Popular Science reports: A raft of thin-film silicon bubbles deployed from Earth into outer space and stretching to the size of Brazil could potentially block the Sun's solar radiation from further warming Earth, possibly helping to not only stave off climate change, but potentially reverse it.

This new "space bubbles" plan offered by scientists at the Massachusetts Institute of Technology rifts off a concept first offered by astronomer Roger Angel. The multidisciplinary team of architects, civil and mechanical engineers, physicists and material scientists have worked on the technical and social aspects of what the group calls a "planetary-scale project" in an effort to find a non-Earth-bound solution to climate change.

The MIT group believes that if the raft of bubbles can deflect 1.8 percent of incident solar radiation before it hits Earth, they can fully reverse today's global warming. Even if they can't establish a 1.8 percent shading, they trust a smaller percentage provides enough benefit to help mitigate global warming.

To make it happen, the group proposes deploying small, inflatable bubbles into outer space that they could then manufacture into a space raft the size of Brazil and suspend near the L1 Lagrangian Point, the location between the Earth and Sun where the gravitational influence of both bodies cancel out. The team does suggest having some sort of system to ensure the raft stays in place and that may provide the ability to move the bubbles closer to the Sun for optimal impact....

MIT cautions they don't view the project as a replacement to current adaption and mitigation efforts, but as a backup solution should climate change spin out of control...

They plan to investigate low vapor-pressure materials to rapidly inflate and assemble the rafts, whether with a silicon-based melt or a graphene-reinforced ionic liquid... The team also believes a bit of science fiction may help in finding "novel ways" of shipping the material to space, such as a magnetic accelerator, known as a railgun.

Slashdot reader DevNull127 writes: The BBC looks at a 100-year art project in which famous authors write books that will not be published until the year 2113. An annual ceremony takes place near a forest of sapling trees which will be turned into paper in the year 2113 and then used for printing those books.
From the article: It began with the author Margaret Atwood, who wrote a story called Scribbler Moon, and since then the library has solicited submissions from all over the world... All the manuscripts will be stored for almost a century inside locked glass drawers in a hidden corner of Oslo's main public library, within a small, wooden repository called the Silent Room. In 2114, the drawers will be unlocked, and the trees chopped down — and 100 stories hidden for a century will finally be published in one go.
It's part of Scottish artist Katie Paterson's fascination with the passage of time: One of her first works, Vatnajokull (the sound of) [included] a phone number that anyone could call to listen to an Icelandic glacier melting. Dial the number, and you'd be routed to a microphone beneath the water in the Jökulsárlón lagoon on Iceland's south coast, where blue-tinged icebergs calve away and float towards the sea....

One of her most recent exhibitions in Edinburgh, Requiem at Ingleby Gallery, featured 364 vials of crushed dust, each one representing a different moment in deep time. Vial #1 was a sample of presolar grains older than the Sun, followed by powdered four-billion-year-old rocks, corals from prehistoric seas, and other traces of the distant past. A few visitors were invited to pour one of the vials into a central urn: when I was there in June, I poured #227, a four-million-year-old Asteroidea fossil, a kind of sea star....

Of all her work exploring the long-term though, Future Library is the project most likely to be remembered across time itself. Indeed, it was deliberately created to be. And this year its longevity was ensured: Oslo's city leaders signed a contract formally committing them and their successors to protect the forest and library over the next 100 years.

The Associated Press reports on a massive new 150-foot (45-meter) tower going up in Berlin — just to hold 56 million liters (14.8 million gallons) of hot water that "will help heat Berlin homes this winter even if Russian gas supplies dry up..."

"[T]he new facility unveiled Thursday at Vattenfall's Reuter power station will hold water brought to almost boiling temperature using electricity from solar and wind power plants across Germany. During periods when renewable energy exceeds demand the facility effectively acts as a giant battery, though instead of storing electricity it stores heat..." "It's a huge thermos that helps us to store the heat when we don't need it," said Tanja Wielgoss, who heads the Sweden-based company's heat unit in Germany. "And then we can release it when we need to use it.... Sometimes you have an abundance of electricity in the grids that you cannot use anymore, and then you need to turn off the wind turbines," said Wielgoss. "Where we are standing we can take in this electricity."

The 50-million-euro ($52 million) facility will have a thermal capacity of 200 Megawatts — enough to meet much of Berlin's hot water needs during the summer and about 10% of what it requires in the winter. The vast, insulated tank can keep water hot for up to 13 hours, helping bridge short periods when there's little wind or sun....

