News Feeds

Though there are no firm plans for a crewed mission to Mars, we all know one’s coming. Astronauts routinely spend months at a time on the ISS, and we’ve learned a lot about the hazards astronauts face on long missions. However, Mars missions can take years, which presents a whole host of problems, including astronaut nutrition.

Nutrition can help astronauts manage spaceflight risks in the ISS, but long-duration missions to Mars are different. There can be no resupply.

In physiological terms, low gravity and radiation exposure are the two chronic hazards astronauts face on the ISS. Low gravity can lead to muscle loss and bone density loss, and radiation exposure increases the risk of developing cancer and other degenerative diseases. When astronauts make the trip to Mars, each leg of the journey can take 6 or 7 months, and they may stay on Mars for 500 days.

This dwarfs the eight days that the Apollo 11 astronauts spent in space. These long trips will tax astronauts’ health and NASA is working to understand what role nutrition can play in helping astronauts stay healthy and manage the risks.

Their current work on astronaut nutrition is a freely available PDF book titled “Human Adaptation to Spaceflight: The Role of Food and Nutrition—2nd Edition.” Its four authors are all researchers working in nutrition, biochemistry, biomedical research, space food systems, and preventative health.

“The importance of nutrition in exploration has been documented repeatedly throughout history, on voyages across oceans, on expeditions across polar ice, and on treks across unexplored continents,” the authors write.

Scientists have learned a lot about nutrition since the age of sailing and exploration, but the authors write that “a key difference between past journeys and space exploration is that astronauts are not likely to find food along the way.” This means that understanding astronaut nutritional requirements and food system requirements on long journeys is “as critical to crew safety and mission success as any of the mechanical systems of the spacecraft itself.”

The book examines the unique challenges astronauts face and presents data from multiple studies that are analogous to those challenges. For example, nutrition research from Antarctica duplicates the isolation and lack of sunlight astronauts can face on long missions, and head-down tilt-bed rest duplicates the musculoskeletal disuse they must endure.

This figure shows how HDT bed rest is used as an analogue for astronauts during long-duration microgravity spaceflight. Image Credit: Hargens AR et al. 2016.

Astronauts face a long list of health risks on long-duration spaceflights. Radiation exposure and its cancer risk and microgravity and its effect on muscle and bone are the most well-known risks. But there are other lesser-known risks, too.

Astronauts can suffer from neuro-ocular syndrome, their immune systems can be weakened, and their gut biota can change. All of these conditions are linked with nutrition. While scientists don’t have a complete understanding of how everything works, it’s clear that nutrition plays a role. The book outlines the types of research being done and what the current understanding is. But the authors are clear about one thing: the system of providing astronauts with proper nutrition needs work.

ISS astronauts, except for Russians, get part of their food in Crew Specific Menu (CSM) containers that each astronaut orders. They provide between 10% and 20% of their food. They also receive a small supply of fresh foods and limited shelf-life foods on each re-supply mission. This has increased the variety of foods for astronauts and helped with nutrition, but astronauts still say they’d like more CSM and fresh foods.

Here in the developed world on Earth, it’s fairly straightforward to meet nutritional needs. Most of us have access to supermarkets and/or farmer’s markets where we can buy fresh produce and other healthy foods. That same variety simply isn’t available in space. ISS astronauts have done some experimental “farming” and have successfully grown a few food plants like lettuce, kale, and cabbage. However, that’s a long way away from growing enough food to help with nutrition, especially on a Mars mission, where presumable space and payload will be at a premium.

Crops successfully grown in Veggie include lettuce, Swiss chard, radishes, Chinese cabbage and peas. Image Credit: NASA

One obvious question about astronaut nutrition is whether supplements can replace nutritious food. The authors present evidence that discredits that idea. “Many previous studies have shown that the complex synergistic benefits provided by whole foods cannot be replicated by supplements,” they write. In fact, in some instances, supplements can be dangerous. “Recent studies have also found that supplementation with certain antioxidants such as vitamin E and vitamin A can increase risks of cancer and all-cause mortality,” the authors explain.

