Kepler telescope glimpses population of free-floating planets

Tantalising evidence has been uncovered for a mysterious population of "free-floating" planets, planets that may be alone in deep space, unbound to any host star. The results include four new discoveries that are consistent with planets of similar masses to Earth, published today in Monthly Notices of the Royal Astronomical Society.

The study, led by Iain McDonald of the University of Manchester, UK, (now based at the Open University, UK) used data obtained in 2016 during the K2 mission phase of NASA's Kepler Space Telescope. During this two-month campaign, Kepler monitored a crowded field of millions of stars near the centre of our Galaxy every 30 minutes in order to find rare gravitational microlensing events.

The study team found 27 short-duration candidate microlensing signals that varied over timescales of between an hour and 10 days. Many of these had been previously seen in data obtained simultaneously from the ground. However, the four shortest events are new discoveries that are consistent with planets of similar masses to Earth.

These new events do not show an accompanying longer signal that might be expected from a host star, suggesting that these new events may be free-floating planets. Such planets may perhaps have originally formed around a host star before being ejected by the gravitational tug of other, heavier planets in the system.

Predicted by Albert Einstein 85 years ago as a consequence of his General Theory of Relativity, microlensing describes how the light from a background star can be temporarily magnified by the presence of other stars in the foreground. This produces a short burst in brightness that can last from hours to a few days. Roughly one out of every million stars in our Galaxy is visibly affected by microlensing at any given time, but only a few percent of these are expected to be caused by planets.

Kepler was not designed to find planets using microlensing, nor to study the extremely dense star fields of the inner Galaxy. This meant that new data reduction techniques had to be developed to look for signals within the Kepler dataset.

Iain notes: "These signals are extremely difficult to find. Our observations pointed an elderly, ailing telescope with blurred vision at one the most densely crowded parts of the sky, where there are already thousands of bright stars that vary in brightness, and thousands of asteroids that skim across our field. From that cacophony, we try to extract tiny, characteristic brightenings caused by planets, and we only have one chance to see a signal before it's gone. It's about as easy as looking for the single blink of a firefly in the middle of a motorway, using only a handheld phone."

Co-author Eamonn Kerins of the University of Manchester also comments, "Kepler has achieved what it was never designed to do, in providing further tentative evidence for the existence of a population of Earth-mass, free-floating planets. Now it passes the baton on to other missions that will be designed to find such signals, signals so elusive that Einstein himself thought that they were unlikely ever to be observed. I am very excited that the upcoming ESA Euclid mission could also join this effort as an additional science activity to its main mission."

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Mystery of heavy elements in galactic cosmic rays

Scientists have used data from the Southwest Research Institute-led Magnetospheric Multiscale (MMS) mission to explain the presence of energetic heavy elements in galactic cosmic rays (GCRs). GCRs are composed of fast-moving energetic particles, mostly hydrogen ions called protons, the lightest and most abundant elements in the universe. Scientists have long debated how trace amounts of heavy ions in GCRs are accelerated.

The supernova explosion of a dying star creates massive shockwaves that propagate through the surrounding space, accelerating ions in their path to very high energies, creating GCRs. How heavy ions are energized and accelerated is important because they affect the redistribution of mass throughout the universe and are essential for the formation of even heavier and more chemically complex elements. They also influence how we perceive astrophysical structures.

"Heavy ions are thought to be insensitive to an incoming shockwave because they are less abundant, and the shock energy is overwhelmingly consumed by the preponderance of protons. Visualize standing on a beach as waves move the sand under your feet, while you remain in place," said SwRI's Dr. Hadi Madanian, the lead author of the paper about this research published in Astrophysical Journal Letters. "However, that classical view of how heavy ions behave under shock conditions is not always what we have seen in high-resolution MMS observations of the near-Earth space environment."

