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Danau air
tawar yang kuno di Mars
Ancient fresh water lake on Mars could have sustained life
Date:
December 9,
2013
Source:
Imperial College London
Summary:
Scientists have found evidence that there was once an
ancient lake on Mars that may have been able to support life.
................
Scientists have found evidence that there was once an
ancient lake on Mars that may have been able to support life, in research
published recently in the journal Science.
A team of
researchers from NASA's Mars Science Laboratory (MSL) Curiosity rover mission,
which includes a researcher from Imperial College London, have analysed a set
of sedimentary rock outcrops at a site named Yellowknife Bay in Gale Crater,
near the Martian equator. These mudstones have revealed that Gale Crater, a 150
km wide impact basin with a mountain at its centre, sustained at least one lake
around 3.6 billion years ago.
The
scientists believe that the lake may have lasted for tens if not hundreds of
thousands of years.
The team's
analysis showed that the lake was calm and likely had fresh water, containing
key biological elements such as carbon, hydrogen, oxygen, nitrogen and sulphur.
Such a lake would provide perfect conditions for simple microbial life such as
chemolithoautotrophs to thrive in.
On Earth,
chemolithoautotrophs are commonly found in caves and around hydrothermal vents.
The microbes break down rocks and minerals for energy.
Mudstones
generally form in calm conditions. They are created by very fine sediment
grains settling layer-by-layer on each other, in still water.
Professor
Sanjeev Gupta, a member of the MSL mission from the Department of Earth Science
and Engineering at Imperial College London and a co-author on the papers, says:
"It is important to note that we have not found signs of ancient life on
Mars. What we have found is that Gale Crater was able to sustain a lake on its
surface at least once in its ancient past that may have been favourable for
microbial life, billions of years ago. This is a huge positive step for the
exploration of Mars.
"It is
exciting to think that billions of years ago, ancient microbial life may have
existed in the lake's calm waters, converting a rich array of elements into
energy. The next phase of the mission, where we will be exploring more rocky
outcrops on the crater's surface, could hold the key whether life did exist on
the red planet."
In previous
studies, Professor Gupta and the MSL team have found evidence of water on Mars'
surface in other rocks such as conglomerates. However, the new research
provides the strongest evidence yet that Mars could have been habitable enough
for life to take hold.
The team
analysed the geology and chemistry of the mudstones by drilling into the rock
using the MSL six-wheeled science laboratory, which is remotely operated by the
MSL team from the Jet Propulsion Laboratory in Pasadena in the USA.
The next
step will see the team using the rover to explore Gale Crater for further
evidence of ancient lakes or other habitable environments in the thick pile of
sedimentary rocks scattered across the crater's surface.
Note: A
Special Collection of papers on the findings can be found on the Science
web site at http://www.sciencemag.org/site/extra/curiosity/
Story
Source:
The above
story is based on materials provided by Imperial College London. The original article was written
by Colin Smith. Note: Materials may be edited for content and length.