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There Are 6 Human Chronotypes, Not Just Morning Larks And Night Owls, Study Says

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Some people are morning larks. Others are night owls. But not everybody falls neatly into those two categories, scientists say – and a new study suggests there are actually multiple distinct ‘chronotypes’ that define people’s wakefulness and rest.

 

Chronotypes are the behavioural manifestations of the circadian rhythms we experience throughout the day and the night. In a sense, they’re your internal body clock, helping to determine whether you’re a morning person or a night person.

Waking life, however, isn’t perhaps quite as binary as those stereotypes might suggest, and at least some evidence suggests alternative chronotypes also exist beyond early birds and night owls.

“The research of individual chronobiological and chronopsychological differences is predominantly focused on the morning and evening chronotypes,” explains human physiology researcher Dmitry S. Sveshnikov from RUDN University in Russia.

“However, recent studies suggest that the existing classification needs to be reconsidered and expanded.”

In their new study, Sveshnikov and fellow researchers surveyed almost 2,300 participants, most of whom were university students. The participants were asked to self-assess their own chronotype based on a range of six possible types identified in previous studies conducted by some of the same researchers.

To validate the self-assessments, the participants completed a number of standard tests and questionnaires used by sleep scientists, designed to estimate participants’ level of sleepiness or alertness at various (and sometimes random) times throughout the day.

Based on the results, it looks like the vast majority of participants did identify with the six hypothetical chronotypes proposed by the researchers, with only 5 percent of people in the study not identifying with any of them.

010 chronotypes 1(RUDN University)

The six chronotypes – which the researchers now consider to be “fully confirmed” on the strength of the results – include the established morning and evening types, along with the four new chronotypes: highly active type, daytime sleepy type, daytime active type, and moderately active type.

In terms of alertness and energy levels, morning types have high alertness in the morning, which proceeds to dip to medium levels in the middle of the day, then drops to low levels in the evening.

 

By contrast, evening types exhibit low alertness in the morning, which rises to medium levels in the middle of the day, then rises to high levels at night.

The four new chronotypes display different patterns: highly active types show high alertness throughout the day; daytime sleepy types start off high in the morning, dip low in the middle of the day, then rise to a medium finish; daytime active types start low, peak at high in middle, then finish the day on middle level alertness; while moderately active types experience low energy levels all day long.

Interestingly, only a bit more than one-third (37 percent) of people in the study actually identified as early birds or night owls (13 percent and 24 percent respectively), although it’s worth noting that evening types on 24 percent were the most common chronotype.

Of the new chronotypes, covering 58 percent of the people studied, 18 percent identified as daytime sleepy, 16 percent were moderately active, 15 percent chose daytime active, and only 9 percent said they were highly active all day long.

It’s worth bearing in mind that this is a relatively small study in the grand scheme of things, but the team says future research using different kinds of experimental methods should be able to tell us more about how these six chronotypes function in people.

The findings are reported in Personality and Individual Differences.

 



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Drones Are Being Sent Straight Into Volcanoes, For Life-Saving Science

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With an estimated 300 active volcanoes on Earth, the challenge is how to monitor them all to send out early warnings before they erupt. Measuring volcanic gas emissions is also no easy task.

 

Now researchers have designed specially-adapted drones to help gather data from an active volcano in Papua New Guinea (PNG).

The drones could help local communities monitor nearby volcanoes and forecast future eruptions. Their measurements could also tell us more about the most inaccessible, highly active volcanoes on the planet and how volcanoes contribute to the global carbon cycle.

The Manam volcano is located on an island just 10 kilometres (6 miles) wide that sits off the northeast coast of PNG. The island is home to over 9,000 people and Manam Motu, as it’s known locally, is one of the most active volcanoes in the country. In 2004, a major eruption from Manam forced the entire island to evacuate to the mainland and devastated people’s crops and homes.

Scientists have a few ways of forecasting when a volcano is going to blow. They can monitor earthquake activity in the area to detect tremors which almost always precede eruptions, and look out for bulging in the volcano’s sloping walls as magma builds up underneath.

When clear skies allow, satellites can also rapidly detect and measure volcanic emissions of gases such as sulphur dioxide (SO2). Changes to these gas emissions can signal more activity in the volcano below.

 

“Manam hasn’t been studied in detail but we could see from satellite data that it was producing strong emissions,” said volcanologist Emma Liu from University College London, who led the research team of earth scientists and aerospace engineers.

“We [also] wanted to quantify the carbon emission[s] from this very large carbon dioxide emitter,” added geochemist Tobias Fischer, from the University of New Mexico.

Although volcanoes emit just a fraction of the carbon emissions humans do, researchers still want to be able to estimate what carbon dioxide (CO2) they do emit, to factor this into the carbon budget we have left to limit the effects of climate change.

