Tedros Adhanom Ghebreyesus, Director General of the World Health Organization (WHO) speaks after Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases during the 148th session of the Executive Board on the coronavirus disease (COVID-19) outbreak in Geneva, Switzerland, January 21, 2021.
Christopher Black | WHO | via Reuters
The Covid-19 pandemic has caused mass trauma on a larger scale than World War II, and the impact will last “for many years to come,” the World Health Organization’s top official said Friday.
“After the Second World War, the world has experienced mass trauma, because Second World War affected many, many lives. And now, even with this Covid pandemic, with bigger magnitude, more lives have been affected,” WHO Director-General Tedros Adhanom Ghebreyesus said at a news conference Friday. “Almost the whole world is affected, each and every individual on the surface of the world actually has been affected.”
“And that means mass trauma, which is beyond proportion, even bigger than what the world experienced after the Second World War,” he added, noting the effect on mental health. “And when there is mass trauma, it affects communities for many years to come.”
His comments came in response to a question about whether countries should take the pandemic’s impact on the economy and mental health into account more as they chart their paths forward. Tedros’ deputies emphasized that mental health ought to be prioritized.
“The answer is absolutely yes,” Maria Van Kerkhove, head of the WHO’s emerging diseases and zoonosis unit, said. “There are variations in terms of the impact that this has had on individuals, whether you have lost a loved one, or a family member or friend to this virus. Whether you’ve lost your job, children who haven’t been in school, people who are forced to stay home in very difficult situations.”
Kerkhove added that the world is still in the “acute phase” of the pandemic, when the virus is tearing through communities, killing tens of thousands every week. She added, though, that the mental health toll of the pandemic will emerge as a major issue in the long term, saying that “there needs to be a lot more emphasis by governments, by communities, by families, by individuals to look after our well-being.”
Dr. Mike Ryan, executive director of the WHO’s health emergencies program, urged people to not just highlight the mental health toll of the pandemic as a problem, but to also discuss solutions.
“It’s one thing to say that mental health is and psychological health is under pressure — that’s true — but also the opposite of that has to be what we’re doing to support and provide psychosocial support to people and communities,” he said.
One day 66 million years ago, Earth suddenly transformed from being a verdant, dinosaur-ridden world to a soot-covered apocalyptic hellscape. The extinction event wiped out 75 percent of the world’s animal and plant species at the time, including dinosaurs.
Evidence of that calamitous day can be found in the Chicxulub crater, a heavily eroded 90-mile wide impact site located on Mexico’s Yucatán Peninsula, which is widely believed to be the impact site for whatever triggered the mass extinction event. And while there is scientific consensus that something hit the Earth that fateful day, there are different theories about exactly what.
Indeed, for decades, geologists and geophysicists have fixated on the idea that an asteroid is to blame. Now, astrophysicists at Harvard University are theorizing that an icy comet from the Oort cloud — a theoretical shell of icy debris at the edge of the solar system— flew too close to the sun, in part due to Jupiter’s strong tidal forces, and eventually broke apart and crashed into Earth. In other words, “cometary shrapnel” from a long-period comet which pinged around our solar system could have caused the impact that led to a mass extinction, rather than an astroid.
Amir Siraj, lead researcher and undergraduate in astrophysics at Harvard University, and Avi Loeb, who is the former chair of astronomy at Harvard University, landed on this theory using statistical analysis and gravitational simulations. Their findings were published in Nature’s Scientific Reports on February 15.
In the paper, the researchers put forth their new calculations that increase by a factor of 10 the likelihood of long-period comets — meaning those which have orbital periods longer than 200 years — striking Earth. They also calculate that 20 percent of long-period comets become sungrazers, meaning comets that fly very close to the Sun and are whipped back through the terrestrial planets. The timing of these calculations would be “consistent with the age of the Chicxulub impact crater,” the researchers explained, providing a “satisfactory explanation for the origin of the impactor.”
Siraj told Salon he didn’t originally seek out to find the answer to the origins of the Chicxulub impactor, but he started to probe deeper while looking into the asteroid impact rates for Earth-like exoplanets. This led him to study cometary impact rates on those systems, which led to him creating numerical simulations to calculate long-period comets in our own solar system.
