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Covid 19: The Facebook survey revealed people holding incorrect beliefs were unwilling to change their minds, even when given accurate information.

Reliance on scientists and experts during an epidemic: evidence from the COVID-19 outbreak in Italy

Pietro Battiston, Ridhi Kashyap, and Valentina Rotondi

Twelve months on, we may be suffering from COVID-19 information overload, but a year ago it was a different matter. The world was frightened and people were eager for facts and information about the deadly new virus. 

Faced with an unknown threat, people initially flocked to experts, scientists and health authorities.  But, as the weeks progressed and the gravity of the pandemic intensified, reliance on experts and trust in them dwindled.

Faced with an unknown threat, people initially flocked to experts, scientists and health authorities.  But, as the weeks progressed and the gravity of the pandemic intensified, reliance on experts and trust in them dwindled

Out of fear, fatigue with anti-pandemic measures and frustration at the inability of countries to control the deadly virus, signs of scepticism began to emerge. 

For researchers from across the academic spectrum, COVID-19 offered an opportunity to study and understand first-hand public responses to the first pandemic of the digital age.

Sociologists and demographers at Oxford’s Leverhulme Centre for Demographic Science, led by Dr Ridhi Kashyap wanted to explore international reactions to COVID-19 as it moved beyond China and reached Europe.  How did information-seeking and trust in scientists and health experts evolve?

To answer this question, Dr Kashyap’s team acted quickly to capture responses to the virus, from the end of February to mid-April 2020, as the number of deaths increased and Italy’s northern regions [the first area affected after China] went into lockdown. The team gathered data from three social media platforms in Italy: Twitter, Telegram (a messaging app) and Facebook.

With social media full of conversations about the virus, it was possible to collect digital trace data in real time – to see what was going on, what people were thinking and, critically, where they were getting their information.

‘We could analyse these digital footprints leading to where people sought information about this novel threat. What’s more, we could conduct rapid online surveys to reveal if reliance on experts and trust in their information was sustained, grew or waned,’ says Dr Kashyap.

We could conduct rapid online surveys to reveal if reliance on experts and trust in their information was sustained, grew or waned

Dr Ridhi Kashyap

On Twitter, they examined  more than two million tweets and retweets in Italy which used the post popular Coronavirus hashtags (#coronavirusitalia and #covid19italia). 

They classified the accounts which posted the tweets into different categories such as scientists, health authorities, media, politicians and government authorities. They then focussed on retweets of the most popular accounts, because they signal interest in the issue and agreement in what is being said.

At the start of the outbreak, the findings showed considerable increases in attention was given to scientists and health authorities. But in mid-March, shortly after the nation went into lockdown, retweets of health experts began to decrease.

On Telegram, the team gathered around 9,000 responses on how keen people were to receive information about COVID-19 from doctors, scientists, the government, health authorities, such as the WHO - and from celebrities. The questionnaires went out in four waves. The first went soon after the first case was detected, then three more, roughly a week apart.

Similar to the findings from Twitter, the Telegram results initially revealed increases in interest in information coming from scientists, health and government authorities, as opposed to celebrities. But, as the weeks passed, that level of interest waned.  

Results initially revealed interest in information from scientists...as opposed to celebrities. But, as the weeks passed, that level of interest waned

Facebook is the country’s most popular social media platform, with 60% of the population using it.  From the middle to end of March 2020, the team quizzed 900 respondents, drawn from Facebook users in Lombardy and Veneto, the area hit hardest by the disease.

In this survey fielded on Facebook, the team asked questions about health behaviours and knowledge linked to COVID-19, as well questions about support for public health measures to contain COVID-19.

The goal of the survey was to examine public health knowledge and attitudes, but also assess the willingness to modify health beliefs when exposed to correct information from experts. The survey asked questions such as: Are antibiotics helpful in preventing the Coronavirus infection? Can young people also contract COVID-19? Is washing hands useful for preventing the Coronavirus infection?