Travelling to PNG, the international team set about testing two types of long-range drones equipped with gas sensors, cameras, and other devices during two field campaigns on Manam Island, in October 2018 and May 2019.

Manam’s steep slopes make it incredibly dangerous to even contemplate collecting gas samples on foot whereas the drones could safely fly right into the billowing plumes, helping the research team measure its volcanic gas emissions more accurately.

Drone used to measure volcanic gasesPreparing one of the drones for a test flight. (Matthew Wordell/ABOVE)

The drones flew over 2,000 metres (6,561 feet) high into Manam’s highly turbulent volcanic plumes and some 6 kilometres (3.7 miles) away from their launching pad, well out of sight of their pilots. 

On each flight, the drones took images of Manam and its two craters, measured the gas composition right above the rising plumes and collected four bags full of extra gas for rapid analysis when the aircraft touched down.

 

Aerial images from the drone fly-overs showed that degassing at Manam’s southern crater intensified between October 2018 and May 2019. In fact, the volcano soon erupted in June, just one month after the researchers’ second field trip. 

But rising volcanic emissions are not alone a reliable indicator of whether an eruption is imminent or likely, so the researchers also looked at the ratio between different gases, namely CO2 and SO2, in Manam’s plumes.

This can help detect the ascent of hot magma to the surface and expulsion of CO2-rich emissions that reportedly precede big eruptions. 

However, the researchers found that the mixture of gases emitted from Manam was much the same during both field trips.

Integrating their drone measurements with satellite data, the researchers were able to show that Manam ranks among the top 10 strongest degassing volcanoes in the world, emitting an estimated 3,700 tons of CO2 and roughly 5,100 tons of SO2 each day – higher than previous estimates. 

Manam summit crater(Emma Liu/ABOVE)

Above: Aerial view into the active vent of Manam volcano, Papua New Guinea, showing molten magma near the surface.

The team also deduced that most of Manam’s emitted carbon is likely derived from the upper mantle, and not sediments from Earth’s shallower crust, which they figured out by analysing different carbon isotopes in the gaseous mix.

 

“Our novel approach – that is, long-range and high-altitude [drone] operations enabling in situ measurements – is presently the only feasible means by which we can characterise gas chemistry at steep, hazardous, and highly active volcanoes like Manam,” the research team concluded in their paper.

Future research will take more diligent work from scientists and flying time from drones, since the measurements from this study spanned just 10 days.

With enough funding for equipment and training for local scientists, the strategy could be used elsewhere to monitor other dangerously inaccessible volcanoes, such as Mayon in the Philippines, and Sinabung in Indonesia.

The research was published in Science Advances. 

 



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A Rare Hybrid of a Comet And an Asteroid Is Showing Off Its Cometary Traits

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Centaurs are rare celestial objects that can combine some of the different features of asteroids and comets. They’re basically rocky in nature, like asteroids, but can also throw out clouds of dust and gas as their exteriors vaporize, like comets.

 

When centaurs emit these gases, they’re considered active. We’ve only ever found 18 chemically active centaurs in the last century or so, but now a new one has been added to the list – and it might be able to tell us more about how these mysterious flying rocks develop their unique characteristics.

Keeping a close eye on centaurs is a huge challenge – they’re a long way away, orbit in irregular ways, and take up a lot of telescope time – but in this case, researchers studied archival images as well as used new data gathered from the Dark Energy Camera at the Inter-American Observatory and the Walter Baade Telescope at the Las Campanas Observatory, both in Chile, and the Large Monolithic Imager at Lowell Observatory’s Discovery Channel Telescope in Arizona.

“We developed a novel technique that combines observational measurements – for example, colour, and dust mass – with modeling efforts to estimate such characteristics as the object’s volatile sublimation and orbital dynamics,” says astronomer Colin Chandler, from the Northern Arizona University.

That technique, involving a specially developed algorithm to look for activity traces in existing space imagery, revealed evidence of Centaur 2014 OG392 converting solids into gases (sublimation) and leaving behind a long comet-like halo.

 

Backed up with new observations recorded over the course of the past two years, it seems clear that this particular centaur is special. Computer modelling then helped the astronomers figure out what types of ice could be burning off the rock.

It’s a tricky calculation to make, not least because the asteroid is probably not made from one type of ice but from a mix of materials that can all burn differently. The researchers think they know what’s happening, however, and what might be happening on other similar objects.

“We detected a coma as far as 400,000 km [248,548 miles] from 2014 OG392,” says Chandler, “and our analysis of sublimation processes and dynamical lifetime suggest carbon dioxide and/or ammonia are the most likely candidates for causing activity on this and other active centaurs.”

A coma is an envelope of ice and comet dust that forms around the comet’s nucleus as it passes close to the Sun. It is the coma that gives comets their fuzzy appearance.