Shock phenomena also occur in the near-Earth environment. The Sun's magnetic field is carried through interplanetary space by the supersonic solar wind flow, which is obstructed and diverted by the Earth's magnetosphere, a bubble of protection around our home planet. This interaction region is called the bow shock due to its curved shape, comparable to the bow waves that occur as a boat travels through water. The Earth's bow shock forms at a much smaller scale than supernova shocks. However, at times, conditions of this small shock resemble those of supernova remnants. The team used high-resolution in-situ measurements from the MMS spacecraft at the bow shock to study how heavy ions are accelerated.

"We observed intense amplification of the magnetic field near the bow shock, a known property associated with strong shocks such as supernova remnants. We then analyzed how different ion species behaved as they encountered the bow shock," Madanian said. "We found that these enhanced fields significantly modify the trajectory of heavy ions, redirecting them into the acceleration zone of the shock."

While this behavior was not expected to occur for heavy ions, the team identified direct evidence for this process in alpha particles, helium ions that are four times more massive than protons and have twice the charge.

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Neanderthal artists? Bones decorated over 50,000 years ago

Since the discovery of the first fossil remains in the 19th century, the image of the Neanderthal has been one of a primitive hominin. People have known for a long time that Neanderthals were able to effectively fashion tools and weapons. But could they also make ornaments, jewellery or even art? A research team led by the University of Göttingen and the Lower Saxony State Office for Heritage has analysed a new find from the Unicorn Cave (Einhornhöhle) in the Harz Mountains. The researchers conclude that, in fact, Neanderthals, genetically the closest relative to modern humans, had remarkable cognitive abilities. The results of the study were published in Nature Ecology and Evolution.

Working with the Unicornu Fossile society, the scientists have been carrying out new excavations at the Unicorn Cave in the Harz Mountains since 2019. For the first time, they succeeded in uncovering well-preserved layers of cultural artefacts from the Neanderthal period in the cave's ruined entrance area. Among the preserved remains from a hunt, an inconspicuous foot bone turned out to be a sensational discovery. After removing the soil sticking to the bone, an angular pattern of six notches was revealed. "We quickly realised that these were not marks made from butchering the animal but were clearly decorative," says the excavation leader Dr Dirk Leder of the Lower Saxony State Office for Heritage. The carved notches could then be analysed with 3D microscopy at the Department of Wood Biology and Wood Products at Göttingen University.

To make a scientific comparison, the team carried out experiments with the foot bones of today's cattle. They showed that the bone probably had to be boiled first in order to carve the pattern into the softened bone surface with stone tools and the work would take about 1.5 hours. The small ancient foot bone that had been discovered was identified as coming from a giant deer (Megaloceros giganteus). "It is probably no coincidence that the Neanderthal chose the bone of an impressive animal with huge antlers for his or her carving," says Professor Antje Schwalb from the Technical University of Braunschweig, who is involved in the project.

The team of Leibniz laboratory at Kiel University dated the carved bone at over 51,000 years using radiocarbon dating technology. This is the first time that anyone has successfully directly dated an object that must have been carved by Neanderthals. Until now, a few ornamental objects from the time of the last Neanderthals in France were known. However, these finds, which are about 40,000 years old, are considered by many to be copies of pendants made by anatomically modern humans because by this time they had already spread to parts of Europe. Decorative objects and small ivory sculptures have survived from cave sites of modern humans on the Swabian Alb in Baden-Württemberg and these were found at about the same time.

"The fact that the new find from the Unicorn Cave dates from so long ago shows that Neanderthals were already able to independently produce patterns on bones and probably also communicate using symbols thousands of years before the arrival of modern humans in Europe," says project leader Professor Thomas Terberger from Göttingen University's Department for Prehistory and Early History, and the Lower Saxony State Office for Heritage. "This means that the creative talents of the Neanderthals must have developed independently. The bone from the Unicorn Cave thus represents the oldest decorated object in Lower Saxony and one of the most important finds from the Neanderthal period in Central Europe."

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Memory making involves extensive DNA breaking

The urgency to remember a dangerous experience requires the brain to make a series of potentially dangerous moves: Neurons and other brain cells snap open their DNA in numerous locations -- more than previously realized, according to a new study -- to provide quick access to genetic instructions for the mechanisms of memory storage.