When respondents gave an incorrect answer to one of these questions, a randomly-selected group was shown information relevant to the question without a clear source, whereas the other half was shown the same information, but with an explicit clarification that it was coming an expert public health source, such as the WHO or Italian Institute for Public Health.

The survey found that, although levels of basic health knowledge about COVID-19 was good, signs of scepticism had emerged of public health experts among those who held incorrect beliefs. For those who had incorrect beliefs, showing information as coming from expert sources led them to become hardened in their beliefs and less likely to modify them. Trust in science and public health authorities was linked to better knowledge of COVID-19 and support for public health measures.

Dr Kashyap says, ‘Our research proves that trust in experts cannot be taken for granted. Yes, people crave trusted professional information at the beginning of an emergency, about which they know little. But that trust is fragile and can fall away...we saw that, although interest in the pandemic did not diminish, interest and trust in what health experts were saying certainly did.

‘We know too well the evolution of the virus, the different stages: waves, peaks, variants and lockdowns. Our study shows that trust moves too.’

Our research proves that trust in experts cannot be taken for granted...But that trust is fragile and can fall away

Dr Kashyap

She adds, ‘Evolution continues. Now we are entering a new phase of the pandemic: the vaccine roll-out. We hope it will lead us back to normality and this hope brought about by the scientific achievements of a new vaccine have the potential to revitalise trust in scientists and health experts again.’

In this context, it is more important than ever to ensure that reliable and trustworthy health information is presented and accepted by the public. Health experts are rallying against anti-vaxx information and its collateral damage of lives lost due to vaccine hesitancy. In the UK, the rates of those accepting the vaccine have generally been good – which suggests that public health experts are being heeded, although this cannot be taken for granted.

But some populations are believed less enthusiastic, with estimates suggesting less than half in some countries are prepared to be vaccinated. The information battle continues.  

Findings in monkeys allow to get an understanding of what may happen in the human brain as well, in the case of fundamental behaviours that both species display

By Dr Alessandro Bongioanni, Department of Experimental Psychology

One thing that makes our brain so fascinating is the staggering range of behaviours it allows. We are not just good at doing things in environments we know well (such as shopping at our usual grocery store), but we are surprisingly successful at navigating novel environments (such as scrolling this blog, making new friends, finding a job, etc.).

When I was an adolescent, I went for the first time to the only Thai restaurant in my city. Every single dish in the menu was new for me. I knew oysters, I knew beef, but I had never tried fried beef in oyster sauce before. Still, I was able to make up my mind and speculate that I would probably like the fried beef more than the chicken in coconut soup. This simple anecdote illustrates something bigger: all human progress required people to leave the comfort of a familiar situation and explore new places or new ideas. Today, with social and technological changes accelerating, we are continuously exposed to novel objects and situations and we generally cope very well with them.

If the ability to make adaptive choices in novel situations is so crucial for our human exploits, surely this is a unique ability of our species? Well, no. Animals too are able to adapt to new environments and to express meaningful preferences among objects or situations that they have never encountered before, based on similarities with what they know.

In the last few decades, scientists have understood a great deal about the neural mechanisms for learning the value of things, and for making decisions based on these values. However, by necessity, most neuroscience research is done with animals, and often with monkeys who are our closest relatives. Findings in monkeys allow to get an understanding of what may happen in the human brain as well, in the case of fundamental behaviours that both species display.

To study decisions in monkeys, scientists use very simplified and abstract tasks. All the irrelevant features of the real world are stripped down, to ensure that the neural activity measured is uniquely due to the key decision process. Many classic studies, for example, required binary choices between coloured images on a screen: initially, the blue stimulus gives a larger reward (in the form of fruit juice) than the red stimulus; in the next stage, the stimulus values reverse. Because this is all so abstract and unnatural for the animals, they may need months of training before data can be collected.

