Begley, Sharon and Rogers, Adam. "War of the Worlds," Newsweek, 10 February 1997, pp.

 

Begley, Sharon and Rogers, Adam. "War of the Worlds," Newsweek, 10 February 1997, pp.
56-57.

Even before scientists from NASA and Stanford University stunned the world last August by
announcing that a meteorite contained evidence of past life on Mars, their research deviated a bit
from run-of-the-mill science. For instance, the NASA team withdrew a paper submitted to a
scientific meeting last March because they worried that "someone might ask a question that
would force us to give away our major finding," says planetary scientist Everett Gibson of
NASA's Johnson Space Center. "If you were on to the biggest scoop of your life, would you tell
people?" And Stanford chemists who were asked to collaborate with the NASA group, by
analyzing meteorite slices for compounds indicative of life, were not even told what they were
looking at. Samples were dubbed Goofy, Micky and Minnie.

But the usual secrecy pales next to what has been happening in the six months since the
announcement. It is normal for scientific claims to be criticized. Rebuttal follows, and eventually
the original claim stands, falls or is modified. But the debate over the claim for life on Mars has
become filled with acrimony, sometimes at the level of "you ignorant slut!" Both sides pretty
much agree that the meteorite fell from Mars and landed in Antarctica 13,000 years ago. Then the
shouting begins. On eminent meteorite researcher, who prefers to keep his invective anonymous,
calls the NASA team "an inferior group of people [who] are setting the agenda for others who
have real science to perform." NASA's Gibson calls one of his critics "someone who has been in
this country for 32 years and hasn't held a permanent job.

This would all make for a fine spectator sport, except for one problem. As the bitterness of the
debate stiffens positions, putting careers and reputations on the line, there is real concern about
whether the claim of past life on Mars which, after all, would be the discovery of this or any
other millennium will ever be properly sorted out. Chemist Edward Anders, one of the deans of
meteorite science, worries that the bitterness "will work against the usual scientific process" and
hurt efforts to find out whether the potato-shaped meteorite truly harbors evidence of life.

Already the polarization may be taking a toll. Soon after the August announcement, NASA
slapped a temporary moratorium on distributing samples of the meteorite known as ALH84001
to scientists until it can sort out all the requests (probably by late spring). In the meantime, what
Jeffrey Bada of the Scripps Institution of Oceanography calls a "black market." in slices of 84001
has sprung up. "It seems like the only people who have gotten the remnants are ones who are
likely to be supportive of the original findings," charges Bada. Researchers at Caltech, for
instance, received a piece when a member of the original NASA tem at Houston'sJohnson Space
Center visited last September. At next month's 28th Lunar and Planetary Science meeting in
Houston, the Caltech geologists will present data that support the life-on-Mars idea. NASA's
David McKay, who led the 84001 team, says, "I don't think we influenced their position."

Scientific disagreements usually get their fullest airing at professional conferences. There
researchers present their most cutting-edge data (the stuff that gets published in journals is
months if not years old). Then critics take their best shots. But with the bitterness surrounding the
Martian meteorite, this crucial step in the scientific process may be undermined: organizers invite
scientists who agree with their position, or researchers choose to attend meetings of the
like-minded. Next month, for instance, at the planetary-science meeting, some 30 papers will
address the question of life on Mars. "More than 80 percent will support our hypothesis," says
Gibson. At the American Chemical Society meeting in Sam Francisco, a session on 84001
organized by Bada is expected to be mostly critical of the life forces. And skeptics have been
"begging to be on the program" of a Mars workshop at JSC in April, says Bada, "but so far no
invitation has been forthcoming. This is simply an awful way to conducting science."

Amid all the acrimony, it is easy to lose sight of the substantive debate over the Martian
meteorite. The NASA-Stanford team offered four lines of evidence last August to support the
conclusion that 84001 contains signs of ancient Martian life. First, the rock contains little
globules of carbonate. These molecules could have gotten there when carbon dioxide that was
dissolved in water (think seltzer) percolated through fissures in the rock; water is a requirement
for life. Second, iron sulfide and a mineral called magnetite are in the rims of the globules; on
Earth, primitive bacteria excrete such sulfides (consider them microbe droppigs) or produce
magnetite to serve as tiny internal compasses. Third, tubelike structures in the rock could be
"nanofossils," the mineralized remains of ancient bacteria. Last, 84001 is full of organic
molecules called polycyclic aromatic hydrocarbons; on Earth, PAHs are often the by-products of
the decomposition of living things.