Berlin's top climate official, Bettina Jarasch, said the faster such heat storage systems are built, the better. "Due to its geographic location the Berlin region is even more dependent on Russian fossil fuels than other parts of Germany," she told The Associated Press. "That's why we're really in a hurry here."
"While it will be Europe's biggest heat storage facility when it's completed at the end of this year, an even bigger one is already being planned in the Netherlands."

Photosynthesis "is very inefficient, with only about 1% of the energy found in sunlight ending up in the plant," according to a new announcement from the University of California, Riverside. But now scientists at the school and the University of Delaware "have found a way to bypass the need for biological photosynthesis altogether and create food independent of sunlight by using artificial photosynthesis." The research, published in Nature Food, uses a two-step electrocatalytic process to convert carbon dioxide, electricity, and water into acetate, the form of the main component of vinegar. Food-producing organisms then consume acetate in the dark to grow. Combined with solar panels to generate the electricity to power the electrocatalysis, this hybrid organic-inorganic system could increase the conversion efficiency of sunlight into food, up to 18 times more efficient for some foods.

"With our approach we sought to identify a new way of producing food that could break through the limits normally imposed by biological photosynthesis," said corresponding author Robert Jinkerson, a UC Riverside assistant professor of chemical and environmental engineering...

Experiments showed that a wide range of food-producing organisms can be grown in the dark directly on the acetate-rich electrolyzer output, including green algae, yeast, and fungal mycelium that produce mushrooms. Producing algae with this technology is approximately fourfold more energy efficient than growing it photosynthetically. Yeast production is about 18-fold more energy efficient than how it is typically cultivated using sugar extracted from corn. "We were able to grow food-producing organisms without any contributions from biological photosynthesis..." said Elizabeth Hann, a doctoral candidate in the Jinkerson Lab and co-lead author of the study. The potential for employing this technology to grow crop plants was also investigated. Cowpea, tomato, tobacco, rice, canola, and green pea were all able to utilize carbon from acetate when cultivated in the dark....

By liberating agriculture from complete dependence on the sun, artificial photosynthesis opens the door to countless possibilities for growing food under the increasingly difficult conditions imposed by anthropogenic climate change. Drought, floods, and reduced land availability would be less of a threat to global food security if crops for humans and animals grew in less resource-intensive, controlled environments. Crops could also be grown in cities and other areas currently unsuitable for agriculture, and even provide food for future space explorers.

"Using artificial photosynthesis approaches to produce food could be a paradigm shift for how we feed people," said corresponding author Robert Jinkerson, a UC Riverside assistant professor of chemical and environmental engineering. "By increasing the efficiency of food production, less land is needed, lessening the impact agriculture has on the environment. And for agriculture in non-traditional environments, like outer space, the increased energy efficiency could help feed more crew members with less inputs...."

"Imagine someday giant vessels growing tomato plants in the dark and on Mars — how much easier would that be for future Martians?" said co-author Martha Orozco-Cárdenas, director of the UC Riverside Plant Transformation Research Center.
Thans to Slashdot reader John.Banister for sharing the link!

Engineers at MIT and the National Renewable Energy Laboratory (NREL) have designed a heat engine with no moving parts. It converts heat to electricity with over 40% efficiency -- making it more efficient than steam turbines, the industrial standard. MIT Technology Review reports: The invention is a thermophotovoltaic (TPV) cell, similar to a solar panel's photovoltaic cells, that passively captures high-energy photons from a white-hot heat source. It can generate electricity from sources that reach 1,900 to 2,400C -- too hot for turbines, with their moving parts. The previous record efficiency for a TPV cell was 32%, but the team improved this performance by using materials that are able to convert higher-temperature, higher-energy photons. The researchers plan to incorporate the TPV cells into a grid-scale thermal battery. The system would absorb excess energy from renewable sources such as the sun and store that energy in heavily insulated banks of hot graphite. Cells would convert the heat into electricity and dispatch it to a power grid when needed.

The researchers have now successfully demonstrated the main parts of the system in small-scale experiments; the experimental TPV cells are about a centimeter square. They are working to integrate the parts to demonstrate a fully operational system. From there, they hope to scale up the system to replace fossil-fuel plants on the power grid. Coauthor Asegun Henry, a professor of mechanical engineering, envisions TPV cells about 10,000 feet square and operating in climate-controlled warehouses to draw power from huge banks of stored solar energy.

