Tag Archives: radiation

Scientists Might Have Unraveled the Mystery of Uranus’ Radiation Belts

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In 1986, NASA’s Voyager 2 conducted the sole direct measurement of Uranus’ radiation environment. These findings revealed a well-recognized system characterized by a weak ion emission band and an unexpectedly strong electron emission band. Nevertheless, these observations might not have been taken under standard conditions. A recent study by scientists at the Southwest Research Institute compared Voyager 2’s data with comparable phenomena on Earth. Their findings, in conjunction with a new interpretation of the Voyager 2 flyby, suggest that the interaction of solar wind with Uranus’ magnetosphere may have amplified electromagnetic waves, enabling electrons to reach relativistic speeds. This opens new avenues for exploration at Uranus and emphasizes the necessity for missions orbiting the planet.

Allen et al. The researchers compared the effects on space weather of the high-speed solar wind structures that caused intense solar storms on Earth in 2019 (first panel) (second panel) with conditions observed on Uranus by Voyager 2 in 1986 (third panel), revealing a potential solution to a 39-year-old mystery regarding the extreme radiation belts discovered. Image credit: SwRI.

In 1986, during its unique flyby of Uranus, Voyager 2 recorded unexpectedly high levels of electron emission bands.

These electron emission belts were surprising, based on extrapolations from other planetary systems.

Since then, scientists have puzzled over how Uranus could maintain such a tightly constrained electron emission belt, making it distinct from other planets in the solar system.

Robert Allen and his colleagues from the Southwest Research Institute hypothesize that the observations made by Voyager 2 might closely resemble processes occurring on Earth due to significant solar wind storms.

They propose that a solar wind structure, known as a corotating interaction region, was traversing the Uranus system at that time.

This accounts for the exceptionally high energy levels detected by Voyager 2.

“Science has progressed significantly since Voyager 2’s flyby,” stated Dr. Allen.

“We aimed to analyze the Voyager 2 data in relation to Earth observations gathered in the years that followed.”

A recent study indicates that during Voyager 2’s mission, the Uranian system may have undergone a space weather event that triggered powerful radio frequency waves—the most intense recorded throughout Voyager 2’s journey.

“In 1986, scientists believed these waves would dissipate and scatter the electrons within Uranus’ atmosphere,” Dr. Allen noted.

“However, they have come to understand that under specific conditions, these same waves can accelerate electrons and contribute additional energy to the planetary system.”

“In 2019, Earth experienced a similar event that resulted in a significant acceleration of radiation belt electrons,” said Sarah Vines from the Southwest Research Institute.

“If a comparable mechanism interacted with the Uranus system, it would explain the unexpected additional energy observed by Voyager 2.”

Nonetheless, these revelations also raise numerous questions regarding the fundamental physics and the sequence of events that allow the emission of such powerful waves.

“This underscores the importance of launching a mission focused on Uranus,” Dr. Allen emphasized.

“This discovery also holds significant implications for analogous star systems like Neptune.”

The results are published in the journal Geophysical Research Letters.

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RC Allen et al. 2025. Unraveling the mystery of Uranus’ electron radiation belts: Using insights from Earth’s radiation belts to reassess Voyager 2 observations. Geophysical Research Letters 52 (22): e2025GL119311; doi: 10.1029/2025GL119311

Source: www.sci.news

Challenging Thermal Radiation Limits May Lead to Improved Solar Cell Technology

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By manipulating fundamental physics, researchers can enhance energy-harvesting devices like solar cells

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Researchers have challenged long-standing principles of physics, paving the way for more efficient energy harvesting technologies, such as solar cells.

Linxiao Zhu from Penn State University has aimed to break Kirchov’s law of thermal radiation for nearly ten years. Established in the 1800s, this law states that the amount of thermal radiation emitted by an object is proportional to the heat it absorbs, linking to the fundamental principles of thermodynamics. Historically, it was believed that these constraints were absolute.

“In standard physics literature, it’s indicated that Kirchov’s law is a fundamental requirement of the second law of thermodynamics. However, this is not entirely accurate,” explains Zhu.

Previous breaches of this law were seen, but only concerning specific wavelengths of radiation. Zhu and his team have achieved a more significant departure from the norm.

This breakthrough required two significant elements: precisely structured materials and magnetic fields. Both the arrangement of the material and the magnetic environment play crucial roles in the behavior of the particles making up the radiation, like photons, and the energy they carry.

The researchers developed thin-layered semiconductors from indium, gallium, and arsenides, meticulously organizing the atoms. They positioned this setup near a strong electromagnet, illuminating it with lights of various colors at distinct temperatures, angles, and magnetic field strengths.

This combination of material structure and ongoing magnetic influence led to a significant disparity between the radiation absorbed and emitted—up to 43% more radiation was released than was originally absorbed. Zhu attributes this phenomenon to the presence of multiple colors of light. This characteristic is particularly beneficial since sunlight comprises a mixture of colors when hitting solar cell devices.

Aaswath Raman from UCLA indicates that this trial is a major advancement toward turning previously theoretical concepts into reality. He remarks that the stark difference between absorbed and emitted radiation is “a significant breakthrough.”

While novel materials can enhance the efficiency of light and heat-absorbing devices, the requirement for magnetic fields presents challenges. However, Raman remains optimistic about the emergence of new materials that display magnetic properties without requiring proximity to magnets, which could resolve these issues through innovative electromagnetic techniques.

Source: www.newscientist.com

Research: Squid Evolved 100 Million Years Ago and Experienced Rapid Radiation

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Paleontologists have adopted a cutting-edge digital fossil mining technique to examine over 250 fossil beaks from 40 ancient squid species. The findings indicate that there is no prolonged slow-moving change associated with the slower parietal layer, previously linked to the mass extinction event of late white matter around 66 million years ago. Early squid species had already established large populations, surpassing the biomass of both ammonites and fish. They evolved into intelligent and agile swimmers, contributing to modern marine ecosystems.

This lithograph features Loligo Forbesii, a squid species from the order Myopsida. Image credit: Comingio Mercuriano.

Squid are recognized as the most diverse and widely distributed group of marine cephalopods in today’s oceans, serving a crucial role in marine ecosystems as both predators and prey.

