Tech News
Have we finally solved mystery of magnetic moon rocks?
Science - Posted On:2025-05-23 16:15:00 Source: arstechnica
NASA's Apollo missions brought back moon rock samples for scientists to study. We've learned a great deal over the ensuing decades, but one enduring mystery remains. Many of those lunar samples show signs of exposure to strong magnetic fields comparable to Earth's, yet the Moon doesn't have such a field today. So, how did the moon rocks get their magnetism?
There have been many attempts to explain this anomaly. The latest comes from MIT scientists, who argue in a new paper published in the journal Science Advances that a large asteroid impact briefly boosted the Moon's early weak magnetic field—and that this spike is what is recorded in some lunar samples.
Evidence gleaned from orbiting spacecraft observations, as well as results announced earlier this year from China's Chang'e 5 and Chang'e 6 missions, is largely consistent with the existence of at least a weak magnetic field on the early Moon. But where did this field come from? These usually form in planetary bodies as a result of a dynamo, in which molten metals in the core start to convect thanks to slowly dissipating heat. The problem is that the early Moon's small core had a mantle that wasn't much cooler than its core, so there would not have been significant convection to produce a sufficiently strong dynamo.
'Landmark' Evolution Study Shows How Rice Inherits Tolerance To Cold Without DNA Changes
science - Posted On:2025-05-23 14:15:00 Source: slashdot
Rice plants can inherit tolerance to cold without changes to their genomes, according to a decade-long study carried out by researchers in China. From a report: The work, published in Cell this week, strengthens the evidence for a form of evolution in which environmental pressures induce heritable changes that do not alter an organism's DNA. The study conducted experiments that demonstrate, for the first time, the mechanism for these changes -- 'epigenetic' tweaks to chemical markers on the plant's DNA that don't actually tinker with the sequences themselves. "What they're showing is extremely convincing; I would say that it's a landmark in the field," says Leandro Quadrana, a plant geneticist at the French National Centre for Scientific Research in Paris-Saclay. Michael Skinner, who studies epigenetic inheritance at Washington State University in Pullman, says the study adds to the growing body of evidence challenging the prevailing view of evolution that the only way that adaptations emerge is through gradual natural selection of randomly arising DNA mutations. This study shows that the environment isn't just a passive actor in evolution, but a selective force inducing a targeted change. Read more of this story at Slashdot.
America's Leading Alien Hunters Depend on AI to Speed Their Search
science - Posted On:2025-05-23 13:30:00 Source: slashdot
Harvard University's Galileo Project is using AI to automate the search for unidentified anomalous phenomena, marking a significant shift in how academics approach what was once considered fringe research. The project operates a Massachusetts observatory equipped with infrared cameras, acoustic sensors, and radio-frequency analyzers that continuously scan the sky for unusual objects. Researchers Laura Domine and Richard Cloete are training machine learning algorithms to recognize all normal aerial phenomena -- planes, birds, drones, weather balloons -- so the system can flag genuine anomalies for human analysis. The team uses computer vision software called YOLO (You Only Look Once) and has generated hundreds of thousands of synthetic images to train their models, though the software currently identifies only 36% of aircraft captured by infrared cameras. The Pentagon is pursuing parallel efforts through its All-domain Anomaly Resolution Office, which has examined over 1,800 UAP reports and identified 50 to 60 cases as "true anomalies" that government scientists cannot explain. AARO has developed its own sensor suite called Gremlin, using similar technology to Harvard's observatory. Both programs represent the growing legitimization of UAP research following 2017 Defense Department disclosures about military encounters with unexplained aerial phenomena. Read more of this story at Slashdot.