“What I ended up finding most striking was that a significant fraction of Earth-crossing comet — Earth-crossing meaning comets 1 AU [astronomical unit] of the sun — were directly preceded by remarkably close encounters with the Sun,” Siraj said. “I found that these comets were passing so close to the Sun that they were within the Roche limit, where you can get tidal disruptions, and I dug into this point further, and what I ended up finding is that these comets were being produced by and large by interactions with Jupiter, which was essentially acting like a pinball machine.”
A common theory on the origin of the Chicxulub crater suggests that the source originated from the main belt, an area between the orbit of Jupiter and Mars populated with asteroids. The researchers say their theory provides a more realistic basis that can eventually be proved.
“Our paper provides a basis for explaining the occurrence of this event,” Loeb said in a media statement. “We are suggesting that, in fact, if you break up an object as it comes close to the sun, it could give rise to the appropriate event rate and also the kind of impact that killed the dinosaurs.”
Previously, evidence from the Chicxulub crater suggested the impact object was made of carbonaceous chondrite.
“Data in the past decade or so, and even before that, show that this composition is quite rare amongst asteroids,” Siraj said. “And we have a fairly good sense of the distribution of asteroid compositions simply as a result of having meteorites, which primarily come from asteroids.”
Yet comets, he noted, are not as well understood. Yet we know from one successful sample-return comet mission that comets do contain carbonaceous chondrite, Siraj said.
Siraj and Loeb aren’t the only ones positing the theory that a comet killed the dinosaurs. Two geoscientists advanced the theory in 2013, partially because the levels of iridium and osmium around the impact site were lower than should appear in an asteroid and more apt for a comet impact. Siraj said studying iridium will be an “important active area of research” to better understand what impactor that caused the Chicxulub crater.
Let’s say scientists eventually prove that a comet led to the extinction of dinosaurs and completely transformed Earth. Will that change how we perceive asteroids (or comets) as a threat to life on Earth?
“Asteroids are still the major short-term risk,” Siraj said. He noted that the good news about their theory is that there’s a low probability that shrapnel from a long-period comet will hit Earth in our lifetime. “We don’t have to worry about cometary impact being extremely common on very short timescales . . . however, it does change the way we think about longer term, like a million years and more — I imagine our civilization will have to have to reckon with these questions of deflecting small asteroids, which is very different from deflecting big asteroids, which is also very different from deflecting comets.”
Humanity’s need to make “contingency plans” to address planet-wide devastation events highlights the importance of future research around the dynamics of small bodies in our solar system.
“Science is really the tool that we can use to address these looming existential threats and be prepared,” Siraj said.
Created in 2016 as a portal for short, humorous clips, TikTok has recently become synonymous with something far more sinister: viral internet challenges.
Pull up the video-sharing app and you’ll inevitably see opportunistic bozos risking their reputations and even bodies on camera for social media clout — like if Snapchat was created by the “Jackass” guys.
In the most notorious stunt recently, a female TikTokker wound up in the hospital after trying to style her hair with gorilla glue.
Unfortunately, the app’s eyeball-seeking algorithm makes it extremely difficult for these oft-harmful trends to be nipped in the bud before they metastasize across the internet.
To help readers know what to avoid, we’ve compiled a list of challenges so ludicrous we might want to reconsider a TikTok ban.
1. Gorilla Glue girl
This might not be a challenge per se. However, Louisiana’s Tessica Brown undoubtedly cemented her place on TikTok stupidity’s Mount Rushmore after slathering her hair with Gorilla Glue and having to get it surgically repaired during a four-hour procedure.
Unfortunately, this cautionary tale might not stick as Brown’s adhesive mishap landed her $20,000 dollars in donations, hundreds of free hair products and even a full-time agent — not to mention an unfortunate imitator.
2. DIY vampire fangs
Speaking of Super Glue fiascos, holiday revelers went viral this past Halloween after supergluing costume vampire fangs to their teeth. The cringe-worthy clips — which, using the hashtag #VampireFangs, amassed over 9 million views — depicted various bozos struggling to remove the faux chompers after fastening them to their incisors using Super Glue, nail glue and other adhesives.
Go figure: Dentists advised against this practice, citing the fact that nail glue “is poisonous and won’t come off.”
3. Tooth filing
In the realm of toothless TikTok challenges, DIY vampire fangs pale in comparison to these amateur cosmeticians remodeling their chompers with nail files.
For the uninitiated, the challenge involved various knuckleheads attempting to fix their uneven smiles by using a nail file to sand their snack-slicers down to size. It was basically the bargain-bin equivalent of an enameloplasty — a reshaping procedure involving enamel removal that one would receive from a cosmetic dentist.
