• Dhaka Sun, 06 OCTOBER 2024,
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Pentagon study says no evidence of alien life
Earth's core has slowed so much it's moving backward, scientists confirm
Deep inside Earth is a solid metal ball that rotates independently of our spinning planet, like a top whirling around inside a bigger top, shrouded in mystery. This inner core has intrigued researchers since its discovery by Danish seismologist Inge Lehmann in 1936, and how it moves — its rotation speed and direction — has been at the center of a decades-long debate. A growing body of evidence suggests the core's spin has changed dramatically in recent years, but scientists have remained divided over what exactly is happening — and what it means. Part of the trouble is that Earth's deep interior is impossible to observe or sample directly. Seismologists have gleaned information about the inner core's motion by examining how waves from large earthquakes that ping this area behave. Variations between waves of similar strengths that passed through the core at different times enabled scientists to measure changes in the inner core's position and calculate its spin. 'Differential rotation of the inner core was proposed as a phenomenon in the 1970s and '80s, but it wasn't until the '90s that seismological evidence was published,' said Dr. Lauren Waszek, a senior lecturer of physical sciences at James Cook University in Australia. But researchers argued over how to interpret these findings, 'primarily due to the challenge of making detailed observations of the inner core, due to its remoteness and limited available data,' Waszek said. As a result, 'studies which followed over the next years and decades disagree on the rate of rotation, and also its direction with respect to the mantle,' she added. Some analyses even proposed that the core didn't rotate at all. One promising model proposed in 2023 described an inner core that in the past had spun faster than Earth itself, but was now spinning slower. For a while, the scientists reported, the core's rotation matched Earth's spin. Then it slowed even more, until the core was moving backward relative to the fluid layers around it. At the time, some experts cautioned that more data was needed to bolster this conclusion, and now another team of scientists has delivered compelling new evidence for this hypothesis about the inner core’s rotation rate. Research published June 12 in the journal Nature not only confirms the core slowdown, it supports the 2023 proposal that this core deceleration is part of a decades-long pattern of slowing down and speeding up. The new findings also confirm that the changes in rotational speed follow a 70-year cycle, said study coauthor Dr. John Vidale, Dean's Professor of Earth Sciences at the University of Southern California’s Dornsife College of Letters, Arts and Sciences. 'We've been arguing about this for 20 years, and I think this nails it,' Vidale said. 'I think we've ended the debate on whether the inner core moves, and what's been its pattern for the last couple of decades.' But not all are convinced that the matter is settled, and how a slowdown of the inner core might affect our planet is still an open question — though some experts say Earth's magnetic field could come into play. Buried about 3,220 miles (5,180 kilometers) deep inside Earth, the solid metal inner core is surrounded by a liquid metal outer core. The inner core is made mostly of iron and nickel, and it is estimated to be as hot as the surface of the sun — about 9,800 degrees Fahrenheit (5,400 degrees Celsius). Earth's magnetic field yanks at this solid ball of hot metal, making it spin. At the same time, the gravity and flow of the fluid outer core and mantle drag at the core. Over many decades, the push and pull of these forces cause variations in the core's rotational speed, Vidale said. The sloshing of metal-rich fluid in the outer core generates electrical currents that power Earth's magnetic field, which protects our planet from deadly solar radiation. Though the inner core's direct influence on the magnetic field is unknown, scientists had previously reported in 2023 that a slower-spinning core could potentially affect it and also fractionally shorten the length of a day. When scientists attempt to 'see' all the way through the planet, they are generally tracking two types of seismic waves: pressure waves, or P waves, and shear waves, or S waves. P waves move through all types of matter; S waves only move through solids or extremely viscous liquids, according to the US Geological Survey. Seismologists noted in the 1880s that S waves generated by earthquakes didn't pass all the way through Earth, and so they concluded that Earth's core was molten. But some P waves, after passing through Earth's core, emerged in unexpected places — a 'shadow zone,' as Lehmann called it — creating anomalies that were impossible to explain. Lehmann was the first to suggest that wayward P waves might be interacting with a solid inner