Tag Archives: #dust

Measuring the Moon’s Nano Dust is No Small Matter (Planetary Science)

Like a chameleon of the night sky, the Moon often changes its appearance. It might look larger, brighter or redder, for example, due to its phases, its position in the solar system or smoke in Earth’s atmosphere. (It is not made of green cheese, however.)

Another factor in its appearance is the size and shape of moon dust particles, the small rock grains that cover the moon’s surface. Researchers at the National Institute of Standards and Technology (NIST) are now measuring tinier moon dust particles than ever before, a step toward more precisely explaining the Moon’s apparent color and brightness. This in turn might help improve tracking of weather patterns and other phenomena by satellite cameras that use the Moon as a calibration source.

NIST researchers and collaborators have developed a complex method of measuring the exact three-dimensional shape of 25 particles of moon dust collected during the Apollo 11 mission in 1969. The team includes researchers from the Air Force Research Laboratory, the Space Science Institute and the University of Missouri-Kansas City.

These researchers have been studying moon dust for several years. But as described in a new journal paper, they now have X-ray nano computed tomography (XCT), which allowed them to examine the shape of particles as small as 400 nanometers (billionths of a meter) in length.

The research team developed a method for both measuring and computationally analyzing how the dust particle shapes scatter light. Follow-up studies will include many more particles, and more clearly link their shape to light scattering. Researchers are especially interested in a feature called “albedo,” moonspeak for how much light or radiation it reflects.

The recipe for measuring the Moon’s nano dust is complicated. First you need to mix it with something, as if making an omelet, and then turn it on a stick for hours like a rotisserie chicken. Straws and dressmakers’ pins are involved too.

“The procedure is elaborate because it is hard to get a small particle by itself, but one needs to measure many particles for good statistics, since they are randomly distributed in size and shape,” NIST Fellow Ed Garboczi said.

“Since they are so tiny and because they only come in powders, a single particle needs to be separated from all the others,” Garboczi continued. “They are too small to do that by hand, at least not in any quantity, so they must be carefully dispersed in a medium. The medium must also freeze their mechanical motion, in order to be able to get good XCT images. If there is any movement of the particles during the several hours of the XCT scan, then the images will be badly blurred and generally not usable. The final form of the sample must also be compatible with getting the X-ray source and camera close to the sample while it rotates, so a narrow, straight cylinder is best.”

The procedure involved stirring the Apollo 11 material into epoxy, which was then dripped over the outside of a tiny straw to get a thin layer. Small pieces of this layer were then removed from the straw and mounted on dressmakers’ pins, which were inserted into the XCT instrument.

The XCT machine generated X-ray images of the samples that were reconstructed by software into slices. NIST software stacked the slices into a 3D image and then converted it into a format that classified units of volume, or voxels, as either inside or outside the particles. The 3D particle shapes were identified computationally from these segmented images. The voxels making up each particle were saved in separate files that were forwarded to software for solving electromagnetic scattering problems in the visible to the infrared frequency range.

The results indicated that the color of light absorbed by a moon dust particle is highly sensitive to its shape and can be significantly different from that of spherical or ellipsoidal particles of the same size. That doesn’t mean too much to the researchers — yet.

“This is our first look at the influence of actual shapes of lunar particles on light scattering and focuses on some fundamental particle properties,” co-author Jay Goguen of the Space Science Institute said. “The models developed here form the basis of future calculations that could model observations of the spectrum, brightness and polarization of the moon’s surface and how those observed quantities change during the moon’s phases.”

The authors are now studying a wider range of moon dust shapes and sizes, including particles collected during the Apollo 14 mission in 1971. The moon dust samples were loaned to NIST by NASA’s Curation and Analysis Planning Team for Extraterrestrial Materials program.