However, unlike the latter, these freelance molar makeovers sparked an outcry from the dental community.
“You’re doing irreparable damage and destruction to your teeth,” Dr. Chad Evans, co-founder of Texas-based Smile Magic Family Dental, said.
4. Face wax challenge
Full facial waxing is the hot new beauty fad with vids of the procedure collectively amassing millions of views on TikTok.
The procedure, demonstrated here by Kapsalon Freedom barbershop in the Netherlands, involves caking a patient’s face — including their eyes — with gloopy green wax as if casting a mold for the “House of Wax” horror movie. They even have wax-dipped Q-Tips stuck in their noses to extract pesky nasal hairs. When finished, the rogue beautician peels the beauty batter off the subject’s face in one piece like a slasher villain mask.
Skin experts are calling the process traumatic “for the skin, especially sensitive areas such as those found around the eyes.”
5. Erection cream pout plumper
TikTok cosmeticians redefined maintaining a stiff upper lip after trying to plump their pouts with erection cream on camera. While one influencer did succeed in fluffing his flappers to life raft proportions, he had to stop the stunt early due to the burning sensation.
Meanwhile doctors said that the hack is “utterly ridiculous and can be extremely dangerous,” adding that the “temporary” procedure could lead to adverse reactions including soreness, swelling and blisters, as well as blood pressure fluctuations and “possible heart problems.”
6. Corn cob challenge
As part of a series of viral lifehacks, enterprising TikTokkers tried to accelerate their corn consumption by eating a cob affixed to a spinning drill bit. This Loony Toons-evoking feat gained international attention after rapper Jason Derulo chipped a tooth while performing the stunt.
However, Anaconda’s cracked kernel didn’t deter him from trying to inhale 22 hamburgers a month later to commemorate reaching 22 million TikTok followers.
7. Cereal challenge
This one just seems nasty from the outset, but it also could have a potentially dangerous end result. In this test of wills, a person pours milk and cereal into the open mouth of a person lying down and then eats breakfast from the human “bowl.” Needless to say, things can get super, super messy, not to mention become a choking hazard for the volunteer vessel.
TikTok provides an extensive list of “community guidelines” that state the company does not allow “content that is excessively gruesome or shocking, especially that promotes or glorifies abject violence or suffering.” It also outlines “risky activities or other dangerous behavior” that are not allowed, including activity that “encourages, promotes, or glorifies such behavior, including amateur stunts or dangerous challenges.”
8. Skull breaker challenge
The title says it all.
This viral craze — reportedly originating in Venezuela as “rompcráneos,” or “skull breaker” — depicts three friends (we use the term loosely) jumping next to each other as the bookending buds kick the middle guy’s feet out from under him. The action sends the person crashing to the ground, landing on their back and hitting their head in the process.
Not only has the alarming trend led to injuries in Miami, New Jersey and Arizona, but Daytona Beach, Florida police have charged two high school teens with misdemeanor battery and cyberbullying following an incident there. In addition, two students in Mexico did their own version of the “skull breaker,” but reportedly used a sweater instead of their feet to trip a girl into doing a face-plant.
Doctors have unsurprisingly condemned the practice for its potential to cause “serious and life-threatening injuries,” ranging from “skull fracture to paralysis and death.”
9. Penny challenge
This shocking fad involves sliding a penny behind a partially plugged-in phone charger, as seen in multiple viral videos circulating on YouTube and TikTok.
While the prank may seem innocuous, the coin can strike the metal prongs, causing “sparks, electrical system damage, and in some cases, fire,” warned Massachusetts Fire Marshall Peter J. Ostroskey in an advisory issued last year.
Case in point: The marshal obtained a photo of a scorched outlet in Holden reportedly caused by the viral prank. In another incident, a student at Plymouth North High School allegedly started a fire after performing the challenge in what Plymouth Schools Superintendent Dr. Gary Maestas called an “irresponsible act. Fortunately, no one was injured — but the accidental arsonist was charged for the crime.
10. Benadryl challenge
This inflammatory challenge, which involves taking enough Benadryl to hallucinate and posting the footage on the video-sharing platform, resulted in the death of a 15-year-old Oklahoma girl last year.
This, along with several other near-fatal incidents, prompted pharmaceutical giant Johnson & Johnson and the FDA to issue PSAs warning teens not to abuse the antihistamines.
