July 27, 2000 08:24 CDT
No less than an authority of the mainstream media than the New York Times reported this week that Mars is, in fact, perhaps not a dying planet.
In an article bylined by staff writer William J. Broad, the newspaper said, "in theory, new findings are increasing the possibility that Martians of one sort or another may be clinging to life on the dying planet."
But perhaps the planet is not dying after all, said the newspaper in its online editions this week: "Reports of a dead Mars are greatly exaggerated." Its the Times take on the announcement by NASA and its consultants last month that recent, liquid water likely exists on the planet.
Broad interviewed a number of scientists for the article, most of whom say theyve changed their view of the planet that was first probed by spacecraft 35 years go this month, by Mariner 4. Mariner captured 22 fuzzy photographs that revealed a wasteland; images from the Mars Global Surveyor (MGS) over the last couple years have yielded great detail of the planets surface.
Todays scientists paint a different picture of Mars than their counterparts who had relied on the old Mariner images. "Now, rather suddenly, Mars is showing new signs of life," said the Times. But perhaps its not Mars that has changed, but scientists interpretation of its geology. Many interviewed by the newspaper are downright enthusiastic over the conditions on Mars that may reveal life beyond Earth.
"Scientists, examining Mars rocks hurled to Earth in upheavals, have found signs that moving water changed the chemical makeup of the surface terrain in recent eras, and they have concluded that the Martian crust harbors up to three times as much water as previously thought," says the Times.
"All this opens up a much more interesting and diverse planet than people expected," said Dr. William K. Hartmann, an astronomer at the Planetary Science Institute in Tucson, Ariz. It was his nine-person team that reported evidence of recent volcanism. "It's the discovery of an active Mars."
The Times agrees that the implications of the new findings are being debated, "but most agree that Mars is showing new signs of heat and vitality, as well as posing a new set of riddles."
"The evidence now says it's not dead," said Dr. Bruce M. Jakosky, a planetary scientist at the University of Colorado. "But we don't comprehend what we're seeing yet, even though we know it's true."
"Like fuzzy visions of Mars through early telescopes, the hints of flowing water and heat are fueling dreams of the ultimate discovery: aliens, not fossils from some long-departed era, but living ones prospering in secluded habitats, perhaps underground, tiny and microbe-like," said the Times.
"It's not crazy to ask if there's oases where life might still exist" close to the Martian surface, said Dr. Andrew H. Knoll, a Harvard biologist who studies early life on Earth and its possibility elsewhere.
Dr. Kenneth H. Nealson, an astrobiologist at the Jet Propulsion Laboratory, said aliens were rising on the Mars agenda. "I had pretty much given up on life near the surface," he said. "I was skeptical about whether in my lifetime we could access any area that would have any possibility of life."
The new findings, he said, "change the game."
"Shallow drilling is now something we should look into," he added. "It's a very exciting debate."
Ever since astronomer Percival Lowell claimed he found evidence of "artificial life" on Mars a century ago, research and findings on the planet have emerged sporadically. "The findings have tended to come out piecemeal in papers and forums, often with little fanfare, so that even Mars experts are struggling with the tide," said the Times.
"I can't keep up with it," said Dr. Maria T. Zuber of the Massachusetts Institute of Technology, who is on a global surveyor science team.
Last year, Hartmann and eight colleagues at Cornell, the United States Geological Survey and other institutions reported that Mars was apparently alive geologically, based on the freshness of some surfaces, said the newspaper.
"The team examined close-up surveyor images of volcanoes and lava flows and found that some had a distinct lack of cratering. All the solar system's planets and moons exhibit impact craters from a steady rain of cosmic debris, with Earth's scars mostly erased by ages of erosion. On any body, the absence of craters implies active resurfacing. For Mars, the team focused on the extraordinarily wide mouth of a very young volcano, Arsia Mons. The huge peak, located just south of the Martian equator, is one of the largest known volcanoes, its summit 5.6 miles higher than the surrounding plains and its summit crater, or caldera, 68 miles wide," reported the Times.
"The crater statistics that we report here suggest that volcanism is continuing on Mars in current geological time," the scientists wrote Feb. 18, 1999, in the journal Nature. The team included Dr. Michael H. Carr, one of the world's top Mars experts.
In an interview, Dr. Hartmann said the finding overturned what had been the conventional view for decades. "There were a lot of people who thought all the volcanism died out two or three billion years ago," he said, adding that molten rock near the surface might explain the evidence of recent water flows.
Dr. Laurie A. Leshin, a geologist at Arizona State University, recently came to similar conclusions by analyzing a Mars meteorite, said the Times. "She measured the concentration of the hydrogen isotope deuterium, a component of so-called heavy water, in the meteorite and concluded that the Martian crust had two to three times the amount of water previously thought."
"It's a tiny meteorite with big implications," she said in an interview. "There's every reason to think we could find water in the Martian crust today."
In a different Mars meteorite, Dr. Timothy D. Swindle of the University of Arizona and seven colleagues found evidence that water had changed the rock's composition in relatively recent geologic times. "It's the youngest evidence for water," he said, adding that all the emerging signs suggest it now lies close to the surface.
And, said the Times, "in the past decade or so, as scientists have discovered a remarkably rich microbial fauna dwelling deep in the Earth's interior, miles down, they have theorized that Mars may be similar. After all, its interior is thought to be wet and warm, potentially a kind of microbe heaven."
Dr. Thomas Gold, a Cornell space, believes that Earths solar system might harbor as many as 10 alien biospheres hidden in deep rocky strata. "The problem for human explorers is that such regions are frustratingly out of reach," he told the Times.
Scientists agree that the discovery of even a single extraterrestrial microbe would be a watershed, shedding light on how life began and the odds of its arising elsewhere in the universe. "This is exciting," Dr. Jakosky of the University of Colorado said of the water evidence and its life implications. "This is big news."
Staff Writer Sally Suddock
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