Because of the discovery, the centaur is no longer a centaur any more – it’s a fully-fledged comet, with the designation C/2014 OG392 (PANSTARRS), something that the researchers are “very excited” about.

These types of objects, and others like them, are thought to have barely changed since the very early days of the Solar System, and that means they’re incredibly useful time capsules for studying how our planets formed and settled into their own orbits.

Any centaurs, comets, and asteroids that are still around are still around for a reason – they haven’t spun out of the Solar System or flown into the Sun – and scientists can work backwards from that.

There’s lots more to discover about centaurs, and we’re learning more about how they work all the time. As more data is gathered and better analysis techniques are developed, we should finally be able to solve some of the mysteries surrounding these weird and wonderful Solar System travellers.

The research has been published in Astrophysical Journal Letters.

 



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Sorry, But Dogs May Prefer The Faces of Other Dogs to Those of Humans

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Many people love squishing their dogs’ cuddly faces while gazing deep into their canines’ soulful eyes to try and understand what they want.

But new research suggests our four-legged friends don’t feel the same way about us. A study published Monday in the Journal of Neuroscience reveals that dogs’ brains are equally as excited by our faces as they are by the backs of our heads.

 

Humans rely on facial cues to gather information, and we have a special area of our brains that activates when we view a face. But the new study shows that dogs don’t quite process human faces in the same way.

“They read emotions from faces and they can recognise people from the face alone, but other bodily signals seem to be similarly informative to them,” Attila Andics, a dog behaviour researcher at Eötvös Loránd University in Hungary and coauthor of the study, told NBC News.

Andics’ group also found that dogs cared more about seeing other dogs than they did about seeing faces, human or otherwise.

Dogs prefer gazing at other dogs than gazing at faces

The researchers used a type of brain scan called functional magnetic resonance imaging, or fMRI. fMRI can show how active different parts of the brain are by measuring where blood is flowing.

The researchers gave 20 pet dogs and 30 humans an fMRI scan, during which the participants were presented with four different 2-second videos.

One clip showed a human face, and another, the back of a human head. The last two videos were of a dog’s face and the back of a dog’s head.

 

Data from the scans showed humans and dogs both prefer gazing at members of their own species. The dogs’ brains were more active when they saw another dog, compared to when they saw a person. The humans’ brains, too, were more active when they saw a person than a dog.

But what separates these pets’ brains from their owners’ is how much they lit up when presented with a face.

The dog’s brains lit up the same amount whether they gazed at a face or the back of a head. The human participants, by contrast, had brains that lit up like Christmas trees when presented with a face, compared to when they saw the back of a head.

According to Carlo Siracusa, director of the animal behaviour service at the University of Pennsylvania School of Veterinary Medicine, dogs can rely on body language and other senses to gather information.

“They use other ways of communicating such as ear position – which can be seen from the front and from behind. The ear position will tell about the mood of the dog. We humans don’t move our ears,” Siracusa, who was not involved in the study, told NBC.

 

Dogs also have an uncanny sense of smell that’s between 10,000 and 100,000 more acute than humans’.

So they can pick up on pheromones left behind by other dogs, which may relay more information than a simple face peek.

Pooches understand speech in the same way we do

That being said, there are aspects of dogs’ brains that are wired similarly to ours.

An August study published in the journal Scientific Reports found that dogs understand verbal communication just as we do, parsing out tone and then meaning as separate aspects of human speech.

When humans hear someone speak, our brains divide the work of processing that communication between the left and right hemispheres. First, the right hemisphere focuses on parsing out the speaker’s underlying tone, and then the left hemisphere processes the meaning of what we’ve heard.

Researchers discovered in 2014 that dogs’ brains divvy up the task of speech processing in the same way, though the scientists weren’t sure of the order in which that happened.

The Scientific Reports study, however, found that dogs understand tone first, then meaning, in the same order as humans. The authors examined the brain activity of 12 pet dogs – six border collies, five golden retrievers, and one German shepherd – using fMRI.

They had the dogs listen to known praise words like “clever,” “well done,” and “that’s it”, as well as unknown words like “as if” and “yet” in both praising and neutral tones.

The data showed that the dogs processed “simpler, emotionally loaded cues” like tone first and then “more complex, learnt cues,” Andics, who was also a coauthor of the August study, said in a press release.

This article was originally published by Business Insider.

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Super Rare ‘Elite Controllers’ Are Able to Completely Overcome HIV Without Any Drugs

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Over a decade ago, Bruce Walker was working at Massachusetts General Hospital (MGH) when he was asked to see a patient who claimed to be infected with the human immunodeficiency virus (HIV) but who was entirely well, despite never taking any medication.

 

“Quite frankly,” Walker, an immunologist and physician, recalls, “I actually didn’t believe him.”

But it turned out to be true, and not just for this one patient.