Their evolutionary success is generally attributed to the loss of a rigid external shell, a significant characteristic of their parietal ancestors.

Yet, their evolutionary beginnings remain unclear due to the scarcity of fossils from soft-bodied organisms.

The fossil record for squid dates back around 45 million years, with most specimens discovered consisting of fossilized statoris, or small calcium carbonites that assist in balance.

The early absence of such fossils has led to hypotheses that squid diversified following the mass extinctions during the Cretaceous period, approximately 66 million years ago.

Molecular studies of living squid species provide estimates regarding their divergence times; however, these estimates have become increasingly uncertain because of the dearth of prior fossil evidence.

In this recent study, Shin Ikegami, a paleontologist from Hokkaido University, and colleagues addressed these deficiencies using high-resolution grinding tomography and advanced image processing to digitally scan rocks as layered cross-sectional images, effectively revealing hidden 3D models.

This method was applied to Cretaceous carbonate rocks in Japan, resulting in the discovery of 263 fossilized squid beaks from 40 species across 23 genera and five families.

Results indicate that squid emerged around the boundaries of the early and late Cretaceous, roughly 100 million years ago, followed by a rapid diversification.

The authors assert that this newly uncovered fossil record significantly extends the documented origins of the two main squid groups: oegopsida extending back about 15 million years and myopsida extending as far back as 55 million years.

Early oegopsids showcased unique anatomical features that later species lacked, hinting at rapid morphological evolution, whereas Myopsids already displayed modern characteristics.

This study further indicates that late Cretaceous squids were more populous and often larger than their contemporaneous ammonite and bony fish counterparts. This ecological dominance might have triggered the radiation of bony fish and marine mammals roughly 30 million years ago, establishing squid as the first intelligent and agile swimmers that shaped modern marine ecosystems.

“In terms of population and size, these ancient squids were evidently proliferating across the oceans,” stated Dr. Ikenakamoto.

“Their body size rivaled that of fish, often even surpassing the ammonites found alongside them.”

“This demonstrates that squid thrived as the most abundant swimmers in the ancient seas.”

“These discoveries revolutionize our understanding of marine ecosystems in the past,” remarked Dr. Yasuhiro Iba from Hokkaido University.

“Squids were likely the pioneers of fast, intelligent swimmers that dominated the modern ocean.”

Study published in the journal Science.

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Shin Ikegami et al. 2025. The origin and radiation of squid revealed by digital fossil mining. Science E 388 (6754): 1406-1409; doi: 10.1126/science.adu6248

Source: www.sci.news

Radiation Risks Faced by Ancient Humans 41,000 Years Ago

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Magnetic field turbulence may have allowed aurora to occur more widely 41,000 years ago

evgeniyq/istockphoto/get ty image

About 41,000 years ago, Earth’s magnetic fields became weaker to only a few modern levels, with a significant increase in radiation impacting the planet’s surface. Some researchers suggest that while the Lasshamps event may have driven Neanderthals to extinction, as is known, modern humans may have protected themselves using tailored clothing and ochre sunscreen.

Earth’s magnetic field spreads out into space and acts as a protective shield against harmful radiation. Magnetic poles usually line up at the North and Antarctic, but sometimes wander due to changes in the planet’s liquid outer core.

“This system variation can lead to variations in the strength and direction of the Earth’s magnetic field, such as those observed during the Laschamps event,” he says. Agnit Mukhopadhyay At the University of Michigan.

By studying magnetic features preserved in volcanic rocks and sediments, Mukopadiyai and his colleagues created a detailed 3D reconstruction of the Earth’s magnetic field during the Raschamp event.

They found evidence that the magnetic pole shifted towards the equator, making the field strength weaker to 10% of today’s levels.

Auroras made by charged particles are usually only visible near the poles, but this will change during the Laschamp event. “The aurora can be seen in a much larger area, perhaps even near the equator,” says Mukopadhyai.

The weakened magnetic field could have allowed more sun and cosmic radiation to reach the Earth’s surface, changing the climate of the region. “These environmental changes may have encouraged adaptive behavior in human populations, including increased use of protective clothing for UV shields and ochre,” says Mukhopadhyay.

Researchers argue that the production of tailored clothing and the use of reddish mineral ochre as sunscreen may have been given Homo sapiens Benefits for Neanderthals who are thought to have become extinct during this period.

“There is definitely a rough overlap in terms of timing between the ancient modern invasion of Europe and the events of Las Shampus,” he says. Amy Mosig Way At the Australian Museum in Sydney. “But it is probably stretch to say that modern humans are better sunscreen in the form of tailored clothing than Neanderthals, and that’s probably what it is to say that this contributed to the ability to travel even further than the Neanderthals and subsequent Eurasian rule.”

Veronica Wowl Yale University says there is evidence of ancients who used ochre at this time. For example, the Ethiopian PORC-EPIC site records ochre use 45,000 years ago, which she says was enhanced 40,000 years ago. They may have used it for other reasons such as creating sunscreen and artwork and adhesives.

Ladis Laf Neyman JCMM in the Czech Republic says it is not known whether modern humans have used ochre as sunscreen. “If that were the case, it could have protected them more, but it didn’t necessarily save them,” he says. “Europeans were really piling up against them at the time.”

He points out that the Raschamp event coincided with a very cold period known as Heinrich Event 4 and a massive volcanic eruption in Italy called the Campania Ignimbrite Explosion.

“The big advantage Homo sapiens What they had as a species compared to Neanderthals was that they had a large population of other people living in Africa and elsewhere. Homo sapiens After these events, we may move to Europe,” says Neyman.

topic:

  • Ancient humans/
  • Earth Science

Source: www.newscientist.com

Ionizing radiation from nearby supernovae impacted the evolution of the virus 2.5 million years ago

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This supernova event may have occurred at the Upper Centaurus Lupus Society. This is a group of giant stars about 457 light years away from Earth.

Illustration of an exoplanet like Earth after X-ray radiation exposure. Image credit: NASA/CXC/M. Weiss.

Life on Earth is constantly evolving under continuous exposure to ionizing radiation from both terrestrial and cosmic origins.

The radioactivity in the bedrock gradually decreases over timescales of billions of years, but the level of cosmic radiation fluctuates as the solar system moves through the Milky Way.