core within the liquid outer core, based on data from a massive earthquake in New Zealand in 1929. By tracking seismic waves from earthquakes that have passed through the Earth's inner core along similar paths since 1964, the authors of the 2023 study found that the spin followed a 70-year cycle. By the 1970s, the inner core was spinning a little faster than the planet. It slowed around 2008, and from 2008 to 2023 began moving slightly in reverse, relative to the mantle. NASA's Solar Dynamics Observatory (SDO) scientists used their computer models to generate a view of the Sun's magnetic field on August 10, 2018. The bright active region right at the central area of the Sun clearly shows a concentration of field lines, as well as the small active region at the Sun's right edge. For the new study, Vidale and his coauthors observed seismic waves produced by earthquakes in the same locations at different times. They found 121 examples of such earthquakes occurring between 1991 and 2023 in the South Sandwich Islands, an archipelago of volcanic islands in the Atlantic Ocean to the east of South America's southernmost tip. The researchers also looked at core-penetrating shock waves from Soviet nuclear tests conducted between 1971 and 1974. When the core turns, Vidale said, that affects the arrival time of the wave. Comparing the timing of seismic signals as they touched the core revealed changes in core rotation over time, confirming the 70-year rotation cycle. According to the researchers' calculations, the core is just about ready to start speeding up again. Compared with other seismographic studies of the core that measure individual earthquakes as they pass through the core — regardless of when they occur — using only paired earthquakes reduces the amount of usable data, 'making the method more challenging,' Waszek said. However, doing so also enabled scientists to measure changes in the core rotation with greater precision, according to Vidale. If his team’s model is correct, core rotation will start speeding up again in about five to 10 years. The seismographs also revealed that, during its 70-year cycle, the core's spin slows and accelerates at different rates, 'which is going to need an explanation,' Vidale said. One possibility is that the metal inner core isn't as solid as expected. If it deforms as it rotates, that could affect the symmetry of its rotational speed, he said. The team's calculations also suggest that the core has different rotation rates for forward and backward motion, which adds 'an interesting contribution to the discourse,' Waszek said. But the depth and inaccessibility of the inner core mean that uncertainties remain, she added. As for whether or not the debate about core rotation has truly ended, 'we need more data and improved interdisciplinary tools to investigate this further,' Waszek said. Changes in core spin — though they can be tracked and measured — are all but imperceptible to people on Earth’s surface, Vidale said. When the core spins more slowly, the mantle speeds up. This shift makes Earth rotate faster, and the length of a day shortens. But such rotational shifts translate to mere thousandths of a second in day length, he said. 'In terms of that effect in a person's lifetime?' he said. 'I can't imagine it means much.' Scientists study the inner core to learn how Earth's deep interior formed and how activity connects across all the planet's subsurface layers. The mysterious region where the liquid outer core envelops the solid inner core is especially interesting, Vidale added. As a place where liquid and solid meet, this boundary is 'filled with potential for activity,' as are the core-mantle boundary and the boundary between mantle and crust. 'We might have volcanoes on the inner core boundary, for example, where solid and fluid are meeting and moving,' he said. Because the spinning of the inner core affects movement in the outer core, inner core rotation is thought to help power Earth's magnetic field, though more research is required to unravel its precise role. And there is still much to be learned about the inner core's overall structure, Waszek said. 'Novel and upcoming methodologies will be central to answering the ongoing questions about Earth's inner core, including that of rotation.' Mindy Weisberger is a science writer and media producer whose work has appeared in Live Science, Scientific American and How It Works magazine. Source: CNN
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Wastewater study finds 18 new psychoactive drugs