Years of recent research has come to show among 35 million people infected with HIV, there are a rare few who might be able to suppress the virus on their own without treatment, and they’re known as ‘elite controllers’.

Now, new research suggests an even rarer subset might actually rid themselves of the virus completely without any medical help.

Such a finding is remarkable because HIV is a lifelong condition with no medical cure, and it usually requires daily antiretroviral therapy (ART) to control the virus’ replication and stop acquired immunodeficiency syndrome (AIDS) from developing.

When HIV infects human cells, it inserts copies of its genetic material into the cell’s genome, creating a viral reservoir for replication.

Antiviral drugs can usually keep replication of these reservoirs at bay, at least to some extent. But there are others who don’t need these drugs at all.

Less than 0.5 percent of those infected with HIV appear to stop the virus being replicated all on their own, and we’re still not sure why or how.

 

“What happens with these individuals, whom we call elite controllers, may shed light on an HIV-1 cure and also help us understand how a person with HIV might control virus and avoid HIV-associated comorbidities,” says Keith Hoots a director if blood disease research at the National Institutes of Health and a veteran HIV researcher himself.

To that end, a collaboration between MGH, MIT and Harvard have gathered together over 1,500 confirmed cases of ‘elite control’. After years of digging, their research has revealed results previously only known to have been achieved through rigorous medical treatment.

While there are currently two cases where HIV is said to have been ‘cured’ through bone marrow transplantations, the authors say elite controllers are the closest thing we have to a possible “natural cure”.

Sequencing billions of cells from 64 HIV patients, who kept the virus at bay for a median of nine years without medication, and 41 individuals, who were taking ART for a median of nine years, the team found something astonishing.

Despite analysing billions of their personal cells, one patient showed absolutely no intact HIV copies, and another patient had only one intact copy that was “blocked and locked” in a sort of genomic straight jacket, which stops the virus from being replicated.

 

This raises the possibility that a ‘sterilising cure’ of HIV, in which the participant’s immune system has removed all intact HIV genomes from the body, may be achieved naturally in extremely rare instances, according to the authors

In a Nature review of the paper, immunologist Nicolas Chomont says it will be hard to demonstrate whether HIV has been completely eradicated in these two patients. That said, he admits, these cases are “certainly reminiscent of previous reports of HIV cure.”

Even elite controllers who had more intact copies of the virus had them securely locked away. 

Instead of being stored in active regions of the human genome, 45 percent of the viral reservoirs in elite controllers were discovered in ‘gene deserts’, where the patient’s DNA nor the genetic sequence inserted by the virus is ever effectively expressed, leading to sustained, drug-free ‘silencing’ of the virus. 

People on ARTs, on the other hand, kept only 17 percent of their viral reservoirs in these inactive regions, which means if they stop taking their medication, most viral copies will begin replicating again.

 

“This positioning of viral genomes in elite controllers,” Yu says, “is highly atypical, as in the vast majority of people living with HIV-1, HIV is located in the active human genes where viruses can be readily produced.”

It’s not clear how these differences came to be, but when the authors infected the cells of elite controllers with HIV, the virus integrated into active genomic sites as per usual. So where did these copies in the elite controllers go?

Recent research indicates that T cells, which seek and destroy infections, might play a role in cleaning up the virus.

Far from integrating HIV at different genomic sites, the authors thus argue, it seems elite controllers can eliminate proviral sequences at active transcription sites, carefully watched by their immune systems.

“By contrast, less transcriptionally active proviral sequences with features of deep latency, leading to lower vulnerability to immune recognition, seem to persist long-term,” they write.

This indicates our immune systems may have a way that researchers could use to target viral sequences at risk of being replicated. And while this doesn’t change anything for HIV patients right now, it does suggest a possible avenue for future treatment.

Virologist Monica Roth from Rutgers University, who was not involved in the study told Science News the idea put forward in this paper is “intriguing” but that “there’s no evidence saying that it happens” in reality.

Genomic research can only tell us so much, so we still need more research to understand how the immune systems of some people living with HIV can suppress the virus naturally.

The study was published in Nature.

 



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This Gas Cloud Is Pulsing With Gamma-Rays From a Distant Black Hole, But How?

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Around 15,000 light-years away, an active black hole seems to be periodically lighting up an otherwise unremarkable cloud of gas with gamma rays. But there’s a catch. The gas cloud is around 100 light-years from the black hole – and exactly how the cloud is pulsing in time with it is a mystery.

 

It’s unlikely, astrophysicists believe, that the pulsations are directly generated by the plasma jets that are emitted by active black holes. But it’s possible the black hole is somehow blasting out cosmic rays in a manner that illuminates the gas cloud.

“This result challenges obvious interpretations and is unexpected from previously published theoretical models,” said astrophysicist Jian Li of the Deutsches Elektronen-Synchrotron in Germany.