Nearby supernova activity could increase the level of radiation on the Earth’s surface by several orders of magnitude, which is expected to have a major impact on the evolution of life.

In particular, radiation levels improve as the solar system passes near a large group of stars known as the OB Association.

The winds associated with these large star factories are expected to inflate the super bubbles of high temperature plasma first. This could be the birthplace of most of the Core Collapse explosions taking place within the AB Association.

The solar system entered such a super bubble, commonly known as the local bubble, about 6 million years ago, and is now close to its centre.

“The Earth entered the local bubble and passed its stardust-rich appearance about 6.5 million years ago, sowing the planet with old iron 60, the radioactive iron of iron produced by the exploding stars. did it,” astronomer Santa Cruz, and colleagues at the University of California.

“Then, 20-3 million years ago, one of our neighboring stars exploded with incredible force, providing another cohort of radioactive iron to the planet.”

When Nojiri and her co-authors simulated what the supernova looked like, they discovered that it hammered the Earth with cosmic rays for 100,000 years of explosion.

This model perfectly described previously recorded spikes of radiation that shocked the Earth around that time.

“We’ve seen from other papers that radiation can damage DNA,” Nojiri said.

“It could be an evolutionary change in the cell or an accelerated mutation.”

Meanwhile, the author came across research into viral diversity in one of the Rift Valley Lakes in Africa.

“I can’t say they’re connected, but there are similar time frames,” Nojiri said.

“We found it interesting that the virus’s diversification is increasing.”

study It was published in Astrophysics Journal Letter.

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Caitlyn Nojiri et al. 2025. Bubble Life: How nearby supernova left short-lived marks on the cosmic ray spectrum, leaving an indelible trace of life. apjl 979, L18; doi: 10.3847/2041-8213/ADA27A

Source: www.sci.news

Recent studies uncover the mechanisms by which Deinococcus bacteria can survive high levels of radiation

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called radiation-resistant bacteria Deinococcus radiodurans It can withstand radiation doses thousands of times higher than what would kill a human. The secret behind this resistance is the existence of a collection of simple metabolites that combine with manganese to form a powerful antioxidant. Now, Northwestern University professor Brian Hoffman and his colleagues have discovered how this antioxidant works.

Deinococcus radiodurans. Image credit: USU/Michael Daly.

First discovered in 1956, Deinococcus radiodurans It is one of the most radiation-resistant organisms known.

It was isolated in an experiment aimed at determining whether high doses of gamma rays could be used to sterilize canned food.

In a new study, Professor Hoffman and co-authors characterized a synthetic designer antioxidant called MDP. Deinococcus radiodurans'Resilience.

They show that the components of MDP, manganese ions, phosphates, and small peptides, form a ternary complex that is a much more powerful protector from radiation damage than when manganese is combined with other individual components alone. I discovered that.

This discovery could ultimately lead to new synthetic antioxidants specifically tailored to human needs.

Applications include protecting astronauts from intense space radiation during deep space missions, preparing for radiation emergencies, and producing radiation-inactivated vaccines.

“This ternary complex is MDP's excellent shield against the effects of radiation,” said Professor Hoffman.

“It has long been known that manganese ions and phosphates together make a powerful antioxidant, but now we discover and understand the 'magical' potency brought about by the addition of a third ingredient. That's a breakthrough.”

“This study provided the key to understanding why this combination is such a powerful and promising radioprotector.”

In a previous study, researchers found that: Deinococcus radiodurans It can withstand 25,000 Grays (or units of X-rays and gamma rays).

But in a 2022 study, Professor Hoffmann and his team found that this bacterium, when dried and frozen, can withstand 140,000 Gy of radiation, 28,000 times the dose that would kill humans. did.

Therefore, if there are dormant frozen microbes buried on Mars, they may have survived the onslaught of galactic cosmic radiation and solar protons to this day.

In an effort to understand radioresistance in microorganisms, researchers investigated a designer decapeptide called DP1.

When combined with phosphate and manganese, DP1 forms the free radical scavenger MDP, which protects cells and proteins from radiation damage.

Professor Michael Daly, from Uniformed Services University, said: “This new understanding of MDP could lead to the development of even more powerful manganese-based antioxidants with applications in areas such as medicine, industry, defense and space exploration. Yes,” he said.

of result will appear in Proceedings of the National Academy of Sciences.

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Hao Yang others. 2024. A ternary complex of Mn2+, synthetic decapeptide DP1 (DEHGTAVMLK), and orthophosphate is an excellent antioxidant. PNAS 121 (51): e2417389121;doi: 10.1073/pnas.2417389121

Source: www.sci.news

Newly discovered species reveals secrets of tardigrade radiation resistance

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Newly discovered tardigrade species using genome, transcriptome and proteome analysis Hypsibius henanensis scientists investigated the molecular basis that contributes to radioresistance in these small invertebrates.

Schematic diagram of the mechanism conferring radiation resistance Hypsibius henanensis. Image credit: Li others., doi: 10.1126/science.adl0799.

Tardigrades, also known as tardigrades or moss piglets, are a diverse group of microscopic invertebrates famous for their ability to withstand extreme conditions.

First discovered in 1773, these organisms can live for up to 60 years, grow up to 0.5 mm in size, and are best seen under a microscope.

They can survive in temperatures as low as -272 degrees Celsius (-457 degrees Fahrenheit) or as hot as 150 degrees Celsius (302 degrees Fahrenheit), and temperatures as low as -20 degrees Celsius for several minutes, and for up to 30 years without food or water. Masu. Minus 4 degrees Celsius (minus 4 degrees Fahrenheit) continues for decades.

It can withstand pressures from virtually 0 atmospheres in outer space to 1,200 atmospheres at the bottom of the Mariana Trench.

They also exhibit excellent resistance to ionizing radiation, withstanding doses of gamma rays as high as 3,000 to 5,000 grays (Gy), approximately 1,000 times the lethal dose for humans.

The mechanism of radioresistance in tardigrades remains largely unknown.

Previous studies investigating how they do this have shown that tardigrades have powerful DNA repair abilities.

They also express tardigrade-specific proteins called damage suppressors (Dsup), when expressed in human cells, protects DNA from radiation damage.