The need for a space food system goes beyond nutrition. There are social and well-being benefits, too. Knowing that you have access to a variety of healthy foods keeps morale up. The ability to share or trade high-value food items with your fellow astronauts can create goodwill and a desire to cooperate. Think of sharing a meal with friends or family and all the social connection it provides.

According to the authors, there’s currently no solution to the nutrition roadblock for Mars missions. In fact, there’s currently no system designed to supply astronauts with the needed nutrition for any long-duration spaceflight. “Currently, no food system exists to meet the nutrition, acceptability, safety, and resource challenges of extended exploration missions, such as a mission to Mars,” the authors write.

However, the researchers say it’s critical that we develop one. Without it, long-duration missions and the astronauts who crew them will suffer and possibly face catastrophic failure.

“A space food system, developed and provisioned to deliver all the defined nutritional requirements, should be available on every human mission as an essential countermeasure to health and performance decrements,” the authors write.

The post Add Astronaut Nutrition to the List of Barriers to Long-Duration Spaceflight appeared first on Universe Today.

A typically fragile quantum superposition has been made to last exceptionally long, and could eventually be used as a probe for discovering new physics

Computer simulations of how influenza A moves through human mucus found it is ideally configured to slide through the sticky stuff on its way to infecting cells

In 1181, Japanese and Chinese astronomers saw a bright light appear in the constellation Cassiopeia. It shone for six months, and those ancient observers couldn’t have known it was an exploding star. To them, it looked like some type of temporary star that shone for 185 days.

In the modern astronomical age, we’ve learned a lot more about the object. It was a supernova called SN 1181 AD, and we know that it left behind a remnant “zombie” star. New research examines the supernova’s aftermath and the strange filaments of gas it left behind.

Though it was seen almost 850 years ago, only modern astronomers have been able to explain SN 1181. For a long time, it was an orphan. While astronomers were able to identify the modern remnants of many other historical supernovae, SN 1181 was stubborn. Finally, in 2013, amateur astronomer Dana Patchick discovered a nebula with a central star and named it Pa 30. Research in 2021 showed that Pa 30 is the remnant of SN 1181. The SN exploded when two white dwarfs merged and created a Type 1ax supernova.

SN 1181 is unusual. When supernovae explode, there’s usually only a black hole or a neutron star left as a remnant. But SN 1181 left part of a white dwarf behind, an intriguing object astronomers like to call a zombie star. Strange filaments resembling dandelion petals extend from this strange star, adding to the object’s mystery.

Researchers have gotten a new, close-up look at Pa 30 and published their results in The Astrophysical Journal Letters. The research is titled “Expansion Properties of the Young Supernova Type Iax Remnant Pa 30 Revealed.” The lead author is Tim Cunningham, a NASA Hubble Fellow at the Center for Astrophysics, Harvard & Smithsonian.

“The recently discovered Pa 30 nebula, the putative type Iax supernova remnant associated with the historical supernova of 1181 AD, shows puzzling characteristics that make it unique among known supernova remnants,” the authors write. Pa 30 has a complex morphology, including a “unique radial and filamentary structure.”

The hot stellar remnant at Pa 30’s center is also unique. Its presence, as well as the lack of hydrogen and helium in its filaments, indicates that it’s the result of a rare Type1ax supernova. Since hydrogen and helium make up 90% of the chemicals in the Universe, objects without either of them are immediately interesting.

In this research, the astronomers used the Keck Cosmic Imager Spectrograph (KCIS) to examine the 3D structure and the velocities of the filaments. The KCIS was built to observe the cosmic web, the intricate arrangement of gas, dust, and dark matter that makes up the large-scale structure of the Universe. The gas and dust are extremely dim, and the KCIS was made to perform spectroscopy on these types of low surface brightness phenomena. That makes it a powerful tool for observing the strange filaments coming from Pa 30.

KCIS is a powerful spectrograph that can capture spectral information for each pixel in an image. It can also measure the redshift and blueshift of objects it observes, meaning it can determine their velocity and direction of movement. The researchers were able to show that material in the filaments travelled ballistically at approximately 1,000 kilometres per second.