With this classic approach researchers discovered that the value estimate of each option is tracked by neurons in the most anterior part of the brain, just above the eyes. We gathered a detailed understanding of how this neural circuit represents the value of each individual item, and how it allows comparing options in order to make choices. But have we learned anything about the way our brain makes choices in our daily lives?

It turns out that if we put a person into an MRI scanner and ask her to make choices based on preferences, a distinct area usually lights up: it is still in the anterior part of the brain, but in the midline, where the two hemispheres face each other. So which one is the key brain area? Because MRI scanners cannot see individual neurons but estimate activity indirectly, for the past decade animal researchers and human researchers have thought that limitations to each others’ techniques have led their colleagues to focus on the wrong areas. But reaching a firm conclusion has been difficult.

A new explanation was put forward by a group led by Matthew Rushworth, professor at Oxford University and fellow of the Royal Society. He thought that different neural circuits may be involved in familiar and novel decision-making. Familiar items have been experienced repeatedly over a long time period and therefore the consequences of a familiar choice may be easily predictable. If, for example, I go to my favourite restaurant and I order my favourite dish, I can feel in advance how the experience is going to unfold. In contrast, novel decisions require constructing “on the fly” a somewhat hypothetical expectation of how the new options may feel like. This is what I did when I went to the Thai restaurant for the first time and I had to choose between fried beef with oyster sauce and chicken in coconut soup.

An experiment run by myself (Dr Alessandro Bongioanni), Dr Miriam Klein-Flügge and others in the Rushworth team, used MRI scans of monkeys to prove that indeed we can identify a specific brain circuit for novel choice; interestingly, its location in the brain corresponds with the one found in human fMRI studies, not previous monkey studies.

This discovery was accomplished thanks to a clever experimental design allowing monkeys to express preferences among items that they had not encountered before: stimuli were made of coloured dots, where colour represented the amount of juice at stake, and dot number the probability of receiving it. Some combinations of dot number and colour were highly familiar to the monkeys, others were new. Neural recordings revealed that it was the different degree of familiarity with the task items that had caused the puzzling mismatch between brain areas activated in humans and monkeys.

The fact that monkeys could solve the novel task quite easily opens new avenues for the study of decision neuroscience in primates: they are more intelligent than they may appear when faced with abstract lab tasks, and if the task is designed carefully, it is possible to elicit and study more complex behaviours than it was previously thought possible, such as choosing among novel options. This also bridges a gap between our knowledge of the human and the animal brains: making novel choices is not a unique human ability, but instead it is rooted in a neural circuit that is already present in our primate cousins.

We did not just find out where in the brain subjective value is computed, we also attempted to find out how this happens. We found that the monkeys mentally located each item offered in the “space” of all possible items (here, dot and colour combinations) and did so using a grid code. It is as if I “placed” the value of a given dish at a location in the space of all possible dishes, where one axis may represent texture, another axis flavour, and then temperature, price, etc.

We know that the brain’s “GPS system” for spatial navigation employs a grid code, the discovery of which led to the 2014 Nobel Prize in Physiology or Medicine to professors O’Keefe, Moser and Moser. Now, our new results suggest that the brain may use the same neural code employed to represent physical position in space, also to represent the value of a novel item in the space determined by the item’s features. This is interesting because it suggests that the mechanisms used by the brain to encode information are evolutionarily preserved and transferred across domains.

As Prof. Rushworth points out: 'It is intriguing to think that mechanisms for finding one’s way in physical space also underlie our ability to navigating an abstract space of choice possibilities.'

In order to validate this result, the same team also tested what happens if one disrupts specifically this small region of the brain. In order to do that, we relied on a newly developed ultrasound technique that permits stimulating deep in the brain without any invasive surgery; such stimulation can reversibly alter brain activity for one or two hours. Ultrasound provided the final proof: when the neural circuit for novel choice was targeted, the animals’ behaviour changed, as if they were no longer able to integrate the different features of a given novel option into a single mental representation.