“It provides us with a chance to unveil the particle transport from SS 433 and to probe the structure of the magnetic field in its vicinity.”

SS 433 is the black hole system, of a type known as a microquasar. It consists, obviously, of the black hole – a relatively titchy fella, weighing in at 10 to 20 times the mass of the Sun. Its binary companion is a main-sequence supergiant, at around 30 times the mass of the Sun.

The two are locked in very close orbit, just a hair over 13 days, so that the black hole is siphoning a steady stream of material off its stellar companion, spooling around it like water around a drain. As it does so, the material glows, just like a mini version of a quasar.

 

But not all the material gets slurped up. Some of it gets channelled away from the inner edge of the accretion disc around the outside of the black hole – we’re not entirely sure how, but scientists think it’s along magnetic field lines.

This material is then beamed away from – presumably – the black hole’s poles in jets of plasma that can approach significant percentages of the speed of light.

In addition, the black hole in SS 433 is wobbling, like a spinning top, on its rotational axis. This wobble is called rotational precession, and it means the jets, rather than shooting in a straight line, spiral out into space, as seen in the video below of another precessing microquasar, V404 Cygni.

By observing SS 433 for a decade, Li and his team were able to determine that the black hole’s precession has a periodicity of just over 162 days, with the jet losing its spiral shape and relaxing into a cone after a few cycles. And the gas cloud pulses with gamma radiation on the same time scales.

This might seem like an open-and-shut case, but there’s a big problem. The cloud isn’t actually within the extrapolated jet cone.

 

“Finding such an unambiguous connection via timing, about 100 light years away from the micro quasar, not even along the direction of the jets is as unexpected as [it is] amazing,” Li said. “But how the black hole can power the gas cloud’s heartbeat is unclear to us.”

Unclear it may be, but that doesn’t mean there are no potential explanations. It’s possible that cosmic rays – high-energy protons that travel almost at the speed of light – are being produced by the black hole, either at the ends of the jets, or from its equator.

At the ends of the jets, or close to the black hole, the subatomic particles of cosmic rays could be ejected towards the cloud. When they hit it, the impact could then produce gamma rays, as described in a 2005 theoretical paper.

Or it’s possible that the cosmic rays originate from the edge of the accretion disc.

“Energetically, the outflow from the disc could be as powerful as that of the jets and is believed to precess in solidarity with the rest of the system,” explained astrophysicist Diego Torres of the  Institute of Space Sciences in Spain.

These cosmic rays would have to be emitted at a sufficient rate to produce the observed gamma ray emission. This, the researchers said, is difficult to reconcile with our current understanding of the source environment.

So, there’s a lot more work to be done to understand the system – and just how it is lighting up a cloud of gas 100 light-years away.

“SS 433 continues to amaze observers at all frequencies and theoreticians alike,” the researchers wrote, “and is certain to provide a testbed for our ideas on cosmic-ray production and propagation near microquasars for years to come.”

The research has been published in Nature Astronomy.

 



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We Just Got Even More Evidence That Venus Has Surprisingly Active Volcanoes

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The planet Venus is scorching hot beneath its suffocatingly thick atmosphere, much of its surface shaped by the surges and flows of volcanic activity. Nevertheless, planetary geologists have been unable to find hard evidence that the planet remains volcanically active.

 

Well, we just got some of the best evidence yet. Venus has plenty of volcanic features on its surface – wide volcanic plains, domes and coronae, mountainous shield volcanoes. Researchers led by geophysicist Anna Gülcher of ETH Zürich in Switzerland used simulations to figure out how volcanic coronae form and grow, and determined that the features observed on Venus must be quite young.

This demonstrates, they say, that Venus is far from volcanically extinct.

“This is the first time we are able to point to specific structures and say ‘Look, this is not an ancient volcano but one that is active today, dormant perhaps, but not dead’,” said geologist Laurent Montési of the University of Maryland.

“This study significantly changes the view of Venus from a mostly inactive planet to one whose interior is still churning and can feed many active volcanoes.”

It’s been understood for some time that the surface of Venus is relatively young compared to other planets like Mars and Mercury. Analysis and geologic mapping of the planet have revealed that most of Venus underwent resurfacing sometime in the last billion or so years.

 

A lot can happen in a billion years. It’s possible that Venus’s interior has cooled, and the crust hardened, to the point that liquid magma can no longer penetrate through to the surface. However, the clues that Venus has not yet reached this point have been mounting.

The Pioneer Venus Orbiter in the 1970s and 80s, for example, found sulphur dioxide features in the Venusian atmosphere. A 2015 paper found that transient bright spots correlated with very young geological features could be consistent with lava flows. And a paper just earlier this year simulated olivine weathering rates on Earth’s ‘sister planet’, and found that the lava flows on Venus were likely very young.

