Scientists find likely source of methane on Mars

Author: 
AFP
ID: 
1554157164158432900
Mon, 2019-04-01 15:14

PARIS: The mystery of methane on Mars may finally be solved as
scientists Monday confirmed the presence of the life-indicating gas
on the Red Planet as well as where it might have come from.
In the 15 years since a European probe reported traces of the gas
in the Martian atmosphere, debate has raged over the accuracy of
the readings showing methane, which on Earth is produced by simple
lifeforms.
Because methane gas dissipates relatively quickly — within around
12 years on Earth — and due to the difficulty of observing
Mars’ atmosphere, many scientists questioned previous studies
that relied on a single data set.
Now an international team of experts have compared observations
from two separate spacecraft, taken just one day apart in 2013, to
find independent proof of methane on our neighboring planet.
Furthermore, they conducted two parallel experiments to determine
the most likely source of methane on Mars to be an ice sheet east
of Gale Crater — itself long assumed to be a dried up lake.
“This is very exciting and largely unexpected,” Marco Giuranna,
from Rome’s National Astrophysics Institute, told AFP.
“Two completely independent lines of investigation pointed to the
same general area of the most likely source for the methane.”
Europe’s Mars Express probe measured 15.5 parts per billion in
the atmosphere above the Gale Crater on June 16, 2013. The presence
of methane in the vicinity was confirmed by readings taken 24 hours
earlier by NASA’s Curiosity rover.
Using the data, Giuranna and the team divided the region around the
crater into grids of 250 by 250 square kilometers.
One study then ran a million computer-modelled emissions scenarios
for each section while another team studied images of the planet
surface for features associated on Earth with the release of
methane.

The most likely source was a sheet of frozen methane beneath a
rock formation, which the team believes periodically ejects the gas
into the atmosphere.
Giuranna said that while methane is a sign of life on Earth, its
presence on Mars doesn’t necessarily constitute evidence of
something similar on the Red Planet.
“Methane is important because it could be an indicator of
microbial life,” he said. “But life is not required to explain
these detections because methane can be produced by abiotic
processes.”
“Though not a direct biosignature of life, methane can add to the
habitability of martian settings, as certain types of microbes can
use methane as a source of carbon and energy,” he added.
Though there is no liquid water on Mars, the European Space Agency
said in February its imaging equipment had shown further evidence
of dried up river beds, suggesting the Red Planet may once have
been home to simple organisms.
Giuranna said that further research was needed to determine the
extent of the methane ice sheet near Gale Crater.
If founded to be extensive, the methane it contains “could
support a sustained human presence” on Mars as a possible source
of fuel for industrial processes and a propellant for returning
manned missions to Earth, he said.

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Scientists find likely source of methane on Mars