In a new study, Lei Li and colleagues at Qingdao University describe a new species of tardigrade. Hypsibius henanensis.

Through detailed morphological and molecular analyses, they also investigated the basis of radioresistance in this species.

The researchers evaluated how exposure to heavy ion beams changes the molecular profiles of animals. They found that 285 stress-related genes were upregulated.

They further uncovered three molecular mechanisms that contribute to radioresistance in organisms.

First, the horizontally transferred bacterial gene DOPA dioxygenase 1 (Doda 1) enhanced radiation resistance by producing betalains (pigments with powerful free radical scavenging properties commonly found in plants, fungi, and bacteria).

Second, proteins unique to tardigrades, TDP1promotes DNA double-strand break repair.

Finally, mitochondrial chaperone genes BCS1Proliferated during the evolution of tardigrades, it is uniquely upregulated in response to radiation and protects cells from radiation-induced mitochondrial damage.

“The extreme environmental tolerance of extremophiles such as tardigrades provides a treasure trove of unexplored molecular mechanisms of stress tolerance,” the authors write.

“Functional studies of these radioresistance mechanisms may further expand our understanding of cell survival under extreme conditions and provide inspiration for promoting human health and fighting disease.”

of result Published in the Journal on October 25, 2024 science.

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Ray Lee others. 2024. The multi-omic landscape of tardigrades and the molecular basis of radioresistance. science 386 (6720);doi: 10.1126/science.adl0799

Source: www.sci.news

Astronomers Propose that X-ray and Ultraviolet Radiation Impact the Protoplanetary Disk in Cygnus OB2

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Cygnus OB2 is the giant young stellar association closest to the Sun.

In this new composite image, Chandra data (purple) shows the diffuse X-ray emission and young stars of Cygnus OB2, along with infrared data (red, green, blue, cyan) from NASA's now-retired Spitzer Space Telescope reveals young stars. And it creates cold dust and gas throughout the region. Image credits: NASA / CXC / SAO / Drake others. / JPL-California Institute of Technology / Spitzer / N. Walk.

At a distance of approximately 1,400 parsecs (4,600 light years), Cygnus OB2 It is a huge young body closest to the Sun.

It contains hundreds of double stars and thousands of low-mass stars.

Dr. Mario Giuseppe Guarcero of the National Institute of Astrophysics, Dr. Juan Facundo Albacete Colombo of the University of Rio Negro, and colleagues used NASA's Chandra X-ray Observatory to study various regions of Cygnus OB2. observed.

This deep observation mapped the diffuse X-ray glow between the stars and also provided an inventory of young stars within the cluster.

This inventory was combined with other inventories using optical and infrared data to create the best survey of young stars within the association.

“These dense stellar environments are home to large amounts of high-energy radiation produced by stars and planets,” the astronomers said.

“X-rays and intense ultraviolet radiation can have devastating effects on planetary disks and systems that are in the process of forming.”

The protoplanetary disk around the star naturally disappears over time. Part of the disk falls onto the star, and some is heated by X-rays and ultraviolet light from the star and evaporates in the wind.

The latter process, known as photoevaporation, typically takes 5 million to 10 million years for an average-sized star to destroy its disk.

This process could be accelerated if there is a nearby massive star that produces the most X-rays and ultraviolet light.

researchers Found Clear evidence that protoplanetary disks around stars actually die out much faster when they approach massive stars that produce large amounts of high-energy radiation.

Also, in regions where stars are more densely packed, the disk dies out faster.

In the region of Cygnus OB2, which has less high-energy radiation and fewer stars, the proportion of young stars with disks is about 40%.

In regions with higher-energy radiation and more stars, the proportion is about 18%.

The strongest influence, and therefore the worst location for a star to become a potential planetary system, is within about 1.6 light-years of the most massive star in the cluster.

In another study, the same team I looked into it Characteristics of the diffuse X-ray emission of Cygnus OB2.

They discovered that the high-energy, diffuse radiation originates from regions where winds of gas blown from massive stars collide with each other.

“This causes the gas to become hot and generate X-rays,” the researchers said.

“The low-energy release is likely caused by gas within the cluster colliding with gas surrounding the cluster.”

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MG Guarcero others. 2024. Photoevaporation and close encounters: How does the environment around Cygnus OB2 affect the evolution of the protoplanetary disk? APJS 269, 13; doi: 10.3847/1538-4365/acdd67

JF Albacete vs Colombo others. 2024. Diffuse X-ray emission in the Cygnus OB2 coalition. APJS 269, 14;doi: 10.3847/1538-4365/acdd65

Source: www.sci.news

JUICE captures unprecedented image of Earth’s radiation belts

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In August 2024, ESA’s Jupiter ICy satellite probe (JUICE) made history with its daring Moon-to-Earth flight and double-gravity assisted maneuver. When the spacecraft passed the moon and the home planet, NASA’s Jupiter’s energetic neutrons and ions The (JENI) instrument aboard JUICE has captured the clearest images yet of Earth’s radiation belts, belts of charged particles trapped in Earth’s magnetosphere.

The center of this infographic shows the clearest image yet of a cloud of charged particles trapped in Earth’s magnetic field, and the inset shows high-energy images detected along JUICE’s flight path. Measurements of ions and electrons are shown. Image credit: ESA / NASA / Johns Hopkins APL / Josh Diaz.

“The moment we saw the clear new image, the whole room erupted in high-fives,” said Dr. Matina Goukiuridou, JENI deputy director at the Johns Hopkins University Applied Physics Laboratory.

“It was clear that we had captured the giant ring of hot plasma surrounding Earth in unprecedented detail, and this result has sparked excitement about what’s to come on Jupiter.”

Unlike traditional cameras that rely on light, JENI uses special sensors to capture high-energy neutral atoms emitted by charged particles that interact with hydrogen gas in the widespread atmosphere surrounding Earth. Masu.

The JENI instrument is the latest generation of this type of camera and builds on the success of similar instruments in NASA’s Cassini mission, which revealed the magnetospheres of Saturn and Jupiter.

August 19th, JENI and its companion particle measuring instrument Jupiter’s energetic electrons (JoEE) made the most of his brief 30-minute encounter with the moon.

