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Is NASA ignoring proof of Martian life from the 1970s?
One of the scientists with the Viking missions says yes.
- A former NASA consultant believes his experiments on the Viking 1 and 2 landers proved the existence of living microorganisms on Mars.
- Because of other conflicting data, his experiments' results have been largely discarded.
- Though other subsequent evidence supports their findings, he says NASA has been frustratingly disinterested in following up.
Gilbert V. Levin is clearly aggravated with NASA, frustrated by the agency's apparent unwillingness to acknowledge what he considers a fact: That NASA has had dispositive proof of living microorganisms on Mars since 1976, and a great deal of additional evidence since then. Levin is no conspiracy theorist, either. He's an engineer, a respected inventor, founder of scientific-research company Spherix, and a participant in that 1976 NASA mission. He's written an opinion piece in Scientific American that asks why NASA won't follow up on what he believes they should already know.
Sunset at the Viking 1 site
Image source: NASA/JPL
As the developer of methods for rapidly detecting and identifying microorganisms, Levin took part in the Labeled Release (LR) experiment landed on Mars by NASA's Viking 1 and 2.
At both landing sites, the Vikings picked up samples of Mars soil, treating each with a drop of a dilute nutrient solution. This solution was tagged with radioactive carbon-14, and so if there were any microorganisms in the samples, they would metabolize it. This would lead to the production of radioactive carbon or radioactive methane. Sensors were positioned above the soil samples to detect the presence of either as signifiers of life.
At both landing sites, four positive indications of life were recorded, backed up by five controls. As a guarantee, the samples were then heated to 160°, hot enough to kill any living organisms in the soil, and then tested again. No further indicators of life were detected.
According to many, including Levin, had this test been performed on Earth, there would have been no doubt that life had been found. In fact, parallel control tests were performed on Earth on two samples known to be lifeless, one from the Moon and one from Iceland's volcanic Surtsey island, and no life was indicated.
However, on Mars, another experiment, a search for organic molecules, had been performed prior to the LR test and found nothing, leaving NASA in doubt regarding the results of the LR experiment, and concluding, according to Levin, that they'd found something imitating life, but not life itself. From there, notes Levin, "Inexplicably, over the 43 years since Viking, none of NASA's subsequent Mars landers has carried a life detection instrument to follow up on these exciting results."
A thin coating of water ice on the rocks and soil photographed by Viking 2
Image source: NASA
Levin presents in his opinion piece 17 discoveries by subsequent Mars landers that support the results of the LR experiment. Among these:
- Surface water sufficient to sustain microorganisms has been found on the red planet by Viking, Pathfinder, Phoenix and Curiosity.
- The excess of carbon-13 over carbon-12 in the Martian atmosphere indicates biological activity since organisms prefer ingesting carbon-12.
- Mars' CO2should long ago have been converted to CO by the sun's UV light, but CO2 is being regenerated, possibly by microorganisms as happens on Earth.
- Ghost-like moving lights, resembling Earth's will-O'-the-wisps produced by spontaneous ignition of methane, have been seen and recorded on the Martian surface.
- "No factor inimical to life has been found on Mars." This is a direct rebuttal of NASA's claim cited above.
A technician checks the soil sampler of a Viking lander.
Image source: NASA
By 1997, Levin was convinced that NASA was wrong and set out to publish followup research supporting his conclusion. It took nearly 20 years to find a venue, he believes due to his controversial certainty that the LR experiment did indeed find life on Mars.
Levin tells phys.org, "Since I first concluded that the LR had detected life (in 1997), major juried journals had refused our publications. I and my co-Experimenter, Dr. Patricia Ann Straat, then published mainly in the astrobiology section of the SPIE Proceedings, after presenting the papers at the annual SPIE conventions. Though these were invited papers, they were largely ignored by the bulk of astrobiologists in their publications." (Staat is the author of To Mars with Love, about her experience as co-experimenter with Levin for the LR experiments.)
Finally, he and Straat decided to craft a paper that answers every objection anyone ever had to their earlier versions, finally publishing it in Astrobiology's October 2016 issue. "You may not agree with the conclusion," he says, "but you cannot disparage the steps leading there. You can say only that the steps are insufficient. But, to us, that seems a tenuous defense, since no one would refute these results had they been obtained on Earth."
Nonetheless, NASA's seeming reluctance to address the LR experiment's finding remains an issue for Levin. He and Straat have petitioned NASA to send a new LR test to the red planets, but, alas, Levin reports that "NASA has already announced that its 2020 Mars lander will not contain a life-detection test."
- NASA videos show what sunsets look like on Venus, Uranus - Big Think ›
- ESA's 'interplanetary cargo ship' to carry Mars rocks to Earth in 2031 - Big Think ›
- Mars had up to 20 separate ice ages, discover scientists - Big Think ›
A new study finds that dogs fed fresh human-grade food don't need to eat—or do their business—as much.
- Most dogs eat a diet that's primarily kibble.
- When fed a fresh-food diet, however, they don't need to consume as much.
- Dogs on fresh-food diets have healthier gut biomes.