A testing program shows a string of new psychoactive substances in widespread use across the globe. Scientists believe criminals are developing substances slightly altered from illegal drugs to stay ahead of the law. An Australian-led team found new psychoactive chemicals — with similar effects to known street drugs — in wastewater from 16 countries, new research shows. The substances are drugs adapted to mimic the effects of established illicit drugs while evading legal restrictions that, in many countries, are tied to specific substances and chemical compositions. What the team discovered The University of Queensland-led team analyzed samples in 47 cities in Europe, the United States, Canada, New Zealand, Australia, China, Brazil and South Korea over three consecutive New Year periods from 2019 to 2022. They detected 18 new substances that were analogous to mind-altering street drugs but with slight alterations to their chemical structure.  "These substances are synthesized to replace banned substances, which means they have a slightly different molecular structure to stay ahead of the law," Bade said. "They are generally manufactured in smaller quantities than traditional illicit drugs, making it difficult for law enforcement to control the circulation." What types of substances were they? The survey showed so-called new psychoactive substance (NPS) use across the globe, but uncovered strong regional trends. Synthetic cathinones — chemically related to the cathinone stimulant found in the khat plant — were the most prevalent class of NPS. One such chemical, 3-methylmethcathinone, was found in particularly high levels in Europe — especially in Spain and Slovakia. It was only found in Europe the first year, but spread to North American and Oceania subsequently. Also prominent were phenethylamines, which can have a similar effect to amphetamines, and designer benzodiazepines. The team found seven new psychoactive substances in Australia alone — mephedrone, ethylone, and eutylone — which all have a similar effect to ecstasy or cocaine. In the United States, the plant-based painkiller mitragynine was found in particularly heavy loads. The US Food and Drug Administration has repeatedly warned of the dangers of the plant, kratom, but mitragynine is not currently federally regulated.
Men want the pill and they are ready to use it responsibly
Male birth control pills are coming soon. A new study shows men are eager to use them responsibly, and so are their partners. Male birth control pills aren't available yet, but there are already accusations that men won't want to take them, or can't be relied upon to take them responsibly. "Let’s say this new non-hormonal pill for guys makes it to market, and men are willing to try it.  Can we really expect them to take a pill every day?" author Susanna Schrobsdorff wrote in The Washington Post in April 2022. Fifty percent of the pregnancies around the world are unintended. It's women who ultimately bear the burden, and the argument goes that men will never take contraception seriously unless they can get pregnant themselves. One reason this bias exists may be that men don't have the best track record with condoms.  Incidences of "stealthing" — taking the condom off during sex without your partner's consent — are common: In Australia, for example, a staggering 32% of women and 19% of men have experienced stealthing. But male contraceptive advocates are fighting back against the criticisms, arguing that the demand for male contraceptives has never been higher. They say that men are ready to share the responsibility of birth control. Men want the pill A new study, presented at the Reproductive Health Innovation Summit in Boston in February 2023, backs the claims, showing that men and their partners are strongly in favor of new forms of male contraception and that women trust their partners to use them responsibly. The survey, funded by The Bill & Melinda Gates Foundation, involved 19,000 adult men from eight different countries: Nigeria, Kenya, Cote d'Ivoire, Democratic Republic of the Congo, Vietnam, Bangladesh, India, and the US. "We asked men if they want contraceptives, and if they do, what forms they want. We thought by assessing the situation objectively we could set some of the issues straight," said Steve Kretschmer, executive director of DesireLine, a consultancy firm involved in the study. The study found that 78% to 98% of men, depending on the country, would take male contraceptive pills. The demand was high among men regardless of their relationship status. Women trust their partners to take the pill The study also aimed to find out what women thought about the issue.  "We also wanted to ask women if they trust men to take contraceptives, and how would it change their use of contraceptives if male contraception became available," Kretschmer told. The survey showed the demand for male contraception was as high among women as it was among men. Moreover, women largely trust their partners to use contraception responsibly — 82% to 88% of women in Vietnam, Nigeria and Bangladesh agreed or strongly agreed they would believe it if their partner told them they were taking a contraceptive. "The data shows men want new birth control forms and women trust their partners to take them," Heather Vahdat, executive director of the US-based Male Contraceptive Initiative, told.  "But if a woman doesn't trust their male partner, then they could both contracept. This isn't an option right now."  