The latter warned, “Taking higher than recommended doses of the common over-the-counter (OTC) allergy medicine diphenhydramine (Benadryl) can lead to serious heart problems, seizures, coma or even death.”
11. ‘Cha-Cha Slide’ challenge
This ridiculous TikTok trend involved teen drivers swerving all over the road like maniacs in time with the stunt’s namesake dance anthem, first released 20 years ago by DJ Casper, a k a Mr. C The Slide Man.
Despite the obvious risks, the trend has taken TikTok by storm, reportedly causing several near-accidents by participants. “The car almost flipped,” reads the caption to a video of one TikTokker performing the stunt with friends.
TikTok warns viewers on several clips that “the action in this video could result in serious injury.”
12. Pee your pants challenge
Nothing to ward off the coronavirus doldrums like a viral video leak, right? At least that’s what one bored livestreamer thought when he heeded nature’s call on camera, inspiring scores of other lonely TikTokkers to follow suit like a Pied Pee-per.
The #peeyourpantschallenge hashtag currently quickly racked up 3.9 million views on TikTok, as well as a flurry of criticism from horrified commenters.
“People seriously need to get back to work soon . . . everybody has gone insane,” sputtered one.
13. The poop challenge
In an even sicker stunt, these parents in lockdown smeared excrement on their progeny and filmed their aghast reactions. “WTF” seemed to be the overwhelming response.
14. Verbal abuse challenge
These moms and dads crapped on their kids figuratively by calling them a “mistake” and in some instances mentioning the word “abort.”
15. Flash mob
These moms bided the lockdown in titillating fashion by exposing their breasts to their babies and recording their enticed reactions.
Called the #DropEmOutChallenge, these jokester mamas post their videos with Wheeler Walker Jr.’s song “Drop ‘Em Out” playing in the background. The country tune’s lyrics are particularly fitting for this game.
“Drop ’em out, let me see them ti - - ies,” the 2015 country song goes. “Gonna take a long look at those tig ol’ bitties.”
Seemingly from behind the camera, the moms bare it all to their hungry, breast-fed babies, filming the excited expressions.
16. The “dipping” challenge
Sauciness takes a turn for the worst courtesy of this salty social media swag.
After months of being bored in the house owing to the pandemic, in June, men voluntarily slam-dunked their junk into small containers of soy sauce in hopes of tasting the savory Asian condiment — typically used to boost the taste of sushi — on their tongues.
And it wok’d!
The tasty testes trend stemmed from a resurfaced 2013 study which found that mice can determine taste through their testicles.
Once the challenge hit digital timelines, guys everywhere were unzipping their flies and using their goodies as saucy napkins in the name of science.
17. The black-out challenge
Also known as the “passout challenge” and “the fainting game,” participants of the deadly, albeit popular black-out challenge were dared to choke themselves until they passed out for several seconds.
A 10-year-old girl in Italy tied a belt around her neck and accidentally asphyxiated herself in January. She was rushed to a hospital in Palermo where doctors ultimately pronounced her brain-dead.
TikTok encouraged users to flag any account holders engaging in the dangerous trend.
18. The “coronavirus challenge”
Crap’s got your tongue??
Ava Louise, a regular attention-seeker on Dr. Phil, took her clout-chasing to the clouds in March when she went viral for licking airplane toilet seats.
Insensitively dubbing her disgusting digital demonstration the “coronavirus challenge,” Louise, 22, caught cyberspace hell for her tone-deaf antics.
19. The silhouette challenge
Small-screen seduction hit a hard stop after perverts found a way to bring a cheeky trend to a creepy end.
Originally, hotties were taking to TikTok to show off their amazing bodies behind a red filter that covered up their private parts. But, geeky freaks found a way to remove the filter and get an eyeful of the women’s unmentionables.
PSAs warning lusty ladies about the pervy privacy breach went viral. And naturally, the sexy challenge slipped into the shadows.
Space: Robin Hanson reveals what ‘should scare you’
Earth’s magnetic field has a weak spot “the size of the continental US” hovering over South America and the southern Atlantic Ocean. Scientists say we are safe from the effects on Earths, but satellites are not so lucky – when they pass through the anomaly they are bombarded with radiation “more intense than anywhere else in orbit”. Known as the South Atlantic Anomaly (SAA), or “the Bermuda Triangle of space” more colloquially, the region sits at the point where Earth’s magnetic field is particularly weak.