Sharp Knives Reduce Onion-Induced Tears By Limiting Droplet Spray, Study Finds
science - Posted On:2025-05-23 12:15:00 Source: slashdot
Cornell University researchers have solved a kitchen mystery by demonstrating that sharp knives produce fewer and slower-moving droplets when cutting onions compared to dull blades. The findings used high-speed cameras and particle tracking to analyze droplet formation during onion cutting at speeds up to 20,000 frames per second. The team discovered that onion droplets form through a two-stage process: an initial violent ejection driven by internal pressure, followed by slower fragmentation of liquid streams in air. Blunter blades create up to 40 times more droplets because the onion's tough outer skin acts as a barrier, allowing the softer interior tissue to compress significantly before rupturing and releasing pressurized liquid. The research reveals that droplets are ejected at speeds between 1 and 40 meters per second, with the fastest ones posing the greatest risk of reaching a cook's eyes. Beyond tear reduction, the study suggests sharp knives may also limit the spread of foodborne pathogens, since atomized droplets can carry bacteria like Salmonella from contaminated cutting boards. Read more of this story at Slashdot.
US solar keeps surging, generating more power than hydro in 2025
Science - Posted On:2025-05-23 12:00:01 Source: arstechnica
In the US, many newly constructed generating facilities are brought online at the end of the year to qualify for tax incentives. Since much of the US's new generating capacity is solar power, that has led to a boom in solar production to start the year in recent years. With the first three months of data in for 2025, it's clear this year is no exception: Solar power is up a staggering 44 percent compared to the prior year.
That's the good news. The bad news is that, in contrast to China, solar's growth hasn't been enough to offset rising demand. Instead, the US also saw significant growth in coal use, which rose by 23 percent compared to the year prior, after years of steady decline.
Short-term fluctuations in demand are normal, generally driven by weather-induced demand for heating or cooling. Despite those changes, demand for electricity in the US has been largely flat for over a decade, largely thanks to gains in efficiency. But 2024 saw demand go up by nearly three percent, and the first quarter of 2025 saw another rise, this time of nearly five percent. It's a bit too early to say that we're seeing a shift to a period of rising demand, but one has been predicted for some time due to rising data center use and the increased electrification of transportation and appliances.
Rocket Report: SpaceX’s expansion at Vandenberg; India’s PSLV fails in flight
Science - Posted On:2025-05-23 09:00:00 Source: arstechnica
Welcome to Edition 7.45 of the Rocket Report! Let's talk about spaceplanes. Since the Space Shuttle, spaceplanes have, at best, been a niche part of the space transportation business. The US Air Force's uncrewed X-37B and a similar vehicle operated by China's military are the only spaceplanes to reach orbit since the last shuttle flight in 2011, and both require a lift from a conventional rocket. Virgin Galactic's suborbital space tourism platform is also a spaceplane of sorts. A generation or two ago, one of the chief arguments in favor of spaceplanes was that they were easier to recover and reuse. Today, SpaceX routinely reuses capsules and rockets that look much more like conventional space vehicles than the winged designs of yesteryear. Spaceplanes are undeniably alluring in appearance, but they have the drawback of carrying extra weight (wings) into space that won't be used until the final minutes of a mission. So, do they have a future?
As always, we welcome reader submissions. If you don't want to miss an issue, please subscribe using the box below (the form will not appear on AMP-enabled versions of the site). Each report will include information on small-, medium-, and heavy-lift rockets, as well as a quick look ahead at the next three launches on the calendar.
One of China's commercial rockets returns to flight. The Kinetica-1 rocket launched Wednesday for the first time since a failure doomed its previous attempt to reach orbit in December, according to the vehicle's developer and operator, CAS Space. The Kinetica-1 is one of several small Chinese solid-fueled launch vehicles managed by a commercial company, although with strict government oversight and support. CAS Space, a spinoff of the Chinese Academy of Sciences, said its Kinetica-1 rocket deployed multiple payloads with "excellent orbit insertion accuracy." This was the seventh flight of a Kinetica-1 rocket since its debut in 2022.