While ultrasound has been around for a long time in medicine, it is only in the last couple of years that it has been used to modify brain functioning in this way. Jérôme Sallet, who developed the experimental setup in Oxford, says: 'Ultrasound neurotechnologies are offering new possibilities to identify the causal roles of brain areas. It is non-invasive and could be coupled with other techniques used to record brain activity. Beyond pure research, ultrasound stimulation might prove to be also a valuable tool to help patients with pharmaco-resistant conditions such as depression.'

This is because it avoids some limitations of current techniques such as TMS, which cannot reach deep into the brain or stimulate with precision. Other techniques such as DBS are precise but require surgery. Ultrasound may have the ideal combination of depth and precision without the need for surgery.

We never stop learning novel things about the brain, and if you think about it, this is the brain learning novel things about itself!

Read the full paper, which was published recently in Nature

cosmic string

Professor Paolo G. Radaelli

Could rust be the secret to next-gen computing technology? Current silicon-based computing technology is incredibly energy-inefficient and, by 2030, information and communications technology (ICT) is projected to gobble up more than 20% of the global electricity production[1].

After the end of the pandemic, climate change is likely to resume its position as the number one challenge for humanity and finding ways decarbonise tech is an obvious target for energy savings.

Professor Paolo Radaelli from Oxford’s Department of Physics, working with Diamond Light Source, has been leading research into silicon alternatives and his group’s surprising findings are published tomorrow in Nature [4 Feb] but online today. 

So just how energy-inefficient are computers? Well, the human brain uses approximately a millionth of the energy required by a computer to perform the same operation. To put that in context, the human brain uses about 12 watts of power, while an equivalent computer would use 12 megawatts: the output of a small power station. However, because of its immense success and ubiquitous nature, it is very difficult to replace silicon technology.

The human brain uses about 12 watts of power, while an equivalent computer would use 12 megawatts: the output of a small power station

The promise of oxide electronics

Researchers have been working for a long time on alternative technologies which might afford greater efficiency. Oxides of common metals, such as iron and copper, are natural targets for this research – not least because oxides are already a technology staple and are present in silicon-based computers, so there is a high chance of compatibility between the two technologies.

how realistic are the prospects of using ‘rust’ in super-efficient computers? We are optimisticCredit: Shutterstock. How realistic are the prospects of using ‘rust’ in super-efficient computers? We are optimistic
Tiny ‘cosmic strings’There is one obvious drawback: oxides are great to store information but not so much to move information around – and the latter is required for computation. One property of oxides however is that many are magnetic and a number of ideas have emerged recently on how it might be possible to move around magnetic ‘bits’, both in oxides and in other magnets, with very little energy being required.

The kinds of bits we are talking about here must be tiny – ten nanometres (ten billionths of a metre, about 20 times the diameter of an atom) is the typical target figure. And it must be robust even when ‘shaken and stirred’. This is very challenging, because the risk of them being simply dissipated away is very high when the bit is small. One possible solution came from the most unlikely of directions: a curious parallel between solid-state physics and cosmology. In fact, the inspiration for this project was set in the form of a challenge: can we replicate cosmic strings in a magnet?

So what are cosmic strings – and do they even exist? Cosmic strings are supposed to be filaments in space, much thinner than an atom but potentially as long as the distance between stars. But do they exist? Certain cosmological theories predict that they could have formed instants after the Big Bang, as the universe was cooling rapidly. Interestingly, once formed, cosmic strings would be stable and would not ‘evaporate’, so astronomers may be able to discover them in the future.

Cosmic strings are supposed to be filaments in space, much thinner than an atom but potentially as long as the distance between stars

But what do cosmic strings have to do with computers? The relevance comes from the fact that the mathematical description of cosmic strings is rather simple, and the same kind of mathematical conditions that favour the formations of strings may be found in many other physical systems, including magnets. It is the beauty of physics: mathematical equations describing the ‘macrocosm’ at parsec scales may also work in the microcosm at nanometre scales. With the challenge set, all that remained to do was to find a suitable magnet. Once again, the candidate turned out to be most unlikely: common rust.