The extent of these DNA double-strand breaks (DSBs) in multiple key brain regions is surprising and concerning, said study senior author Li-Huei Tsai, Picower Professor of Neuroscience at MIT and director of The Picower Institute for Learning and Memory, because while the breaks are routinely repaired, that process may become more flawed and fragile with age. Tsai's lab has shown that lingering DSBs are associated with neurodegeneration and cognitive decline and that repair mechanisms can falter.

"We wanted to understand exactly how widespread and extensive this natural activity is in the brain upon memory formation because that can give us insight into how genomic instability could undermine brain health down the road," said Tsai, who is also a professor in the Department of Brain and Cognitive Sciences and a leader of MIT's Aging Brain Initiative. "Clearly memory formation is an urgent priority for healthy brain function but these new results showing that several types of brain cells break their DNA in so many places to quickly express genes is still striking."

Tracking breaks

In 2015, Tsai's lab provided the first demonstration that neuronal activity caused DSBs and that they induced rapid gene expression. But those findings, mostly made in lab preparations of neurons, did not capture the full extent of the activity in the context of memory formation in a behaving animal and did not investigate what happened in cells other than neurons.

In the new study published July 1 in PLOS ONE, lead author and former graduate student Ryan Stott and co-author and former research technician Oleg Kritsky sought to investigate the full landscape of DSB activity in learning and memory. To do so, they gave mice little electrical zaps to the feet when they entered a box, to condition a fear memory of that context. They then used several methods to assess DSBs and gene expression in the brains of the mice over the next half hour, particularly among a variety of cell types in the prefrontal cortex and hippocampus, two regions essential for the formation and storage of conditioned fear memories. They also made measurements in the brains of mice who did not experience the foot shock to establish a baseline of activity for comparison.

The creation of a fear memory doubled the number of DSBs among neurons in the hippocampus and the prefrontal cortex, affecting more than 300 genes in each region. Among 206 affected genes common to both regions, the researchers then looked at what those genes do. Many were associated with the function of the connections neurons make with each other, called synapses. This makes sense because learning arises when neurons change their connections (a phenomenon called "synaptic plasticity") and memories are formed when groups of neurons connect together into ensembles called engrams.

"Many genes essential for neuronal function and memory formation, and significantly more of them than expected based on previous observations in cultured neurons...are potentially hotspots of DSB formation," the authors wrote in the study.

In another analysis, the researchers confirmed through measurements of RNA that the increase in DSBs indeed correlated closely with increased transcription and expression of affected genes, including ones affecting synapse function, as quickly as 10-30 minutes after the foot shock exposure.

"Overall, we find transcriptional changes are more strongly associated with [DSBs] in the brain than anticipated," they wrote. "Previously we observed 20 gene-associated [DSB] loci following stimulation of cultured neurons, while in the hippocampus and prefrontal cortex we see more than 100-150 gene associated [DSB] loci that are transcriptionally induced."

Snapping with stress

In the analysis of gene expression, the neuroscientists looked at not only neurons but also non-neuronal brain cells, or glia, and found that they also showed changes in expression of hundreds of genes after fear conditioning. Glia called astrocytes are known to be involved in fear learning, for instance, and they showed significant DSB and gene expression changes after fear conditioning.

Among the most important functions of genes associated with fear conditioning-related DSBs in glia was the response to hormones. The researchers therefore looked to see which hormones might be particularly involved and discovered that it was glutocortocoids, which are secreted in response to stress. Sure enough, the study data showed that in glia, many of the DSBs that occurred following fear conditioning occurred at genomic sites related to glutocortocoid receptors. Further tests revealed that directly stimulating those hormone receptors could trigger the same DSBs that fear conditioning did and that blocking the receptors could prevent transcription of key genes after fear conditioning.

Tsai said the finding that glia are so deeply involved in establishing memories from fear conditioning is an important surprise of the new study.