This means particles of solar cosmic rays are not being held back to the same extent as they are elsewhere above the planet.
As a result, solar rays come as close as 124 miles to the Earth’s surface – in a range of probes in Low-Earth Orbit (LEO).
John Tarduno, professor of geophysics at the University of Rochester, explained: “I’m not fond of its nickname, but in that region, the lower geomagnetic field intensity eventually results in a greater vulnerability of satellites to energetic particles, to the point that spacecraft damage could occur as they traverse the area.
“Thus satellites passing through this region will experience higher amounts of radiation to the point that damage could occur.
The ISS was affected by the radiation (Image: GETTY)
Earth is protected by the magnetic field (Image: GETTY)
“Think about an electrical discharge or arc.
“With more incoming radiation, a satellite can become charged, and attendant arcs can result in serious damage.”
Normally, the Earth’s magnetic field protects at an altitude of between 620 and 37,000 miles above the planet’s surface.
But the low altitude of the radiation hotspot puts it within the orbit of certain satellites, which become bombarded by protons that exceed energies of 10 million electron volts.
In the early days of the ISS, the anomaly would crash astronauts’ computers, forcing space agencies to power down their on board systems.
Astronauts were affected by the SAA too.
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Part of Earth’s magnetic field is weak (Image: GETTY)
Some reported seeing odd white lights flashing before their eyes, and steps have been taken to protect astronauts since.
Strong shielding is in place over the most frequently occupied parts of the ISS, such as the gallery and the sleeping quarters to reduce the amount of radiation the astronauts are exposed to.
Astronauts also wear dosimeters, which are devices that measure their personal exposure to ionising radiation in real-time, and send out a warning if they reach dangerous levels.
The Hubble telescope, which passes through the SAA 10 times a day and spends roughly 15 percent of its time there, is unable to collect astronomical data during these moments.
Failure to take these measures would likely lead to system failure.
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ISS astronauts felt the effects in the early days (Image: GETTY)
Dr Tarduno added: “Putting equipment into a ‘safe mode’ means operations that are more vulnerable to radiation are curtailed.”
Damage caused by the SAA can also prove very costly, as evidenced when the area sent the Japanese satellite Hitomi crashing down to Earth.
Hitomi, or ASTRO-H, was commissioned by the Japan Aerospace Exploration Agency (JAXA) to study extremely energetic processes in the universe.
Just over a month after its February 2016 launch, its operators lost contact and the satellite broke into several pieces.
Experts later discovered that the problem was due to the spacecraft’s inertial reference unit reporting a rotation of 21.7 degrees per hour when the craft was actually stable.
When the attitude control system sought to counteract the non-existent spin, a succession of events caused it to break.
Hubble has to power down during journeys through the anomaly (Image: GETTY)
Had the operators been able to spot the error in real-time, they could have corrected it, but it happened while the satellite was travelling through the SAA, so communication was lost.
The unfortunate saga cost JAXA about $273million (£210million) and three years of prepared studies.
And it could pose more problems in the future.
A recent forecast from NASA scientist Dr Weijia Kuang and Professor Andrew Tangborn of the University of Maryland, Baltimore County, shows that in addition to migrating westward, the anomaly is growing in size.
Five years from now, one area could grow as much as 10 percent compared with 2019 values.
The dent may also be splitting, Dr Kuang said, or perhaps another weak spot is emerging independently and biting into it.
Julien Aubert, a researcher at the Paris Institute of Earth Physics, stated more research is needed.
She said in January: “Just like weather forecasts, you can’t predict the evolution of the core beyond a few decades.”
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Changes in Mars’ geography always attract significant scientific and even public attention. A hope for signs of liquid water (and therefore life) is likely one of the primary driving forces behind this interest.
One particularly striking changing feature is the Recurring Slope Lineae (RSL) originally found by the Mars Reconnaissance Orbiter (MRO).
Now, scientists at the SETI Institute have a modified theory for where those RSLs might develop – a combination of water ice and salt just under the Martian surface.
According to the SETI team, led by Senior Research Scientist Janice Bishop, there is a two-step process going on that creates these RSLs.
First, underground water ice must mix with a combination of chlorine salts and sulfates to create a type of slurry that destabilizes the regolith in the area.
Then, the dry wind and dust storms of Mars take over, blowing the destabilized material into new patterns across the Martian surface.
