How we discovered the dark side of wearable fitness trackers

Under the electronic thumb Shutterstock

You no longer have to look to science fiction to find the cyborg. We are all cyborgs now. Mobile phones, activity trackers, pacemakers, breast implants and even aspirins all act as biological, cognitive or social extensions and enhancements of our bodies and minds. Some have even predicted that human beings as we know them will be replaced by technically enhanced, god-like immortal beings within 200 years. Or at least rich people will.

The next generation of wearable technology is set to take us one step closer to this predicted future. We are now looking at a future of bionic, data-rich and in-body technologies that may forever change what it means to be human.

The company Athos plans to launch fitness clothes that measure muscle activity, heart rate and respiration in real time. Its marketing material encourages consumers to “upgrade” and become “the ideal version” of themselves. In doing so, Athos clearly reveals its transhumanist stance: the idea that technology will take our species to the next evolutionary stage.

Together with jeans manufacturer Levi Strauss & Co, Google is developing clothing that interacts with your devices. With touch-sensitive surfaces, the garments will be able to monitor weight gain, understand your gestures, make phone calls and more.

Fitness and activity trackers as we know them may also soon be surpassed by biometric wristbands that can measure what is going on inside your body. Researchers at Echo Labs are currently working on a biometric band that can measure your oxygen, CO2, PH, hydration and blood pressure levels via optical signals.

Several initiatives are even underway to create implantable technologies, that could essentially augment human biology. Internal microchips and digital tattoos could replace smart wristbands, payment devices and the like in the next few years.

The question that is often not asked however is: “How do we feel about living with technology on (or in) our bodies 24/7?”

Always on, always on me

We recently conducted a study with 200 women who wore a Fitbit activity tracker. It revealed that most users embraced the devices as part of themselves and stopped treating it as an external technology. It was “always on, always on me” with 89% of participants wearing it almost constantly, only taking it off to recharge the battery.

We also found that the Fitbit was an active participant in the construction of everyday life. It had a profound impact on the women’s decision-making in terms of their diet, exercise and how they travelled from one place to another. Almost every participant took a longer route to increase the number of steps they took (91%) and amount of weekly exercise (95%) they did. Most increased their walking speed to reach their Fitbit targets faster (56%). We also saw a change in eating habits to more healthy food, smaller portion sizes and fewer takeaways (76%).

Fitness handcuff? Shutterstock

Most women in the study believed it was important to quantify their daily activities (88%) and checked their progress dashboard more than twice a day (84%). The chase was on to receive gratifying “hooray” and “champ” messages when a target was reached. One person even said: “I love my Fitbit Flex because it gives me a pat on the back every night.”

We were particular interested in finding out how women related to their Fitbit. For many, it was seen as a friend who helps them reach their targets (68%). Reaching the daily targets creates feelings of happiness (99%), self-satisfaction (100%), pride (98%) and motivation (98%). A good day where the targets were reached made them like Fitbit more (96%). Most (77%) would even go back home to fetch their Fitbit if they had left without it.

The darker side

But in analysing these findings, we also started to notice that the relationship is perhaps not as pure and unproblematic as first believed. The idea that technology is both liberating and oppressive, first articulated by philosopher Lewis Mumford in the 1930s, started to shine through. When we asked the women how they felt without their Fitbit, many reported feeling “naked” (45%) and that the activities they completed were wasted (43%). Some even felt less motivated to exercise (22%).

Perhaps more alarming, many felt under pressure to reach their daily targets (79%) and that their daily routines were controlled by Fitbit (59%). Add to this that almost 30% felt that Fitbit was an enemy and made them feel guilty, and suddenly this technology doesn’t seem so perfect.

Wearable technologies can have a positive impact on the way we lead our lives by giving us insight into ourselves and enabling us to interact in new ways. However, it is also clear that when we invite technology onto or into our bodies, we have to be willing to share everyday decision making. As wearables crunch our every move, we will increasingly be told what to do and how best to behave and communicate with others.

For now, we believe wearables can be our companions, but the early signs of a technology takeover are there, questioning the sustainability of the current relationship. Whether we want to or not, we are slowly, but steadily, transforming into a new human species. Enter: homo cyberneticus.