"The ability of glia to mount a robust transcriptional response to glutocorticoids suggest that glia may have a much larger role to play in the response to stress and its impact on the brain during learning than previously appreciated," she and her co-authors wrote.

Damage and danger?

More research will have to be done to prove that the DSBs required for forming and storing fear memories are a threat to later brain health, but the new study only adds to evidence that it may be the case, the authors said.

"Overall we have identified sites of DSBs at genes important for neuronal and glial functions, suggesting that impaired DNA repair of these recurrent DNA breaks which are generated as part of brain activity could result in genomic instability that contribute to aging and disease in the brain," they wrote.

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Astronomers discover an oversized black hole population in the star cluster Palomar 5

Palomar 5 is a unique star cluster. This is firstly because it is one of the "fluffiest" clusters in the halo of our Galaxy, with the average distance between the stars being a few light-years, comparable to the distance from the Sun to the nearest star. Secondly, it has a specular stellar stream associated with it that spans more than 20 degrees across the sky. In a paper published today in Nature Astronomy, an international team of astronomers and astrophysicists led by the University of Barcelona show that both distinguishing features of Palomar 5 are likely the result of an oversized black hole population of more than 100 black holes in the center of the cluster.

"The number of black holes is roughly three times larger than expected from the number of stars in the cluster, and it means that more than 20% of the total cluster mass is made up of black holes. They each have a mass of about 20 times the mass of the Sun, and they formed in supernova explosions at the end of the lives of massive stars, when the cluster was still very young" says Prof Mark Gieles, from the Institute of Cosmos Sciences of the University of Barcelona (ICCUB) and lead author of the paper.

Tidal streams are streams of stars that were ejected from disrupting star clusters or dwarf galaxies. In the last few years, nearly thirty thin streams have been discovered in the Milky Way halo. "We do not know how these streams form, but one idea is that they are disrupted star clusters. However, none of the recently discovered streams have a star cluster associated with them, hence we can not be sure. So, to understand how these streams formed, we need to study one with a stellar system associated with it. Palomar 5 is the only case, making it a Rosetta Stone for understanding stream formation and that is why we studied it in detail" explains Gieles.

The authors simulate the orbits and the evolution of each star from the formation of the cluster until the final dissolution. They varied the initial properties of the cluster until a good match with observations of the stream and the cluster was found. The team finds that Palomar 5 formed with a lower black hole fraction, but stars escaped more efficiently than black holes, such that the black hole fraction gradually increased. The black holes dynamically puffed up the cluster in gravitational slingshot interactions with stars, which led to even more escaping stars and the formation of the stream. Just before it completely dissolves -- roughly a billion years from now -- the cluster will consist entirely of black holes. "This work has helped us understand that even though the fluffy Palomar 5 cluster has the brightest and longest tails of any cluster in the Milky Way, it is not unique. Instead, we believe that many similarly puffed up, black hole-dominated clusters have already disintegrated in the Milky Way tides to form the recently discovered thin stellar streams" says co-author Dr. Denis Erkal at the University of Surrey.

Gieles points out that in this paper "we have shown that the presence of a large black hole population may have been common in all the clusters that formed the streams." This is important for our understanding of globular cluster formation, the initial masses of stars and the evolution of massive stars. This work also has important implications for gravitational waves. "It is believed that a large fraction of binary black hole mergers form in star clusters. A big unknown in this scenario is how many black holes there are in clusters, which is hard to constrain observationally because we can not see black holes. Our method gives us a way to learn how many BHs there are in a star cluster by looking at the stars they eject.'', says Dr. Fabio Antonini from Cardiff University, a co-author of the paper.

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Solving a long-standing mystery about the desert's rock art canvas

Wander around a desert most anywhere in the world, and eventually you'll notice dark-stained rocks, especially where the sun shines most brightly and water trickles down or dew gathers. In some spots, if you're lucky, you might stumble upon ancient art -- petroglyphs -- carved into the stain. For years, however, researchers have understood more about the petroglyphs than the mysterious dark stain, called rock varnish, in which they were drawn.