Featured image: Colorized screenshots of the exact shapes of moon dust collected during the Apollo 11 mission. NIST researchers and collaborators developed a method of measuring these nanoscale particles as a prelude to studying their light-scattering properties. © Credit: E. Garboczi/NIST and A. Sharits/AFRL

Paper: S. Baidya, M. Melius, A.M. Hassan, A. Sharits, A.N. Chiaramonti, T. Lafarge, J.D. Goguen and E.J. Garboczi. Optical Scattering Characteristics of 3D Lunar Regolith Particles Measured using X-Ray Nano Computed Tomography. IEEE Geoscience and Remote Sensing Letters. Published online April 27, 2021. DOI: 10.1109/LGRS.2021.3073344

Provided by NIST

Asteroid Dust Found in Crater Closes Case of Dinosaur Extinction (Geology / Paleontology)

Researchers believe they have closed the case of what killed the dinosaurs, definitively linking their extinction with an asteroid that slammed into Earth 66 million years ago by finding a key piece of evidence: asteroid dust inside the impact crater.

Death by asteroid rather than by a series of volcanic eruptions or some other global calamity has been the leading hypothesis since the 1980s, when scientists found asteroid dust in the geologic layer that marks the extinction of the dinosaurs. This discovery painted an apocalyptic picture of dust from the vaporized asteroid and rocks from impact circling the planet, blocking out the sun and bringing about mass death through a dark, sustained global winter – all before drifting back to Earth to form the layer enriched in asteroid material that’s visible today.

In the 1990s, the connection was strengthened with the discovery of a 125-mile-wide Chicxulub impact crater beneath the Gulf of Mexico that is the same age as the rock layer. The new study seals the deal, researchers said, by finding asteroid dust with a matching chemical fingerprint within that crater at the precise geological location that marks the time of the extinction.

The crater left by the asteroid that wiped out the dinosaurs is located in the Yucatán Peninsula. It is called Chicxulub after a nearby town. Part of the crater is offshore and part of it is on land. The crater is buried beneath many layers of rock and sediment. A 2016 mission led by the International Ocean Discovery Program extracted rock cores from the offshore portion of the crater. Credit: The University of Texas at Austin/Jackson School of Geosciences/ Google Map.

“The circle is now finally complete,” said Steven Goderis, a geochemistry professor at the Vrije Universiteit Brussel, who led the study published in Science Advances on Feb. 24.

The study is the latest to come from a 2016 International Ocean Discovery Program mission co-led by The University of Texas at Austin that collected nearly 3,000 feet of rock core from the crater buried under the seafloor. Research from this mission has helped fill in gaps about the impactthe aftermath and the recovery of life.

The telltale sign of asteroid dust is the element iridium – which is rare in the Earth’s crust, but present at elevated levels in certain types of asteroids. An iridium spike in the geologic layer found all over the world is how the asteroid hypothesis was born. In the new study, researchers found a similar spike in a section of rock pulled from the crater. In the crater, the sediment layer deposited in the days to years after the strike is so thick that scientists were able to precisely date the dust to a mere two decades after impact.

“We are now at the level of coincidence that geologically doesn’t happen without causation,” said co-author Sean Gulick, a research professor at the UT Jackson School of Geosciences who co-led the 2016 expedition with Joanna Morgan of Imperial College London. “It puts to bed any doubts that the iridium anomaly [in the geologic layer] is not related to the Chicxulub crater.”

Sean Gulick, a research professor at The University of Texas at Austin Jackson School of Geosciences (right), and Joanna Morgan, a professor at Imperial College London, examine rock cores retrieved from the crater during the 2016 research mission led by the International Ocean Discovery Program. Credit: The University of Texas at Austin/ Jackson School of Geosciences.

The dust is all that remains of the 7-mile-wide asteroid that slammed into the planet millions of years ago, triggering the extinction of 75% of life on Earth, including all nonavian dinosaurs.

Researchers estimate that the dust kicked up by the impact circulated in the atmosphere for no more than a couple of decades – which, Gulick points out, helps time how long extinction took.