An anonymous reader quotes a report from The Register: Scientists at top universities in China propose sending a spacecraft powered by nuclear fission to orbit Neptune -- the outermost planet in our solar system -- in 2030. Astronomers have not yet been able to look at Uranus and Neptune in much detail. The best data collected so far comes from NASA's Voyager 2, the only spacecraft to have flown by the big blue orbs way back in 1986 and 1989. [...] The challenges involved are considerable. The outer solar system is cold, dark, and cruel. Spacecraft flying far from the Sun cannot rely on solar power, and need other sources of energy to maintain steady orbits and keep their instruments from freezing.

The Chinese authors envisioned a spacecraft with a mass up to 3,000 kilograms powered by a nuclear fission reactor at one end. It would also carry four smaller satellites -- two to study Neptune's atmosphere and another two to probe Triton, its largest moon, The Planetary Society first reported. Triton is an odd object -- it orbits in the opposite direction to its host planet, is geologically active, and may harbor liquid oceans beneath its icy crust. The best time to launch such a spacecraft would be 2030, the scientists reckoned. It could fly aboard China National Space Administration's Long March 5 rocket, and would reach Neptune a decade later after flying by the gas giants Jupiter and Saturn.

A group of MIT researchers is exploring a radical idea for reversing global warming: using a raft of "space bubbles" to reflect sunlight away from our planet. Freethink reports: The copious amounts of greenhouse gasses humans have been releasing into the air ever since the Industrial Revolution are forming a sort of blanket around our planet, trapping heat in the atmosphere and causing global temperatures to creep ever higher. [...] Instead of injecting particles into Earth's atmosphere to cool the planet, an interdisciplinary team of MIT researchers proposes we take solar geoengineering to space. Specifically, the group is investigating what might happen if we positioned a shield made of bubbles at Lagrangian Point 1 -- a point in space where the gravitational pulls of the Earth and the sun form a sort of equilibrium that would keep the shield in orbit there indefinitely.

The proposed shield would be about the size of Brazil, and the bubbles for it could be manufactured and deployed in space, possibly out of silicon -- the group has already experimented with creating these "space bubbles" in the lab. "In our preliminary experiments, we succeeded at inflating a thin-film bubble at a pressure of 0.0028 atm, and maintaining it at around -50C (to approximate space conditions of zero pressure and near-zero temperature)," they said in a press release. Because the bubbles would be almost a million miles away from Earth, the MIT team says this approach to solar geoengineering wouldn't be as risky as methods that directly involve Earth's atmosphere. [...] This isn't the first time someone has proposed placing a solar shield in space to cool the planet, but creating it out of bubbles would give us a relatively straightforward way to abort the mission if it went awry: just pop the bubbles.

nickwinlund77 shares a report from Phys.Org: A new study led by University of Arizona researchers may have solved two mysteries that have long puzzled paleo-climate experts: Where did the ice sheets that rang in the last ice age more than 100,000 years ago come from, and how could they grow so quickly? Understanding what drives Earth's glacial -- interglacial cycles -- the periodic advance and retreat of ice sheets in the Northern Hemisphere -- is no easy feat, and researchers have devoted substantial effort to explaining the expansion and shrinking of large ice masses over thousands of years. The new study, published in the journal Nature Geoscience, proposes an explanation for the rapid expansion of the ice sheets that covered much of the Northern Hemisphere during the most recent ice age, and the findings could also apply to other glacial periods throughout Earth's history.

About 100,000 years ago, when mammoths roamed the Earth, the Northern Hemisphere climate plummeted into a deep freeze that allowed massive ice sheets to form. Over a period of about 10,000 years, local mountain glaciers grew and formed large ice sheets covering much of today's Canada, Siberia and northern Europe. While it has been widely accepted that periodic "wobbling" in the Earth's orbit around the sun triggered cooling in the Northern Hemisphere summer that caused the onset of widespread glaciation, scientists have struggled to explain the extensive ice sheets covering much of Scandinavia and northern Europe, where temperatures are much more mild. [...] "Using both climate model simulations and marine sediment analysis, we show that ice forming in northern Canada can obstruct ocean gateways and divert water transport from the Arctic into the North Atlantic," [said Lofverstrom, an assistant professor of geosciences and head of the UArizona Earth System Dynamics Lab], "and that in turn leads to a weakened ocean circulation and cold conditions off the coast of Scandinavia, which is sufficient to start growing ice in that region."

"These findings are supported by marine sediment records from the North Atlantic, which show evidence of glaciers in northern Canada several thousand years before the European side," said Diane Thompson, assistant professor in the UArizona Department of Geosciences. "The sediment records also show compelling evidence of a weakened deep ocean circulation before the glaciers form in Scandinavia, similar to our modeling results." Together, the experiments suggest that the formation of marine ice in northern Canada may be a necessary precursor to glaciation in Scandinavia, the authors write. [...] "It is possible that the mechanisms we identified here apply to every glacial period, not just the most recent one," [Lofverstrom] said. "It may even help explain more short-lived cold periods such as the Younger Dryas cold reversal (12,900 to 11,700 years ago) that punctuated the general warming at the end of the last ice age."

