Water On Mars - Door For Life On Red Planet Now Officially Open
Source: By BBC News Online science editor Dr David Whitehouse
21st June 2000
There is currently water on the surface of Mars, Nasa scientists believe.
The evidence is contained in pictures taken by the Mars Global Surveyor
spacecraft, which is in orbit around the Red Planet.
The images show what appears to be brackish water seeping from beneath
the Martian surface.
The discovery, if confirmed, will mark a turning point in our exploration
of the Red Planet, with future missions to Mars being directed to the
locations of seepage.
Although there is abundant evidence that water flowed freely, billions
of years ago, on the Martian surface, it was thought the planet's current
atmosphere would be too thin to retain any water there today.
The Valles Marineris is a very distinctive feature
on the surface of Mars
However, it seems this may not be the case at the bottom of deep canyons
Some of these areas are among the lowest parts of Mars, being several
kilometres below the average surface level.
This would make the atmospheric pressure slightly higher and possibly
high enough to support pools of salty water.
This is what Nasa scientists think they may have discovered in the central
part of the mighty Valles Marineris, the 6,000-km long (3,700 miles)
canyon that scars the Martian surface.
The complex terrain of the canyon floor includes a great variety of
landforms, including landslides, volcanic deposits, windblown material
and sediments from long-gone seas. It is several kilometres below the
average surface level of Mars.
Crater walls show what appears to be channelling
caused by the seepage [Scale bar is 5km]
In the MGS images of the area, the scientists think they can see layered
terrains that they suspect were deposited by ancient shallow seas or
by water deposits that were once below an ice layer. It is here that
there are features which appear to indicate brackish water is seeping
from beneath the surface of the planet. The seepage may be seasonal,
as it has not been seen in all images of the region. Similar seepage
may also have been detected on the walls of at least two craters in
other regions of Mars.
The depths of the canyon will now become the focus for the search for
life on Mars.
Testifying before the science committee of the House of Representatives
on Tuesday, Nasa's chief said that to look for life on Mars "we should
follow the water".
If life ever developed on Mars in the past, and the evidence from Mars
rocks blasted to the Earth is controversial, then it may be hanging
on in the damp regions.
At one level, this discovery is not that surprising. Scientists know
that water once flowed on Mars and that it is still probably trapped
beneath the surface.
But finding water springs is an unexpected and very welcome discovery.
Now, it seems that the water has been found, investigating it will become
the main thrust for future Mars exploration.
Putting a lander down on the wet surface and looking for life will become
a major priority
Mysteries, UFOs, etc.
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