Baboons don't play follow the leader – they're democratic travellers

Well if you'd just ASK someone Bernard... Courtesy of Rob Nelson

Baboons in the wild are known for their highly strategic and hierarchical societies. So when it comes to decisions about where to go, one might expect that some bolshie individuals will direct the group through its habitat. However, a new study of the collective movements of wild olive baboons in Kenya suggests that there are more democratic processes at play.

For wild animals location is everything. The decision to head north instead of south may lead you to a fruiting tree, a pool with water or a place of shelter: all of these things could be the difference between life and death. For that reason, animal movements are never random. Even when searching for things, animals will use specific patterns of movements to sweep their environment. Social animal species like monkeys may not sit down and have a confab over a map, but they still need to make a decision about where the group should be heading.

A baboon in sheep’s clothing?

Numerous theoretical studies show the more you use collective information, the better the decision making process turns out. So it actually makes sense for clever animals like baboons to ignore a dominant individual no matter how much of a despot they are, but instead use a democratic process.

Oliver might be resourceful but look at that silly stroll. He clearly has no idea where he’s going. Andicat/wikipedia

So far, there has been a limited amount of knowledge about how baboons make decisions about movements. The problem is how to study simultaneous and collective decision making in animals that live in large groups. Baboons typically live in groups of around 100. High accuracy GPS devices mounted on the majority of group members is the answer: this will reveal how animals coordinate their movements relative to one another. I have used this technique in the past on a much smaller scale to investigate the secretive lives of mated pairs of maned wolves in Brazil.

The researchers monitoring baboons in Kenya did just this. When an animal moved off, its influence on the other members of the group was observed. Did the other members follow (that is, did it “pull” them along)? Or did the other members resist the initiative to move off (that is, “anchor” the group). And what happened when several individuals moved off at the same time in different directions?

The researchers found that there was no relationship between position in the hierarchy and pulling the crowd along. In other words, top baboons were as likely to be followers as being followed. This illustrates that leadership and social roles within a social group can be distinct roles. Just because you are the leader does not mean that everyone else in the group treats you like you are infallible in your decision making.

In general individuals were followed when they moved purposefully off in a set direction and were able to rapidly recruit or “pull” other individuals in that direction. This makes sense in that it suggests to other group members that the moving individual’s behaviour is goal driven, for example by looking for food. Perhaps the individual has suddenly remembered the location of a fruiting tree. It would therefore appear that baboons like to follow the crowd – this is similar to quorum sensing behaviour in bees and ants when they are choosing a new nest. The option with the most votes wins.

The 90-degree rule

A big problem of group movement is how to resolve disagreement about the direction to be taken. It is rather like being lost in a strange city on a night out with a group of friends with widely differing opinions about where to go. One effect of this for both humans and baboons is that it delays any decision being made as the conflict is being resolved.

So what’s the solution? It turns out that baboons have a special rule. When the difference between two individuals trying to initiate movements in different directions is less than 90 degrees from one another, then it is resolved by splitting the difference and taking a middle path. However, if the difference of opinion about directions is greater than 90 degrees then individuals accept the choice of one individual over the other. Initiators of movement in a certain direction build up followers, and the individual that has accumulated most followers will end up determining the group’s direction.

You are wrong - the difference is 91 degrees, not 88. Let’s follow Jack. Rod Waddington/wikimedia, CC BY-SA

It is surprising that something as important as group movement in baboons can be determined by a few simple rules, which are based on the idea that it is better to use the group’s collective knowledge than trust in the opinion of their leader. And perhaps even more so the fact that a dominant individual accepts that it is better to be a sheep than a shepherd in certain situations.

'Kennewick Man' was Native American, study suggests

Umatilla people, one of the tribes fighting to bury the Kennewick Man. U.S. National Archives and Records Administration/wikimedia

When a nearly complete 9,000-year old human skeleton washed out of a Columbia River cutbank at Kennewick in Washington State in 1996, archaeologists hailed it as the most important find of the century. But the discovery sparked a fierce legal battle between scientists and local Native Americans about Kennewick Man’s ancestry and what to do with the remains that has been raging ever since. A new study that will further fuel the debate shows that he was, most likely, Native American.

