August 27, 1998, Thursday, FINAL EDITION

SECTION: NEWS; Pg. 15A

LENGTH: 732 words

HEADLINE: Level head is key to talk of Martians

BYLINE: Alcestis "Cooky" Oberg

BODY:
Sensational headlines in politics and sports are standard fare
these days, but they need to be used with caution in the world
of science.

Consider how, two years ago, NASA scientists announced they may
have found the fossilized remains of life on Mars inside a meteorite
that had been blasted off the Red Planet and found in Antarctica
in 1984. News anchormen could hardly contain themselves when they
announced the astounding information, and the great popularizer
of science, Carl Sagan, called it "a possible turning point in
human history."

The NASA scientists who discovered the wormlike formations, Everett
Gibson and David McKay, were far less comfortable with the announcement.
For two years, these careful scientists kept the conclusions to
themselves, going over and over the data, trying to verify their
own research.

Richard Zare of Stanford University, a brilliant scientist by
anyone's standards, was brought onto the team, too, for his independent
assessments. The men sent their manuscript to Science magazine
-- known for its high standards of peer review -- without telling
their colleagues at NASA anything about it.

White House leaked Mars story

When they finally briefed their management at Johnson Space Center
and NASA on the discovery, NASA Administrator Daniel Goldin informed
the White House. Unfortunately, the White House leaked a garbled,
headline-screaming version of the news before the formal news
conference -- honest, forthright and including many cautions and
opposing views -- could take place.

Two years later, at an important conference on Mars exploration
that concluded earlier this month, Gibson and McKay's findings
on life on Mars were challenged by several different explanations.
Here are some views on what the "polycyclic aromatic hydrocarbons"
in the Mars rock and carbonate crystal structures that looked
like tiny worms might, or might not, be:

-- Scientists at the University of Arkansas, among them
Derek Sears, think they've found the same structures in lunar
meteorites, suggesting that some exotic chemical process is accountable
for these structures, rather than a biological one.

-- Another group suggested that temperatures were too
high during the rocks' formation for tiny bacteria to form at
all.

-- *The Mars rock doesn't contain other water-related
minerals required for the presence of life.

-- The organics originated in Antarctica, where it was found.

None of these theories has reached any unanimity either. The NASA
team has reinforced its findings on Mars life with new data, including
pictures that suggest cell walls. Many of McKay's and Gibson's
colleagues at NASA feel the controversy will never be settled
until we go to Mars and get a bigger inventory of samples. What
we do have arrived accidentally: All the Mars rocks on Earth were
blasted off the Martian surface by a comet or meteorite thousands
of years ago.

Not even moon findings are certain

Yet even if we did collect Mars rocks systematically, as we did
during the Apollo moon program, the scientific debate might not
be settled: I remember attending the 20th-anniversary celebration
of the moon landings in Houston in 1989. One distinguished scientist
after another rose to present the long-studied findings on the
unshakable truth about the moon. At the end of it, the world-renowned
planetary scientist, Eugene Shoemaker, stood up in the audience
and pointed out: "Are you guys aware that you're all contradicting
each other?"
 

The great contribution McKay, Gibson and Zare have made is to
get the public and the scientific community not to dismiss the
possibility of life on other planets. Future space ventures to
Mars and the moons of Jupiter and Saturn will be much more likely
to find evidence of life because they will be looking for it.
Think of all the places on our planet where we've found the most
exotic forms of life against all odds -- for instance, beside
acid-belching volcano vents on the ocean floor.

For the moment, those bizarre little wormlike structures the NASA
team found are -- well -- what you'd expect extraterrestrial life
to be: provocative to the point of prompting sensationalism, difficult
to explain and puzzling. Like all great discoveries, they leave
us with a sense of how much more we need to know.