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Ancient Mars May Have Been Less Wet Than We Thought

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Ice sheets, and not rushing rivers, sculpted many Martian valleys, according to scientists. The new research suggests ancient Mars wasn’t as warm and wet as we thought, but an expert we spoke to remains unconvinced.

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New research published in Nature Geoscience suggests rushing rivers weren’t responsible for the distinctive shape of certain Martian valleys located in the planet’s southern highlands. Rather, these geological features were forged by melting water coursing beneath gigantic glaciers, in a geological process known as subglacial erosion. Ancient Mars, the new research suggests, was likely cold and icy, and not the temperate wet planet it’s often presumed to be.

“Our study challenges the widely held view that most valley networks on Mars were formed by rivers fed by precipitation,” explained Gordon Osinski, a co-author of the new paper and a planetary geologist from Western University, in a Western press release. “While we found evidence consistent with a small handful of valley networks having formed in this way, our observations suggest that the majority formed beneath ice sheets.”

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Interestingly, these results, while surprising, seem to match the results from climate models. Computer simulations of ancient Mars suggest the Red Planet was cold and covered with ice some 3.8 billion years ago.

For the new study, Osinski, along with Anna Grau Galofre from Arizona State University and Mark Jellinek from the University of British Columbia, examined satellite photos of 10,276 individual valleys found in 66 valley networks on Mars, which they did using custom-built software. Their algorithm was able to match surface features to specific erosional processes, including glacial, subglacial, fluvial (surface water), and sapping (ground water) erosion.

“If you look at Earth from a satellite, you see a lot of valleys: Some of them made by rivers, some made by glaciers, some made by other processes, and each type has a distinctive shape,” explained Grau Galofre in an ASU press release. “Mars is similar, in that valleys look very different from each other, suggesting that many processes were at play to carve them.”

Martian valleys were also compared to known subglacial features on Earth. Devon Island, located in the Canadian Arctic, is “one of the best analogues we have for Mars here on Earth,” said Osinski, as it’s a “cold, dry polar desert and we know the glaciation is largely cold-based.”

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Of the 66 valley systems studied, the researchers identified 22 as being formed from subglacial erosion: 14 fluvial, nine glacial, three sapping, and 18 indeterminate. These findings are “the first evidence for extensive subglacial erosion driven by channelized meltwater drainage beneath an ancient ice sheet on Mars,” said Jellinek in the ASU press release, adding that these results “demonstrate that only a fraction of valley networks match patterns typical of surface water erosion, which is in marked contrast to the conventional view.”

Bruce Jakosky, a geology professor at the University of Colorado and Principal Investigator on the Mars Atmosphere and Volatile Evolution (MAVEN) mission, described the new analysis as “interesting” but not “definitive.”

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“Based on their figures, there appears to be a smooth gradation between the properties of the individual valley networks,” said Jakosky in an email. “Having a smooth gradation in properties, but classifying them into a limited number of formation processes, seems to leave one open to significant uncertainties.”

As a result, Jakosky is not very confident in the specific numbers used in the study. He was also unimpressed with the relatively small sample size of 66, given the authors’ declaration that “hundreds” of valley networks exist on Mars.

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“With the exception of the low number for sapping erosion, this seems consistent with a random distribution between the other processes,” he explained. “That is, even though subglacial erosion is the most prominent, it is not so dominant as to justify a conclusion that they are the major process. That is, they state that subglacial and fluvial dominate, but it looks more roughly equal among all processes.”

To which he added: “Their conclusions should have been that all of the processes that they examined played a role, and we have to look for a climate/environment that could support all of them.”

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Scott King a geoscientist from Virginia Tech, found the new result to be reasonable, and even likely.

“I think the problem is that it’s Mars and we have some pretty strong ideas about Mars and sometimes that gets in the way of our looking at the observations,” wrote King in an email. “This is one of those studies that makes us stop and ask ourselves just why did we assume that all the valley networks on Mars were fluvial? Why wouldn’t both fluvial and glacial erosion have occurred on Mars? The climate models tell us that Mars was cold and icy so these researchers asked a very logical question, ‘what kind of valley networks do we see?’”