Changing gender roles According to Vahdat, society lost track of men's role in contraception and conception since the female pill was introduced in the 1960s. "Contraception became synonymous with women's rights. But we're now reaching a tipping point with male contraceptives and people are paying attention to them," she said. Data in the survey shows men in committed relationships want to be part of the decision-making progress around contraception, as much as they are around conception.   "It comes at a time when men are discussing masculinity more, especially toxic masculinity, and wanting to become more engaged partners," said Vahdat. Barriers to male birth control? While men theoretically want to be part of contraceptive decision making, there are still barriers to overcome before they will actually take a pill. Not least, the marketing needs to change. Male birth control pills work by causing temporary infertility. How many men would be happy to be infertile? Could they trust infertility to be, in fact, temporary? On-going large-scale clinical trials testing efficacy and safety of different male birth control forms are looking positive, but some trials have even been canceled due to concerns about irreversible infertility and other adverse side effects. Pill needs to be proven safe and effective Commentators on social media have suggested that men are just being wusses and that women have been suffering similar side effects with the pill for decades. But drug regulators like the FDA are being strict with male contraceptive pill trials. Concerns over sterilization are not matters to scoff at — they need to be addressed before drugs go onto the market. After all, men need to be able to trust the pills are safe and effective before women can trust men to take them.
The ozone hole is still there
Ozone-killing materials in Earth's stratosphere fell over 50% to levels seen before the ozone hole became a problem, scientists say. But there's still a way to go. Here's why we need a healthy ozone layer. It’s not much but the ozone layer is all there is between you and UV. As the United Nations puts it, if we could bring the entire ozone layer to sea level, it would be only about 3mm [0.118 inches] thick. That’s what protects us from harmful ultraviolet radiation. That really isn’t very much, is it just 3mm of protection? You can’t even see it. And in some regions of the stratosphere, the ozone is so depleted that we refer to an ozone hole. In fact, we have known for decades that the ozone layer is itself under threat and needs our protection. The UN has been working to repair the hole for three decades via international treaties such as the Montreal Protocol on Substances that Deplete the Ozone Layer. According to meteorologists at the US-based National Oceanic and Atmospheric Administration, in early 2022, the amount of ozone-killing materials in our stratosphere had fallen by 50% to levels last seen before the ozone hole became a problem. But we still have a way to go before the ozone layer has healed. Here’s our brief guide to what you need to know about our very precious ozone. What is the ozone layer? Ozone is a molecule, consisting of three oxygen atoms (O3). Ozone molecules occur naturally in the upper atmosphere known as the stratosphere and form a layer of gas. This layer of gas protects life on Earth by filtering some (but not all) of the sun’s ultraviolet radiation. Ozone is also created by chemical reactions between air pollutants and other emissions in the lower atmosphere the troposphere. While ozone provides us with a protective shield in the stratosphere, direct contact in the troposphere can be harmful to plants, animals and humans. So, what’s the problem with ultraviolet radiation (UV)? It is often said we need the ozone layer to stop UV radiation from sterilizing the Earth’s surface. We know that sun rays do have the power to sterilize things, and that can be good, think about your washing drying on the line on a hot summer’s day. But what we really mean to say is that UV radiation can kill. There are three types of UV radiation: A, B and C. The ozone layer and atmosphere absorb all of the UVC the most energetic form of UV radiation and some UVB. UVA is not absorbed by the ozone layer and reaches the Earth’s surface in its entirety. Humans need UVB radiation to generate vitamin D, which is good for people in appropriate doses. But too much UVB and UVA can cause serious illnesses, such as skin cancer, cataracts, suppression of the immune system, and premature aging of the skin. An excess of UV is also linked with reduced crop yields and adverse effects in the marine food chain. What causes ozone depletion? To a large extent, humans cause ozone depletion through our use of ozone depleting substances (ODSs). Gases such as chlorofluorocarbons (CFCs), halons, CH3CCl3 (Methyl chloroform), CCI4 (Carbon tetrachloride), hydrochlorofluorocarbons (HCFCs) and methyl bromide destroy the ozone layer. These substances can be found in refrigerators, air conditioners, aerosols, solvents