“If you’re actually going to put a clock on extinction 66 million years ago, you could easily make an argument that it all happened within a couple of decades, which is basically how long it takes for everything to starve to death,” he said.

A section of rock core pulled from the crater left by the asteroid impact that wiped out the dinosaurs. Researchers found high concentrations of the element iridium –a marker for asteroid material –in the middle section of the core, which contains a mixture of ash from the impact and ocean sediment deposited over decades. The iridium is measured in parts per billion. Credit: International Ocean Discovery Program.

The highest concentrations of iridium were found within a 5-centimeter section of the rock core retrieved from the top of the crater’s peak ring – a high-elevation point in the crater that formed when rocks rebounded then collapsed from the force of impact.

The iridium analysis was carried out by labs in Austria, Belgium, Japan and the United States.

“We combined the results from four independent laboratories around the world to make sure we got this right,” said Goderis.

In addition to iridium, the crater section showed elevated levels of other elements associated with asteroid material. The concentration and composition of these “asteroid elements” resembled measurements taken from the geologic layer at 52 sites around the world.

The core section and geologic layer also have earthbound elements in common, including sulfurous compounds. A 2019 study found that sulfur-bearing rocks are missing from much of the rest of the core despite being present in large volumes in the surrounding limestone. This indicates that the impact blew the original sulfur into the atmosphere, where it may have made a bad situation worse by exacerbating global cooling and seeding acid rain.

Gulick and colleagues at the University of Texas Institute for Geophysics and Bureau of Economic Geology – both units of the UT Jackson School – plan to return to the crater this summer to begin surveying sites at its center, where they hope to plan a future drilling effort to recover more asteroid material.

Featured image: The asteroid impact led to the extinction of 75% of life, including all non-avian dinosaurs. Credit: Willgard Krause/Pixabay.

Reference: Steven Goderis, Honami Sato, Ludovic Ferrière, Birger Schmitz, David Burney, Pim Kaskes, Johan Vellekoop, Axel Wittmann, Toni Schulz, Stepan M. Chernonozhkin, Philippe Claeys, Sietze J. de Graaff, Thomas Déhais, Niels J. de Winter, Mikael Elfman, Jean-Guillaume Feignon, Akira Ishikawa, Christian Koeberl, Per Kristiansson, Clive R. Neal, Jeremy D. Owens, Martin Schmieder, Matthias Sinnesael, Frank Vanhaecke, Stijn J. M. Van Malderen, Timothy J. Bralower, Sean P. S. Gulick, David A. Kring, Christopher M. Lowery, Joanna V. Morgan, Jan Smit, Michael T. Whalen, IODP-ICDP Expedition 364 Scientists, “Globally distributed iridium layer preserved within the Chicxulub impact structure”, Science Advances 24 Feb 2021: Vol. 7, no. 9, eabe3647 DOI: 10.1126/sciadv.abe3647

Provided by University of Texas

Will Global Warming Bring a Change in the Winds? Dust From the Deep Sea Provides a Clue (Earth Science)

Westerlies moved poleward in the past, as they are doing now.

The westerlies–or westerly winds–play an important role in weather and climate both locally and on a global scale, by influencing precipitation patterns, impacting ocean circulation and steering tropical cyclones. So, finding a way to assess how they will change as the climate warms is crucial.

Image of a dust plume leaving China and crossing the Korean Peninsula and Japan. Researchers studied the dust deposited in ancient ocean sediments in order to understand how wind patterns in this area have shifted in the past. Their findings provide a better understanding of how the winds may change in the future. © SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

Typically, the westerlies blow from west to east across the planet’s middle latitudes. But scientists have noticed that over the last several decades, these winds are changing, migrating poleward. Research suggests this is because of climate change. But, scientists have been debating whether the poleward movement of the westerlies will continue as temperatures and atmospheric carbon dioxide (CO2) increase further under future warming scenarios. It’s been difficult to resolve this scientific question because our knowledge of the westerlies in past warm climates has until now been limited.

