Milky Way ate another galaxy

 Scientists think they have found bones of a galaxy called Loki, ate by The Milky Way        

An unusual collection of stars may represent the remnants of a dwarf galaxy that the Milky Way devoured about 10 billion years ago. Astronomers have dubbed the ancient galaxy Loki. The finding could change the current understanding of how the Milky Way evolved in the distant past. An unusual collection of stars may represent the remnants of a dwarf galaxy that the Milky Way devoured. The finding could change the current understanding of how the Milky Way evolved in the distant past. The vast Milky Way spans about 100,000 light-years and contains anywhere between 100 billion and 400 billion stars. A light-year is the distance light travels in one year, which is 5.88 trillion miles (9.46 trillion km's).  It grew over time starting about 12 billion years ago by merging with a multitude of dwarf galaxies. But the original size and mass of the Milky Way remain an open question, driving scientists to search for evidence of the galaxies it consumed to determine its history and evolution. To identify those missing puzzle pieces, astronomers have now zeroed in on a cluster of metal-lacking stars detected oddly close to the galactic disk. 

By studying the chemistry of these stars and their motion close to the galactic disk, the researchers found that the stars' home galaxy, nicknamed "Loki," might have merged with our galaxy about 10 billion years ago. Studying these stars could be "very important" in understanding the history of the Milky Way and the universe itself, lead author of the study Federico Sestito, an astrophysicist at the University of Hertfordshire in the U.K, said. Sestito added that Loki may have been among "the very first small galaxies formed in the young universe." The Milky Way's Central Molecular Zone (CMZ) surrounds our galaxy's supermassive black hole and may share characteristics with the dense and chaotic galaxies of the early universe. Massive galaxies are not born whole. They are assembled over billions of years through mergers with smaller galaxies, which are sometimes absorbed. In the early universe, shortly after the Big Bang, matter clumped into clouds of gas which collapsed into the first primitive galaxies. These small systems then fell into one another, merged and gradually built up into the large structures we see today. The astronomers are interested in these stars near the disk, a massive rotating pancake-like region containing much of the Milky Way’s stars, because the first stars in the universe were comprised of hydrogen and helium, which fused heavier elements together in their cores before exploding and unleashing the heavy elements which enriched future generations of stars. Metal-poor stars are often associated with ancient dwarf galaxies, which the Milky Way might have consumed over time to grow to its current massive state, and remnants of these cosmic meals might be hiding deep within the galaxy. The metal-poor composition of such ancient stars close to the galactic disk suggests that the Milky Way once made a rather large meal of another galaxy early in its history, and it could represent a critical, previously overlooked building block of our galaxy.

In the study, astronomers identified 20 old, very-metal-poor stars orbiting unusually close to the galactic disk, the flat, rotating region of the Milky Way where most stars, including the sun, reside, and examined whether a past merger might explain what they were seeing. The very first stars which formed in the universe were made of hydrogen and helium. It was only inside those early stars that hydrogen and helium fused into heavier elements, which astronomers call metals. These stars, when they eventually exploded, enriched the surrounding gas with those metals. Each successive generation of stars was therefore born from material slightly more enriched than the last. As these small galaxies collided and merged, their stars, gas and dark matter became part of the growing young Milky Way. Because of this, computer simulations suggest that stars from the earliest mergers are expected to be found deeper inside the Milky Way today, while stars from galaxies which merged later are more likely to be scattered farther out in the galactic halo, a vast, spherical region that extends beyond the bright disk. However, very few metal-poor stars have been found in the inner regions of the Milky Way to test this idea. So, when the team identified 20 metal-poor stars orbiting close to the galactic disk, they wondered whether the stars could be remnants of an ancient merger.

The Milky Way is suspected to have merged with up to a dozen or more dwarf galaxies over its 12-billion-year history. Astronomers are like the detectives of the universe, searching the cosmos for clues of its origins, and very-metal-poor, or VMP, stars are a powerful tool in that quest, said Dr. Cara Battersby, associate professor of physics at the University of Connecticut, who did not participate in the study. “VMP stars have been around for billions of years, holding within them clues to the formation of the Universe’s earliest generations of stars,” Battersby said. Studying the metal-poor stars’ composition and motion can unlock details about the conditions and dynamics of the early universe, she added. The search for metal-poor stars in the Milky Way has largely centered on the plentiful range of old stars in the galaxy’s stellar halo, so named because it’s a large, round diffuse cloud that surrounds the galactic disk. Some astronomers believe evidence of more ancient mergers could be found deeper inside the Milky Way, such as in its disk. An abundance of young, metal-rich stars, as well as a plethora of dust, crowded within the galactic disk has made it hard to spot metal-poor stars there, said Dr. Federico Sestito.