When the skeleton was first found, many Native Americans denounced the scientific studies as a desecration and demanded that “The Ancient One”, as they call it, be immediately reburied without analysis. An acrimonious and highly public argument ensured, complete with multi-million dollar lawsuit.

Scientific studies over the past decade concluded that Kennewick Man probably descended from an ancient population that today survives as Japan’s Ainu people and the Polynesian people. The implication, of course, was that the Americas were first inhabited by Caucasian people and that Native Americans came later.

The new study turns this argument on its head. A broad coalition of scientists present the first genomic sequence of Kennewick Man, suggesting that American Indian people have been in the US for at least eight millennia. These results indicate that not only that Kennewick Man was a Native American, but that his mostly likely descendants include the members of the Colville tribe, living today less than 200 miles from the Kennewick burial site.

Rewriting history

The new evidence will continue the controversy. The initial bio-archaeological analysis concluded that the individual was a Caucasoid male, about 45 years old at death. He’d suffered multiple wounds in life, including a hip injury that left some sort of projectile still embedded. When a CT scan showed that the projectile was a stone spear point, a small bone sample was submitted for radiocarbon dating. Three weeks later, the lab produced results that would rock New World archaeology: The man had died 9,400 years ago – making Kennewick Man one of the most complete ancient skeletons in the Americas.

On the basis of scarce and uncertain evidence, archaeologists and journalists alike began framing fresh theories about the earliest Americans. Who had first populated the continent? Had there been a race war? As theories proliferated, archaeologists seemed to agree on only one point: Kennewick was a monumental find that must be studied extensively by specialists. As the scientific teams geared up, the already dramatic story of Kennewick Man took an extraordinary turn.

Five days after the startling results of the radiocarbon tests were made public, the Army Corps of Engineers announced its intent to repatriate the bones to an alliance of five north-west tribes: the Umatilla, Yakima, Nez Perce, Wanapum and Colville tribes. The tribal coalition rejected the scientist’s name, preferring the name Oyt.pa.ma.na.tit.tite (The Ancient One).

Ainu people. Bronislaw Pilsudski

They argued that scientific probing and destruction of human bones was offensive, sacrilegious and illegal under the Native American Graves Protection and Repatriation Act (NAGPRA) of 1990. They demanded that the bones be immediately surrendered, without analysis. Armand Minthorn, an Umatilla leader said: “Our oral history goes back ten thousand years. We know how time began and how Indian people were created. They can say whatever they want, the scientists. They are being disrespectful.”

But many archaeologists countered that Kennewick Man could not be affiliated with any tribe. Eight prominent archaeologists and physical anthropologists filed a lawsuit in federal district court to stop the transfer to the tribes and obtain access to study the skeleton. After years of legal wrangling, the Ninth District court concluded in 2005 that Kennewick Man was not a Native American and found in favour of the plaintiffs, permitting scientific study and awarding more than US$2m in attorney’s fees and costs to the plaintiffs.

For nearly a decade, a broad coalition of scientists intensively studied the bones of Kennewick Man, presently curated at Seattle’s University of Washington Burke Museum. Their conclusions generally supported the initial analysis: Kennewick Man was not a Native American and hence could not be closely affiliated to any modern tribe, including those today living today in the north-west. He was more closely related to Ainu and Polynesians.

Modern science to the rescue

Despite several efforts to recover genetic materials from Kennewick Man, none were successful – until now. The new study published the genomic sequence of Kennewick Man based on DNA extracted from a hand bone. This is a crucial step because earlier analyses of Kennewick Man employed cranial morphology as a genetic proxy, assuming skull shape is both highly heritable and selectively neutral.

But this this approach, grounded in the tradition of 19th-century skull science, does not represent mainstream thinking in bio-archaeology. The new study relies on voluminous experimental, epidemological and skeletal biology records that demonstrate the profound influence of dietary shift and food consistency on craniofacial architecture. Skull shape does not map an unchanging genetic highway into the past because bone is a remarkably dynamic medium.