As JUICE zoomed just 750 km (465 miles) above the lunar surface, the instrument collected data about the space environment and its interactions with our closest celestial companion star.

Scientists expect this interaction to be magnified and observed on Jupiter’s moons as the gas giant’s radiation-rich magnetosphere passes over them.

On August 20, JUICE entered Earth’s magnetosphere, passing approximately 60,000 km (37,000 miles) over the Pacific Ocean. There, the instruments experienced for the first time the harsh environment that awaits them on Jupiter.

As JoEE and JENI raced through the magnetic tail, they encountered the dense, low-energy plasma typical of the region before plunging into the heart of the radiation belt.

There, instruments measured the millions of degrees of plasma surrounding Earth to investigate the secrets of plasma heating, which is known to drive dramatic phenomena in planetary magnetospheres.

“We couldn’t have expected a better flyby,” said Dr. Pontus Brandt, principal investigator for JoEE and JENI at the Johns Hopkins University Applied Physics Laboratory.

“The wealth of data we have obtained from our deep dive into the magnetosphere is amazing. JENI’s image of the entire system that we just flew was simply the best.”

“This is a powerful combination to leverage in the Jupiter system.”

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This article has been adapted from the original release by NASA.

Source: www.sci.news

Researchers develop 3D radiation map of Jupiter’s moons

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Using data collected by the Advanced Stellar Compass (ASC) and Stellar Reference Unit (SRU) on NASA’s Juno spacecraft, scientists have created the first complete 3D radiation map of the Jupiter system. The map characterizes the intensity of high-energy particles near the orbit of the icy moon Europa and shows how the radiation environment is shaped by small moons orbiting close to Jupiter’s rings.

This diagram shows a model of radiation intensity at different points on the Juno spacecraft’s orbit around Jupiter. Image credit: NASA / JPL-Caltech / DTU.

“With Juno, we’ve been trying to invent new ways to use sensors to learn about nature, and we’ve been using many of our science instruments in ways that were not originally intended,” said Juno principal investigator Dr. Scott Bolton, a planetary scientist at the Southwest Research Institute.

“This is the first detailed radiation map of this high-energy region and marks a major step forward in understanding how Jupiter’s radiation environment works.”

“It’s significant that we’ve been able to map this area in detail for the first time, because we don’t have instruments designed to look for radiation.”

“This map will help plan observations for future missions to the Jovian system.”

Juno’s ASC instrument, consisting of four star cameras mounted on the spacecraft’s magnetometer boom, takes images of the stars to determine the spacecraft’s orientation in space.

But the instrument is also a valuable detector for detecting the flow of high-energy particles within Jupiter’s magnetosphere.

The cameras record “hard radiation” – ionizing radiation that affects the spacecraft with enough energy to penetrate the ASC’s shielding.

“The ASC takes an image of the star every quarter of a second,” said Juno scientist Dr. John Leif Jorgensen, a researcher at the Technical University of Denmark.

“The highly energetic electrons that penetrate the shield leave distinctive signatures in our images, like firefly trails.”

“The device is programmed to count the number of fireflies, allowing us to accurately calculate the amount of radiation.”

Juno’s orbit is constantly changing, so the spacecraft has traversed nearly every region of space near Jupiter.

The ASC data suggests that there is more very high-energy radiation, relative to low-energy radiation, near Europa’s orbit than previously thought.

The data also confirm that there are more energetic electrons on the side of Europa facing in the direction of its orbital motion than on the rear side of Europa.

This is because most of the electrons in Jupiter’s magnetosphere pass Europa from behind due to the planet’s rotation, but the very energetic electrons flow backwards, like a fish swimming upstream, and slam into the front of Europa.

The Jupiter radiation data is not the ASC’s first scientific contribution to the mission: even before it arrived at Jupiter, ASC data was used to measure interstellar dust bombarding Juno.

Using the same dust-detection techniques, the imager also discovered a previously undiscovered comet, identifying tiny pieces of the spacecraft ejected by fine dust particles that collided with Juno at high speed.

Like Juno’s ASC, the SRU will act as a radiation detector and low-light imaging instrument.

Data from both instruments show that, like Europa, small shepherd moons that orbit inside or near the edges of Jupiter’s rings and help maintain their shape also appear to interact with the planet’s radiation environment.

If the spacecraft flies over magnetic field lines that connect to ring moons or dense dust, the radiation dose to both the ASC and SRU drops sharply.

The SRU is also collecting rare low-light images of the rings from Juno’s unique vantage point.

“Many mysteries remain about how Jupiter’s rings formed, and very few images have been collected by previous spacecraft,” said SRU principal investigator Dr. Heidi Becker, a scientist at NASA’s Jet Propulsion Laboratory.

“If you’re lucky, you might even be able to capture a little shepherd moon in your photo.”

“These images allow us to get a better idea of where the ring moons are currently located and to see the distribution of dust relative to the distance from Jupiter.”

of Survey results Will be published in the journal Geophysical Research Letters.

Source: www.sci.news

Building the moon base 3 meters underground to prevent radiation exposure.

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A base below the surface of the moon may be needed to protect moon residents from radiation.

Shutterstock/Shiva Shankara

To protect astronauts on the Moon from harmful radiation, a long-term lunar base would need to be protected by 2-3 metres of regolith – the layer of rock and dust on the Moon’s surface.

Guo Jingnan and Mikhail Dbinde Researchers at the Hefei University of Science and Technology in China analyzed how the thickness of shielding for a lunar base would affect radiation doses for people living on the Moon. Their study included using lunar soil as shielding as well as additional artificial shielding.

According to Guo, there are two main types of radiation that are dangerous to astronauts: the ubiquitous background levels of galactic cosmic rays, which pose a long-term cancer risk, and solar energetic particles (SEPs) from sporadic solar activity. These SEPs can cause more serious symptoms of radiation exposure, such as skin damage and damage to bone marrow and lymphatic tissue, which are involved in the production of blood cells and platelets. In severe cases, exposure to SEPs can lead to death.

“The amount of radiation on the lunar surface is not constant,” Guo said. “For a short lunar stay that does not encounter a strong SEP, the radiation impact should be small.”