"In late 2021, operators of the European Space Agency's Swarm constellation noticed something worrying," reports Space.com. "The satellites, which measure the magnetic field around Earth, started sinking toward the atmosphere at an unusually fast rate — up to 10 times faster than before.

"The change coincided with the onset of the new solar cycle, and experts think it might be the beginning of some difficult years for spacecraft orbiting our planet." "In the last five, six years, the satellites were sinking about two and a half kilometers [1.5 miles] a year," Anja Stromme, ESA's Swarm mission manager, told Space.com. "But since December last year, they have been virtually diving. The sink rate between December and April has been 20 kilometers [12 miles] per year."

Satellites orbiting close to Earth always face the drag of the residual atmosphere, which gradually slows the spacecraft and eventually makes them fall back to the planet. (They usually don't survive this so-called re-entry and burn up in the atmosphere.) This atmospheric drag forces the International Space Station's controllers to perform regular "reboost" maneuvers to maintain the station's orbit of 250 miles (400 km) above Earth. This drag also helps clean up the near-Earth environment from space junk.

Scientists know that the intensity of this drag depends on solar activity — the amount of solar wind spewed by the sun, which varies depending on the 11-year solar cycle.... [S]ince last fall, the star has been waking up, spewing more and more solar wind and generating sunspots, solar flares and coronal mass ejections at a growing rate. And the Earth's upper atmosphere has felt the effects. "There is a lot of complex physics that we still don't fully understand going on in the upper layers of the atmosphere where it interacts with the solar wind," Stromme said. "We know that this interaction causes an upwelling of the atmosphere. That means that the denser air shifts upwards to higher altitudes."

Denser air means higher drag for the satellites. Even though this density is still incredibly low 250 miles above Earth, the increase caused by the upwelling atmosphere is enough to virtually send some of the low-orbiting satellites plummeting. "It's almost like running with the wind against you," Stromme said. "It's harder, it's drag — so it slows the satellites down, and when they slow down, they sink...." The lower the orbit of the satellites when the solar storm hits, the higher the risk of the spacecraft not being able to recover, leaving operators helplessly watching as the craft fall to their demise in the atmosphere....

All spacecraft around the 250-mile altitude are bound to have problems, Stromme said. That includes the International Space Station, which will have to perform more frequent reboost maneuvers to keep afloat, but also the hundreds of cubesats and small satellites that have populated low Earth orbit in the past decade.... "Many of these [new satellites] don't have propulsion systems," Stromme said. "They don't have ways to get up. That basically means that they will have a shorter lifetime in orbit. They will reenter sooner than they would during the solar minimum."
Thanks to long-time Slashdot reader schwit1 for sharing the article!

"China's Mars sample return mission aims to collect samples from the Red Planet and deliver them to Earth in 2031, or two years ahead of a NASA and ESA joint mission," reports SpaceNews: Lifting off in late 2028... the complex, multi-launch mission will have simpler architecture in comparison with the joint NASA-ESA project, with a single Mars landing and no rovers sampling different sites. However, if successful, it would deliver to Earth the first collected Martian samples; an objective widely noted as one of the major scientific goals of space exploration....

The mission will build on the Mars entry, descent and landing technologies and techniques demonstrated by Tianwen-1 in May 2021, as well as the regolith sampling, automated lunar orbit rendezvous and docking, and high velocity atmospheric reentry success achieved by the 2020 Chang'e-5 lunar sample return mission.... Landing on Mars would take place around September 2029. Sampling techniques will include surface sampling, drilling and mobile intelligent sampling, potentially using a four-legged robot.

The ascent vehicle will consist of two stages, using either solid or liquid propulsion, and will be required to reach a speed of 4.5 kilometers per second, according to the presentation. After rendezvous and docking with the waiting orbiter, the spacecraft will depart Mars orbit in late October 2030 for a return to Earth in July 2031.

Sun Zezhou [chief designer of the Tianwen-1 Mars orbiter and rover mission], added that the Tianwen-1 orbiter will conduct an aerobraking test in Mars orbit later this year as part of the sample return mission preparation.
Thanks to Slashdot reader Hmmmmmm for sharing the story!