Krupac Crater also shows RSL development. (NASA/JPL/University of Arizona)
This is not the first time that researchers have suggested that chlorine salts might be involved in the creation of RSL. As with much good science, this theory has now been fleshed out more through data gathered in both field and lab experiments.
Unfortunately, the field experiments were not able to be carried out on Mars itself (at least not yet).
However, there are several places on our home planet that are considered “Mars analogs”, including the Dead Sea in Israel, Salar de Pajonales in the Atacama Desert, and the Dry Valleys in Antarctica.
The SETI team collected data at some of those locations and noted that surface destabilization has already been observed when salt interacted with gypsum, a type of sulfate.
For this project, the team collected data in the Dry Valleys, where the soil geology and temperature are remarkably similar to those found on Mars by the Phoenix lander and MRO.
Fieldwork was then followed by lab work, as the team subjected Mars analog regolith to tests using colored indicators that would show how the regolith simulant would react when subjects to the same kind of chemical reactions that were taking place in Antarctica.
All this data collecting resulted in a geological model involving sulfates, chlorides, and water that can account for the appearance of the RSLs seen on Mars’ surface.
The model also has implications of the habitability of sub-surface Mars and how the presence of this slurry might affect any biosphere the red planet might have.
Until there are some further on-site tests this model will be hard to prove, but there are plenty of those planned for Mars in the near future.
This article was originally published by Universe Today. Read the original article.
Martian landslides might help explain mystery lines seen on the surface of the Red Planet, a new study finds.
For years, scientists analyzing the Martian surface have detected clusters of dark, narrow lines that seasonally appear on steep, sun-facing slopes in the warmer regions. Previous research has suggested that these enigmatic dark streaks, called recurring slope lineae (RSL), are signs that salty water regularly flows on the Red Planet during its warmest seasons.
Recent missions to Mars have revealed that the planet does possess huge underground pockets of ice. Prior work suggested that warmer temperatures during the Martian spring and summer could help generate salty brines capable, at least for a time, of staying liquid in the cold, thin air of the Red Planet.
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However, geologists have discovered problems with the concept of brines causing RSL, explained study lead author Janice Bishop, a planetary scientist at the SETI (Search for Extraterrestrial Intelligence) Institute and NASA Ames Research Center, both of which are in California’s Silicon Valley. For example, the angle of slopes where RSL occur and the features surrounding where they start “largely are inconsistent with a liquid flow process,” she told Space.com.
Now Bishop and her colleagues suggest that chemical reactions could make the Martian surface vulnerable to landslides that might explain RSL.
“Although the surface of Mars today is dry and harsh and cold and dominated by wind and abrasion, underneath the surface, micro-scale interactions of salts with tiny ice and liquid water particles can be still occurring today,” Bishop said.
The scientists focused on chemical reactions between sulfate minerals such as gypsum with chloride salts, of which table salt is one variety. “On Earth, interactions between gypsum and chloride salts have caused collapse of parts of caves, sinkholes in soft sediments near salty lakes and ponds, and uplift of roads,” Bishop said.
The researchers speculated that similar interactions could happen on Mars, although the cold and dry conditions there would slow these reactions down. “I am super excited about the prospect of active chemistry below the surface on Mars, albeit at a slow rate,” Bishop said.
In the new study, the scientists conducted lab experiments on mixtures of sulfates, chloride salts, tiny ice particles and volcanic ash similar to Martian soil. They froze and thawed such mixtures at the kinds of low temperatures found on the Red Planet.
The researchers found thin films of slushy water formed on the surfaces of the mineral grains. They suggested these films could expand and contract over time, leading to upheavals and contractions under the Martian surface. Wind and dust on these unstable surfaces could then set off landslides, producing the lines seen on the Red Planet, Bishop explained.
The scientists noted that in the future, surface missions on Mars to recent RSL sites could help test their model. They detailed their findings online today (Feb. 3) in the journal Science Advances.
The NASA InSight mission has helped researchers determine that the planet experiences Marsquakes, making it seismically active.
And then there is the mystery of Recurring Slope Lineae, known as RSL, that have intrigued scientists for years. These RSL are a form of landslide on Mars, but no one knows what causes them, said Janice Bishop, author of a new study on the phenomena.
“We see them from orbit by the dark streaks they produce on the ground and they tend to always occur on sun-facing slopes, which led geologists to think they were related to melting ice early on,” said Bishop, senior research scientist at the SETI Institute in California.
