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Monday, December 09, 2019 {{ new Date().getDay() }}

By Amina Khan, Los Angeles Times (TNS)

Climbing up Mt. Sharp in the middle of Gale Crater, NASA’s Mars rover Curiosity has discovered a two-tone vein of minerals that reveal multiple episodes of water flowing through rock — even after the lake that once filled the bottom of the crater had ceased to be.

The rover’s discovery points to an even more complex, and perhaps long-lived, watery environment on the Red Planet.

“Not only does this help us try to understand the chemistry of the rocks that we measure in the region, but on a different sort of scale it tells us that fluids were around on Mars for a long time,” said Linda Kah, a sedimentary geologist at the University of Tennessee, Knoxville, and a member of Curiosity’s science team.

The duo-tone deposits, at a spot called Garden City, sit some 39 feet above the lower edge of the Pahrump Hills outcrop, which is part of the basal layer of the 3-mile-high Mt. Sharp. They feature both light and dark regions. They rise about 2.5 inches above the rock surface like ridges, because the rock that once surrounded them has worn away. These kinds of veins are formed when fluid flows through cracks in a rock and leaves some minerals behind.

Most veins have been bright and light-colored, Kah said, often filled with calcium sulfate. On Earth, such mineral deposits are often associated with salty water. But the dark deposits were somewhat unexpected, she said.

The dark parts often seem to line either side of the white veins, rather like an ice cream sandwich — a description Kah’s 10-year-old son Douglas came up with while looking over his mother’s shoulder at images of the deposits.

“I think they’re incredibly gorgeous and beautiful,” she said.

Whether appetizing or attractive, the two different tones are scientifically telling. Researchers look at Martian rocks in part to see how water (and the stuff in the water) may have affected a particular rock during a particular era. But if the same rock is getting soaked with very different kinds of water sources over time, then it may show a confusing mix of traits from a long period in which the environment dramatically changed over and over again.

That’s why the mineral veins are so helpful. The deposits in the cracks can look very different from the surrounding rock because they were formed much later than the rock itself. So while the rock’s chemistry and mineralogy will have been affected by multiple environments, the mineral vein offers a snapshot of at least one individual era in the Red Planet’s history.

In this case, this mineral vein actually offers snapshots into three environments. At first the scientists thought there were two different epochs, represented by the light and dark deposits, but it turns out that some dark spots are chemically very different from other dark areas.

“It was really very exciting for us,” Kah said. “Now we’ve just added complexity, so it makes it more fun to figure it out in the long run.”

The scientists think this environment existed long after the lake that once filled the bottom of Gale Crater dried up for good, and that these deposits were created by water under a significant amount of rock — enough to exert the kind of pressure that would force the fluid to push through cracks in the stone.

It’s also unclear how hot or cold or acidic or salty this water was; the fluid’s chemistry could have been very different from the potentially potable liquid in that long-gone lake.

But it’s still quite possible that microbial life, if it ever existed, could have thrived in this environment, just as they thrive in the rock fractures at the hot springs of Yellowstone National Park, she added.

(c)2015 Los Angeles Times, Distributed by Tribune Content Agency, LLC

Image Credit: NASA/JPL-Caltech/MSSS

Actor as Donald Trump in Russia Today video ad

Screenshot from RT's 'Trump is here to make RT Great Again'

Russia Today, the network known in this country as RT, has produced a new "deep fake" video that portrays Donald Trump in post-presidential mode as an anchor for the Kremlin outlet. Using snippets of Trump's own voice and an actor in an outlandish blond wig, the ad suggests broadly that the US president is indeed a wholly owned puppet of Vladimir Putin– as he has so often given us reason to suspect.

"They're very nice. I make a lot of money with them," says the actor in Trump's own voice. "They pay me millions and hundreds of millions."

But when American journalists described the video as "disturbing," RT retorted that their aim wasn't to mock Trump, but his critics and every American who objects to the Russian manipulations that helped bring him to power.

As an ad for RT the video is amusing, but the network's description of it is just another lie. Putin's propagandists are again trolling Trump and America, as they've done many times over the past few years –- and this should be taken as a warning of what they're doing as Election Day approaches.

The Lincoln Project aptly observed that the Russians "said the quiet part out loud" this time, (Which is a bad habit they share with Trump.)