It is the beauty of physics: mathematical equations describing the ‘macrocosm’ at parsec scales may also work in the microcosm at nanometre scales...all that remained was to find a suitable magnet...the candidate turned out to be most unlikely: common rust.

Rust to riches

Iron oxide (chemical formula Fe2O3) is a main constituent of rust. Each iron atom acts as a tiny compass, but this particular form of Fe2O3 is not magnetic in the ordinary sense of attracting and being attracted by other magnets: it is an antiferromagnet, so that half of the Fe compasses point ‘north’ and the other half ‘south’.

Two years ago, working at the Diamond Light Source on samples produced at University of Wisconsin, Madison, our Oxford group had already discovered the magnetic equivalent of cosmic strings in Fe2O3, and imaged them using a powerful X-ray microscope.[2]

P180 laser MBEP180 laser MBE
In essence, these tiny objects known as ‘merons’ are magnetic whirls, where the compass needle rotates (NESW or NWSE) as one moves from one atom to the next in a nanometre-scale loop. With hindsight, finding magnetic merons was a huge stroke of luck, since we know that they are very difficult to stabilise in the conditions used for that first experiment.

For the paper published today, we extended our collaboration to the National University of Singapore and managed to find the key to create and destroy magnetic merons at will, exploiting the mathematical equivalent of the ‘Big Bang cooling’.

Back to the future

This is undoubtedly fascinating basic research, but how realistic are the prospects of using ‘rust’ in super-efficient computers? We are optimistic. Though very simple in architecture, the Fe2O3-based device, where merons and bimerons were found, already contains all the ingredients to manipulate these tiny bits quickly and efficiently – by flowing a tiny electrical current in an extremely thin metallic ‘overcoat’. Indeed, controlling and observing the movement of merons and bimerons in real time is the goal of a future X-ray microscopy experiment, currently in the planning phase.

How realistic are the prospects of using ‘rust’ in super-efficient computers? We are optimistic.

When moving from basic to applied research, cost and compatibility considerations are also of paramount importance. Iron oxide itself is extremely abundant and cheap, but the fabrication techniques employed by colleagues at Singapore and Madison are rather complex and require atomic-scale control. Here again, we are optimistic. Very recently, they demonstrated that is possible to ‘peel off’ a thin layer of oxide from its growth medium and stick it almost anywhere, its properties being largely unaffected. Next steps? Design and fabrication of proof-of-principle devices based on ‘cosmic strings’ to follow in short order…



[1] https://www.nature.com/articles/d41586-018-06610-y

In the vinegar fly, males compete for a mate through courtship displays; thus, the ability to chase other flies is adaptive to males, but of little use to females

The evolutionary biologist Olivia Judson wrote, ‘The battle of the sexes is an eternal war.’

Males and females not only behave differently in terms of sex, they are evolutionarily programmed to do so, according to a new study from Oxford, which found sex-specific signals affect behaviour.

Males and females not only behave differently in terms of sex, they are evolutionarily programmed to do so

The new study from Oxford’s Goodwin group from the Department of Physiology, Anatomy and Genetics says, despite sharing very similar genome and nervous system, males and females ‘differ profoundly in reproductive investments and require distinct behavioural, morphological, and physiological adaptations’.

The team argues, ‘In most animal species, the costs associated with reproduction differ between the sexes: females often benefit most from producing high-quality offspring, while males often benefit from mating with as many females as possible. As a result, males and females have evolved profoundly different adaptations to suit their own reproductive needs.’

Males and females have evolved profoundly different adaptations to suit their own reproductive needs

The question for the researchers was: how does selection act on the nervous system to produce adaptive sex-differences in behaviour within the bounds set by physical constraints, including both size and energy, and a largely shared genome?