There also important implications for the relationship between scientists and the Native American Tribes. The new DNA results indicate that some members of the Colville tribe are direct descendants of the population that likely included Kennewick Man (or at least his close relatives). How ironic is it that in 1996, the Colville were among the five north-west tribes protesting against scientific study of The Ancient One. Nearly two decades later, the Confederated Tribes of the Colville Reservation were instrumental in supporting the new genomic study of Kennewick Man, even to the point of tribal members contributing their own DNA for the project.

The chaos surrounding the discovery and analysis of Kennewick Man has become a negative role model for the practice of 21st-century archaeology. That descendant communities get involved in scientific study is today commonplace in American archaeology and it is heartening to see the results of this sea change reflected in the study of Kennewick Man/The Ancient One.

The next step will also be controversial, as new DNA studies will be debated and deconstructed to determine the ultimate destination of Kennewick Man. Should his bones still be curated for further study? Can the Colville tribe prove affiliation and request return through the NAGPRA law? Or could an innovative collaborative solution be crafted to resolve the continuing skull wars?

Realistic robot faces aren't enough – we need emotion to put us at ease with androids

How can I serve you? Franck Robichon/EPA

When the first guests arrive at Nagasaki’s Hotel Henn Na in July this year, they will be greeted and served by robots. In a similar approach, Toshiba’s android Aiko recently held a short-term role greeting customers at a department store in Tokyo. Customers were comfortable approaching Aiko to ask for directions and even the receptionist who normally holds the post felt her android colleague was doing a reasonable job.

There is no doubt that developments in android technology mean that robots now look more lifelike than ever. It is even possible to imagine mistaking a robot such as Aiko for a human, at least at first glance. However, encountering near-human agents may not always be a comfortable experience.

Hotel Henn Na claims it is looking to explore the elements that “personify” hotels and to recreate that by using person-like entities. The big question is how people interact with robots, such as Aiko, that have a human appearance. Such interactions require considerably more than a robot with an apparently human face.

Our research at the Open University has considered aspects of how it might feel to be in a situation similar to interacting with a robot receptionist. It asks whether the properties of a robot receptionist’s appearance and behaviour are able to make us feel comfortable or may make us decidedly uncomfortable. Our work into the so-called uncanny valley effect also suggests that a key aspect of such interactions will be the ability of the robot to reproduce and convey realistic emotions, particularly through their facial expressions.

The uncanny valley effect is now a well-known relationship how “human-like” a robot is and how comfortable people feel when interacting with it. There is a point where something can seem too close to human to be comfortable – and our research has explored some explanations for why this might occur. For a long time, research in this area was mainly focused on the practical aspects of how near-human agents appear and on the techniques that might make them look more realistic and acceptable enough to bridge this uncanny valley.

Our early research had observed that that some of the eeriest and most unsettling near-human agents were those with exaggerated features, such as a “cute” doll with dark, wide and blank eyes. Building on the idea of disturbing facial features, our more recent research looked at the role of emotions in the uncanny valley effect and considered whether that eeriness may actually be a result of those near-human faces being unable to present realistic emotional expressions.

Most of the research into this area has considered how artificial faces can be made to appear more human-like, but we looked at how even human faces can appear eerie under certain conditions. We have found that when parts of photographs of faces posing emotional expressions were combined, certain combinations of emotions evoked a sense of eeriness. This effect was particularly strong when happy mouths were paired with scared or angry eyes.

Easier to love? Daniel Karmann/EPA

In other words, encountering a face where the mouth is clearly smiling, but the eyes are not displaying the same emotion, can be quite disturbing. It follows that unless a robot face can display emotions accurately and appropriately, just as a human would, a human viewer could be left with a distinct feeling of unease.

So, it will be a long time before human receptionists superseded. Even now that the design of robot faces is at a point where they can be made to appear human-like, robots will need better abilities to be able to perform convincing emotional interactions.

Creating near-human agents that can portray genuinely believable emotional expressions presents a highly complex technological challenge. So while this tension between appearance and emotional interaction may currently confine robots to the uncanny valley, it could also offer a way out.

