Thursday, July 31, 2008

Water on Mars Confirmed?

By Joe Pappalardo

In a discovery that could qualify as one of the most important in the history of space exploration, NASA’s Phoenix Mission may have confirmed the presence of water ice on the planet, Popular Mechanics has learned. The scheduling of a press conference for Thursday at 2 p.m. Eastern by NASA and the University of Arizona has raised hopes in the space community that scientists will announce the breakthrough. When pressed for details, a spokesperson for the agency’s Jet Propulsion Laboratory refused to elaborate beyond saying that the Phoenix team would unveil new findings from the ongoing robotic mission to Mars. If the rumor holds true, it would be the first direct confirmation of water ice beyond Earth.

Data from recent missions to Mars has been building toward a confirmation of the presence of water ice. However, “this would be the first time we held it in our hands, so to speak,” says Bryan DeBates, a senior aerospace education specialist at the Space Foundation. Evidence from other locations in the solar system, including Earth’s moon, Saturn’s Enceladus moon and Jupiter’s Europa moon, have strongly hinted at the presence of water—NASA confirmed a liquid lake on Saturn’s Titan moon on Wednesday—but no direct observation of water has been made.

If the presence of water is confirmed on a small patch near the lander, the volume of ice on the Martian surface could be “extraordinary,” says Mary Bourke, a planetary research scientist with the Planetary Science Institute in Tuscon, Ariz. The landing site was chosen because the porosity of the soil appeared to lend itself to a build-up of water ice—and that type of soil is widespread on Mars. The presence of widespread water would make any mission to establish a manned Martian base far more feasible. (Of course, the presence of water would also greatly increase the likelihood that life exists, or once did exist, on the planet.)

Staff operating the Phoenix Lander from mission control in Arizona have been closely watching a patch of what they believed to be ice that was uncovered as the lander descended. The Phoenix Mars Lander has been scraping samples and dropping them into a spectrometer that heats the samples to determine their chemical composition. On Sunday, the Phoenix team changed the way it dug to reduce friction that prematurely heated the samples. On Tuesday, NASA scientists stated that the surface of the patch, dubbed “Snow Queen,” has changed between June and July. A camera mounted on a robotic arm captured those changes, which include 4-in. cracks and a visibly rougher surface texture.

Sources within NASA's Jet Propulsion Laboratory hinted that the new findings could reveal details of the atmosphere as well as the ground—perhaps indicating that researchers have learned new lessons about the dynamics of the Martian environment by the way the exposed material reacts to the carbon dioxide-rich atmosphere. The fractures could have appeared as ice sublimated off the surface. It’s also possible that temperature changes made the surface crack. However, any findings about the atmosphere could have come independently of observations of the ice surface, since there are atmospheric instruments such as laser radar on Phoenix, so any atmospheric findings could be separate from the water ice issue. For some Mars researchers, that would be fine. “Research into Mars’ atmosphere really needs to be beefed up,” Bourke says. “Any information about it could be invaluable.”

Also, two European orbiters circling Mars have recently captured geological features that indicate the planet once had standing water for thousands of years, including river valleys and 13,000-ft. waterfalls. Next step after confirming the ice would be finding out if life ever existed—or still does, in some deep Martian aquifer. “NASA’s mantra has been ‘Follow the ice to find life,’” says DeBates. And if life does not exist there, earthlings may import some. “Establishing a Mars colony is going to be a lot easier to maintain, having water there,” DeBates says.

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