In a paper published January 6 in Nature, climate researchers from Columbia University’s Lamont-Doherty Earth Observatory describe a new method of tracking the ancient history of the westerly winds–a proxy for what we may experience in a future warming world. The lead author, Lamont graduate student Jordan Abell and his advisor, Gisela Winckler, developed a way to apply paleoclimatology–the study of past climate–to the question of the behavior of the westerly winds, and found evidence suggesting that atmospheric circulation patterns will change with climate warming.

The finding represents a breakthrough in our understanding of how the winds changed in the past, and how they may continue to change in the future.

Sediment cores like the one shown here, drilled from the bottom of the ocean, contain records of past climate conditions within their layers. Dust in cores collected by the research vessel JOIDES Resolution and stored at Texas A&M University helped to reveal changing patterns in the westerly winds. © Jordan Abell/Lamont-Doherty Earth Observatory

By using dust in ancient, deep sea sediments as an indirect tracer of wind, the researchers were able to reconstruct wind patterns that occurred three to five million years ago. Knowing that winds–in this case the westerlies–transport dust from desert regions to faraway locations, the authors examined cores from the North Pacific Ocean. This area is downwind from Eastern Asia, one of the largest dust sources today and a known dust-generating region for the past several million years. By measuring the dust in cores from two different sites thousands of kilometers apart, the researchers were able to map changes in dust, and in turn the westerly winds.

“We could immediately see the patterns. The data are so clear. Our work is consistent with modern observations, and suggests that wind patterns will change with climate warming,” said Abell.

They found that during the warm parts of the Pliocene (a period three to five million years ago, when the Earth was about two to four degrees Celsius warmer than today but had approximately the same concentration of CO2 in the air as we do now), the westerlies, globally, were located closer towards the poles than during the colder intervals afterwards.

The researchers found that during the warm parts of the Pliocene (3-5 million years ago), the westerlies were located closer to the poles. The image on the right shows how the westerlies moved toward the equator during colder intervals afterward. Recent observations indicate that as the planet warms due to climate change, the westerlies are once again shifting poleward. © Abell et al., Nature 2021

“By using the Pliocene as an analogue for modern global warming, it seems likely that the movement of the westerlies towards the poles observed in the modern era will continue with further human-induced warming,” explained Winckler.

The movement of these winds have huge implications for storm systems and precipitation patterns. And while this research does not indicate exactly where it will rain more or less, it confirms that the wind and precipitation patterns will change with climate warming.

“In the Earth history record, tracking down movements of wind and how they’ve changed, that’s been elusive because we didn’t have a tracer for it,” said Winckler. “Now we do.”

Provided by Earth Institute at Columbia University

Hubble Captured Lenticular Galaxy NGC 1947 (Cosmology / Astronomy)

Hubble Captured snapshot of an unusual lenticular galaxy, known as NGC 1947. The galaxy has lost almost all the gas and dust from its signature spiral arms, which used to orbit around its centre. Discovered almost 200 years ago by James Dunlop, a Scottish-born astronomer who later studied the sky from Australia, NGC 1947 can only be seen from the southern hemisphere, in the constellation Dorado (The Dolphinfish).

NGC 1947 Credit: ESA/Hubble & NASA, D. Rosario

Residing around 40 million light-years away from Earth, this galaxy shows off its structure by backlighting its remaining faint gas and dust disc with millions of stars. In this picture, taken with the NASA/ESA Hubble Space Telescope, the faint remnants of the galaxy’s spiral arms can still be made out in the stretched thin threads of dark gas encircling it. Without most of its star-forming material, it is unlikely that many new stars will be born within NGC 1947, leaving this galaxy to continue fading with time.