An alternative would be for robot designers to avoid trying to mimic human faces too closely until technology has progressed to allow their feelings to be represented realistically as well. Otherwise, our expectations about emotions would just be raised by the their human-like nature and then not met by their expressive ability. Choosing to make robots less human in appearance could avoid a constant race where robots that appear more human-like also require ever more convincing emotional abilities, offering a way around the uncanny valley.

Who really benefits from the 'internet space race'?

Solar-powered drones could fly for years at a time delivering internet access. Titan Aerospace

In the film Elysium, the ultra-rich have left an apocalyptic Earth ravaged by global warming and overpopulation. Their utopian colony orbits high above Earth which festers below. Science fiction, but Silicon Valley techno-utopians also dream of rising above the planet’s problems.

The Seasteading Institute, for example, seeks to create floating cities far enough from land as to be outside of any regulatory jurisdiction. There, farseers such as the likes of Google CEO Larry Page might be able to innovate, untethered by regulations. At Google’s annual developers’ conference in 2013, Page said: “I think as technologists we should have some safe places where we can try out some new things and figure out.”

The seas of Earth appeal to some while the dry seas of Mars attract others: Elon Musk, CEO of Tesla Motors, is at the forefront of commercial space travel for the ultra-rich. At a cost of US$36 billion he hopes his company SpaceX can start a Mars colony. Space tourist tickets come in at a mere US$500,000. He also plans to provide planet-wide internet access, beamed from 4,000 satellites.

Facebook and Google have shelved similar plans for satellite internet access for those it has yet to reach. Instead, Facebook has opted for a less lofty approach, targeting not space but the stratosphere: its Connectivity Lab is tasked with bringing about an internet-saturated planet. To do this, they have invested in solar-powered drones capable of providing internet to underserved and disconnected areas. Google on the other hand, through its secretive X lab, devised Project Loon to provide internet via high-flying balloons.

Why are some of the world’s most powerful technologists so focused on providing internet access by hook, crook, drones, balloon or satellite?

Above the Facebook flag at Facebook HQ flies another, bearing the symbol of Facebook’s non-profit organisation, Internet.org. The internet-dispersing drones under development are designed to bring about the objectives of Internet.org – connecting up the next three billion people yet to join the internet. But it isn’t the “internet” as we know it today, instead, Internet.org allows users to access only Facebook and select other sites, not the entire internet. In an open letter to Facebook CEO Mark Zuckerberg, 65 organisations from 31 countries criticised the project, claiming it violated the principle of network neutrality, that no site should be favoured over others. Security, privacy, censorship, and freedom of expression were among the other concerns voiced over Facebook’s growing control.

It may seem axiomatic to those in the West, but what if people don’t want access to the internet – of the type provided by Facebook, Google and SpaceX, or any other? There are well over a billion people living in states under governments that resist Western-style internet connectivity in order to preserve that country’s status quo.

Technical approaches towards national internet sovereignty including IP address blocking, domain names, key words, and packet filtering. Non-technical forms of censorship include laws, regulations, threats, bribes, and arrests of publishers, ISPs, and authors. Reporters without Borders identifies 19 countries – including the US and the UK – along with Cuba, China, Iran, and North Korea, all of which use one or several of these tactics to create a distinct national internet.

Certainly, what governments want for their people and what the people want for themselves frequently diverge. But while we may agree that internet censorship by authoritarian dictatorships is an affront to free communication, can we really put our faith in Facebook’s drones? It is possible to overthrow a government and depose a dictator but it is nearly impossible to revolt against corporate drones and extraterritorial CEOs.

With solar powered balloons raining internet down where it wasn’t before, from inaccessible places such as high in the atmosphere or beyond, is resistance to the internet even an option? As US president Ronald Reagan knew when he initiated his Star Wars defence programme in the 1980s, space is the ultimate high ground. In the stratosphere and in space, the techno-liberal social engineering ideal – that the internet is inherently good – meets the desire to be above the fray of terrestrial, democratic regulation.