An anonymous reader quotes a report from Interesting Engineering: Seattle-based Zap Energy is using a lesser-known approach to nuclear fusion to build modular, garage-sized reactors. They are cheaper and don't require the large, incredibly powerful magnets used in traditional fusion experiments. Ultimately, they may also provide a quicker route to achieving commercially viable nuclear fusion, a press statement reveals.

Nuclear fusion has the potential to remove our reliance on fossil fuels by providing a practically limitless energy source that produces power in a similar way to the Sun and the stars. Fusion experiments, such as Europe's ITER, typically rely on large donut-shaped tokamak reactors using extremely powerful magnets to control the plasma generated during the fusion reaction. Zap Energy has developed a different approach with its Z-pinch technology. The company uses an electromagnetic field instead of the expensive magnetic coils and shielding materials used in tokamaks. This, they say, pins the plasma inside a relatively small space and "pinches" it until it becomes hot and dense enough for the required reaction to take place.

Z-pinch technology was first thought up in the 1950s, but until recently, instability problems meant that research had been largely focused on the more stable tokamak technology. In 2019, a group of researchers from the University of Washington proposed the use of sheared axial flow to smooth the plasma streams, preventing distortions that previously led to instability. One of the authors of that study, Uri Shumlak, co-founded Zap Energy in 2017 in a bid to leverage the sheared axial flow technique to make Z-pinch technology commercially viable. Just last week, Zap Energy reached a key milestone by creating the first plasmas inside its prototype reactor, called the FuZE-Q. The Zap Energy team also just closed a $160-million Series C funding round, which will help it to further develop its Z-pinch technology and hopefully bring it to the market. The company says its reactors could be small enough to fit inside a garage, meaning it could give both micro nuclear reactor and nuclear fusion firms a run for their money.

The Sun shone 20% less brightly on early Earth, and yet fossil evidence shows that our planet had warm shallow seas where stromatolites -- microbial mats -- thrived. Now a study may have solved the "faint young Sun paradox," showing that saltier oceans could have prevented Earth from freezing over during Archean times, 3bn years ago. From a report: We all know that the composition of the atmosphere (particularly the abundance of greenhouse gases) plays a crucial role in tempering Earth's climate, but what about the composition of the oceans? To answer this question researchers used an ocean-atmosphere general circulation model to investigate the impact of salinity.

They show that saltier oceans result in warmer climates, partly because the salt depresses the freezing point of seawater and inhibits sea-ice formation, but mostly because the greater density of salty water alters ocean circulation patterns and aids heat transport to the poles. Under their Archean scenario they show that present-day levels of salinity produce a severely glaciated world with only a narrow strip of open water at the equator. But pushing salinity up to 40% greater than today revealed a warmer Archean world, with average surface temperatures of more than 20C, and ice only appearing seasonally at the poles. Their findings are reported in Geophysical Research Letters.

Nasa has begun turning off the spacecraft Voyager's systems, signaling the beginning of the end of the probe's 50-year career. The Independent reports: Voyager 1 and Voyager 2 -- two identical probes -- were launched in 1977 and travelled across interstellar space to the edge of the solar system, giving humanity its closest look at the moons of Jupiter and Saturn. Now, however, Nasa must start limiting the Voyagers' processes in order to keep them operating until 2030. "We're at 44 and a half years," says Ralph McNutt, a physicist at the Johns Hopkins University Applied Physics Laboratory, told Scientific American. "So we've done 10 times the warranty on the darn things."

The first Voyager craft has four remaining functioning instruments, while Voyager 2 has five, all of which are powered by converting decaying plutonium into electricity. This battery has had its output decreasing by approximately four watts every year, leading to Nasa making some tough choices about what to disable; in 2019, engineers had to turn off the heater for the cosmic-ray detector, a key piece of equipment for detecting when Voyager 2 exited the heliosphere- the magnetosphere, astrosphere and outermost atmospheric layer of the Sun.

The final instruments Nasa will disable are likely to be the magnetometer and the plasma science instrument, which are contained in the body of the spacecraft. These are warmed by the excess heat of the computers, while the others are suspended on a 13 meter fiberglass boom, meaning that they are likely to take the longest to get cold. Both craft remain so far from Earth that it takes a radio signal almost 22 hours to reach Voyager 1 and just over 18 for Voyager 2 -- even when traveling at the speed of light.