Gülcher’s team sought their answer in a type of volcanic feature called a corona. Coronae look a bit like impact craters, and consist of a raised ring (like a crown) around a sunken centre, with concentric fractures radiating outwards; they can be hundreds of kilometres across.

Scientists initially thought these structures were craters, but closer analysis revealed that they’re volcanic in nature. They’re caused by plumes of hot molten material welling up from the planet’s interior, pushing the surface upward into a dome that then collapses inward when the plume cools, leaking out the sides to form the ring.

 

On Earth, the formation of corona-like features is restricted because of the movement of tectonic plates, but Venus has no tectonic plates, so coronae burst upwards like planetary pimples.

To understand this formation process, the researchers numerically modelled the thermo-mechanic activity in the interior of Venus. This allowed them to generate high-resolution 3D simulations of the corona formation process, varying parameters such as plume size and temperature, and the thickness of the lithosphere to encompass a range of outcomes.

By simulating the evolution of coronae over time, the team was able to identify features primarily seen in very young, recently active coronae, as well as determine the changes those coronae underwent over time.

corona comparison(Gülcher et al., Nature Geoscience, 2020)

These simulations were then compared with actual coronae on the surface of Venus, as seen in the image above.

Not only did the team match recently active features from their simulations to real coronae, they were able to show that variations in coronae on the Venusian surface actually represent different stages in geological development. That strongly suggests those coronae are still evolving – and that the planet’s interior is still active.

active coronae(Anna Gülcher)

Above: In this global map of Venus, active coronae appear in red and inactive coronae appear in white.

“The improved degree of realism in these models over previous studies makes it possible to identify several stages in corona evolution and define diagnostic geological features present only at currently active coronae,” Montési said.

“We are able to tell that at least 37 coronae have been very recently active.”

These 37 coronae were clustered in a few locations, suggesting that some regions are more active than others – and highlighting where future orbital (and even lander, if the technical hurdles can be leapt) missions might best focus their attention.

The research has been published in Nature Geoscience.

 



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An Ancient Meteorite Is The First Chemical Evidence of Volcanic Convection on Mars

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For many years, we thought Mars was dead. A dusty, dry, barren planet, where nothing moves but the howling wind. Recently, however, pieces of evidence have started to emerge, hinting that Mars is both volcanically and geologically active.

 

Well, the idea of a volcanically active Mars just got a little more real. A meteorite that formed deep within the belly of Mars has just provided the first solid chemical proof of magma convection within the Martian mantle, scientists say. 

Crystals of olivine in the Tissint meteorite that fell to Earth in 2011 could only have formed in changing temperatures as it was rapidly swirled about in magma convection currents – showing that the planet was volcanically active when the crystals formed around 574 to 582 million years ago – and it could still be intermittently so today.

“There was no previous evidence of convection on Mars, but the question ‘Is Mars a still volcanically active planet?’ was previously investigated using different methods,” explained planetary geologist Nicola Mari of the University of Glasgow to ScienceAlert.

“However, this is the first study that proves activity in the Mars interior from a purely chemical point of view, on real Martian samples.”

Olivine, a magnesium iron silicate, isn’t rare. It crystallises from cooling magma, and it’s very common in Earth’s mantle; in fact, the olivine group dominates Earth’s mantle, usually as part of a rock mass. On Earth’s surface, it’s found in igneous rock.

 

It’s fairly common in meteorites. And olivine is also fairly common on Mars. In fact, the presence of olivine on the surface of Mars has previously been taken as evidence of the planet’s dryness, since the mineral weathers rapidly in the presence of water.

But when Mari and his team started studying the olivine crystals in the Tissint meteorite to try to understand the magma chamber where it formed, they noticed something strange. The crystals had irregularly spaced phosphorus-rich bands.

We know of this phenomenon on Earth – it’s a process called solute trapping. But it was a surprise to find it on Mars.

magma olivine(Mari et al., Meteoritics & Planetary Science, 2020)

“This occurs when the rate of crystal growth exceeds the rate at which phosphorus can diffuse through the melt, thus the phosphorus is obliged to enter the crystal structure instead of ‘swimming’ in the liquid magma,” Mari said.

“In the magma chamber that generated the lava that I studied, the convection was so vigorous that the olivines were moved from the bottom of the chamber (hotter) to the top (cooler) very rapidly – to be precise, this likely generated cooling rates of 15-30 degrees Celsius per hour for the olivines.”

 

The larger of the olivine crystals were also revealing. Traces of nickel and cobalt are in agreement with previous findings that they originated from deep under the Martian crust, a depth of 40 to 80 kilometres (25 to 50 miles).

This supplied the pressure at which they formed; along with the equilibration temperature of olivine, the team could now perform thermodynamic calculations to discover the temperature in the mantle at which the crystals formed.