Provided by NASA

A Step Towards Understanding Cloud Mysteries (Geology)

In Geophysical Research Letters, the scientists from the Max Planck Institute for Dynamics and Self-Organization (MPIDS), Germany, and the Politecnico di Torino reported their new findings on how precipitating large raindrops, ice particles can favor growth of aerosols to produce new cloud condensation nuclei or ice nucleating particles.

Atmospheric clouds play a crucial role in defining the local weather and global climate. The activation of cloud aerosols, such as mineral dust, soot particles, pollutants, acid molecules and ions, impacts the life cycle of a cloud. Therefore, a detailed understanding is necessary for reliable climate prediction and weather forecasting. Out of many mysteries of clouds, we still do not understand how and why the number of ice particles inside clouds exceed the number of ice nucleating particles that could be activated. What are the major sources behind this excess (secondary) production of particles?

(Figure 1): Excess water vapor (S>0) behind a precipitating frozen hydrometeor at 0°C temperature falling through an ambient at -15°C and 90% relative humidity condition. An aerosol in black line can be seen to enter the water vapor rich environment.© Bhowmick et al.

In this letter, the scientists of MPIDS and POLITO have numerically investigated one such secondary particle production processes inside clouds resulting to new water droplets or ice particles. Out of several proposed physical processes for new droplet generation, recent experimental studies have shown that a large droplet can nucleate aerosols in the wake behind it when falling under gravity. Extending the experiments, this letter presents a detailed analysis of various physical factors that lead to an excess of water vapor behind the hydrometeors (e.g., droplets, sleet, or hail) and investigates the effectiveness of this process on activation of aerosols to create new cloud particles. This letter reports that not all aerosols, but only some “lucky aerosols” are entrained in the wake behind such precipitating hydrometeors, where they can reside in a highly humid environment for sufficiently long time. This fulfills the necessary condition for the aerosols to be activated as new cloud condensation nuclei or ice nucleating particles. This letter also reports how this activation of aerosols by hydrometeors can contribute to the life cycle of the clouds.

This study opened new potential research areas. According to TaraprasadBhowmick, PhD final year student of POLITO and scientist of MPIDS, “This letter marks a great achievement for us with new results, pointing towards the future studies relevant for cloud physics and climate sciences.

(Figure 2): A track of the excess water vapor that two aerosols experience when they entered the water vapor rich environment behind a precipitating frozen hydrometeor at 0°C temperature falling through an ambient at -15°C and 95% relative humidity condition. © Bhowmick et al.

This group of scientists from MPIDS are looking forward to extend this work with more realistic modeling of the cloud conditions, and plan to carry out a detailed growth tracking of individual aerosols that come in contact with such precipitating cloud hydrometeors.

References: Bhowmick, T., Wang, Y., Iovieno, M., Bagheri, G., & Bodenschatz, E.(2020). Supersaturation in the wake of a precipitating hydrometeor and its impact on aerosol activation. Geophysical Research Letters, 47, e2020GL091179. https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020GL091179 https://doi.org/10.1029/2020GL091179

Provided by Politecnico Di Torino

Quasars Rip Across Galaxies Like Tsunamis (Astronomy)

Using the unique capabilities of NASA’s Hubble Space Telescope, a team of astronomers has discovered the most energetic outflows ever witnessed in the universe. They emanate from quasars and tear across interstellar space like tsunamis, wreaking havoc on the galaxies in which the quasars live.

Image Credit: NASA, ESA and J. Olmsted (STScI)

This illustration shows a distant galaxy with an active quasar at its center. A quasar emits exceptionally large amounts of energy generated by a supermassive black hole fueled by infalling matter. Using the unique capabilities of Hubble, astronomers have discovered that blistering radiation pressure from the vicinity of the black hole pushes material away from the galaxy’s center at a fraction of the speed of light. The “quasar winds” are propelling hundreds of solar masses of material each year. This affects the entire galaxy as the material snowplows into surrounding gas and dust.