Unfortunately, no one can think of a definitive experiment that would prove not only that
something in 84001 could - which no one disputes - but that it did. Each and every bit of
"evidence" for ancient life can also be produced by chemical, geological or other nonbiological
processes... That was the fist of an exchange of letters between scientists skeptical of the
life-in-the-meteorite conclusions and the NASA-Stanford team in a recent issue of the journal
Science, which published the original claim. Anders describes the NASA-Stanford team as
"heading straight for biological interpretations without considering inorganic alternatives." As he
added to Newsweek, "They have a blind spot." The point-counterpoint in highly abstruse (don't
expect to follow it if you don't know your greigite from your hyrrhotite). To take just two of the
issues, the simplified version goes like this:

On the claim that the megnetite is a likely sign of life: Researchers led by John Bradley, an expert
microscopist at MVA Inc. in Geogia, published a paper in December showing that the magnetite
in 84001 takes the form of rods, ribbons and platelets. Some of the rods grew like a spiral
staircase. On Earth, such magnetite is found at steaming-hot fumaroles (volcanoes without the
mountain), suggesting that 84001's magnetite also foumed at temperatures between 500 and 800
degrees Celsius. In that caldron, says planetary scientist John Kerridge of the University of
California, San Diego, "life could not hae survived." No, sayd McKay's group: a 1990 paper
reports whiskery and ribbony magnetites produced bybacteria at normal temperatures.

On the claim that PAHs "can be the product of the decay of living matter," as McKay says: "Can
be"? No question. But Anders dug up a paper from 1862 (he gripes that "no one pays attention to
papers more than three years old anymore") showing that nonbiological matter easily forms
PAHs, too. And Jeff Bada and Luann Becker of USCD will soon publish an analysis showing
that PAHs like those in 84001 are also in meltwater from Antarctic ice. The NASA team's
response: yes, the PAHs could arise without life, but they are "are equally consistent with the
decomposition of biological matter."

One needn't have a Ph.D. in logic to realize that something is amiss here. "The NASA team has
tended to answer criticism by saying ‘Yes, what you say my be true. But what about...' and then
they introduce something extraneous," says John Bradley. "I detect some obfuscation." Planetary
geologist Robert Walker of Washington University complains that the NASA group has "tried to
shift the argument so that others have to prove that the observations are not due to fossil life."
Usually, the burden of proof lies on those making the new claim. The NASA scientists have
committed another unorthodoxy, in the eyes of critics: they admit that none of their four lines of
evidence makes the case for life on Mars, but then assert that taken together they do precisely
that. It's sort of like admitting that none of the four legs of a stool is long enough to reach a
countertop, but claiming that all of them together will reach. "They lowered the standards of
evidence rather than raised them, which is what you would expect for a claim this extraordinary,"
says meteorite expert Allan Treiman of the Lunar and Planetary Institute. In fact, Newsweek has
learned, that NASA-Stanford team got ahead of its evidence from the start, in the eyes of some:
an eminent astronomer who advised Science on whether to publish the paper calls the first
version "even more assertive. Even the title something like ‘Life on Mars: Evidence From
Meteorites';" which was eventually toned down to "Possible Relic Biogenic Activity in Martian
Meteorite ALH84001."

No one charges that the NASA-Stanford team got its numbers wrong, or misread an instrument
dial. The controversy turns, instead, on different, subjective interpretations of the same data. And
that's about as personal as science gets. Still, says McKay, "I didn't expect that it would become
so personal and exaggerated." Why has it? Truman attributes the bitterness to a "profound fear"
by meteorite scientists "of what this might do to our field. We're at the bottom of the pecking
order in NASA's budget, and people are concerned that if this turns out to be as tupid as cold
fusions we'll be out on the street."

Six months after it made headlines, the life-on-Mars claim is battered but still standing.
"Meteoriticists are virtually unanimous in being highly skeptical," says Anders. But the farther
you get from this discipline, the more scientists accept it. When Harry McSween of the
University of Tennessee gives talks at universities about his finding that crystals in 84001 likely
formed at temperatures too hot for life, "the questions I get from scientists are really hostile.
They try to twist our data so that they will be compatible with the hypothesis of life." Next month
those rooting for life on Mars will get more ammunition. NASA's Ev Gibson and colleagues will
unveil data that 84001 contains "biofilms," he says, "organic molecules that drape across crystals
when bacteria move. We will also present data showing that there is a chain of magnetite crystals
within the carbonates, and that the chain is identical to those produced by [certain] bacteria."

While the case for life on Mars is far from settled, one thing is clear. The bitterness of the debate
has hurt what used to be a congenial community, and has shown the public that, contrary to the
idealized portrait painted in textbooks, "the scientific process is overprinted with personalities
and personal prejudices," as University of Washington astronomer Don Brownlee says. Adds
McSween, "We'd all like to think that science is perfectly objective, but it's an intensely human
experience." And that, of course, might given reason to hope life could evolve a bit differently on
Mars.