Weird Planet Is Orbiting Backwards Between Two Stars
science - Posted On:2025-05-23 03:15:01 Source: slashdot
Astronomers have confirmed the existence of a bizarre planet in the Nu Octantis binary star system that orbits in reverse between two stars -- one of which is now a white dwarf. This retrograde orbit, once thought impossible, defies traditional planetary formation models and may have resulted from dramatic shifts in the system's history. New Scientist reports: The key observation was that the Nu Octantis planet is retrograde -- the planet and one star both orbit the second star, but they do so in opposite directions, with the planet having the tighter orbit around the second star. [Man Hoi Lee at the University of Hong Kong] says this is unusual but makes the system's configuration stable -- even though it means that the planet repeatedly moves through the narrow space between the two stars. His team was able to determine this with lots of certainty thanks to improved measuring devices, such as the HARPS spectrograph at the European Southern Observatory's 3.6-metre telescope in Chile. The fact that the planet's signal persisted through years of observation helped too. "We are pretty sure [the planet] is real, because if it was something like stellar activity, it shouldn't be so consistent in years of data," says Lee. But this backwards-moving planet isn't the only exotic feature of Nu Octantis. The researchers used the European Southern Observatory's Very Large Telescope, also in Chile, to determine that one of its stars is a white dwarf, which means that it has reached the end of its life cycle, becoming denser and smaller. Lee says this complicates the Nu Octantis threesome's history because mathematical models of its past show that the planet's current orbit was impossible when this star was younger, bigger and brighter. So, the planet either used to orbit both stars at once, but then radically shifted trajectory when one of the two stars became a white dwarf, or it was formed from the mass that the star ejected as it transformed into a white dwarf. Future observations, and a lot more mathematical modelling, may be able to pinpoint which of these scenarios is more likely to have occurred, but both are rather novel, says Lee. The research has been published in the journal Nature. Read more of this story at Slashdot.
Infrared Contact Lenses Allow People To See In the Dark, Even With Eyes Closed
science - Posted On:2025-05-22 23:45:00 Source: slashdot
An anonymous reader quotes a report from Phys.Org: Neuroscientists and materials scientists have created contact lenses that enable infrared vision in both humans and mice by converting infrared light into visible light. Unlike infrared night vision goggles, the contact lenses, described in the journal Cell, do not require a power source -- and they enable the wearer to perceive multiple infrared wavelengths. Because they're transparent, users can see both infrared and visible light simultaneously, though infrared vision was enhanced when participants had their eyes closed. [...] The contact lens technology uses nanoparticles that absorb infrared light and convert it into wavelengths that are visible to mammalian eyes (e.g., electromagnetic radiation in the 400-700 nm range). The nanoparticles specifically enable the detection of "near-infrared light," which is infrared light in the 800-1600 nm range, just beyond what humans can already see. The team previously showed that these nanoparticles enable infrared vision in mice when injected into the retina, but they wanted to design a less invasive option. To create the contact lenses, the team combined the nanoparticles with flexible, nontoxic polymers that are used in standard soft contact lenses. After showing that the contact lenses were nontoxic, they tested their function in both humans and mice. They found that contact lens-wearing mice displayed behaviors suggesting that they could see infrared wavelengths. For example, when the mice were given the choice of a dark box and an infrared-illuminated box, contact-wearing mice chose the dark box whereas contact-less mice showed no preference. The mice also showed physiological signals of infrared vision: the pupils of contact-wearing mice constricted in the presence of infrared light, and brain imaging revealed that infrared light caused their visual processing centers to light up. In humans, the infrared contact lenses enabled participants to accurately detect flashing morse code-like signals and to perceive the direction of incoming infrared light. An additional tweak to the contact lenses allows users to differentiate between different spectra of infrared light by engineering the nanoparticles to color-code different infrared wavelengths. For example, infrared wavelengths of 980 nm were converted to blue light, wavelengths of 808 nm were converted to green light, and wavelengths of 1,532 nm were converted to red light. In addition to enabling wearers to perceive more detail within the infrared spectrum, these color-coding nanoparticles could be modified to help color-blind people see wavelengths that they would otherwise be unable to detect. [...] Because the contact lenses have limited ability to capture fine details (due to their close proximity to the retina, which causes the converted light particles to scatter), the team also developed a wearable glass system using the same nanoparticle technology, which enabled participants to perceive higher-resolution infrared information. Currently, the contact lenses are only able to detect infrared radiation projected from an LED light source, but the researchers are working to increase the nanoparticles' sensitivity so that they can detect lower levels of infrared light. Read more of this story at Slashdot.