In particular, science has yet to come to a conclusion about where rock varnish, which is unusually rich in manganese, comes from.

Now, scientists at the California Institute of Technology, the Department of Energy's SLAC National Accelerator Laboratory and elsewhere think they have an answer. According to a recent paper in Proceedings of the National Academy of Sciences, rock varnish is left behind by microbial communities that use manganese to defend against the punishing desert sun.

The mystery of rock varnish is old, said Usha Lingappa, a graduate student at Caltech and the study's lead author. "Charles Darwin wrote about it, Alexander von Humboldt wrote about it," she said, and there is a long-standing debate about whether it has a biological or inorganic origin.

But, Lingappa said, she and her colleagues didn't actually set out to understand where rock varnish comes from. Instead, they were interested in how microbial ecosystems in the desert interact with rock varnish. To do so, they deployed as many techniques as they could come up with: DNA sequencing, mineralogical analyses, electron microscopy, and -- aided by Stanford Synchroton Radiation Lightsource (SSRL) scientist Samuel Webb -- advanced X-ray spectroscopy methods that could map different kinds of manganese and other elements within samples of rock varnish.

"By combining these different perspectives, maybe we could draw a picture of this ecosystem and understand it in new ways," Lingappa said. "That's where we started, and then we just stumbled into this hypothesis" for rock varnish formation.

Among the team's key observations was that, while manganese in desert dust is usually in particle form, it was deposited in more continuous layers in varnish, a fact revealed by X-ray spectroscopy methods at SSRL that can tell not only what chemical compounds make up a sample but also how they are distributed, on a microscopic scale, throughout the sample.

That same analysis showed that the kinds of manganese compounds in varnish were the result of ongoing chemical cycles, rather than being left out in the sun for millennia. That information, combined with the prevalence of bacteria called Chroococcidiopsis that use manganese to combat the oxidative effects of the harsh desert sun, led Lingappa and her team to conclude that rock varnish was left behind by those bacteria.

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Being clean and hygienic need not impair childhood immunity

The theory that modern society is too clean, leading to defective immune systems in children, should be swept under the rug, according to a new study by researchers at UCL and the London School of Hygiene & Tropical Medicine.

In medicine, the 'hygiene hypothesis' states that early childhood exposure to particular microorganisms protects against allergic diseases by contributing to the development of the immune system.

However, there is a pervading view (public narrative) that Western 21st century society is too hygienic, which means toddlers and children are likely to be less exposed to germs in early life and so become less resistant to allergies.

In this paper, published in the Journal of Allergy and Clinical Immunology, researchers point to four significant reasons which, they say, disprove this theory and conclude we are not "too clean for our own good."

Lead author, Emeritus Professor of Medical Microbiology Graham Rook (UCL Infection & Immunity), said: "Exposure to microorganisms in early life is essential for the 'education' of the immune and metabolic systems.

"Organisms that populate our guts, skin and airways also play an important role in maintaining our health right into old age: so throughout life we need exposure to these beneficial microorganisms, derived mostly from our mothers, other family members and the natural environment.

"But for more than 20 years there has been a public narrative that hand and domestic hygiene practices, that are essential for stopping exposure to disease-causing pathogens, are also blocking exposure to the beneficial organisms.

"In this paper, we set out to reconcile the apparent conflict between the need for cleaning and hygiene to keep us free of pathogens, and the need for microbial inputs to populate our guts and set up our immune and metabolic systems."

In a review of evidence, the researchers point to four factors.
 

• Firstly, the microorganisms found in a modern home are, to a significant degree, not the ones that we need for immunity.
• Secondly, vaccines, in addition to protecting us from the infection that they target, do a lot more to strengthen our immune systems, so we now know that we do not need to risk death by being exposed to the pathogens.
• Thirdly, we now have concrete evidence that the microorganisms of the natural green environment are particularly important for our health; domestic cleaning and hygiene have no bearing on our exposure to the natural environment.
• Finally, recent research demonstrates that when epidemiologists find an association between cleaning the home and health problems such as allergies, this is often not caused by the removal of organisms, but rather by exposure of the lungs to cleaning products that cause a type of damage that encourages the development of allergic responses.