RISC OS, the operating system of the original Arm computer, the Acorn Archimedes, is still very much alive -- and doing relatively well for its age. The Register reports: In June 1987, Acorn launched the Archimedes A305 and A310, starting at $982 and running a new operating system called Arthur. At the time, it was a radical and very fast computer. In his review (PDF) for Personal Computer World, Dick Pountain memorably said: "It loads huge programs with a faint burping noise, in the time it takes to blink an eye." Arthur was loosely related to Acorn's earlier MOS, the BBC Micro operating system but looked very different thanks to a prototype graphical desktop, implemented in BBC BASIC, that could charitably be called "technicolor." Renamed RISC OS, version 2 followed in 1989 -- the same year that Sun started selling its new SPARCstation 1 (a snip at $9,200) and DEC launched the MIPS R2000-chipset-based DECstation 3100 (for $10,800).

RISC OS has had a rather convoluted history, partly due to Acorn spinning out Arm, eventually pulling out of the computer market, rebranding as Element 14 and being acquired by Broadcom, where Arm co-designer Sophie Wilson still works today. And partly due to drama over the ownership of the OS post-Acorn at one point. One fork of RISC OS still supports Acorn-era Arm's odd 26-bit mode, meaning that today it mostly runs on the commercial Virtual Acorn emulator. The other branch, designed for the 32-bit mode of more recent Arm chips, is now owned by RISC OS Developments, which made it fully open source back in 2018. Development and maintenance is done by the team at RISC OS Open Ltd -- ROOL for short -- which offers downloads for a variety of current Arm hardware, such as the Titanium desktops. [...]

RISC OS Developments are still working on new functionality for the OS. Notably, it recently released a new TCP/IP stack, derived from OpenBSD. Right now, the main benefit is IPv6 support. A feature more significant to most users is still in development: Wi-Fi support. Also still under development, but available to paid backers, is a new RISC OS web browser, Iris. RISC OS does come with a choice of browsers -- NetSurf and Otter -- but the plan is that the new Iris browser will be a native app, with the RISC OS look and feel, but using the WebKit engine for better compatibility with the modern web. The main remaining limitation is SMP. As an OS from the 1980s, long before the 21st-century technology of mainstream multicore processors, RISC OS practically only supports a single CPU core. Various experimental efforts are under way to address this. One has got NetBSD running on another core, and another has the experimental Genode OS running alongside RISC OS. Another effort is working on adding SMP support into the RISC OS kernel itself.

Earlier this week China's giant Sky Eye telescope detected signals it thought could be from an alien civilizations.

But now there's an update from LiveScience: Dan Werthimer, a Search For Extraterrestrial Intelligence (SETI) researcher at the University of Berkeley, California and a coauthor on the research project which first spotted the signals, told Live Science that the narrow-band radio signals he and his fellow researchers found "are from [human] radio interference, and not from extraterrestrials....

"The big problem, and the problem in this particular case, is that we're looking for signals from extraterrestrials, but what we find is a zillion signals from terrestrials," Werthimer told Live Science. "They're very weak signals, but the cryogenic receivers on the telescopes are super sensitive and can pick up signals from cell phones, television, radar and satellites — and there are more and more satellites in the sky every day. If you're kind of new in the game, and you don't know all these different ways that interference can get into your data and corrupt it, it's pretty easy to get excited...."

The recent false alarm is one of several instances in which alien-hunting scientists have been misled by noise from human activity. In 2019, astronomers spotted a signal beamed to Earth from Proxima Centauri — the nearest star system to our sun (sitting roughly 4.2 light-years away) and home to at least one potentially habitable planet. The signal was a narrow-band radio wave typically associated with human-made objects, which led scientists to entertain the thrilling possibility that it came from alien technology. Studies released two years later, however, suggested that the signal was most likely produced by malfunctioning human equipment, Live Science previously reported. Similarly, another famous set of signals once supposed to have come from aliens, detected between 2011 and 2014, turned out to have actually been made by scientists microwaving their lunches.
Werthimer tells the New York Times unequivocally that "These signals are from radio interference; they are due to radio pollution from earthlings, not from E.T."

But the Times also got a comment from Paul Horowitz, an emeritus professor of physics at Harvard who created his own alien-listening campaign called Project Meta, funded by the Planetary Society. Those who endure profess not to be discouraged by the Great Silence, as it is called, from out there. They've always been in the search for the long run, they say. "The Great Silence is hardly unexpected," said Dr. Horowitz, including because only a fraction of a percent of the 200 million stars in the Milky Way have been surveyed. Nobody ever said that detecting that rain of alien radio signals would be easy.
Even Dan Werthimer concedes to LiveScience, "I think it'd be very strange if we're the only ones. If you look at the numbers, there's a trillion planets in the galaxy — five times more planets than there are stars. A lot of them are little dinky planets like Earth. Many of them have liquid water, so intelligent life, while not as common as bacterial life, could still be fairly common."