They found that the Martian mantle probably had a temperature of around 1,560 degrees Celsius in the Martian Late Amazonian period when the olivine formed. This is very close to the ambient mantle temperature of Earth of 1,650 degrees Celsius during the Archean Eon, 4 to 2.5 billion years ago.

That doesn’t mean Mars is just like an early Earth. But it does mean that Mars could have retained quite a bit of heat under its mantle; it’s thought that, because it lacks the plate tectonics that help to dissipate heat on Earth, Mars may cool more slowly.

“I really think that Mars could be a still volcanically active world today, and these new results point toward this,” Mari told ScienceAlert.

“We may not see a volcanic eruption on Mars for the next 5 million years, but this doesn’t mean that the planet is inactive. It could just mean that the timing between eruptions between Mars and Earth is different, and instead of seeing one or more eruptions per day (as on Earth) we could see a Martian eruption every n-millions of years.”

We’ll need more research to confidently say this hypothesis checks out. But these results also mean that previous interpretations of the planet’s dryness based on surface olivine may need to be revisited. (Although let us be clear, Mars is still extremely dry.)

The ongoing NASA InSight mission that recently found evidence of Marsquakes, measures – among other things – the heat flux from the Martian crust. If Mars is still volcanically active, we may know more about it really soon.

The research has been published in Meteoritics & Planetary Science.

 



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First Direct Evidence of Marsquakes Was Just Revealed Amongst New InSight Discoveries

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Although we’re yet to detect any sort of life on Mars, the planet is not a quiet one. Deep in its guts, the Red Planet rumbles – the seismic stirrings of a geologically active chunk of rock.

 

The first slew of data from NASA’s Mars InSight lander is in, and the results have given us the first direct evidence of marsquakes. This puts the planet’s profile of seismic activity somewhere between Earth’s (high) and the Moon’s (low).

A series of papers detailing the new results from InSight have just appeared in a special issue of Nature.

“This is the first mission focused on taking direct geophysical measurements of any planet besides Earth, and it’s given us our first real understanding of Mars’ interior structure and geological processes,” said geologist Nicholas Schmerr of the University of Maryland.

“These data are helping us understand how the planet works, its rate of seismicity, how active it is and where it’s active.”

InSight – a lander destined to teach us more about what’s inside Mars – felt its first tremors in April of last year with its Seismic Experiment for Interior Structure (SEIS) instrument.

These tremors, if they’re strong enough, can act a bit like a planet-sized ground-penetrating radar, only with seismic waves instead of electromagnetic. As these waves propagate through a planet, they can slow down as they move through certain materials, or bounce off others, letting seismologists infer the interior composition.

 

And the type of tremor can reveal clues, too. For instance, much of Earth’s seismic activity is produced by the moving tectonic plates of the planet’s crust. The Moon, however, has no tectonic plates; its seismic activity is caused by the slow and slight shrinking that occurs as our satellite cools, a process that has been ongoing since it formed 4.5 billion years ago.

Back on Mars, that first tremor wasn’t strong enough to gauge much. But over 235 Martian days, the instrument recorded 174 marsquakes. Of these, 150 were high-frequency tremors like those recorded by Apollo experiments on the Moon.

The remaining 24, however, were low-frequency quakes. This is really interesting, because although planetary geologists believe Mars was tectonically active once upon a time, it’s generally thought that the planet is pretty quiet now.

“The other 24 have dominantly low-frequency content, and their spectral shapes follow the same scaling laws as earthquakes and moonquakes, leading us to conclude that they are of tectonic origin,” wrote a team of scientists in a paper summing up the results.

“The characteristics of these spectra are compatible with expectations for distant tectonic events.”

 

In addition, the way the waves propagate through the crust can be used to trace the quakes to a source. Three of the 24 Earth-like quakes were strong enough for this to be attempted.

The team was able to trace two of those three quakes to the Cerberus Fossae region, where a series of fissures can be found, created by faults that pulled the crust apart. Evidence suggests it was tectonically and volcanically active recently, i.e., within the last 10 million years (hey, that’s recent for rocks).

A second paper based on the data from SEIS looked for something different – the interior composition of Mars. They found that a layer of regolith down to a few metres, and beyond that, the crust of Mars, to a depth of between 8 and 11 kilometres (5 to 7 miles), is highly altered or damaged.

And the way the waves are stretched out in the crust suggests that it contains small amounts of volatiles – more than the Moon, but less than Earth.

But there’s even more. InSight isn’t just equipped with seismic instruments, it’s also measuring the atmosphere and the surrounding geology of its landing site.

 

We know, thanks to orbiters, that atmospheric gravity waves – ripples in a fluid medium, such as gases and liquids – can occur on Mars. In a paper on the Martian atmosphere, InSight has provided a catalogue of the different kinds of such waves in the Martian atmosphere.