“The interesting thing is that they increase over months following dust storms and then fade away, and they appear to form repeatedly in the same regions. Also, a large number of these are forming in the equatorial part of Mars, where there is very little ice.”
Any ice in these regions would have to be in tiny frozen particles that exist between grains of soil below the surface.
These puzzling landslides have never been seen up close by a rover or lander, and until they can be investigated by a robotic explorer, scientists are using lab experiments and Martian analogs on Earth to try and understand them.
Some of the strange environments on Earth that are similar to that of Mars include the Atacama desert in Chile, parts of Antarctica and even the Dead Sea. These places show that surface collapse and landslides occur when salt interacts with sulfates or water underground.
“Antarctica and the Atacama are excellent analogs for Mars because they are ultra dry environments,” Bishop said. “Antarctica has the added benefit that it is super cold. Parts of Antarctica including Beacon Valley are actually on par with Mars for temperature and aridity.”
While water may have once been plentiful on the Martian surface billions of years ago, when the planet was warmer and still retained most of its atmosphere, the current surface of Mars is a freezing cold and barren landscape.
What lies beneath
However, Mars missions and imaging by orbiters have revealed that frozen salty water is below the surface — and that water could be driving activity that appears on the Martian surface, like the landslides.
Bishop and her colleagues collected samples from some similar environments on Earth, including Wright Valley in Antarctica, to test how salts and melting ice underground could cause chemical reactions that trigger these seasonal landslides on Mars. The researchers wanted to test if processes observed in places like Antarctica, where salty sediments can have an effect on surface soil, could be happening on Mars.
The scientists modeled the briny water beneath the surface of Mars in a lab by taking the collected soil samples and exposing them to water and chlorine salts and sulfates — all of which could exist beneath the Martian surface. This experiment resulted in the creation of thin, moving films of slushy water.
To model Martian temperatures where ice exists beneath the surface at the planet’s mid-latitudes, the researchers found slushy ice formed near negative 58 degrees Fahrenheit and a slow, gradual melting of the ice between negative 40 degrees Fahrenheit and negative 4 degrees Fahrenheit.
These temperatures may sound cold, but on Mars, they’re actually considered to be slightly warmer temperatures found near the equator — which could support briny water beneath the surface in the Martian spring and summer.
If this subsurface brine on Mars expands and contracts over time on Mars, it could weaken the surface and cause sinkholes, ground collapse and landslides.
Previously, scientists believed that flows of liquid debris or dry grainy material could be causing the landslides, but neither completely matched up with what scientists saw in the RSL.
However, if ice is melting just beneath the surface, that change would also alter the surface itself. The Martian surface is also at the mercy of wind and seasonal dust storms, which could also play a part in this phenomenon.
“During my fieldwork at Salar de Pajonales, a dry salt bed in Northern Chile, I have observed numerous examples of the action of salts on the local geology. It’s gratifying to find that it could play a role in shaping Mars as well,” said study coauthor Nancy Hinman, a professor of geosciences at the University of Montana, in a statement.
The study published Wednesday in the journal Science Advances.
Chemical activity
“If our hypothesis is correct, then RSL could be indicators for salts on Mars and for near-surface active chemistry,” Bishop said. “Most of us Mars scientists have considered modern Mars as a cold and dry and dormant place, shaped mostly by dust storms. This is certainly true of the surface, but our work shows that the subsurface could be much more chemically active than realized before.”
Bishop noted that this underground process that could result in landslides on the surface would be a slow and limited one.
While this brine would be too salty to support life, the experiments in the study support the idea that this subsurface liquid water can actually move around the salt and mineral grains. If that’s the case, water on Mars 4 billion years ago could have filtered down into the subsurface as a type of permafrost soil. This ice could have thawed and refrozen over time.
“It could be that more of this early water on Mars persisted longer than we realized below the surface,” Bishop said. “If true, this could indicate that the subsurface of Mars was habitable longer than the surface environment. It is difficult to estimate how long, but perhaps liquid water was present around soil grains below the surface until 3 or 2 billion years ago or even more recently.”
Previous research has also suggested that the most habitable part of Mars actually lies beneath its surface.
Future robotic explorers, like the European Space Agency’s Rosalind Franklin rover scheduled to launch in 2022, can drill beneath the surface and investigate what’s going on.
“Once we send rovers to Mars that can drill down into the surface, I think we will see signs of salt reactions below the surface — especially if we investigate some of the equatorial regions where RSL are occurring,” Bishop said.
