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    NASA Envisions Mars With Water

    This is an artist's concept of an ancient, habitable Mars capable of supporting liquid water on its surface. (Michael Lentz/NASA Goddard Conceptual Image Lab)
    This is an artist's concept of an ancient, habitable Mars capable of supporting liquid water on its surface. (Michael Lentz/NASA Goddard Conceptual Image Lab)

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    A new NASA video shows what Mars may have been like long ago when it had a denser atmosphere and liquid water.

    The concept is based on evidence that Mars was once very different.

    "There are characteristic dendritic structured channels that, like on Earth, are consistent with surface erosion by water flows,” said Joseph Grebowsky of NASA's Goddard Space Flight Center in Greenbelt, Maryland. “The interiors of some impact craters have basins suggesting crater lakes, with many showing connecting channels consistent with water flows into and out of the crater.”

    He added that small impact craters have been removed with time and larger craters show signs of erosion by water more than 3.7 billion years ago, and sedimentary layering is seen on valley walls. Minerals are present on the surface that can only be produced in the presence of liquid water, Grebowsky said.

    Estimates about the amount of water needed to explain these features have equated to possibly as much as a planet-wide layer one-half a kilometer (1,640 feet) deep or more, according to Grebowsky.

    It's unknown if the habitable climate lasted long enough for life to emerge on Mars.

    "The only direct evidence for life early in the history of a planet's evolution is that on Earth," said Grebowsky. "The earliest evidence for terrestrial life is the organic chemical structure of a rock found on the surface in Greenland. The surface was thought to be from an ancient sea floor sediment. The age of the rock was estimated to be 3.8 billion years, 700 million years from the Earth's creation.”

    The video ends with an illustration of NASA's MAVEN mission in orbit around present-day Mars. MAVEN will investigate how Mars lost its atmosphere. Scheduled to be launched in November, it will arrive at Mars in September 2014.

    There are several theories of how Mars was stripped of its thick atmosphere.

    "Hydrodynamic outflow and ejection from massive asteroid impacts during the later heavy bombardment period (ending 4.1 billion to 3.8 billion years ago) were early processes removing part of the atmosphere, but these were not prominent loss processes afterwards," said Grebowsky. "The leading theory is that Mars lost its intrinsic magnetic field that was protecting the atmosphere from direct erosion by the impact of the solar wind."

    The solar wind is a thin stream of electrically charged particles (plasma) blowing continuously from the sun into space at about a million miles per hour.

    Here's the video:

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    Comments
         
    by: Maeda Atsukoh from: Akiba
    November 15, 2013 7:04 PM
    Good image is first and important thing for them in order to get big budget for their salary.
    Scientific theory is too difficult for most people who have only low education, so producing good image easy to understand is their fist priority.

    by: Markt from: Virginia
    November 15, 2013 4:32 PM
    it is interested to think that Mars once could have looked like Earth, and that is certainly one artist's view of what Mars COULD have looked like......but remember that Mars is a very cold planet and any water on its surface would be ice, lots and lots of ice..not flowing rivers and thundering waterfalls.
    It's nice to compare Mars and Earth in the context of what we see Earth as today, but Mars was never close enough to the Sun to be habitable enough to sustain free flowing water and lakes...and sustainable life.
    Its a nice thought, and such a nice though will once again prompt me bring out the big binoculars tonight and gaze fondly into the heavens.

    by: Yoshi from: Sapporo
    November 14, 2013 10:10 PM
    Now, I can imagine the view of Mars date back about 4 billion years. It is yet to be investigated how its dense atmosphere and water were lost. But there is one thing we could clealy say that the present-day view of Mars is the that of Earth 4 billion years later from now on.

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