Nasa scientists find evidence of flowing water on Mars
Source: The Guardian
Liquid water runs down canyons and crater walls over the summer months on Mars, according to researchers who say the discovery raises the chances of being home to some form of life.
The trickles leave long, dark stains on the Martian terrain that can reach hundreds of metres downhill in the warmer months, before they dry up in the autumn as surface temperatures drop.
Images taken from the Mars orbit show cliffs, and the steep walls of valleys and craters, streaked with summertime flows that in the most active spots combine to form intricate fan-like patterns.
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Researchers have now turned to another instrument on board the Mars Reconnaissance Orbiter to analyse the chemistry of the mysterious RSL flows. Lujendra Ojha, of Georgia Institute of Technology in Atlanta, and his colleagues used a spectrometer on the MRO to look at infrared light reflected off steep rocky walls when the dark streaks had just begun to appear, and when they had grown to full length at the end of the Martian summer.
Read more: http://www.theguardian.com/science/2015/sep/28/nasa-scientists-find-evidence-flowing-water-mars
Paper in Nature Geosciences:
Determining whether liquid water exists on the Martian surface is central to understanding the hydrologic cycle and potential for extant life on Mars. Recurring slope lineae, narrow streaks of low reflectance compared to the surrounding terrain, appear and grow incrementally in the downslope direction during warm seasons when temperatures reach about 250–300?K, a pattern consistent with the transient flow of a volatile species1, 2, 3. Brine flows (or seeps) have been proposed to explain the formation of recurring slope lineae1, 2, 3, yet no direct evidence for either liquid water or hydrated salts has been found4. Here we analyse spectral data from the Compact Reconnaissance Imaging Spectrometer for Mars instrument onboard the Mars Reconnaissance Orbiter from four different locations where recurring slope lineae are present. We find evidence for hydrated salts at all four locations in the seasons when recurring slope lineae are most extensive, which suggests that the source of hydration is recurring slope lineae activity. The hydrated salts most consistent with the spectral absorption features we detect are magnesium perchlorate, magnesium chlorate and sodium perchlorate. Our findings strongly support the hypothesis that recurring slope lineae form as a result of contemporary water activity on Mars.
http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2546.html
= new reply since forum marked as read
Here are lineae on Jupiter's moon, Europa.
Thanks for an interesting post.
A couple of days early but right on time for DU! No October surprises please! 
Alien lifeforms can be sneaky!
What are we waiting for? We know the surface is sterile. Probe them!
We know where the life should be hiding
we'll be getting our building materials from the Moon and from captured asteroids. So, those figures pretty much go out the window
So... manufacturing mining machines on Mars, so you don't have to send them from Earth, requires you to initially spend a fortune and send mining equipment from Earth -- pump priming, I guess.
Ah, wouldn't phasers come in handy at times. 
Don't drink the water. Don't even touch it. Not one drop.
The Waters of Mars
http://www.bbc.co.uk/doctorwho/s4/episodes/S0_07
