now have direct access to Mars data using off-the-shelf computer systems. "Its a totally new time in Mars research," Albee said.

NASA presently has two healthy Mars Exploration Rovers Spirit and Opportunity on trajectory toward the planet. Also outbound is the European Space Agencys Mars Express and its scientific sidekick, the British-built Beagle 2 lander.

If all goes well, theyll join two other NASA spacecraft already in orbit around Mars the Mars Global Surveyor (MGS) and the Mars Odyssey.

"Mars Global Surveyor has brought a lot of data into our labs. Some of us still are having a hard time trying to figure out what that data means," said Michael Malin, principal investigator of MGSs Mars Orbiter Camera. He is president of Malin Space Science Systems, based near San Diego, California.

Malin pointed to layered deposits on Mars, showing that the planet has a multifaceted history yet to be understood. The old view that Mars is sort of like a moon with an atmosphere is clearly suspect.

"Its a much more complex history," Malin added, with processes at work where craters are formed, buried, and exhumed. In some areas massive amounts of displaced rock are mysteriously missing from the scene.

Looking for a paradigm shift in how best to explore Mars is Chris McKay, planetary scientist at NASAs Ames Research Center, neighboring San Francisco, California.

"Yes, there are more details provided by all the Mars orbiters. But there is no deeper understanding of the big questions. To me, that says we need a paradigm shift in the way we explore Mars," McKay told SPACE.com.

"I think that might be a sample return from Mars. It might be deep drilling. Whatever it is, it certainly involves getting on the ground," McKay said.

To uncover the real Mars, McKay said, "you have to get there with boots and shovels and dig."

More pictures taken from Mars orbit dont tell the story, McKay said. "We need to do what geologists should really be doing. Not taking pictures but getting dirtyinto the dirt and rocks."

McKay said that there is a "fear of landing," with everyone retreating back to a "comfort zone" of just flying in orbit around Mars. Thats more a look-and-see, but dont touch type of exploration, he said.

"It takes guts to land. If the two new Mars Exploration Rovers land successfully, I think well get our Mars legs back. If they dont land successfully, I think its going to be Mars orbiters for the rest of eternity," McKay concluded.