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Indeed, the new data has to be reconciled with other geological evidence from ancient Mars, such as the sites of former lakes and river deltas (including Jezero crater, the destination site for the Mars Perseverance rover), clay formations (as discovered by the Curiosity rover), and even evidence of an ancient mega-tsunami on Mars.

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Ancient Mars was wet, but the new paper complicates our understanding of this planet’s past by showing how erosional processes other than free-flowing surface water can sculpt certain geological features. Moving forward, planetary scientists would do well to remember this paper, even if it’s somewhat incomplete. It’s becoming increasingly clear, however, that ancient Mars was a complex and dynamic place.

Source : Gizmodo Read More

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Charge Your Phone Wirelessly With 50% off a Multifunctional LED Lamp

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Best Tech DealsBest Tech DealsThe best tech deals from around the web, updated daily.

White Wireless Charge Lamp | $18 | Amazon | Clip coupon + code ABC88699
Black Wireless Charger Lamp | $20 | Amazon | Promo code ABC88699

When you’re ready to turn in for the night, you don’t want to forget to charge your phone— especially if your mobile device doubles as your alarm clock.

With this wireless charger lamp, you can make this crucial step of your nightly routine even easier by just setting your phone on the wireless charging pad and… well, that’s all there is to it!

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Other functions include multiple lighting modes as well as a sleep timer option for auto shut-off of the light after 30 or 60 minutes.

This lamp can be yours in white for $18 if you clip the coupon on Amazon (it’s below the original $40 price) and add promo code ABC88699 at checkout.

You can snag the black version for $20 using the same code—no coupon though, sorry.

Don’t sleep on this deal! Who knows how long stock or the coupon code will last?

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Keep That Hotdish Hot With 65% Off a Luncia Casserole Carrier, Only $11 With Promo Code

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Best Home DealsBest Home DealsThe best home, kitchen, smart home, and automotive deals from around the web, updated daily.

Luncia Double-Decker Dish Carrier | $11 | Amazon | Promo code SDDU9S7F

It has been a long time since the days we could safely have a potluck or other gatherings, but we have a fantastic deal perfect for once those times return. These double-decker Luncia dish carriers can be had for 65% off when you add promo code SDDU9S7F at checkout and clip the coupon on the site (it’s just below the price). These holders fit 9″x 13″ sized baking dishes.

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That means you can insulate and keep two dishes of food warm for only $11 instead of $30. What’s more, your Luncia carrier will arrive by Christmas if you order today as a Prime member.

Just add promo code SDDU9S7F and clip the 5% off coupon to bring the price down to $11 for the blue or the grey option.

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Grab this offer while it’s still around!


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Conquer Your Pup’s Dander and Fur With $700 Off a Cobalt or Charcoal Bobsweep PetHair Plus Robot Vacuum

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Best Home DealsBest Home DealsThe best home, kitchen, smart home, and automotive deals from around the web, updated daily.

Bobsweep PetHair Plus Robot Vacuum & Mop (Cobalt) | $200 | Best Buy

Bobsweep PetHair Plus Robot Vacuum & Mop (Charcoal) | $200 | Best Buy

Allergies can be bad enough as the seasons change. Don’t let pet hair and dander add to that by vacuuming it up early and often. That chore is easier said than done— unless you have a robot vacuum to do the work for you. This lovely bright cobalt Bobsweep PetHair Plus robot vacuum and mop, only $200 today at Best Buy seems like an ideal option. That’s a whopping $700 off, by the way.

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You can get the same deal for the charcoal version of the robot vac, too. This model is not only specially made for picking up pet hair, it self docks and charges when it’s finished with the work.

It also comes with a mop attachment, so it can take care of those kitchen floors for you as well. Grab it while it’s still available for this fantastic price!

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