But if a solar explosion were to occur, the danger could be enormous. For example, at the end of the Apollo program, Apollo 16 landed astronauts on the Moon for a few days in April 1972. It was followed by Apollo 17 in December of the same year. During that time, there was a massive radiation storm.

“A very large SEP event could have occurred during September, potentially killing any unprotected astronauts on the lunar surface,” Guo said.

The study also found that too little regolith shielding could be worse than no shielding at all, because lunar soil scatters radiation and produces various types of secondary particles, including neutrons. This secondary radiation peaks about 50 centimetres deep on the lunar surface but drops off rapidly beyond that.

“Neutrons have a large biological impact because they interact efficiently with the human body and induce radiation effects in internal organs,” Guo said. “With about 50 centimeters of shielding, neutrons can account for more than 90 percent of the total effective radiation dose.”

The study found that a three-metre deep base could safely house the same crew for more than 20 years without exceeding lifetime and annual radiation limits set by the space agency.

NASA and the Russian Space Agency impose different occupational radiation dose limits for astronauts, at 600 millisieverts and 1000 mSv, respectively. Both agencies also impose annual radiation exposure limits. The annual natural radiation exposure on Earth is approximately 2.4 mSv..

Guo says two metres of shielding would be enough for a single crew member to stay on the moon for no more than a few months, and that crew members could return to Earth frequently enough to avoid exceeding lifetime and annual radiation health limits, she says.

The most practical way to reduce radiation exposure would be to give the base natural shielding, by building it in an existing cave or lava tube, or by constructing habitats below the surface, Guo said.

Better prediction of solar storms is also important to keep astronauts safe when they leave base and conduct surface activities, she said.

topic:

  • Moon/
  • Space Exploration

Source: www.newscientist.com

Study shows ability to capture solar radiation at 1,922 degrees Fahrenheit

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As the world focuses on decarbonizing power and transportation, reducing heat emissions from industrial processes remains a challenge. Although using solar energy is an attractive alternative, current solar converters have poor performance and are expensive when process temperatures above 1,000 degrees Celsius (1,832 degrees Fahrenheit) are required. In a new study, scientists at ETH Zurich show that the heat-trapping effect caused by exposing common translucent materials (such as quartz or water) to solar radiation absorbs sunlight by suppressing radiation losses at high temperatures. We have shown how the viability of the photoreceiver can be increased. They demonstrated this effect experimentally at industrially relevant temperatures of 1,050 degrees Celsius (1,922 degrees Fahrenheit).

Casati other. The solar capture effect was experimentally demonstrated at temperatures as high as 1,050 degrees Celsius. They performed stagnation experiments under concentrated thermal radiation and achieved a steady-state temperature difference of about 600 degrees Celsius between the absorber and the outer surface by using quartz as a volumetric absorption medium.Image credit: Casati other., doi: 10.1016/j.device.2024.100399.

“To tackle climate change, we need to decarbonize energy in general,” said Dr. Emiliano Casati, a researcher at ETH Zurich.

“Electricity can only be thought of as energy, but in reality, about half of that energy is used as heat.”

Glass, steel, cement, and ceramics are at the heart of modern civilization, essential to the construction of everything from car engines to skyscrapers.

However, manufacturing these materials requires temperatures in excess of 1,000 degrees Celsius and relies heavily on the combustion of fossil fuels for heat. These industries account for approximately 25% of global energy consumption.

Researchers have been exploring clean energy alternatives using solar receivers that concentrate and store heat with thousands of sun-tracking mirrors.

However, this technology has difficulty transmitting solar energy efficiently at temperatures above 1,000 degrees Celsius.

To increase the efficiency of solar receivers, Dr. Casati and his colleagues turned to translucent materials such as quartz that can trap sunlight. This is a phenomenon called the thermal trap effect.

The researchers created a heat-trapping device by attaching synthetic quartz rods to opaque silicon disks as energy absorbers.

When the device was exposed to an energy flux equivalent to 136 solar rays, the absorber plate reached a temperature of 1,050 degrees Celsius, while the other end of the quartz rod remained at 600 degrees Celsius (1,112 degrees Fahrenheit).

“Previous studies have only been able to demonstrate heat-trapping effects up to 170 degrees Celsius (338 degrees Fahrenheit),” Dr. Casati said.

“Our research shows that solar heat capture works not only at low temperatures, but also at temperatures well above 1,000 degrees Celsius. This is very important to demonstrate its potential in real-world industrial applications. is.”

The scientists also simulated the heat-trapping efficiency of quartz under various conditions using a heat transfer model.

The model showed that the heat trap achieves the target temperature at a lower concentration with the same performance, or the same concentration and higher thermal efficiency.

For example, a state-of-the-art (unshielded) receiver has an efficiency of 40% at 1,200 degrees Celsius (2,192 degrees Fahrenheit) and a concentration of 500 suns.

A 300 mm quartz shielded receiver achieves 70% efficiency at the same temperature and concentration.

A concentration of at least 1,000 suns is required for equivalent performance with an unshielded receiver.

The authors are currently optimizing the heat trapping effect and investigating new applications of the method. So far, their research is promising.

By studying other materials, such as various fluids and gases, even higher temperatures could be reached.

They also noted that the ability of these translucent materials to absorb light and radiation is not limited to solar radiation.

“Energy issues are fundamental to the survival of our society,” Dr. Casati said.

“Solar energy is readily available and the technology already exists.”

“To truly accelerate industry adoption, we need to demonstrate the economic viability and benefits of this technology at scale.”

The team's results were published online today. journal device.

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Emiliano Casati other. Captures solar heat over 1,000℃. device, published online on May 15, 2024. doi: 10.1016/j.device.2024.100399

Source: www.sci.news

New study shows tardigrades display unusual responses to ionizing radiation

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Tardigrades can withstand amazing amounts of ionizing radiation, about 1,000 times more lethal than humans. How they do so is not fully understood. In a new study, scientists at the University of North Carolina found that tardigrade species Hypsibius exemplaris Gamma irradiation causes DNA damage, but that damage can be repaired. This study shows that this species has a specific and strong response to ionizing radiation. In short, irradiation induces rapid upregulation of many DNA repair genes.

Artist's impression of tardigrade species Hypsibius exemplaris.