Provided by NASA

The Niels Bohr Institute Develops Calibration Target, Now On its Way to Mars (Planetary Science)

Researchers at the Niels Bohr Institute, University of Copenhagen, have developed a color reference for one of the cameras on NASA’s newest Mars mission, the robotic vehicle Perseverance. The vehicle, aka rover, has several cameras installed, but the atmospheric conditions on Mars change the colors recorded, depending on the amount of dust in the atmosphere and the time of acquisition of the photos. For these reasons the cameras need a reference in order to compare or calibrate its images accordingly. This reference has been developed and manufactured in a collaboration between the researchers, the workshop at the Niels Bohr Institute and local businesses, and supported by the Carlsberg Foundation.

The calibration target with color references and pictograms. The total height of the primary target is 45.5 mm (The vertical center, casting a shadow) while the base of the target fits inside a square with a side of 98 mm. Photo: NASA

The colors change on Mars and so does the possibility to compare recordings

“The calibration target consist of a small base, containing different, well-known ceramic color references”, Kjartan Kinch, Associate professor at the Niels Bohr Institute explains. “Obviously, we take a lot of pictures on Mars, and the camera on the rover can do a little more than your ordinary camera. It has different, so-called narrow-band color filters and can do more color analysis than yellow-red-green-blue. It can “see” UV light and move out into the infrared area as well. When you take a picture, it is the color of the photographed object times the color of the light which determines how we can “read” the photo. What happens is, quite simply, that the camera on the rover records a photo of e.g. rock formations and then, within half an hour or so, the camera turns to record a picture of the calibration target. When we have divided out the color of the light at the recording time, the picture is far more suited for comparison with earlier recordings or recordings from other areas. That is, in short, what our calibration target does”.

What is the purpose of the pictures of rocks and landscapes on Mars?

The rover has a robotic arm with a series of different instruments to investigate elements of the Martian surface. When a rock formation has been investigated for which elements and minerals it contains or other details, the pictures recorded of it can be used for comparison. So if this information is available – like the presence of a certain mineral in a single stone – and it is compared with pictures taken in a much wider perspective out into the landscape on Mars, it is possible to identify other rocks with similar properties of color – but obviously only if the pictures are read and interpreted correctly. Alternatively the camera can be used for identifying stones and rocks with dissimilar properties from former investigations. “If we have the detailed information from a single rock or a single area, we can check its color properties and assume that if the same color properties are present in the landscape, we shall find the same mineralogy here – we can expand detailed knowledge out into the landscape,” says Kjartan Kinch. “Moreover, our photographic information connects to observations from satellites and other instruments, precisely because we take pictures out into the landscape”.

The instrument is a further development of former calibration targets from the Niels Bohr Institute

The researchers and students from the Mars group have taken part in former missions and have improved on the instrument. Along the way a magnetic system, removing the ever present Martian dust from the color references has been developed, keeping the references as clean as possible. The dust on Mars is magnetic, so what started as an experiment on former missions has now become a built in element. “The aluminum base was designed and cut at the workshop of the Niels Bohr Institute, the magnets and ceramics ordered from international companies, the base was silvered and gold plated in Farum, engraved in Ishøj and the whole thing assembled in the Niels Bohr Institute clean room”, Kjartan Kinch explains.

Pictograms on the calibration target

The motto and pictograms seen on the Niels Bohr Institute target are made in collaboration with the team in the USA. There is a tiny stick protruding from the center casting a shadow, just like a solar watch. Solar watches traditionally have a motto, so the instrument was given one as well: “Two worlds, one beginning”. The pictograms show the development of life on Earth from bacterial life over plants and dinosaurs to people launching rockets into space. “It will be one of the most photographed objects on Mars, so we believed a decoration was justified”, Kjartan Kinch says.

