Page 28 - aruba-today-20180609

A28 SCIENCE
Saturday 9 June 2018
New Mars discoveries advance case for possible life

By MARCIA DUNN seasonal peaks — by a
Associated Press factor of three — was
CAPE CANAVERAL, Fla. (AP) far more than scientists
— New Mars discoveries expected. "We were just
are advancing the case blown away," he said. "It's
for possible life on the tripling ... that's a huge,
red planet, past or even huge difference."
present. Webster theorizes the
Scientists reported Thursday methane created either
that NASA's Curiosity now or long ago is seeping
rover has found potential from deep underground
building blocks of life in an reservoirs up through cracks
ancient Martian lakebed. and fissures in the crust.
Hints have been found Once at the surface, the
before, but this is the best methane sticks to dirt and
evidence yet. rocks, with more released
The organic molecules into the atmosphere when
preserved in 3.5 billion-year- it's hotter.
old bedrock in Gale Crater "We have no proof that
— believed to once contain the methane is formed
a shallow lake the size of biologically, but we cannot
Florida's Lake Okeechobee rule it out, even with this
— suggest conditions back new data set," Webster
then may have been said.
conducive to life. That Scientists have been
leaves open the possibility seeking organic molecules
that microorganisms once on Mars ever since the 1976
populated our planetary Viking landers. The twin
neighbor and might still Vikings came up pretty
exist there. much empty.
"The chances of being able Arriving at Mars in 2012 with
to find signs of ancient life a drill and its own onboard
with future missions, if life labs, Curiosity confirmed
ever was present, just went the presence of organics
up," said Curiosity's project in rocks in 2013, but the
scientist, Ashwin Vasavada molecules weren't exactly
of NASA's Jet Propulsion what scientists expected.
Laboratory in Pasadena, So they looked elsewhere.
California. This composite image made from a series of Jan. 23, 2018 photos shows a self-portrait of NASA's The key samples in the
Curiosity also has confirmed Curiosity Mars rover on Vera Rubin Ridge. latest findings came from a
sharp seasonal increases Associated Press spot 4 miles (6.4 kilometers)
of methane in the Martian away.
atmosphere. Researchers molecules were present that are more than 3 billion tiny organisms like bacteria As with methane, there
said they can't rule out a on its surface at the time," years old," Siebach said. ever existed on the red could well be non-
biological source. Most wrote Utrecht University "And we see releases of gas planet. biological explanations for
of Earth's atmospheric astrobiologist Inge Loes ten today that could be related Curiosity's methane the presence of carbon-
methane comes from Kate of the Netherlands. to life in the subsurface or at measurements occurred containing molecules on
animal and plant life, and Kirsten Siebach, a Rice the very least are probably over 4 ½ Earth years, Mars, such as geologic
the environment itself. University geologist who related to warm water or covering parts of three processes or impacts by
The two studies appear also was not involved in the environments where Earth Martian years. Seasonal asteroids, comet, meteors
in the journal Science . In studies, is equally excited. life would be happy living." peaks were detected in and interplanetary dust.
a companion article, an She said the discoveries The methane observations late summer in the northern Jennifer Eigenbrode, an
outside expert describes the break down some of the provide "one of the most hemisphere and late winter astrobiologist at NASA's
findings as "breakthroughs strongest arguments put compelling" cases for in the southern hemisphere. Goddard Space Flight
in astrobiology." forward by life-on-Mars present-day life, she said. JPL's Christopher Webster, Center in Greenbelt,
"The question of whether skeptics, herself included. Scientists agree more lead author on the study, Maryland who led the
life might have originated "The big takeaway is that powerful spacecraft — said it's the first time organics study, said she's
or existed on Mars is a lot we can find evidence. We and, ideally, rocks returned Martian methane has intrigued by the possibility
more opportune now that can find organic matter to Earth from Mars — are shown a repeated pattern. that life might have existed
we know that organic preserved in mudstones needed to prove whether The magnitude of these and adapted on Mars.
"I'm equally as fascinated
by the idea that life never
got started on Mars in
the first place. That's a
harder question to address
scientifically, but I think
that we need to give the
search for life on Mars due
diligence. We need to go
to places that we think are
the most likely places to
find it."q