Odyssey: Damp Ground at Mars' Seasonal Streaks Not Found

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bystander
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Odyssey: Damp Ground at Mars' Seasonal Streaks Not Found

Post by bystander » Wed Aug 24, 2016 1:59 pm

Test for Damp Ground at Mars' Seasonal Streaks Finds None
NASA | JPL-Caltech | Mars Odyssey | 2016 Aug 23

Seasonal dark streaks on Mars that have become one of the hottest topics in interplanetary research don't hold much water, according to new findings from a NASA Mars orbiter.
[img3="Blue dots on this map indicate sites of recurring slope lineae (RSL) in part of the Valles Marineris canyon network on Mars. RSL are seasonal dark streaks that may be indicators of liquid water. The area mapped here has the highest density of known RSL on Mars. Image Credit: NASA/JPL-Caltech/Univ. of Arizona"]http://www.jpl.nasa.gov/images/mro/2016 ... 756-16.jpg[/img3][hr][/hr]
The new results from NASA's Mars Odyssey mission rely on ground temperature, measured by infrared imaging using the spacecraft's Thermal Emission Imaging System (THEMIS). They do not contradict last year's identification of hydrated salt at these flows, which since their 2011 discovery have been regarded as possible markers for the presence of liquid water on modern Mars. However, the temperature measurements now identify an upper limit on how much water is present at these darkened streaks: about as much as in the driest desert sands on Earth.

When water is present in the spaces between particles of soil or grains of sand, it affects how quickly a patch of ground heats up during the day and cools off at night. ...

The features, called recurring slope lineae or RSL, have been identified at dozens of sites on Mars. A darkening of the ground extends downhill in fingerlike flows during spring or summer, fades away in fall and winter, then repeats the pattern in another year at the same location. The process that causes the streaks to appear is still a puzzle. ...

The Water Content of Recurring Slope Lineae on Mars - Christopher Edwards, Sylvain Piqueux
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Re: Odyssey: Damp Ground at Mars' Seasonal Streaks Not Found

Post by neufer » Wed Aug 24, 2016 2:31 pm

https://idiomation.wordpress.com/2013/07/22/hold-water/ wrote:
_Hold Water_ (Posted by Elyse Bruce on July 22, 2013)

<<If an idea, reason or argument is strong and coherent, doesn’t seem to have any holes, and stands up under critical examination, it’s said to hold water. Conversely, if it’s a bad idea or a poor argument, you’ll hear people say it won’t hold water.

English actor, playwright, and poet laureate, Colley Cibber (June 11, 1671 – November 12, 1757) wrote “She Wou’d, and She Wou’d Not: Or the Kind Imposter. A Comedy, as it is Acted at the Theatre-Royal in Drury-Lane by His Majesty’s Servants” which was published in 1703. In Act IV of this play, the expression was used here:
  • This business will never hold water.
As research continued, an old Swedish proverb was found that read: “Don’t throw away the old bucket until you know whether the new one holds water.” Now that’s very good advice indeed, and certainly drives home the point that an old bucket without holes in it beats a new bucket that won’t hold water … both literally and figuratively speaking.

Although Idiomation was unable to pin an exact date to the Swedish proverb, the expression dates back to at least the early 1600s, and this is suggested based in part on the ease with which Colley Cibber used it in his play in 1703.>>
Art Neuendorffer

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