Today’s study offers a solution to this long-standing question by uncovering a novel circuit architecture principle which allows deployment of completely different behavioural repertoires in males and females, with minimal circuit changes. 

The research team, led by Dr Tetsuya Nojima and Dr Annika Rings, found that the nervous system of vinegar flies, Drosophila melanogaster, produced differences in behaviour by delivering different information to the sexes.

In the vinegar fly, males compete for a mate through courtship displays; thus, the ability to chase other flies is adaptive to males, but of little use to females. A female’s investment is focused on the success of their offspring; thus, the ability to choose the best sites to lay eggs is adaptive to females.

When investigating the different role of only four neurons clustered in pairs in each hemisphere of the central brain of both male and female flies, the researchers found the sex differences in their neuronal connectivity reconfigures circuit logic in a sex-specific manner. In essence, males received visual inputs and females received primarily olfactory (odour) inputs. Importantly, the team demonstrated that this dimorphism leads to sex-specific behavioural roles for these neurons: visually guided courtship pursuit in males and communal egg-laying in females. 

In essence, males received visual inputs and females received primarily olfactory (odour) inputs

These small changes in connectivity between the sexes allowed for the performance of sex-specific adaptive behaviour most suited to these reproductive needs through minimal modifications of shared neuronal networks. This circuit principle may increase the evolvability of brain circuitry, as sexual circuits become less constrained by different optima in male and females.

And it works, the study says, ‘Ultimately, these circuit reconfigurations lead to the same end result—an increase in reproductive success.

'Our findings suggest a flexible strategy used to structure the nervous system, where relatively minor modifications in neuronal networks allow each sex to react to their surroundings in a sex-appropriate manner.'

Furthermore, this is the first time a firm link between sex-specific differences in neuronal networks have been explicitly linked to behaviour.

According to Professor Stephen Goodwin, 'Previous high-profile papers in the field have suggested that sex-specific differences in higher-order processing of sensory information could lead to sex-specific behaviours; however, those experiments remained exclusively at the level of differences in neuroanatomy and physiology without any demonstrable link to behaviour. I think we have gone further as we have linked higher-order sexually dimorphic anatomical inputs, with sex-specific physiology and sex-specific behavioural roles.'

We have linked higher-order sexually dimorphic anatomical inputs, with sex-specific physiology and sex-specific behavioural roles

Professor Stephen Goodwin

The researchers maintain ‘evolutionary forces’ have driven these adaptations, ‘Drosophila, males compete for a mate through courtship displays, while a female’s investment is focused on the success of their offspring.’

They conclude, ‘In this study, we have shown how a sex-specific switch between visual and olfactory inputs underlies adaptive sex differences in behaviour and provides insight on how similar mechanisms maybe implemented in the brains of other sexually-dimorphic species.’

The full paper, A sex-specific switch between visual and olfactory inputs underlies adaptive sex differences in behaviour, joint-first authored by Dr Tetsuya Nojima and Dr Annika Rings, is available to read in Current Biology.

At the point it enters the atmosphere, it will be travelling at more than 15,000 km/h and its heat shield will reach more than 1,300 degrees centigrade during the descent

We may not have found life on Mars, but there is considerable excitement in the Oxford scientific community about the imminent possibility of detecting the landing of NASA’s Perseverance Rover using InSight, another spacecraft which is already on the red planet.  

University physicists believe that, for the first time, they might be able to ‘hear’ a spacecraft land on Mars, when Perseverance arrives at Earth’s ‘near’ neighbour in about a month’s time around 18 February.

And NASA’s new probe is certainly not arriving quietly. The unmanned craft will plunge through the Martian atmosphere at enormous speeds, accompanied by a sonic boom created by its rapid deceleration. At the point it enters the atmosphere, it will be travelling at more than 15,000 km/h and its heat shield will reach more than 1,300 degrees centigrade during the descent. 