Astronomers have unveiled the most detailed survey of the Milky Way, revealing thousands of "starquakes" and stellar DNA, and helping to identify the most habitable corners of our home galaxy. From a report: The observations from the European Space Agency's Gaia probe cover almost two billion stars -- about 1% of the total number in the galaxy -- and are allowing astronomers to reconstruct our home galaxy's structure and find out how it has evolved over billions of years. Previous surveys by Gaia, a robotic spacecraft launched in 2013, have pinpointed the motion of the stars in our home galaxy in exquisite detail. By rewinding these movements astronomers can model how our galaxy has morphed over time. The latest observations add details of chemical compositions, stellar temperatures, colours, masses and ages based on spectroscopy, where starlight is split into different wavelengths.

These measurements unexpectedly revealed thousands of starquakes, cataclysmic tsunami-like events on the surface of stars. "Starquakes teach us a lot about stars -- notably, their internal workings," said Conny Aerts of KU Leuven in Belgium, who is a member of the Gaia collaboration. "Gaia is opening a goldmine for asteroseismology of massive stars." Dr George Seabroke, senior research associate at Mullard space science laboratory at University College London, said: "If you can see these stars changing in brightness halfway across the Milky Way, if you were anywhere near them, it would be like the sun changing shape in front of your eyes." Gaia is fitted with a 1bn pixel camera -- the largest ever in space -- complete with more than 100 electronic detectors. The latest dataset represents the largest chemical map of the galaxy to date, cataloguing the composition of six million stars, ten times the number measured in previous ground-based catalogues.

"If, as astronomers believe, the death of large stars leave behind black holes, there should be hundreds of millions of them scattered throughout the Milky Way galaxy," notes an announcement from the University of California at Berkeley. "The problem is, isolated black holes are invisible.

"Now, a team led by University of California, Berkeley, astronomers has for the first time discovered what may be a free-floating black hole by observing the brightening of a more distant star as its light was distorted by the object's strong gravitational field — so-called gravitational microlensing." The team, led by graduate student Casey Lam and Jessica Lu, a UC Berkeley associate professor of astronomy, estimates that the mass of the invisible compact object is between 1.6 and 4.4 times that of the sun. Because astronomers think that the leftover remnant of a dead star must be heavier than 2.2 solar masses in order to collapse to a black hole, the UC Berkeley researchers caution that the object could be a neutron star instead of a black hole. Neutron stars are also dense, highly compact objects, but their gravity is balanced by internal neutron pressure, which prevents further collapse to a black hole.

Whether a black hole or a neutron star, the object is the first dark stellar remnant — a stellar "ghost" — discovered wandering through the galaxy unpaired with another star.

"This is the first free-floating black hole or neutron star discovered with gravitational microlensing," Lu said. "With microlensing, we're able to probe these lonely, compact objects and weigh them. I think we have opened a new window onto these dark objects, which can't be seen any other way...." The analysis by Lam, Lu and their international team has been accepted for publication in The Astrophysical Journal Letters. The analysis includes four other microlensing events that the team concluded were not caused by a black hole, though two were likely caused by a white dwarf or a neutron star.

The team also concluded that the likely population of black holes in the galaxy is 200 million — about what most theorists predicted.

Notably, a competing team from the Space Telescope Science Institute (STScI) in Baltimore analyzed the same microlensing event and claims that the mass of the compact object is closer to 7.1 solar masses and indisputably a black hole. A paper describing the analysis by the STScI team, led by Kailash Sahu, has been accepted for publication in The Astrophysical Journal....

The astrometric data came from NASA's Hubble Space Telescope.... While surveys like these discover about 2,000 stars brightened by microlensing each year in the Milky Way galaxy, the addition of astrometric data is what allowed the two teams to determine the mass of the compact object and its distance from Earth.

"Power-hungry, fossil-fuel dependent Japan has successfully tested a system that could provide a constant, steady form of renewable energy, regardless of the wind or the sun," reports Bloomberg: For more than a decade, Japanese heavy machinery maker IHI Corp. has been developing a subsea turbine that harnesses the energy in deep ocean currents and converts it into a steady and reliable source of electricity.... Called Kairyu, the 330-ton prototype is designed to be anchored to the sea floor at a depth of 30-50 meters (100-160 feet).

In commercial production, the plan is to site the turbines in the Kuroshio Current, one of the world's strongest, which runs along Japan's eastern coast, and transmit the power via seabed cables.... Japan's New Energy and Industrial Technology Development Organization (NEDO) estimates the Kuroshio Current could potentially generate as much as 200 gigawatts — about 60% of Japan's present generating capacity....