In the dramatic conclusion of Elysium, Max Da Costa (played by Matt Damon) flies a pod of illegal immigrants from Earth and crash-lands it into the luxurious orbiting utopia, rebooting the computer that keeps the citizens of Earth and Elysium in inequality. Those who do not want the internet may need a similar radical approach, because when the ultra-rich take to the skies it becomes nearly impossible to protest their decisions.

Artificial recreation of happy memories may become the next big weapon against depression

How happy days can be remembered as they really were. Surkov Vladimir/Shutterstock

Urging a depressed person to stay positive by remembering the good things in life is unlikely to be helpful advice. That is because depression blocks access to happy memories. But what if we could somehow artificially recreate such memories to allow for some more positive thinking? A study suggests that this is indeed possible – at least in rats.

Surprisingly, the psychology and physiology of rodents is not so distant from our own. And if the same effect could be observed in humans, it might help open depressed individuals up to positive general interpretation of life experiences that make it possible to lift the dark veil of depression.

The brain and depression

Clinical depression, which is different from a temporary bout of sadness, is a rather common psychopathological disorder characterised by persistent negative moods, feelings of sadness, loss of interest and motivation. It has negative consequences on sleep and affects many aspects of an individual’s life, including what would otherwise be rewarding behaviours – like eating.

In humans it affects both adults and children, but general behaviour consistent with depression can be observed in animals. This has limits of course. For example, human depression is characterised by hopelessness and suicidal thoughts, which cannot be detected in animals. However, loss of interest is present in both. In rodents, more specifically, loss of interest can be easily detected by measuring sucrose preference – depressed animals lose interest in sugar.

Animal models for depression are extremely helpful in trying to understand biological, physiological and genetic bases of this pathology. The new research does shows that the artificial reactivation of brain cells spontaneously active during positive experiences, substantially decreases depression (anhaedonia) in rats.

A cross-section of a positive memory. Seen here is the hippocampus; the brain cells glowing in red were previously active during the encoding of a positive memory. Credit: Steve Ramirez

The researchers used a method called optogenetics, in which specific brain cells are genetically sensitised to light and then activated using pulses of light, in the experiment. Light-sensitive molecules were in this way used to detect which brain cells were activated by a certain experience in the animals. The area of the brain chosen by the researchers to be tagged by these molecules is the hippocampus, more specifically a subarea of the hippocampus called the dentate gyrus. This is linked to the formation of memories and to responses of avoidance and of appetite, and thus records positive and negative experiences.

The researchers first induced anhaedonia in male rodents by exposing them to repeated stress by making it impossible for them to move, such as hanging them by the tail. They then exposed them to three types of experiences: positive (being put in a cage with a female), negative (being immobilised in a cage) or neutral (being put in an empty cage) and recorded which brain cells were active during these experiences.

Mmmm at least three sugars in this one. Lori Leaumont/Flickr, CC BY-SA

The researchers then used pulses of light to activate the cells they had pinpointed. They found that only the reactivation of cells in the dentate gyrus that were active during positive experiences (but not the reactivation of those active during negative or neutral experiences) made rats show interest in sugar again, meaning they had been relieved from depression.

Next steps

What’s so interesting about this, particularly for a memory researcher, is that it was the artificial reactivation of the cells (the reactivation of the positive memories) and not re-exposure to these positive experiences that did the trick.

In other words, being put again in a cage with a female did not lift the rats from depression. One can speculate that being put again in a cage with a female does not necessarily reactivate a memory, as it can be encoded as a new experience. It seems, then, that it is the reactivation of the neural network linked with a positive past experience, and not the positive experience in itself, that helps.

But can these results be extended to humans as they are? Not immediately, of course. However there is hope, as for example clinical studies have shown that therapeutic cognitive-behavioral interventions using positive mental imagery or the restructuring of how past experiences are interpreted, might be of help. The link between personal memories and depression is also currently experimentally investigated.

Crucially, what this study shows is that it might be indispensable in treating depression in humans to use an external and artificial trigger to unblock the access to positive memories. Optogenetics is already starting to be used in humans, but with great caution, as it can require implants. But it is not inconceivable that these external and artificial triggers could be light pulses in the future.

Either way, an important building brick has been laid that helps not only to understand how depression works, but also how it can be treated. However, more research will be necessary to obtain a clearer picture of how this might work in humans.