New data confirms: There really is a planet squeezed in between two stars
Science - Posted On:2025-05-22 16:15:00 Source: arstechnica
While our Sun prefers to go solo, many other stars are parts of binary systems, with a pair of stars gravitationally bound to each other. In some cases, the stars are far enough apart that planets can form around each of them. But there are also plenty of tight binary systems, where the stars orbit each other at a radius that would place them both comfortably inside our Solar System. In these systems, exoplanets tend to be found at greater distances, in orbits that have them circling both stars.
On Wednesday, scientists described a system that seems to be neither of the above. It is a tight binary system, with a heavy central star that's orbited by a white dwarf at a distance two to three times larger than Earth's orbit. The lone planet confirmed to be in the system is squeezed in between the two, orbiting at a distance similar to Earth's distance from the Sun. And, as an added bonus, the planet is orbiting backward relative to the white dwarf.
The exosolar system is termed ν Octantis (or Nu Octantis), and its primary star is just a bit heavier than our Sun (1.6 solar masses). It's orbited by a far dimmer companion that's roughly half of our Sun's mass, but which hasn't been characterized in detail until now. The companion's orbit relative to the central star is a bit lopsided, ranging from about two astronomical units (AU, the typical Earth-Sun distance) at its closest approach to roughly three AU at its farthest. And, until yesterday, the exact nature of the companion star was not clear.
FAA: Airplanes should stay far away from SpaceX’s next Starship launch
Science - Posted On:2025-05-22 16:15:00 Source: arstechnica
The Federal Aviation Administration gave the green light Thursday for SpaceX to launch the next test flight of its Starship mega-rocket as soon as next week, following two consecutive failures earlier this year.
The failures set back SpaceX's Starship program by several months. The company aims to get the rocket's development back on track with the upcoming launch, Starship's ninth full-scale test flight since its debut in April 2023. Starship is central to SpaceX's long-held ambition to send humans to Mars and is the vehicle NASA has selected to land astronauts on the Moon under the umbrella of the government's Artemis program.
In a statement Thursday, the FAA said SpaceX is authorized to launch the next Starship test flight, known as Flight 9, after finding the company "meets all of the rigorous safety, environmental and other licensing requirements."
Planet found orbiting backward between two stars
Science - Posted On:2025-05-22 14:30:00 Source: arstechnica
While our Sun prefers to go solo, many other stars are parts of binary systems, with a pair of stars gravitationally bound to each other. In some cases, the stars are far enough apart that planets can form around each of them. But there are also plenty of tight binary systems, where the stars orbit each other at a radius that would place them both comfortably inside our Solar System. In these systems, exoplanets tend to be found at greater distances, in orbits that have them circling both stars.
On Wednesday, scientists described a system that seems to be neither of the above. It is a tight binary system, with a heavy central star that's orbited by a white dwarf at a distance two to three times larger than Earth's orbit. The lone planet confirmed to be in the system is squeezed in between the two, orbiting at a distance similar to Earth's distance from the Sun. And, as an added bonus, the planet is orbiting backward relative to the white dwarf.
The exosolar system is termed ν Octantis (or Nu Octantis), and its primary star is just a bit heavier than our Sun (1.6 solar masses). It's orbited by a far dimmer companion that's roughly half of our Sun's mass, but which hasn't been characterized in detail until now. The companion's orbit relative to the central star is a bit lopsided, ranging from about two astronomical units (AU, the typical Earth-Sun distance) at its closest approach to roughly three AU at its farthest. And, until yesterday, the exact nature of the companion star was not clear.
