by Joe Palca
November 20, 2012
dug up five scoops of
sand from a patch nicknamed "Rocknest."
A suite of
instruments called SAM analyzed Martian soil samples,
but the findings have
not yet been released.
Scientists working on NASA's six-wheeled rover on Mars have a
problem. But it's a good problem.
They have some exciting new results from one of the rover's
On the one hand, they'd like to tell
everybody what they found, but on the other, they have to wait
because they want to make sure their results are not just some fluke
or error in their instrument.
It's a bind scientists frequently find themselves in, because by
their nature, scientists like to share their results. At the same
time, they're cautious because no one likes to make a big
announcement and then have to say "never mind."
The exciting results are coming from an instrument in the
rover called SAM.
"We're getting data from SAM as we
sit here and speak, and the data looks really interesting," John
Grotzinger, the principal investigator for the rover mission,
says during my visit last week to his office at NASA's Jet
Propulsion Laboratory in Pasadena, Calif.
That's where data from SAM first arrive
"The science team is busily chewing
away on it as it comes down," says Grotzinger.
SAM is a kind of miniature chemistry
lab. Put a sample of Martian soil or rock or even air inside SAM,
and it will tell you what the sample is made of.
Grotzinger says they recently put a soil sample in SAM, and
the analysis shows something remarkable.
"This data is going to be one for
the history books. It's looking really good," he says.
Grotzinger can see the pained look on my
face as I wait, hoping he'll tell me what the heck he's found, but
he's not providing any more information.
So why doesn't Grotzinger want to share his exciting news? The main
reason is caution.
Grotzinger and his team were almost
stung once before. When SAM analyzed an air sample, it looked like
there was methane in it, and at least here on Earth, some methane
comes from living organisms.
But Grotzinger says they held up announcing the finding because they
wanted to be sure they were measuring Martian air, and not air
brought along from the rover's launch-pad at Cape Canaveral.
"We knew from the very beginning
that we had this risk of having brought air from Florida. And we
needed to diminish it and then make the measurement again," he
And when they made the measurement
again, the signs of methane disappeared.
Grotzinger says it will take several weeks before he and his team
are ready to talk about their latest finding. In the meantime he'll
fend off requests from pesky reporters, and probably from NASA brass
as well. Like any big institution, NASA would love to trumpet a
major finding, especially at a time when budget decisions are being
made. Nothing succeeds like success, as the saying goes.
Richard Zare, a chemist at Stanford University, appreciates
the uncomfortable position John Grotzinger is in. He's been there.
In 1996, he was part of a team that reported finding organic
compounds in a
meteorite from Mars that landed in Antarctica.
When the news came out, it caused a huge
sensation because finding organic compounds in a Martian rock
suggested the possibility at least that there was once life on Mars.
"You're bursting with a feeling that
you want to share this information, and it's frustrating when
you feel you can't talk about it, "says Zare.
It wasn't scientific caution that kept
Zare from announcing his results. It was a rule many scientific
journals enforce that says scientists are not allowed to talk about
their research until the day it's officially published.
Zare had to follow the rules if he
wanted his paper to come out.
He did break down and tell his family.
"I remember at the dinner table with
great excitement explaining to my wife, Susan, and my daughter,
Bethany, what it was we were doing," says Zare. And then he
experienced something many parents can relate to when talking to
"Bethany looked at me and said, 'pass the ketchup.' So, not
everybody was as excited as I was," he says.
Zare says in a way, scientists are like
artists. Sharing what they do is a big part of why they get out of
bed in the morning.
"How many composers would actually
compose music if they were told no one else could listen to
their compositions? How many painters would make a painting if
they were told no one else could see them?" says Zare. It's the
same for scientists.
"The great joy of science is to be
able to share it. And so you want to say, 'Isn't this
interesting? Isn't that cool?' "
For now, though, we'll have to wait to
see what's got Mars rover scientists itching to say what they found.