Professor Rook added: "So cleaning the home is good, and personal cleanliness is good, but, as explained in some detail in the paper, to prevent spread of infection it needs to be targeted to hands and surfaces most often involved in infection transmission. By targeting our cleaning practices, we also limit direct exposure of children to cleaning agents.

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More filling? Tastes great? How flies, and maybe people, choose their food

Flies have discriminating taste. Like a gourmet perusing a menu, they spend much of their time seeking sweet nutritious calories and avoiding bitter, potentially toxic food. But what happens in their brains when they make these food choices?

Yale researchers discovered an interesting way to find out. They tricked them.

In a study that could also help illuminate how people make food choices, the researchers gave hungry fruit flies the choice between sweet, nutritious food laced with bitter quinine and a less sweet, but not bitter, food containing fewer calories. Then, using neuroimaging, they tracked neural activity in their brains as they made these tough choices.

So which won? Calories or better taste?

"It depends on how hungry they are," said Michael Nitabach, professor of cellular and molecular physiology, genetics, and neuroscience at Yale School of Medicine and senior author of the study. "The hungrier they are, the more likely they will tolerate bitter taste to obtain more calories."

But the real answer to how flies make these decisions is a little more complex, according to the study published July 5 in the journal Nature Communications.

According to the research team, led by Preeti Sareen, associate research scientist at Yale, flies relay sensory information to a portion of their brain called the fan-shaped body, where signals are integrated, triggering what amounts to the insect version of an executive decision. The researchers found that patterns of neuronal activity in the fan-shaped body change adaptively when novel food choices are introduced, which dictates the fly's decision over what food to eat.

But researchers went a step further. And things got even stranger. They found they could change a fly's choice by manipulating neurons in areas of the brain that feed into the fan-shaped body. For example, when they caused a decrease in activity in the neurons involved in metabolism, the found that it made hungry flies choose the lower calorie food.

"It is one big feedback loop, not just top-down decision making," Nitabach said.

And this is where there are connections to food choices of humans, he said. Neural activity in both a fly's brain and a human's brain are regulated by the secretion of neuropeptides and the neurotransmitter dopamine, which in humans helps regulate sensations of reward. Changes in this network may alter how the brain responds to different types of food. In other words, neurochemistry may sometimes dictate food choices we think we are making consciously.

"The study provides a template to understand how it is that things like hunger and internal emotional states influence our behavior," Nitabach said.

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Why does Mercury have such a big iron core? Magnetism!

A new study disputes the prevailing hypothesis on why Mercury has a big core relative to its mantle (the layer between a planet's core and crust). For decades, scientists argued that hit-and-run collisions with other bodies during the formation of our solar system blew away much of Mercury's rocky mantle and left the big, dense, metal core inside. But new research reveals that collisions are not to blame -- the sun's magnetism is.

William McDonough, a professor of geology at the University of Maryland, and Takashi Yoshizaki from Tohoku University developed a model showing that the density, mass and iron content of a rocky planet's core are influenced by its distance from the sun's magnetic field. The paper describing the model was published on July 2, 2021, in the journal Progress in Earth and Planetary Science.

"The four inner planets of our solar system -- Mercury, Venus, Earth and Mars -- are made up of different proportions of metal and rock," McDonough said. "There is a gradient in which the metal content in the core drops off as the planets get farther from the sun. Our paper explains how this happened by showing that the distribution of raw materials in the early forming solar system was controlled by the sun's magnetic field."

McDonough previously developed a model for Earth's composition that is commonly used by planetary scientists to determine the composition of exoplanets. (His seminal paper on this work has been cited more than 8,000 times.)