Infrared contact lenses let you see in the dark
Science - Posted On:2025-05-22 12:30:00 Source: arstechnica
Tired of using bulky night vision goggles for your clandestine nocturnal activities? An interdisciplinary team of Chinese neuroscientists and materials scientists has developed near-infrared contact lenses that enabled both mice and humans to see in the dark, even with their eyes closed, according to a new paper published in the journal Cell.
Humans and other mammals can only perceive a limited range of the electromagnetic spectrum (light), usually in the 400–700 nm range. There are creatures that can see in infrared (snakes, mosquitoes, bullfrogs) or ultraviolet (bees, birds), and goldfish can perceive both. But humans must augment themselves with technology in order to expand our range of vision.
Night vision goggles and similar devices have been around since the 1930s, including infrared-visible converters, but these require external energy sources, and the converters have a multilayer structure that makes them opaque and hence challenging to integrate with a human eye. The authors previously were able to confer near-infrared vision to mice by injecting nanoparticles that bind to photoreceptors into their eyes—basically creating a near-infrared nanoantenna—but realized that most people would be averse to the prospect of sticking needles in their eyes. So they looked for a better alternative. Contact lenses seemed the obvious choice.
Wisk Aero, NASA Sign 5-Year Partnership To Advance Sustainable Autonomous Flights
science - Posted On:2025-05-22 06:15:00 Source: slashdot
Wisk Aero and NASA have signed a new five-year partnership to advance the safe integration of autonomous, all-electric aircraft into U.S. airspace, focusing on urban air mobility and regulated eVTOL flight. Electrek reports: Wisk Aero shared details of its refreshed partnership with NASA this week. The autonomous aviation specialist has signed a new five-year Non-Reimbursable Space Act Agreement (NRSAA) with the renowned space administration. Per Wisk, this new agreement focuses on critical research led by NASA's Air Traffic Management Exploration (ATM-X) project, which is centered around the advancement of commercialized autonomous aircraft travel under Instrument Flight Rules (IFR) in the National Airspace System (NAS). As a specialist in autonomous, zero-emission aircraft, Wisk intends to continue its research alongside NASA to help regulators determine future eVTOL flight procedures and capabilities in the US. Regulatory developments on the to-do list for the latest NRSAA include optimizing airspace and route designs for highly automated UAM operations, establishing critical aircraft and ground-based safety system requirements for autonomous flight in urban environments, and establishing Air Traffic Control (ATC) communication protocols and procedures for seamless integration of future UAM aircraft. To achieve these goals, Wisk said its research with NASA will more specifically focus on utilizing advanced simulation and Live Virtual Constructive (LVC) flight environments, which combine live flights with a simulated airspace to enable researchers to assess future operations. The teams from Wisk and NASA already met last month, continuing their research while beginning to determine how instrument flight procedures and advanced technologies can work together to enable safe autonomous passenger flights by 2030. Wisk Aero is a wholly owned subsidiary of Boeing based in California. The aerospace manufacturer said last year that it expects its pilotless air-taxi to begin carrying passengers "later in the decade." Read more of this story at Slashdot.
New Bacteria Have Been Discovered on a Chinese Space Station
science - Posted On:2025-05-22 03:15:00 Source: slashdot
Scientists have discovered a previously unknown bacterium aboard China's Tiangong space station. "It has been named Niallia tiangongensis, and it inhabited the cockpit controls on the station, living in microgravity conditions," reports Wired. From the report: According to China Central Television, the country's national broadcaster, taikonauts (Chinese astronauts) collected swab samples from the space station in May 2023, which were then frozen and sent back to Earth for study. The aim of this work was to investigate the behavior of microorganisms, gathered from a completely sealed environment with a human crew, during space travel, as part of the China Space Station Habitation Area Microbiome Program (CHAMP). A paper published in the Journal of Systematic and Evolutionary Microbiology describes how analysis of samples from the space station revealed this previously unseen bacterial species, which belongs to the genus Niallia. Genomic sequencing showed that its closest terrestrial relative is the bacterium Niallia circulans, although the Tiangong species has substantial genetic differences. [...] It is unclear whether the newly discovered microbe evolved on the space station or whether it is part of the vast sea of as yet unidentified microorganisms on Earth. To date, tens of thousands of bacterial species have been cataloged, although there are estimated to be billions more unclassified species on Earth. The discovery of Niallia tiangongensis will provide a better understanding of the microscopic hazards that the next generation of space travelers will face and help design sanitation protocols for extended missions. It is still too early to determine whether the space bacterium poses any danger to taikonauts aboard Tiangong, although it is known that its terrestrial relative, Niallia circulans, can cause sepsis, especially in immunocompromised people. Read more of this story at Slashdot.