These three panels from the research are velocity maps of ionized sulphide emissions in Pa 30’s filaments. The upper panel shows the detected redshift and the middle panel shows the blueshift. The bottom panel is a combined velocity map for all the filaments. Image Credit: Cunningham et al. 2024.

“This means that the ejected material has not been slowed down, or sped up, since the explosion,” said lead author Cunningham. “Thus, from the measured velocities, looking back in time allowed us to pinpoint the explosion to almost exactly the year 1181.”

Pa 30 has some unusual features. It’s unusually asymmetrical, while most SN remnants are more spherical. Its filamentary structure displays significant variation in ejecta distribution along the line of sight. Some filaments are more prominent than others and extend further, creating an irregular and lopsided appearance. Some parts of the nebula are travelling at different speeds and in different directions. Elements in the nebula are also distributed unevenly. Iron, for example, is far more concentrated in some regions than others. All of these features suggest that the initial explosion mechanism was asymmetric and that the ejecta in the filaments stem from the initial explosion observed in 1181. Pa 30 also has a very sharp inner edge with an inner gap that surrounds the zombie star.

Two Wide-field Infrared Survey Explorer (WISE) images of Pa 30. The one on the right has the filaments overlain. The inner nebula is compact and surrounds the massive, hot, white dwarf zombie star. The outer nebula is characterized by the wispy filaments that extend out from the central region. Image Credit: Cunningham et al. 2024.

Many of Pa 30’s features suggest an asymmetric explosion as the cause. “The ejecta show a strong asymmetry in flux along the line of sight, which may hint at an asymmetric explosion,” the authors explain. The researchers found that the total flux from redshifted filaments is 40% higher than from blueshifted filaments. “This is tantalizing evidence for asymmetry in the explosion,” they write.

An asymmetric supernova explosion suggests that the underlying physics are complex. Rotation, complex magnetic fields, and the presence of a stellar companion can all contribute to asymmetry. Coupled with the unusually hot white dwarf left behind and its high-velocity stellar wind, the evidence suggests that it was a Type 1ax supernova.

That means the zombie star is likely the remnant of a failed thermonuclear explosion in a white dwarf. The white dwarf could have been just below the Chandrasekhar mass and not exploded completely. Or it could’ve been one of the theoretically possible but elusive super-Chandrasekhar mass white dwarfs. These objects are of great interest because they could be the cause of unusually bright supernovae. If Pa 30’s progenitor was a super-Chandrasekhar mass white dwarf, it could explain some of the remnant’s unusual characteristics.

“Our first detailed 3D characterization of the velocity and spatial structure of a supernova remnant tells us a lot about a unique cosmic event that our ancestors observed centuries ago. But it also raises new questions and sets new challenges for astronomers to tackle next,” said co-author Ilaria Caiazzo.

Some of the questions could be answered with more Keck Cosmic Imager Spectrograph IFU observations.

“Further IFU spectroscopic observations with wider coverage of the nebula will confirm if there exists a global asymmetry in the nebula ejecta, providing important constraints on dynamical models of the ejecta,” the authors conclude.

The post This Ancient Supernova Remnant Looks Like a Stellar Dandelion appeared first on Universe Today.

Lower cooling requirements, longer operating times, lower error rates: Quantum computers based on spin photons and diamond promise significant advantages over competing quantum computing technologies. The consortium of the BMBF project SPINNING coordinated by Fraunhofer IAF has succeeded in decisively advancing the development of spin-photon-based quantum computers.

Lower cooling requirements, longer operating times, lower error rates: Quantum computers based on spin photons and diamond promise significant advantages over competing quantum computing technologies. The consortium of the BMBF project SPINNING coordinated by Fraunhofer IAF has succeeded in decisively advancing the development of spin-photon-based quantum computers.

Researchers are finding new ways to make the hydrogen evolution reaction harder, better, faster, and stronger.

Researchers show that the improvements in signal strength during surface-enhanced fluorescence and Raman spectroscopy can extend even through a nanoscale protective layer. This research may lead to significant improvements in the sensitivity of biosensors and the development of novel point-of-care diagnostics.