First discovered in 1773, tardigrades are a diverse group of microscopic invertebrates famous for their ability to withstand extreme conditions.

Also known as tardigrades or moss piglets, they can live up to 60 years, grow to a maximum size of 0.5 mm, and are best seen under a microscope.

Tardigrades can survive for up to 30 years without food or water at temperatures as low as -272 degrees Celsius (-457 degrees Fahrenheit) or as hot as 150 degrees Celsius (-302 degrees Fahrenheit) and for a few minutes at temperatures as low as -20 degrees Celsius. can. Minus 4 degrees Celsius (minus 4 degrees Fahrenheit) continues for decades.

It can withstand pressures from virtually 0 atmospheres in outer space to 1,200 atmospheres at the bottom of the Mariana Trench.

It is also resistant to radiation levels up to 5,000-6,200 Gy.

“What we saw surprised us. Tardigrades are behaving in ways we didn’t expect,” said researcher Professor Bob Goldstein from the University of North Carolina at Chapel Hill.

In their research, Professor Goldstein and his colleagues Hypsibius exemplaris Tardigrades can also withstand strong radiation.

The researchers found that although tardigrades are not immune to DNA damage, and that radiation damages their DNA, tardigrades can repair extensive damage.

They were surprised to discover that tardigrades can increase production of DNA repair genes.

Unlike humans, they are able to produce extremely high levels of DNA repair gene products, making them some of the most abundant gene products of any animal.

“These animals have an incredible response to radiation, and that seems to be the secret to their extreme survivability,” said Dr. Courtney Clark-Hachtel, a researcher at the University of North Carolina at Asheville. Ta.

“What we’re learning about how tardigrades overcome radiation stress could lead to new ideas about how we try to protect other animals and microorganisms from harmful radiation. “

of findings appear in the diary current biology.

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Courtney M. Clark Hucktell other.Tardigrade Hypsibius exemplaris Dramatically upregulates DNA repair pathway genes in response to ionizing radiation. current biology, published online on April 12, 2024. doi: 10.1016/j.cub.2024.03.019

Source: www.sci.news

Massive star ultraviolet radiation influences nearby planetary systems

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Astronomers have known for decades that the powerful light emitted by massive stars can disrupt planetary disks of dust and gas that swirl around young stars, the cradles of planetary birth. However, important questions remained unanswered. How fast does this process occur and will there be enough material left to form a planet?

NASA/ESA/CSA Using the James Webb Space Telescope and the Atacama Large Millimeter Array (ALMA), astronomers are now discovering the Orion Nebula, a nursery for stars, and specifically the protoplanetary disk named d203-506. I’m researching. Although it was confined to a small area, it exploded to an abnormally large size. This makes it possible to measure material loss rates with unprecedented precision.

bernet other. We observed the protoplanetary disk d203-506 illuminated by the far-ultraviolet rays of the Orion Nebula.Image credit: Berne other., doi: 10.1126/science.adh2861.

Young, low-mass stars are often surrounded by relatively short-lived protoplanetary disks of dust and gas, which are the raw materials for planet formation.

Therefore, the formation of gas giant planets is limited by processes that remove mass from the protoplanetary disk, such as photoevaporation.

Photoevaporation occurs when the upper layers of a protoplanetary disk are heated by X-rays or ultraviolet protons, raising the temperature of the gas and ejecting it from the system.

Because most low-mass stars form in clusters that also include high-mass stars, protoplanetary disks are expected to be exposed to external radiation and experience photoevaporation due to ultraviolet radiation.

Theoretical models predict that deep ultraviolet light creates a region of photodissociation, a region where ultraviolet photons projected from nearby massive stars strongly influence the gas chemistry on the surface of the protoplanetary disk. However, it has been difficult to observe these processes directly.

Dr. Thomas Howarth of Queen Mary University of London and his colleagues investigated the effects of ultraviolet irradiation using a combination of infrared, submillimeter wave, and optical observations of the protoplanetary disk d203-506 in the Orion Nebula using the Webb and ALMA telescopes.

By modeling the kinematics and excitation of the emission lines detected within the photodissociation region, they found that d203-506 loses mass rapidly due to heating and ionization by deep ultraviolet light.

According to the research team, the rate at which this mass is lost from d203-506 indicates that gas could be removed from the disk within a million years, suppressing the ability of gas giants to form within the system. It is said that there is.

“This is a truly exceptional case study,” said Dr Howarth, co-author of the paper. paper It was published in the magazine science.

“The results are clear: this young star is losing a staggering 20 Earth masses of material per year, suggesting that Jupiter-like planets are unlikely to form in this system.” .”

“The velocities we measured are in perfect agreement with theoretical models and give us confidence in understanding how different environments shape planet formation across the universe.”

“Unlike other known cases, this young star is exposed to only one type of ultraviolet light from a nearby massive star.”

“Because there is no 'hot cocoon' created by higher-energy ultraviolet light, the planet-forming material is larger and easier to study.”

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Olivier Verne other. 2024. Photoevaporation flow caused by far ultraviolet rays observed in a protoplanetary disk. science 383 (6686): 988-992; doi: 10.1126/science.adh2861

Source: www.sci.news

Webb Observatory detects radiation from the neutron star remnant of supernova 1987A

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SN 1987A is the only supernova visible to the naked eye in the past 400 years and the most studied supernova in history. This event was a nuclear collapse supernova, meaning that the compressed remains of its core formed either a neutron star or a black hole. Evidence for such compact objects has long been sought, and while indirect evidence for the existence of neutron stars has been found before, most likely the effects of high-energy emissions from young neutron stars have not been detected. This is the first time I have done so.

Webb observed the best evidence to date for radiation from neutron stars in SN 1987A. Image credits: NASA / ESA / CSA / STScI / C. Fransson, Stockholm University / M. Matsuura, Cardiff University / MJ Barlow, University College London / PJ Kavanagh, Maynooth University / J. Larsson, KTH Royal Institute of Technology.

SN 1987A was first observed on February 23, 1987 at the edge of the Large Magellanic Cloud, about 163,000 light-years away.

This was the first supernova to be observed with the naked eye since Johannes Kepler witnessed one more than 400 years ago.

About two hours before the first visible light observation of SN 1987A, three observatories around the world detected a burst of neutrinos that lasted just a few seconds.