The physics of frilly Swiss cheese “flowers”
Science - Posted On:2025-05-21 17:30:00 Source: arstechnica
Cheese connoisseurs are no doubt familiar with a particular kind of semi-hard Swiss cheese called "Tête de Moine." Rather than spreading or slicing the cheese, Tête de Moine is usually served by scraping the top of the cheese wheel in a circular motion using a specialized tool called a Girolle. This produces elegant thin shavings known as rosettes, since they resemble a frilly flower.
The method is both aesthetically pleasing and serves to enhance the aromas and mouth feel of the cheese, according to the authors of a new paper published in the journal Physical Review Letters (PRL). This group of physicists based in Paris noted a marked similarity between the frilly edges of those cheese flowers and certain leaves, fungi, corals, and even torn plastic sheets—all formed by different mechanisms. So naturally the physicists decided to conduct their own research to determine the underlying mechanism(s) for the delicate frills of Tête de Moine shavings.
Tête de Moine translates as "monk's head," and the name dates back to the 1790s, although the actual cheese originates back to a 12th-century Bellelay monastery in Switzerland. It's made from raw unpasteurized cow's milk and is matured for a minimum of 75 days on spruce boards and boasts a firm reddish-brown crust. The Girolle (named after the French word for chanterelles, which have a similar rosette shape) is a more recent innovation, invented in 1982 specifically for Tête de Moine by a man named Nicolas Crevoisier. It's just a round wooden plate with a pin stuck vertically in the middle—the better to skewer one's cheese wheel—and a crank handle to control the slicing blade.
Scientists figure out how the brain forms emotional connections
Paris Agreement target won’t protect polar ice sheets, scientists warn
Science - Posted On:2025-05-21 14:15:00 Source: arstechnica
This article originally appeared on Inside Climate News, a nonprofit, nonpartisan news organization that covers climate, energy, and the environment. Sign up for their newsletter here.
Sea levels in some parts of the world could be rising by as much as 8 to 12 inches per decade within the lifetime of today’s youngest generations, outpacing the ability of many coastal communities to adapt, scientists warned in a new study published this week.
The research by an international team of sea level and polar ice experts suggests that limiting warming to 2.7° Fahrenheit (1.5° Celsius) above the pre-industrial temperature—the Paris Climate Agreement’s target—isn’t low enough to prevent a worst-case meltdown of Earth’s polar ice sheets.
Incredible shrinking clownfish beats the heat
Science - Posted On:2025-05-21 14:15:00 Source: arstechnica
Pixar's Finding Nemo immortalized the colorful clownfish, with its distinctive orange body and white stripes, in the popular imagination. Clownfish, like many other species, are feeling the stress of rising temperatures and other environmental stressors. Fortunately, they have a superpower to cope: They can shrink their body size during dangerous heat waves to substantially boost their odds of survival, according to a new paper published in the journal Science Advances.
“This is not just about getting skinnier under stressful conditions; these fish are actually getting shorter," said co-author Melissa Versteeg, a graduate student at Newcastle University. "We don’t know yet exactly how they do it, but we do know that a few other animals can do this too."