and pesticides, to name a few. They deplete the ozone layer by releasing chlorine and bromine atoms, which degrade ozone molecules in the stratosphere. Scientists warn that very short-lived substances (VSLSs) also threaten the ozone layer. VSLSs occur naturally in marine life, among seaweed and phytoplankton. But we also produce human-made VSLSs, such as dichloromethane. The ozone hole- it’s not really a hole, is it? No, strictly speaking, there is no ozone hole rather, there is a region of exceptionally depleted ozone over the Antarctic. It is also referred to as a dramatic thinning of ozone, which shows up during spring in the southern hemisphere (August-October). There are mini-holes and other aberrations in the northern hemisphere, too. Will the ozone layer ever heal completely? Scientists say the future looks good for the ozone layer. It may recover to pre-1980 levels over the next 50 years sometime between 2050 and 2065 if we stick to goals set in international treaties. The Vienna Convention and the Montreal Protocol, for instance, became the first treaties in the history of the UN to achieve universal ratification on September 16, 2009. And September 16 is now commonly known as World Ozone Day, or the International Day for the Preservation of the Ozone Layer. NASA’s Ozone Watch provides daily updates, including images and animations from 1979 to 2022.
China launches second module of space station
A rocket carrying Wentian — the second of the three modules needed to complete China's new space station Tiangong — has blasted off into space. In the latest step towards an ambitious space program, China has launched the second of three modules needed to complete its new space station. On Sunday, live feed on state broadcaster CCTV showed the unmanned craft  named Wentian being propelled by the country’s most powerful rocket the Long March 5B from the Wenchang launch center on China’s southern island of Hainan at 2:22 p.m. (0822 CET). Shortly after the launch, CCTV reported it to be a complete success. The 23-ton laboratory module is almost 18 meters long and has three sleeping areas, along with a space for scientific experiments. Beijing began constructing its space station called Tiangong (heavenly palace) in April 2021, with the launch of the Tianhe module. Tianhe, the central module, would be the main living quarters, in the first of 11 crewed and uncrewed missions in the undertaking. What’s next? In a challenging maneuver, Wentian would now have to dock with the existing module in space. Experts say that the operation would require the use of a robotic arm and a number of high-precision manipulations. The newly launched module will also serve as a backup platform to control the space station in case of a failure. Tiangong is expected to have a lifespan of at least 10 years and Beijing is looking to make it fully operational by the end of the year. The third and final module is slated to dock in October. China’s space dream has been given a major push under President Xi Jinping. The completion of the new space station is also set to cap the president’s 10 years as the leader of the ruling Communist Party.
The need for diversity in genome sequencing
A majority of the DNA that has been sequenced for research comes from donors of European ancestry. That causes a knowledge gap about the genome of people from the rest of the world. Among various things that unite humans around the world, the DNA sequence hovers at the top: a whopping 99.9% of human DNA sequences are identical among people. Gregor Mendel, a monk and scientist whose 200th birthday is this Wednesday (July 20), proposed that certain invisible factors were responsible for the various characteristics we display. Today, we know that these factors are genes, which make up our DNA, or deoxyribonucleic acid. This acid molecule gives genetic instructions to living beings. If humans share so much of the same DNA, why is diversity important in the context of DNA sequencing? To understand that, we have to shift our focus to the 0.1% of the difference in the human DNA sequences. The seemingly small difference stems from variations among the nearly 3 billion bases (or nitrogen-based compounds) in our DNA. All the dissimilarities we know between different humans including hair or eye color or the height of a person, are due to these variations. However, over the years scientists found that these variations could also give us vital information on a person’s or a population’s risk for developing a specific disease. We can then use the risk assessment from the genetic data to design a health-care strategy that is tailored to the individual. Genetics and disease risk assessment Many of us have had the experience of filling out forms at the doctor’s office that ask us about the different diseases our parents or relatives suffered. You are warned to stay away from sweets and processed sugars if a parent was diabetic, for example. While transfer of heart diseases, cancer or diabetes between one generation to another