Japan is already the world's third largest generator of solar power and is investing heavily in offshore wind, but harnessing ocean currents could provide the reliable baseline power needed to reduce the need for energy storage or fossil fuels.
Thanks to long-time Slashdot reader AmiMoJo for sharing the article!

"NASA's DAVINCI mission to Venus is scheduled for launch in 2029," reports Gizmodo, adding that a new paper "details this upcoming journey, a daring mission that could shed new light on the scorching hot planet's mysterious, and potentially habitable, past." Upon its arrival at the second planet from the Sun, the probe will plunge through Venus' atmosphere, ingesting its gases for approximately one hour before landing on the planet's surface, according to the paper published in The Planetary Science Journal. DAVINCI is designed to act as a flying chemistry lab, and it will use its built-in instruments to analyze Venus's atmosphere, temperatures, pressure and wind speed, while taking a few photos of its trip through planetary hell...

If it survives the atmospheric entry, the probe will — hopefully — land in the Alpha Regio mountains, which are roughly the size of Texas, according to the researchers behind the new paper. Under ideal conditions, the probe will operate for 17 to 18 minutes once it sticks the landing, but it isn't really required to operate on Venus since all the precious data will have already been collected during its atmospheric plunge.
Digital Trends calls Venus "a frontier in planetary science about which very little is known" — then explains why that is. The biggest issue for any potential mission to Venus is the heat, as the surface temperatures can be as high as 900 degrees Fahrenheit (475 degrees Celsius). That's hot enough to melt lead, and it wreaks havoc with electronics... The pressure at the surface is around 95 bars, or nearly 100 times the atmospheric pressure on Earth's surface, so engineering a probe for this kind of environment is kind of like building a submarine... To keep the probe active for as long as possible, it is spherical and covered in a thick titanium shell to withstand the pressure and insulate against the heat. Then there's more insulation inside this shell, made of special materials including astroquartz, a type of fiber made from fused quartz... It's then filled with carbon dioxide gas to protect the high-voltage electronics from sparking and to stop any Earth gases from leaking in during launch....

The descent sphere will also have a camera that will be snapping high-contrast images of the surface, which can then be built up into 3D maps. For a camera to operate from inside a metal sphere, though, you need a window. And glass isn't a great material for dealing with intensely high-pressure environments. That's why DAVINCI's window will be made not of glass but sapphire... "Our final images will have 10-centimeter resolution," said the team's principal investigator, Jim Garvin. "That's the scale you'd see looking out across your living room...."

Researchers know that the clouds of Venus have drops of sulfuric acid in them — and sulfuric acid eats through materials. It's a particular concern for the Kevlar lanyard that will attach the descent sphere to the parachute. So to test whether the lanyard can withstand the acidic environment, the engineers don't just suspend it in a few drops of acid — they coat the entire surface in acid, then test the lanyard's pull strength to make sure it can survive long enough to take the probe through the atmosphere even in the worst possible case.
SciTechDaily notes DAVINCI "is the first mission to study Venus using both spacecraft flybys and a descent probe....

"It will also provide the first descent imaging of the mountainous highlands of Venus while mapping their rock composition and surface relief at scales not possible from orbit."

"Venus crossed the sun's face 10 years ago today," writes Space.com. "Most people alive will never see the sight again."

Long-time Slashdot reader davidwr is still thinking about it: Slashdot, what are your memories of the 2012 or 2004 transits? What about other celestial events that you probably won't live long enough to see again?
At Space.com, astronomer Tom Kress points out Mercury transits are more common, occurring about 13 times each century — and supplies some context (along with some cool photos): In 1639, English astronomer Jeremiah Horrocks had improved on Kepler's tables using his own observations and aptitude for mathematics. He predicted a transit of Venus in December of that year with just a few weeks' notice, and sure enough it occurred. Kepler had miscalculated, and Horrocks became one of the only people in the world to have seen a transit of Venus....

Only six Venus transits have occurred since: in 1761 (as predicted by Kepler), 1769, 1874, 1882, 2004 and 2012. They come in pairs separated by eight years, but with more than a century between each set. The next transit won't occur until 2117 and, with this in mind, I made every effort to witness the entirety of the last one 10 years ago....

Shortly after noon local time, the black edge of the silhouette of Venus emerged on the face of the sun... A chorus of vocal awe erupted across the crowd of skywatchers, culminating in cheers of excitement as Venus' night-side began its rapid ingress onto the disk of the sun — a process that took just over 15 minutes....

I couldn't help but feel closer to Venus than I really was, standing on a huge terrestrial volcano and looking out at the most volcanic planet in the solar system.