The Mars mission Perseverance is part of a bigger mission to send samples back to Earth

This mission is in many ways similar to the very successful mission the rover Curiosity is still undertaking. It landed on Mars in 2012. The new rover is basically built using the same template. What’s new about Perseverance is that it will be covering another area than Curiosity and pick up samples from stones and rocks, later to be picked up by a collaborate ESA-NASA mission and sent back to Earth. So a set of samples from Mars are collected, hopefully telling us a lot about Mars later on. “But first we have to understand the landscape”, says Kjartan Kinch. We have to understand which locations are best suited for collecting samples, to gain maximum benefit from the mission. It is in this context we, at the Niels Bohr Institute, have contributed with a small, but important piece in a larger, scientific puzzle”.

Provided by University of Copenhagen Neil Bohr Institute

Bed Dust Microorganisms May Boost Children’s Health (Biology)

In the most extensive study of its kind, researchers from the University of Copenhagen, in collaboration with the Danish Pediatric Asthma Center at Herlev and Gentofte Hospital, have found a link between microorganisms living in the dust of children’s beds and the children’s own bacteria. The correlation suggests that microorganisms may reduce a child’s risk of developing asthma, allergies and autoimmune diseases later on in life.

From previous studies, the researchers also know that pets, older siblings and rural living also contribute to a lowered risk of developing autoimmune diseases. Photo: Gettyimages

Invisible to the human eye, our beds are teeming with microbial life. It is life that, especially during early childhood, can affect how microorganisms in our bodies develop, and thereby how resilient we become to various diseases.

To get a better grasp of this relationship, researchers at the University of Copenhagen’s Department of Biology and the Danish Pediatric Asthma Center analyzed bed dust samples from the beds of 577 infants before comparing them with respiratory samples from 542 children. It is the largest study of its kind, the aim of which was to determine which environmental factors affected the composition of microorganisms in the bed dust and if there was a correlation between bed dust microorganisms and the bacteria in the children’s airways.

“We see a correlation between the bacteria we find in bed dust and those we find in the children. While they are not the same bacteria, it is an interesting discovery that suggests that these bacteria affect each other. It may prove to have an impact on reducing asthma and allergy risks in later years,” explains Professor Søren J. Sørensen of UCPH’s Department of Biology.

Constant sheet changing may not be necessary

The science was already clear — a high diversity of microorganisms in the home contributes to the development of a child’s resistance to a host of diseases and allergies. Beds can be a central collector of bacteria, microscopic fungi and other microorganisms.

“We are well aware that microorganisms living within us are important for our health, with regards to asthma and allergies for example, but also for human diseases such as diabetes II and obesity. But to get better at treating these diseases, we need to understand the processes by which microorganisms emerge during our earliest stages of life. And, it seems that the bed plays a role,” says Søren J. Sørensen, adding:

“Microorganisms in a bed are affected by a dwelling’s surroundings, where high bacterial diversity is beneficial. The simple message is that constantly changing bedsheets may not be necessary, but we need to investigate this a bit more closely before being able to say so for sure.”

The benefits of rural life, pets and older siblings

A total of 930 different types of bacteria and fungi were found in the dust collected from the beds of the roughly six-month old children. The richness of bacteria depended largely upon the type of dwelling from which the sample was taken from.

Researchers studied both rural and urban dwellings. Rural homes had significantly higher levels of bacteria compared to urban apartments.

“Previous studies inform us that city-dwellers have less diverse gut flora than people who live in more rural settings. This is typically attributed to their spending greater amounts of time outdoors and having more contact with nature. Our studies demonstrate that changes in bacterial flora in bed dust can be an important reason for this difference as well,” says Søren J. Sørensen

From previous studies, the researchers also know that pets, older siblings and rural living also contribute to a lowered risk of developing autoimmune diseases.

The researchers’ next step is to investigate whether the differences in bacterial flora in bed dust can be correlated directly to the development of diseases such as allergies and asthma.

The research is published in the scientific journal Microbiome Journal 7 August 2020: https://microbiomejournal.biomedcentral.com/articles/10.1186/s40168-020-00895-w

Facts: * A total of 930 different types of bacteria were found in beds.
* Dust from the beds of 577 infants was examined along with respiratory samples from 542 children.
* The children were roughly six months old.