is known more commonly, there are many more diseases that can be inherited genetically. For example, we know that sickle cell anemia occurs when a person inherits two abnormal copies of the gene that makes hemoglobin, a protein in our red blood cells, one from each parent. In recent decades, genetic research has advanced to the point that scientists can isolate the genes responsible for many of these diseases. Here’s the catch: We know this correlation between genes and diseases for a very restricted population. Euro-centric data Sarah Tishkoff, a geneticist and evolutionary biologist at the University of Pennsylvania in the US, is one of many in the scientific community pushing for more diverse genomic datasets. "Let's say that a study focused on people with European ancestry identifies genetic variants associated with risk for heart disease or diabetes, and uses that information to predict risk for disease in patients not included in the original study," said Tishkoff. We know from experience that this prediction of disease risk doesn’t work well when applied to individuals with different ancestries, particularly if they have African ancestry. Historically, the people who have provided their DNA for genomics research have been overwhelmingly of European ancestry, which creates gaps in knowledge about the genomes from people in the rest of the world, according to the National Human Genome Research Institute (NHGRI) in the US. The institute states that 87% of all the genome data we have is from individuals of European ancestry, followed by 10% of Asian and 2% of African ancestry. As a result, the potential benefits of genetic research, which includes understanding early diagnoses and treatment of various diseases, may not benefit the underrepresented populations. Lack of equitability in treatment The problem does not stop with disease risk assessment. It permeates the space of equitable health care as well, says Jan Witkowski, a professor from the Graduate School of Biological Sciences at the Cold Spring Harbor Laboratory in the US state of New York. Say you have two groups: group A and group B, who are very different. The knowledge and information you learn about people in group A may not apply to people in group B. But imagine developing medical treatments based on information from just group A for everyone, he said, adding, it is not going to work on group B. By including diverse populations in genomic studies, researchers can identify genomic variants associated with various health outcomes at both the individual and population levels. The NHGRI also states, however, that diversifying the participants in genomics research is an expensive affair and requires the establishment of trust and respectful long-term relationships between communities and researchers. 
Why the new images of space are so important for science
The first images from the Webb Telescope have wowed the world with their beauty. But what do they mean for the future of astronomy? Planet Earth had its head in the sky when the James Webb Space Telescope’s first images of the cosmos were revealed. Five stunning images showcased the telescope’s capabilities, capturing views of stars being born and a group of galaxies locked in a cosmic dance. The pictures are the deepest and sharpest color images of the universe so far. While celebrating the beauty of the images, scientists have been keen to point out the scientific significance of the international project, which is a collaboration between NASA, the European Space Agency (ESA) and the Canadian Space Agency (CSA). These images show us that Webb works incredibly well. Webb will help us to study our universe in much more detail, said Kai Noeske, an astronomer and communications officer at the European Space Operations Centre (ESOC). Looking back in time Webb’s first image was a deep field image of a tiny spec of the vast universe, showing distant galaxy clusters. Some of these galaxies are more than 13 billion years old and were created when the universe was in its infancy. It is light from the early universe, in its first 500 million years, which is reaching us today, Noeske told DW. The curious effect of looking back in time is caused by the speed of light and how long light takes to reach us. Light travels at 300,000 kilometers every second (about 670 million miles per hour). This is extremely fast. But space is really big, so it can still take a long time for light to travel. For example, the sun is about 150 million kilometers (93 million miles) from Earth, and it takes around eight minutes for light to reach us from our sun. The objects in Webb’s images are many billions of light-years away. One light-year is the distance traveled by light in one year, which is about 9.5 trillion kilometers. This means the light has traveled through space and time to reach us over billions of years. We would have to wait another 13 billion years to see these galaxies as they are today. The scale of these distances is difficult to imagine, but it certainly