Huge dust cloud discovered around the Moon -- but 'lunar glow' remains a mystery

Veiled beauty holds many secrets. MMT/Flickr, CC BY-SA

Astronauts on the early Apollo missions orbiting over to the dark side of the moon were surprised to discover a mysterious, bright crescent of light glowing at the horizon. The controversial explanation was sunlight scattered by dust high in the Moon’s tenuous atmosphere, but proof has been hard to come by. Fast forward half a century and, for the first time, a team of scientists has analysed the Moon’s atmospheric dust in real time, discovering a permanent dust cloud. Surprisingly, however, they have failed to explain the glow.

At 384,400 km away, the Moon is our nearest planetary neighbour. It is the only celestial body that humans have set foot on and has it provided a natural tool for understanding the origin of water on Earth, the physics of our Sun and for testing fundamental theories of physics. It has even been discussed as a possible alternative home for humanity.

Despite its proximity, there’s a lot we don’t know about the Moon – in particular about its atmosphere. The glow was first spotted in 1966 and 1968 by cameras onboard NASA’s Surveyer landers – the robotic precursors to manned Apollo landings. It has later been seen by astronauts on some Apollo missions, but not all.

The white area on the edge of the moon is the glow, and the bright dot at the top is the planet Venus. NASA

The team of scientists trying to understand the dust environment of the Moon, including the lunar glow, discovered a permanent, elongated cloud of dust around the Moon at heights between 10 to 260 km above the lunar surface using NASA’s Lunar Astmosphere and Dust Environment Explorer (LADEE) spacecraft. The authors argue that this cloud is caused by high-speed bombardment by dust particles from comets.

Interplanetary dust particles are thought to hit the surfaces of airless bodies in the solar system, generating charged and neutral gas clouds, as well as secondary dust particles that are ejected from the surface of the body on impact.

Clouds of dust particles, bound by gravitational forces, have been found around the icy moons of Jupiter and Saturn. But until now, none had been identified around rocky bodies with dusty surfaces such as the Earth, Moon and Mars.

Has lunar glow explanation turned to dust?

The gravitational pull of the Moon is approximately one-sixth of that of Earth, which is thought to be too weak to maintain a permanent and substantial atmosphere. Instead, the Moon has a tenuous layer of neutral gas called an exosphere. Debate over the presence of dust in that exosphere has raged ever since sightings of the lunar horizon glow during the Apollo era.

Ladee looking for answers NASA

The team behind the study used an instrument called the Lunar Dust Experiment (LDEX) designed to study the physical characteristics and origin of lunar dust over a period of time, including during meteoroid showers. It was developed to search for a high-density dust cloud that could account for the glow seen by the Apollo astronauts. With superior sensitivity and closer approach to the Moon than previous missions, LDEX recorded 140,000 dust hits at various altitudes from the lunar surface and for a range of dust particle sizes.

The team estimated the average total mass of the dust cloud to be 120kg. However, unlike the dust atmosphere’s of Jupiter’s moons, the lunar dust cloud is not evenly distributed or spherically symmetric. Instead, the authors found that the cloud is elongated in a way that matches the properties of the incoming interplanetary dust bombardment and indicates that comets are the dominant source of this dust rather than slower dust particles from asteroids.

The LADEE mission ended with its planned impact into the far side of the Moon in April 2014 at a speedy 3,600 miles per hour, destroying and probably vapourising it on impact.

Mysteries remain

For the origin of the glow seen on Apollo missions’, the team failed to find evidence of the relatively dense cloud of tiny dust particles lofted into the exosphere that would explain Apollo observations. In fact, the cloud the study recorded was 100 times less dense than the Apollo missions had predicted. Although disappointing for those seeking an explanation, this may be more positive for future human exploration missions or aspirations to use the Moon as a base for conducting sensitive astronomical observations, which require a clear view of the sky.

The result means that unless we want to dismiss the observations by the Apollo missions, we may need to re-assess our understanding of the conditions of the lunar surface and perhaps even the solar wind and resulting radiation field that was predicted to charge the dust and lift it into the atmosphere.