In their peer-reviewed work, Calcea Johnson and Ne'Kiya Jackson present five new ways of proving Pythagoras' Theorem via trigonometry. They also detail a new method for finding proofs that yield at least five more.

Researchers have revealed the 3D structure of lab-made light-harvesting complex II (LHCII), a key component in photosynthesis. Using cryo-electron microscopy, they found that artificial LHCII closely mirrors the natural version, advancing research into solar energy harnessing and artificial photosynthesis technologies.

Researchers have invented a new way to align 3D semiconductor chips by shining a laser through concentric metalenses patterned on the chips to produce a hologram. Their work can help to lower the cost of producing 2D semiconductor chips, enable 3D photonic and electronic chips, and may pave the way for other low-cost, compact sensors.

The human genetic code is fully mapped out, providing scientists with a blueprint of the DNA to identify genomic regions and their variations responsible for diseases. Traditional statistical tools effectively pinpoint these genetic 'needles in the haystack,' yet they face challenges in understanding how many genes contribute to diseases, as seen in diabetes or schizophrenia.

Increasing amounts of data require storage, often for long periods. Synthetic polymers are an alternative to conventional storage media because they maintain stored information while using less space and energy. However, data retrieval by mass spectrometry limits the length and thus the storage capacity of individual polymer chains. Researchers have now introduced a method that overcomes this limitation and allows direct access to specific bits without reading the entire chain.

Increasing amounts of data require storage, often for long periods. Synthetic polymers are an alternative to conventional storage media because they maintain stored information while using less space and energy. However, data retrieval by mass spectrometry limits the length and thus the storage capacity of individual polymer chains. Researchers have now introduced a method that overcomes this limitation and allows direct access to specific bits without reading the entire chain.

Researchers have developed a new binarized neural network (BNN) scheme using ternary gradients to address the computational challenges of IoT edge devices. They introduced a magnetic RAM-based computing-in-memory architecture, significantly reducing circuit size and power consumption. Their design achieved near-identical accuracy and faster training times compared to traditional BNNs, making it a promising solution for efficient AI implementation in resource-limited devices, such as those used in IoT systems.

Improvements in three-dimensional (3D) scanning have enabled quick and accurate scanning of 3D objects, including cultural heritage objects, as 3D point cloud data. However, conventional edge-highlighting visualization techniques, used for understanding complex 3D structures, result in excessive line clutter, reducing clarity. Addressing these issues, a multinational team of researchers have developed a novel technique, involving independent rendering of soft and sharp edges in 3D structures, resulting in improved clarity and depth perception.

Improvements in three-dimensional (3D) scanning have enabled quick and accurate scanning of 3D objects, including cultural heritage objects, as 3D point cloud data. However, conventional edge-highlighting visualization techniques, used for understanding complex 3D structures, result in excessive line clutter, reducing clarity. Addressing these issues, a multinational team of researchers have developed a novel technique, involving independent rendering of soft and sharp edges in 3D structures, resulting in improved clarity and depth perception.

In earthquake-prone areas like Japan, there is a need for better prediction of soil stability to mitigate liquefaction risks. Towards this end, researchers have used machine learning models, including artificial neural networks and bagging techniques, to create accurate 3D maps of bearing layers using data from 433 locations in Setagaya, Tokyo. This approach can identify stable construction sites, enhance disaster planning, and contribute to safer urban development, making cities more resilient to liquefaction risks.

In earthquake-prone areas like Japan, there is a need for better prediction of soil stability to mitigate liquefaction risks. Towards this end, researchers have used machine learning models, including artificial neural networks and bagging techniques, to create accurate 3D maps of bearing layers using data from 433 locations in Setagaya, Tokyo. This approach can identify stable construction sites, enhance disaster planning, and contribute to safer urban development, making cities more resilient to liquefaction risks.

A team has developed a highly efficient alkaline membrane electrolyser that approaches the performance of established PEM electrolysers. What makes this achievement remarkable is the use of inexpensive nickel compounds for the anode catalyst, replacing costly and rare iridium.