makes a walk to the store feel rather short by comparison. Making the invisible visible In the kaleidoscopic images of the Carina Nebula and Stephan’s Quintet, Webb shows us emerging stellar nurseries where stars are being born and developing. Scientists have never been able to observe galaxies interacting in this much detail. It’s thanks to Webb’s infrared cameras that we’re able to see the stars in all their glory. Infrared gives us a lot more information on the young universe than was possible before. The light from these galaxies was stretched as it traveled to us. Webb lets us see that, says Noeske. The colors in the Cosmic Cliffs were artificially added to the original image by Webb’s science team. However, that’s not to say the colors are not there. In fact, the light emitted from stars contains information far richer than we can see with the human eye. Researchers use data about light emitted from stars to understand how galaxies form, grow, and merge with each other, and in some cases why they stop forming stars altogether. For example, blue galaxies contain stars but very little dust. The red objects are enshrouded in thick layers of dust, while green galaxies are populated with hydrocarbons and other chemical compounds. Webb will address some of the great, open questions of modern astrophysics: What determines the number of stars that form in a certain region? Why do stars form with a certain mass? NASA said in a press release on Tuesday. Richer information about the universe It will take weeks and months to analyze the first images and demonstrate more of what Webb is capable of doing in the future. Each photo we see is a composite of many hours of imaging. Study teams will slice and dice the information into many images for detailed study, much like clinicians do with magnetic resonance imaging (MRI). It was a big step forward from what Hubble showed us. The sharpness and level of detail made it clear how much potential Webb has for scientific research. Webb not only looks further back in time, but also in higher detail, Noeske told DW. Webb will help scientists to answer questions about how planets, stars, galaxies, and ultimately the universe itself, are formed. Finding Earth 2.0? While less beautiful than the Cosmic Cliffs, Webb’s spectrographic analysis of the exoplanet WASP-96’s atmosphere is an example of perhaps more exciting information to come in the future. WASP-96 b is a type of gas giant around 1,150 light-years away that bears little similarity to the planets in our solar system. Webb’s team has analyzed the planet’s transmission spectrum, measuring starlight filtered through the planet’s atmosphere like a barcode. This is an amazing trick that astronomers use. The planet passes in front of its star a bit of light passes through the planet’s atmosphere, and that light shining contains the chemical signature of the atmosphere imprinted into it like a barcode, said Noeske. The analysis showed the planet has an atmosphere that contains water, along with clouds and haze. But WASP-96b won’t be supporting life as we know it any time soon, as the planet is made of gas and orbits its star extremely closely, making it an extremely hot and hostile environment. The analysis of WASP-96 b provides a hint of what Webb has in store for exoplanet research. Exactly what will happen is yet to be determined. The telescope is open to proposals from worldwide scientific communities about which exoplanets to study in the future.
How can we make steel green?
The wonder material is single-handedly responsible for almost 10% of global warming — but solutions for cleaning up steel are expensive and hard to scale. Its a building block of modern life and is both a driver of climate change and vital for stopping it. Steel a cheap, strong, and long-lasting metal is found in everything, from homes and hospitals to cars and kitchen sinks. It is an essential component of the wind turbines and electricity pylons that world leaders are banking on building to end our addiction to fossil fuels. Its like the lifeblood of the economy. It feeds into every sector. Gauri Khandekar, an analyst at the Free University of Brussels who studies the decarbonization of heavy industries. Making the metal is also one of the reasons the climate is changing. The industry is responsible for 7-9% of the greenhouse gas pollution that traps sunlight, heats the planet and makes heat waves hotter and tropical cyclones stronger. This decade for decarbonizing steel Steelmaking is so dirty because it involves heating iron ore with colossal amounts of energy in blast furnaces to extract pure iron. The resulting chemical reaction releases carbon dioxide. About 75% of steel is made this way mostly with coal, the dirtiest fossil fuel in furnaces that operate for 15-20 years before they need to be retired or repaired at great cost. Demand for steel is set to grow a third by 2050, according to the International Energy Agency (IEA). Choices made today on how that steel is produced are decisive for meeting