Provided by Faculty of Science- University of Copenhagen

Heat And Dust Help Launch Martian Water Into Space, Scientists Find (Planetary Science)

Scientists using an instrument aboard NASA’s Mars Atmosphere and Volatile EvolutioN, or MAVEN, spacecraft have discovered that water vapor near the surface of the Red Planet is lofted higher into the atmosphere than anyone expected was possible. There, it is easily destroyed by electrically charged gas particles — or ions — and lost to space.

This graph shows how the amount of water in the atmosphere of Mars varies depending on the season. During global and regional dust storms, which happen during southern spring and summer, the amount of water spikes. ©University of Arizona/Shane Stone/NASA Goddard/Dan Gallagher

Researchers said that the phenomenon they uncovered is one of several that has led Mars to lose the equivalent of a global ocean of water up to hundreds of feet (or up to hundreds of meters) deep over billions of years. Reporting on their finding on Nov. 13 in the journal Science, researchers said that Mars continues to lose water today as vapor is transported to high altitudes after sublimating from the frozen polar caps during warmer seasons.

“We were all surprised to find water so high in the atmosphere,” said Shane W. Stone, a doctoral student in planetary science at the University of Arizona’s Lunar and Planetary Laboratory in Tucson. “The measurements we used could have only come from MAVEN as it soars through the atmosphere of Mars, high above the planet’s surface.”

To make their discovery, Stone and his colleagues relied on data from MAVEN’s Neutral Gas and Ion Mass Spectrometer (NGIMS), which was developed at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. The mass spectrometer inhales air and separates the ions that comprise it by their mass, which is how scientists identify them.

Stone and his team tracked the abundance of water ions high over Mars for more than two Martian years. In doing so, they determined that the amount of water vapor near the top of the atmosphere at about 93 miles, or 150 kilometers, above the surface is highest during summer in the southern hemisphere. During this time, the planet is closest to the Sun, and thus warmer, and dust storms are more likely to happen.

The warm summer temperatures and strong winds associated with dust storms help water vapor reach the uppermost parts of the atmosphere, where it can easily be broken into its constituent oxygen and hydrogen. The hydrogen and oxygen then escape to space. Previously, scientists thought that water vapor was trapped close to the Martian surface like it is on Earth.

“Everything that makes it up to the higher part of the atmosphere is destroyed, on Mars or on Earth,” Stone said, “because this is the part of the atmosphere that is exposed to the full force of the Sun.”

This illustration shows how water is lost on Mars normally vs. during regional or global dust storms. ©NASA/Goddard/CI Lab/Adriana Manrique Gutierrez/Krysrofer Kim

The researchers measured 20 times more water than usual over two days in June 2018, when a severe global dust storm enveloped Mars (the one that put NASA’s Opportunity rover out of commission). Stone and his colleagues estimated Mars lost as much water in 45 days during this storm as it typically does throughout an entire Martian year, which lasts two Earth years.

“We have shown that dust storms interrupt the water cycle on Mars and push water molecules higher in the atmosphere, where chemical reactions can release their hydrogen atoms, which are then lost to space,” said Paul Mahaffy, director of the Solar System Exploration Division at NASA Goddard and principal investigator of NGIMS.

Other scientists have also found that Martian dust storms can lift water vapor far above the surface. But nobody realized until now that the water would make it all the way to the top of the atmosphere. There are abundant ions in this region of the atmosphere that can break apart water molecules 10 times faster than they’re destroyed at lower levels.

“What’s unique about this discovery is that it provides us with a new pathway that we didn’t think existed for water to escape the Martian environment,” said Mehdi Benna, a Goddard planetary scientist and co-investigator of MAVEN’s NGIMS instrument. “It will fundamentally change our estimates of how fast water is escaping today and how fast it escaped in the past.”

Provided by NASA Goddard