And they discovered infrasound in the Martian atmosphere, too.

“From these measurements, we have discovered Martian infrasound and unexpected similarities between atmospheric turbulence on Earth and Mars,” the researchers wrote. “We suggest that the observations of Mars’s atmosphere by InSight will be key for prediction capabilities and future exploration.”

In yet another paper, a team of researchers studied the planet’s magnetic field at the InSight landing site. It’s been established that Mars has a pretty weak magnetic field, which is thought to contribute to its inhospitable nature.

Their results suggest that Mars wasn’t always this way.

“We find that the field is ten times stronger than predicted by satellite-based models,” the researchers wrote. “We infer magnetised rocks beneath the surface, within ~150 km of the landing site, consistent with a past dynamo with Earth-like strength.”

All together, the results are adding to the pile of evidence that suggests Mars was once a very different place. And, of course, they could help inform crewed missions to the planet – not just telling us what to expect, but where to look to find more clues to Mars’ secrets.

Meanwhile, the InSight mission is scheduled to continue for another Earth year… so we should be finding out more about what’s hiding underneath that enigmatic red surface.

The papers have been published in a special issue of Nature. You can find them here, here, here, here, here and here.

 



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Astronomers Have Detected Molecular Oxygen in Another Galaxy For The First Time

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In a wild galaxy over half a billion light-years away, astronomers have detected molecular oxygen. It’s only the third such detection ever outside the Solar System – and the first outside the Milky Way.

 

Oxygen is the third most abundant element in the Universe, behind hydrogen (naturally) and helium. So its chemistry and abundance in interstellar clouds are important for understanding the role of molecular gas in galaxies.

Astronomers have searched for oxygen again and again, using millimetre astronomy, which detects the radio wavelengths emitted by molecules; and spectroscopy, which analyses the spectrum to look for wavelengths absorbed or emitted by specific molecules.

But these searches have turned up a puzzling lack of oxygen molecules. Which means “a comprehensive picture of oxygen chemistry in different interstellar environments is still missing,” wrote a team of astronomers led by Junzhi Wang of the Chinese Academy of Sciences in a new paper.

One place molecular oxygen has been detected is the Orion nebula; it’s been hypothesised that out in space, oxygen is bound up with hydrogen in the form of water ice that is clinging to dust grains.

But the Orion nebula is a stellar nursery, and it’s possible that the intense radiation from very hot young stars shocks the water ice into sublimation and splits the molecules, releasing the oxygen.

 

Which brings us to a galaxy called Markarian 231.

Markarian 231 is special. It’s 561 million light-years away, and powered by a quasar. That’s an extremely luminous galactic nucleus with an active supermassive black hole in the centre. They’re the brightest objects in the Universe, and Markarian 231 contains the closest quasar to Earth.

In fact, astronomers think Markarian 231 might have two active supermassive black holes in its centre, whirling around each other at a furious rate.

An active galactic nucleus drives molecular outflows, producing continuous shocks of the kind that might release oxygen from water in molecular clouds. The molecular outflows in Markarian 231 are particularly high velocity, so Wang and colleagues went looking for oxygen.

Using the IRAM 30-metre radio telescope in Spain, they took observations of the galaxy for four days across a number of wavelengths. In those data, they found the spectral signature of oxygen, in line with the shock hypothesis.

“With deep observations toward Markarian 231 using the IRAM 30 meter telescope and NOEMA, we detected [molecular oxygen] emission in [an] external galaxy for the first time,” the researchers wrote in their paper.

 

“The detected O2 emission is located in regions about 10 kpc (32,615 light-years) away from the center of Markarian 231 and may be caused by the interaction between the active galactic nucleus-driven molecular outflow and the outer disc molecular clouds.”

The team’s measurements revealed that the abundance of oxygen compared to hydrogen was around 100 times higher than that found in the Orion nebula, so the galaxy could be undergoing a more intense version of the same molecule-splitting process.

As Markarian is a starburst galaxy, undergoing furious star formation, this could be possible. Just one region in the galaxy is forming new stars at a rate of over 100 solar masses a year. The Milky Way, by contrast, is pretty quiet, with a star formation rate of around 1 to two solar masses.

On the other hand,these findings could also mean that more observations need to be taken to confirm that the astronomers are correct in interpreting their results as oxygen.

If the results hold, the phenomenon could be used to understand more about both molecular oxygen in galaxies, and the molecular outflow from an active galactic nucleus, the researchers said.

“This first detection of extragalactic molecular oxygen provides an ideal tool to study active galactic nucleus-driven molecular outflows on dynamic timescales of tens of megayears,” they wrote.

“O2 may be a significant coolant for molecular gas in such regions affected by active galactic nucleus-driven outflows.”

The research has been published in The Astrophysical Journal.

 



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