Paris Agreement temperature targets, analysts say. The 2020s are a very critical decade in this regard because more than 70% of the global blast furnace fleet will reach the end of their campaign life and require reinvestment decisions said Wido Witecka, a steel analyst at German climate think tank Agora Energiewende. But in contrast to sectors like power and agriculture, where clean technologies like solar panels and plant-based meats are relatively cheap and easy to scale up, heavy industry’s most promising alternatives are mostly still being developed. Many come with logistical challenges that policymakers have been reluctant to address. Replacing coal and gas with hydrogen made from green electricity One solution is to ditch coal-fired blast furnaces. Steelmakers can instead extract iron from ore by reacting the rock with gas in facilities called direct-reduced iron plants. These iron pellets can then be made into steel in an electric arc furnace, which can run on electricity made from renewable energy. Using fossil gas in the first step is cleaner than using coal, though it still pollutes the atmosphere and heats the planet. European manufacturers like SSAB and ThyssenKrupp are betting they could instead run these plants on hydrogen a gas that can be made cleanly with renewable energy. Instead of oxygen atoms in the ore reacting with carbon atoms in the fossil fuels to make CO2, as they do today, they would instead react with hydrogen atoms to make H2O. The beauty about this concept is, yes, you need a new production process, but as a by-product, you have water instead of carbon dioxide, said Witecka. Last year, SSAB announced it had delivered its first batch of fossil-free steel to carmaker Volvo, which used it to build a truck. But producing this much hydrogen cleanly would require colossal amounts of green energy and could divert supplies away from other sectors that are difficult to clean. Making all of Europe’s steel with hydrogen produced from renewable energy would require 340 terawatt-hours (TWh) of green electricity, according to one recent study. Last year, the European Union’s wind turbines generated 437 TWh of electricity. One of the big challenges is where we build these hydrogen production facilities, said Caitlin Swalec, a steel analyst at US-based non-profit Global Energy Monitor. It needs to happen in places that have that renewable energy capacity. Capturing and storing carbon Another option for steelmakers is to capture carbon coming out of steel plants and store it underground. Carbon capture and storage (CCS) technologies involve catching pollutants before they escape into the atmosphere. But it is unclear what share of emissions CCS can capture from steel or at what cost. The process is likely to be more expensive than in industries like cement because steel factories have multiple sources of pollution. Still, a roadmap to meeting temperature targets from the IEA expects carbon capture to cover half of all steel production by 2050. That would free up hydrogen to be used in other processes that are hard to clean like shipping or fertilizers. But to get there, analysts say, policymakers would need to incentivize CCS development by taxing emissions so traditional production methods reflect the societal cost of polluting. They would also need to fund research and pilot projects to increase CO2 capture rates. One of the reasons why we dont know answers to questions like capture rates or how would it work in a commercial scale is because steel companies havent had to actually reduce their emissions, said Eadbhard Pernot from the Clean Air Task Force, one of the few environmental organizations calling for more investment in carbon capture technology. What about recycling steel? Analysts worry that steelmakers may use the promise of distant fixes to avoid acting now. If steelmakers stick to blast furnaces but CCS doesn’t quickly become cheap or efficient, the coal they burn will keep polluting the atmosphere. If they build direct-reduced iron plants and there isn’t enough green hydrogen, they’ll keep using fossil gas to purify iron ore. Its quite a big risk, said Khandekar. Companies can’t be left alone to take the decisions on their own. To buy more time, society could use steel more carefully. More than a quarter of steel is already made with recycled scrap. There are limits to how often steel can go through this process impurities like nickel and copper can sneak in and weaken the metal. But increasing recycling rates would reduce the amount of iron that needs to be purified. What’s more, the IEA says using steel more efficiently could shave 20% off demand by 2050. Governments could use less of it in public projects, maintain infrastructure for longer and update national building codes to be less wasteful. They could regulate carmakers to build lighter cars instead of heavy SUVs. We’re not going to get completely away from it and we’re never going to reach 100% recycling rates, said Swalec. But we can certainly do much better. Source: DW AH