NASA’s new probe is certainly not arriving quietly. The unmanned craft will plunge through the Martian atmosphere at enormous speeds, accompanied by a sonic boom created by its rapid deceleration

It will deploy two large balance masses which will hit the ground at hypersonic speeds, crashing down at a speed of 4,000 metres per second. It is these two masses which the scientists are hoping will create detectable seismic waves - which will travel the 3,452 kilometres between Perseverance’s landing site and InSight’s location.

The ears to ‘hear’ the impact are the InSight probe, which was sent to Mars three years ago to listen for seismic activity and impacts from meteorites. Parts of the spacecraft were built at Imperial College London and tested in the Department of Physics at the University of Oxford.

InSight detects seismic activity (marsquakes) to help scientists understand better the interior structure of Mars. Although many hundreds of marsquakes have been detected since InSight’s landing in 2018, no impact events (meteorites hitting the surface and producing seismic waves) have been detected. Impact events are of particular interest because they can be constrained in timing and location from pictures taken by orbiting satellites, and thus used to ‘calibrate’ seismic measurements.

So, the arrival of Perseverance Rover potentially offers the first opportunity to detect a known, planned landing of a foreign body on the surface of the planet.  It could provide a wealth of evidence on the structure and atmosphere of Mars and has got the scientific community very excited about its potential.

According to Oxford physicist, Ben Fernando, a member of the InSight team, ‘This is an incredibly exciting experiment. This is the first time that this has ever been tried on another planet, so we’re very much looking forward to seeing how it turns out.’

This is the first time that this has ever been tried on another planet, so we’re very much looking forward to seeing how it turns out

InSight team member, Ben Fernando

InSight’s seismometers are potentially sensitive enough to detect Perseverance’s landing, even though this is expected to be very challenging - given the significant distance between the two landing sites. It is around the same distance as from London to Cairo. Nevertheless, the Oxford team believes the impact could potentially be detected by InSight and thus provide an immensely useful ‘calibration’.

According to Ben Fernando, ‘This would be the first event detected on Mars by InSight with a known temporal and spatial localisation. If we do detect it, it will enable us exactly to constrain the speed at which seismic waves propagate between Perseverance and InSight.’

A newly-published paper from the InSight team states, ‘Perseverance’s landing is targeted for approximately 15:00 Local True Solar Time (LTST) on February 18, 2021 (this is 20:00 UTC/GMT on Earth).’

InSight’s seismometers are potentially sensitive enough to detect Perseverance’s landing, even though this is expected to be very challenging - given the significant distance between the two landing sites. It is around the same distance as from London to

The paper continues, ‘The spacecraft will generate a sonic boom during descent, from the time at which the atmosphere is dense enough for substantial compression to occur (altitudes around 100 km and below), until the spacecraft’s speed becomes sub-sonic, just under three minutes prior to touchdown.  This sonic boom will rapidly decay into a linear acoustic wave, with some of its energy striking the surface and undergoing seismo-acoustic conversion into elasto-dynamic seismic waves, whilst some energy remains in the atmosphere and propagates as infrasonic pressure waves.’

The paper concludes, ‘We identified three possible sources of seismo-acoustic signals generated by the EDL (entry, descent, landing) sequence of the Perseverance lander:  (1 ) the propagation of acoustic waves in the atmosphere formed by the decay of the Mach shock, (2) the seismo-acoustic air-to-ground coupling of these waves inducing signals in the solid ground, and  the elasto-dynamic seismic waves propagating in the ground from the hypersonic impact of the CMBDs.’

InSight will ‘listen’ for the acoustic signal of the sonic boom in the atmosphere. But scientists think the best chance of detecting the landing will be the seismic impact of the balance masses.

The team expects to receive data from InSight within a day or two of Perseverance’s landing, after which they will investigate whether they have made a successful detection.

Short explanatory video: http://bit.ly/insight-m2020-video

Instagram film: https://www.instagram.com/tv/CJvxmSaokd3/