Mars Lives!
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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