Four diets were tested<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTU5ODI1MS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY1NjY0NjIxMn0._w0k-qFOC86AqmtPHJBK_i-9F5oVyVYsYtUrdvfUxWQ/img.jpg?width=980" id="1b1e4" class="rm-shortcode" data-rm-shortcode-id="87937436a81c700a8ab3b1d763354843" data-rm-shortcode-name="rebelmouse-image" data-width="1440" data-height="960" />
Credit: AntonioDiaz/Adobe Stock<p>The researchers tested refrigerated and fresh human-grade foods against kibble, the food most dogs live on. The <a href="https://frontierpets.com.au/blogs/news/how-kibble-or-dry-dog-food-is-made" target="_blank">ingredients</a> of kibble are mashed into a dough and then extruded, forced through a die of some kind into the desired shape — think a <a href="https://en.wikipedia.org/wiki/Food_extrusion" target="_blank">pasta maker</a>. The resulting pellets are sprayed with additional flavor and color.</p><p>For four weeks, researchers fed 12 beagles one of four diets:</p><ol><li>a extruded diet — Blue Buffalo Chicken and Brown Rice Recipe</li><li>a fresh refrigerated diet — Freshpet Roasted Meals Tender Chicken Recipe</li><li>a fresh diet — JustFoodforDogs Beef & Russet Potato Recipe</li><li>another fresh diet — JustFoodforDogs Chicken & White Rice Recipe.</li></ol><p>The two fresh diets contained minimally processed beef, chicken, broccoli, rice, carrots, and various food chunks in a canine casserole of sorts. </p><p>(One can't help but think how hard it would be to get finicky cats to test new diets. As if.)</p><p>Senior author <a href="https://ansc.illinois.edu/directory/ksswanso" target="_blank" rel="noopener noreferrer">Kelly S. Swanson</a> of U of I's Department of Animal Sciences and the Division of Nutritional Sciences, was a bit surprised at how much better dogs did on people food than even refrigerated dog chow. "Based on past research we've conducted I'm not surprised with the results when feeding human-grade compared to an extruded dry diet," he <a href="https://aces.illinois.edu/news/feed-fido-fresh-human-grade-dog-food-scoop-less-poop" target="_blank">says</a>, adding, "However, I did not expect to see how well the human-grade fresh food performed, even compared to a fresh commercial processed brand."</p>
Tracking the effect of each diet<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTU5ODI1OC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY3NjY1NTgyOX0.AdyMb8OEcjCD6iWYnXjToDmcnjfTSn-0-dfG96SIpUA/img.jpg?width=980" id="da892" class="rm-shortcode" data-rm-shortcode-id="880d952420679aeccd1eaf32b5339810" data-rm-shortcode-name="rebelmouse-image" data-width="1440" data-height="960" />
Credit: Patryk Kosmider/Adobe Stock<p>The researchers tracked the dogs' weights and analyzed the microbiota in their fecal matter.</p><p>It turned out that the dogs on kibble had to eat more to maintain their body weight. This resulted in their producing 1.5 to 2.9 times the amount of poop produced by dogs on the fresh diets.</p><p>Says Swanson, "This is consistent with a 2019 National Institute of Health study in humans that found people eating a fresh whole food diet consumed on average 500 less calories per day, and reported being more satisfied, than people eating a more processed diet."</p><p>Maybe even more interesting was the effect of fresh food on the gut biome. Though there remains much we don't yet know about microbiota, it was nonetheless the case that the microbial communities found in fresh-food poo was different.</p><p>"Because a healthy gut means a healthy mutt," says Swanson, "fecal microbial and metabolite profiles are important readouts of diet assessment. As we have shown in <a href="https://academic.oup.com/jas/article/92/9/3781/4702209#110855647" target="_blank">previous studies</a>, the fecal microbial communities of healthy dogs fed fresh diets were different than those fed kibble. These unique microbial profiles were likely due to differences in diet processing, ingredient source, and the concentration and type of dietary fibers, proteins, and fats that are known to influence what is digested by the dog and what reaches the colon for fermentation."</p>
How did kibble take over canine diets?<p>Historically, dogs ate scraps left over by humans. It has only been <a href="https://www.thefarmersdog.com/digest/the-history-of-commercial-pet-food-a-great-american-marketing-story/" target="_blank">since 1870</a>, with the arrival of the luxe Spratt's Meat Fibrine Dog Cakes—made from "the dried unsalted gelatinous parts of Prairie Beef", mmm—that commercial dog food began to take hold. Dog bone-shaped biscuits first appeared in 1907. Ken-L Ration dates from 1922. Kibble was first extruded in 1956. Pet food had become a great way to turn <a href="https://www.dogfoodadvisor.com/choosing-dog-food/animal-by-products/" target="_blank">human-food waste</a> into profit.</p><p>Commercial dog food became the norm for most household canines only after a massive marketing campaign led by a group of dog-food industry lobbyists called the Pet Food Institute in 1964. Over time, for most households, dog food was what dogs ate — what else? Human food? These days more than half of U.S. dogs are <a href="https://www.nytimes.com/2014/08/03/magazine/who-made-that-dog-biscuit.html" target="_blank">overweight or obese</a>, and certainly their diet is a factor.<span></span></p><p>We're not so special among animals after all. If something's healthy for us to eat—we're <em>not</em> looking at you, chocolate—maybe we should remember to share with our canine compatriots. Not from the table, though.</p>
What makes some people more likely to shiver than others?
Some people just aren't bothered by the cold, no matter how low the temperature dips. And the reason for this may be in a person's genes.
Eating veggies is good for you. Now we can stop debating how much we should eat.
- A massive new study confirms that five servings of fruit and veggies a day can lower the risk of death.
- The maximum benefit is found at two servings of fruit and three of veggies—anything more offers no extra benefit according to the researchers.
- Not all fruits and veggies are equal. Leafy greens are better for you than starchy corn and potatoes.