The two different types of observations were associated with the same supernova event and provided important evidence that informs theories about how nuclear collapse supernovae occur.

This theory included the expectation that supernovae of this type would form neutron stars or black holes.

Since then, astronomers have been searching for evidence of these compact objects at the center of expanding debris.

Indirect evidence for the presence of neutron stars at the center of remnants has been discovered in recent years, with observations of much older supernova remnants such as the Crab Nebula showing that neutron stars have been found in many supernova remnants. has been confirmed.

However, until now no direct evidence of neutron star formation in the aftermath of SN 1987A has been observed.

“Theoretical models of SN 1987A suggest that the 10-second burst of neutrinos observed just before the supernova explosion led to the formation of a neutron star or black hole,” said lead author of the study. said Claes Fransson, an astronomer at Stockholm University.

“However, no convincing signs of such a newborn object due to a supernova explosion have been observed.”

“With this observatory, we found direct evidence of ejection caused by a newborn compact object, likely a neutron star.”

In the study, Dr. Franson et al. mm and NIR spec Instruments on NASA/ESA/CSA's James Webb Space Telescope observed SN 1987A at infrared wavelengths, showing that a heavy mass whose outer electrons have been stripped (i.e., atoms have become ionized) near where the star exploded occurred. They found evidence of argon and sulfur atoms. .

They modeled a variety of scenarios in which these atoms could be driven solely by ultraviolet or They discovered that it could have been ionized only by the wind. (Pulsar wind nebula).

If the former scenario were true, the neutron star's surface would be about 1 million degrees Celsius, cooling from about 100 billion degrees Celsius at the moment it formed at its collapse center more than 30 years ago.

Professor Mike Barlow of University College London said: “The detection of strong ionizing argon and sulfur emission lines from the very center of the nebula surrounding SN1987A using Webb's MIRI and NIRSpec spectrometers suggests a central source of ionizing radiation. This is direct evidence of the existence of .

“Our data can only match neutron stars as the power source of ionizing radiation.”

“This radiation is not only emitted from the multi-million-degree surface of a hot neutron star, but also from the pulsar winds that may be produced when a neutron star spins rapidly, dragging charged particles around it. It can also be emitted from nebulae.”

“The mystery surrounding whether neutron stars are hidden in dust has been going on for more than 30 years, so we are very happy to have solved it.”

“Supernovae are the main source of the chemical elements that make life possible, so we want to accurately derive the supernova model.”

“No other object like the neutron star SN 1987A is so close to us and formed so recently. The surrounding material is expanding, so we'll see more of it over time. It will be.”

“It was clear that there had to be a high-energy radiation source at the center of the SN 1987A debris to produce the ions observed in the ejecta,” Dr. Franson said.

“The paper discusses a variety of possibilities, but we found that only a few scenarios are likely, and all of them involve newly formed neutron stars.”

of paper Published in the February 22, 2024 edition of the Journal science.

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C. Franson other. 2024. Emission lines from ionizing radiation from a compact object in the remains of supernova 1987A. science 383 (6685): 898-903; doi: 10.1126/science.adj5796

Source: www.sci.news

Uncovering the Hidden Physics of Temperature and Radiation

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by Institute of Atmospheric Physics, Chinese Academy of Sciences December 16, 2023

A groundbreaking study investigated the complex relationship between Earth’s surface temperature and emitted longwave radiation, revealing deviations from the expected quaternary pattern. This research improves our understanding of climate sensitivity and the factors that influence it, such as greenhouse gases and atmospheric dynamics. Credit: SciTechDaily.com

Climate science research has revealed new insights into the relationship between surface temperature and emitted longwave radiation, challenging traditional models and improving our understanding of Earth’s climate sensitivity.

Want to know what causes Earth’s climate sensitivity? Recent research shows Advances in atmospheric science. We investigate a complex relationship that transforms the relationship between surface temperature and outgoing longwave radiation (OLR) from fourth-order to sublinear. Led by Dr. Jie Sun florida state university this study elucidates the hidden mechanisms that shape Earth’s climate and provides new insights into why the relationship between temperature and OLR deviates from the fourth-order pattern described by the Stefan-Boltzmann law. Masu.

Stefan-Boltzmann law and climate dynamics

What is the Stefan-Boltzmann law? Atmospheric greenhouse gases create a contrast between surface heat release and OLR, which is related to the fourth power of surface temperature.

Professor Hu Xiaoming of Sun Yat-sen University, corresponding author of the study, explained: This allows the relationship between surface temperature and OLR to follow a quartic pattern, since the radiation-emitting layer is lowered. ”

Diagram showing two main processes: sublinear surface temperature and outgoing longwave radiation (OLR). Left: Increased meridional surface temperature gradient due to the greenhouse effect of water vapor. Right: Poleward energy transport reroutes part of the OLR from warmer to colder regions. Credit: Ming Cai and Xiaoming Hu

Factors affecting surface temperature and OLR

This study reveals how various factors influence surface temperature and OLR. The water vapor greenhouse effect acts as a magnifying glass, amplifying temperature differences across the Earth’s surface without changing the latitudinal variation of the OLR. This suppresses the nonlinearity between OLR and surface temperature.

Polar energy transport, on the other hand, acts as an equalizer to harmonize temperature differences across different regions of the Earth. One of the by-products of this global heat redistribution is the rerouting of OLR from warmer to colder regions, which acts to reduce the differences in OLR between different regions. This further suppresses nonlinearities.

“Understanding these complex climate interactions is like deciphering a puzzle. Each piece brings us closer to deciphering the complexity of Earth’s climate,” said Ming Kai, a professor at Florida State University. Masu.”

By uncovering these relationships, scientists are learning more about Earth’s climate and how its complex components regulate overall climate sensitivity, i.e., not just the rate of energy output, but also where the output occurs to make significant progress in understanding.

Reference: “Sublinear relationship between planetary outward longwave radiation and surface temperature in a gray atmosphere radiative-convective transport climate model” Jie Sun, Michael Secor, Ming Cai, Xiaoming Hu, November 25, 2023. Advances in atmospheric science.
DOI: 10.1007/s00376-023-2386-1

Source: scitechdaily.com