Many vertebrates have shown growth decline in response to environmental stressors, especially higher temperatures. Marine iguanas, for example, reabsorb some of their bone material to shrink when their watery habitat gets warmer, while young salmon have been known to shrink at winter's onset. This can also happen when there is less food available. And social factors can also influence growth. When female meerkats, for example, are dominant, they have growth spurts, while a disruption in their social status can cause stunted growth in male cichlids
Starfish Space Announces Plans For First Commercial Satellite Docking
science - Posted On:2025-05-21 06:15:00 Source: slashdot
Starfish Space plans to perform the first commercial satellite docking in orbit with its Otter Pup 2 mission, aiming to connect to an unprepared D-Orbit ION spacecraft using an electrostatic capture mechanism and autonomous navigation software. NASASpaceFlight.com reports: This follows the company's first attempt, which saw the Otter Pup 1 mission unable to dock with its target due to a thruster failure. The Otter Pup 2 spacecraft will be deployed from a quarter plate on the upper stage adapter of the SpaceX Falcon 9 rocket, placing it into a sun synchronous orbit altitude of 510 km inclined 97.4 degrees. The target will be a D-Orbit ION spacecraft which will simulate a client payload, which is not equipped with a traditional docking adapter or capture plate as you might see aboard a space station or other rendezvous target. Instead, Starfish Space's Nautilus capture mechanism will feature a special end effector connected to the end of the capture mechanism. This end effector will enable Otter Pup 2 to dock with the ION through electrostatic adhesion. "An electromagnet will be integrated into the end effector and will be used as a backup option to the electrostatic end effector, to dock with the ION through magnetic attraction," the company notes. The goal is to eventually commission its Otter satellite servicing vehicle to allow for servicing of previously launched satellites. The company's first Otter missions include customers such as NASA, the U.S. Space Force, and Intelsat, with the goal of flying those missions as soon as 2026. [...] Following the thruster issues on the first mission, this flight will feature two ThrustMe thrusters, which use an electric propulsion system based on gridded ion thruster technology. Read more of this story at Slashdot.
Jupiter Was Formerly Twice Its Current Size and Had a Much Stronger Magnetic Field
science - Posted On:2025-05-21 03:15:00 Source: slashdot
A new study reveals that about 3.8 million years after the solar system's first solids formed, Jupiter was twice its current size with a magnetic field 50 times stronger, profoundly influencing the structure of the early solar system. Phys.Org reports: [Konstantin Batygin, professor of planetary science at Caltech] and [Fred C. Adams, professor of physics and astronomy at the University of Michigan] approached this question by studying Jupiter's tiny moons Amalthea and Thebe, which orbit even closer to Jupiter than Io, the smallest and nearest of the planet's four large Galilean moons. Because Amalthea and Thebe have slightly tilted orbits, Batygin and Adams analyzed these small orbital discrepancies to calculate Jupiter's original size: approximately twice its current radius, with a predicted volume that is the equivalent of over 2,000 Earths. The researchers also determined that Jupiter's magnetic field at that time was approximately 50 times stronger than it is today. Adams highlights the remarkable imprint the past has left on today's solar system: "It's astonishing that even after 4.5 billion years, enough clues remain to let us reconstruct Jupiter's physical state at the dawn of its existence." Importantly, these insights were achieved through independent constraints that bypass traditional uncertainties in planetary formation models -- which often rely on assumptions about gas opacity, accretion rate, or the mass of the heavy element core. Instead, the team focused on the orbital dynamics of Jupiter's moons and the conservation of the planet's angular momentum -- quantities that are directly measurable. Their analysis establishes a clear snapshot of Jupiter at the moment the surrounding solar nebula evaporated, a pivotal transition point when the building materials for planet formation disappeared and the primordial architecture of the solar system was locked in. The results add crucial details to existing planet formation theories, which suggest that Jupiter and other giant planets around other stars formed via core accretion, a process by which a rocky and icy core rapidly gathers gas. The findings have been published in the journal Nature Astronomy. Read more of this story at Slashdot.