McDonough's new model shows that during the early formation of our solar system, when the young sun was surrounded by a swirling cloud of dust and gas, grains of iron were drawn toward the center by the sun's magnetic field. When the planets began to form from clumps of that dust and gas, planets closer to the sun incorporated more iron into their cores than those farther away.

The researchers found that the density and proportion of iron in a rocky planet's core correlates with the strength of the magnetic field around the sun during planetary formation. Their new study suggests that magnetism should be factored into future attempts to describe the composition of rocky planets, including those outside our solar system.

The composition of a planet's core is important for its potential to support life. On Earth, for instance, a molten iron core creates a magnetosphere that protects the planet from cancer-causing cosmic rays. The core also contains the majority of the planet's phosphorus, which is an important nutrient for sustaining carbon-based life.

Using existing models of planetary formation, McDonough determined the speed at which gas and dust was pulled into the center of our solar system during its formation. He factored in the magnetic field that would have been generated by the sun as it burst into being and calculated how that magnetic field would draw iron through the dust and gas cloud.

As the early solar system began to cool, dust and gas that were not drawn into the sun began to clump together. The clumps closer to the sun would have been exposed to a stronger magnetic field and thus would contain more iron than those farther away from the sun. As the clumps coalesced and cooled into spinning planets, gravitational forces drew the iron into their core.

When McDonough incorporated this model into calculations of planetary formation, it revealed a gradient in metal content and density that corresponds perfectly with what scientists know about the planets in our solar system. Mercury has a metallic core that makes up about three-quarters of its mass. The cores of Earth and Venus are only about one-third of their mass, and Mars, the outermost of the rocky planets, has a small core that is only about one-quarter of its mass.

This new understanding of the role magnetism plays in planetary formation creates a kink in the study of exoplanets, because there is currently no method to determine the magnetic properties of a star from Earth-based observations. Scientists infer the composition of an exoplanet based on the spectrum of light radiated from its sun. Different elements in a star emit radiation in different wavelengths, so measuring those wavelengths reveals what the star, and presumably the planets around it, are made of.

"You can no longer just say, 'Oh, the composition of a star looks like this, so the planets around it must look like this,'" McDonough said. "Now you have to say, 'Each planet could have more or less iron based on the magnetic properties of the star in the early growth of the solar system.'"

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Smart technology is not making us dumber

There are plenty of negatives associated with smart technology -- tech neck, texting and driving, blue light rays -- but there is also a positive: the digital age is not making us stupid, says University of Cincinnati social/behavioral expert Anthony Chemero.

"Despite the headlines, there is no scientific evidence that shows that smartphones and digital technology harm our biological cognitive abilities," says the UC professor of philosophy and psychology who recently co-authored a paper stating such in Nature Human Behaviour.

In the paper, Chemero and colleagues at the University of Toronto's Rotman School of Management expound on the evolution of the digital age, explaining how smart technology supplements thinking, thus helping us to excel.

"What smartphones and digital technology seem to do instead is to change the ways in which we engage our biological cognitive abilities," Chemero says, adding "these changes are actually cognitively beneficial."

For example, he says, your smart phone knows the way to the baseball stadium so that you don't have to dig out a map or ask for directions, which frees up brain energy to think about something else. The same holds true in a professional setting: "We're not solving complex mathematical problems with pen and paper or memorizing phone numbers in 2021."

Computers, tablets and smart phones, he says, function as an auxiliary, serving as tools which are good at memorization, calculation and storing information and presenting information when you need it.

Additionally, smart technology augments decision making skills that we would be hard pressed to accomplish on our own, says the paper's lead author Lorenzo Cecutti, a PhD candidate at the University of Toronto. Using GPS technology on our phones, he says, can not only help us get there, but lets us choose a route based on traffic conditions. "That would be a challenging task when driving round in a new city."

Chemero adds: "You put all this technology) together with a naked human brain and you get something that's smarter...and the result is that we, supplemented by our technology, are actually capable of accomplishing much more complex tasks than we could with our un-supplemented biological abilities."

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