The team observed existing catalog of metal-poor stars using a powerful spectrograph at the Canada-France-Hawaii Telescope, which revealed their chemical abundances. Using precise positional data from the Gaia space telescope, they calculated the stars' distances and how they orbit in our galaxy. Sestito said that "a mixture of information from the chemistry and the orbits of these stars" nudged them to examine the stars' origin. Rather than drifting through the halo of the galaxy where ancient, metal-poor stars have been mostly observed, these stars were tracing paths close to the Milky Way's disk within just 6,500 light-years from the sun. "Usually, stars in the disk are metal-rich and younger, like the sun," he said, "while our stars [in the study] are old and very metal-poor (like in dwarf galaxies)." Additionally, some of these stars were found moving in the same direction as the Milky Way's rotation, while others traveled in the opposite direction. But these two groups did not show any difference in their chemical abundances. Explaining how a single in falling galaxy could leave stars moving in opposite directions was also challenging. The answer came from computer simulations of galaxy formation. If the merger happened early enough, when the young Milky Way was still lightweight and had not yet settled into a spinning disk, the in falling galaxy would have had enough freedom to scatter its stars in all directions.

"The early merging history of a large galaxy might be very chaotic, with various smaller systems merging together and dispersing their stars with many different orbits," Sestito explained. This scenario could produce both prograde and retrograde orbits, placing the merger event around 3 billion years after the Big Bang. As a result, the simulations showed that a single dwarf galaxy swallowed by the young Milky Way more than 10 billion years ago, could have scattered its stars into exactly the orbital pattern observed today. The models also helped estimate the total mass of this galaxy to be around 1.4 billion solar masses. The exact age of the stars is hard to pin down, but their chemical composition suggests they are older than 10 billion years, Sestito said, and all of them are located roughly 7,000 light-years from our solar system. The stars also have similar chemical compositions, suggesting they all came from the same metal-poor dwarf galaxy. Gaia's mapping shows how 40,000 stars, all located within 326 light-years of the solar system, will move in the next 400,000 years. Eleven of the stars were in a prograde orbit, or moving in the same direction of the galactic disk, while nine were on a retrograde orbit, or moving in the opposite direction, possible remnants of a dwarf galaxy gobbled up by the Milky Way. The study authors believe the accreted, or hijacked, stars, simply remained as part of our galaxy, getting knocked around and ending up in different orbital patterns, Battersby said.

“If the Loki scenario is correct, then a system merged with our galaxy could deposit its stars into both prograde and in the opposite direction,” Sestito said. “This can be allowed only if the merger event happened when our Milky Way was still infant/smaller and its gravitational potential was weaker than nowadays. Cosmological simulations suggest that this could have happened no later than 3 or 4 billion years from the Big Bang.” Dr. Hans-Walter Rix, director of the department of galaxies and cosmology at the Max Planck Institute for Astronomy in Germany, said what was most impressive about the study was “how they use the detailed chemical element abundances as a fingerprint to identify a common birth origin of these stars in a now-shredded satellite galaxy, even though some of the stars are going the right way around and some the wrong way.” “Similarly, our accreted stars gave us some hard time in understanding their origin,” Sestito said. “At first it was not easy to reconcile the fact that an accreted system can disperse its stars in both prograde and opposite orbits.” Another explanation for the stars could be that they stem from more than one merger event with the Milky Way, he said. Because researchers are still in the early stages of exploring the chemical signatures of the lowest-metallicity stars in the Milky Way disk, it remains plausible that these stars belong to a subgroup of stars or substructure within the Milky Way, Chiti noted. "I'm looking forward to what future work mapping the chemistry of large samples of very metal-poor stars in the Milky Way disk may show," he said. To confirm the nature of Loki, the team would need to observe its stars and other non-Loki targets with the same telescope setup to better understand the differences between this system and other parts of the Milky Way halo.

The Milky Way has grown through galactic cannibalism, or when a large galaxy eats a small galaxy and uses immense gravitational force to absorb its stars and gas. The leftover shreds of such meals enable astronomers to assemble the galaxy’s “eating history,” said Dr. Alexander Ji, assistant professor in the department of astronomy and astrophysics at the University of Chicago. There are lots of little mergers happening all the time, but the really big meals can change the growth history of the Milky Way,” Ji said. One such transformative event occurred as the Milky Way merged with the Gaia-Sausage-Enceladus galaxy between 8 billion and 10 billion years ago. “We think it helped ‘reset’ the Milky Way from its early turbulent phase to the more stable growing disk that it has today,” Ji said. The new study suggests that the Milky Way merging with the Loki galaxy was almost on the scale of the Gaia-Sausage-Enceladus event. But the evidence is largely hidden because Loki’s remnants are hard to find near the Milky Way’s disk, Ji added. “If this is real, it would indicate that we are missing a major part of our Milky Way’s formation history, and we might need to revisit our current picture to see the impact of such an event,” Ji said. Ji doubts Loki is a previously unknown galaxy, given that possible discoveries of merger events often turn out to be extensions of known systems, but he noted the study authors included appropriate caveats in their work. “It’s an interesting new possibility worth pursuing, and I expect there will be people looking to test whether Loki is real with larger datasets,” Ji said. With upcoming advanced spectroscopic facilities, astronomers will be able to observe hundreds of stars with available high-quality data on their trajectories and chemical abundances. The hidden systems in the inner regions of the galaxy could hold clues to the primitive galaxies of the young universe, though detecting them in the crowded disk would be challenging in our universe.

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US F-47 Fighter Vs China J-36 and J-50

 US Air Dominance at stake because of J-36 and J-50 development

The Pentagon’s acknowledgment of China’s active sixth-generation fighter testing represents a strategic inflection point in great-power competition. With the Chengdu J-36 and Shenyang J-50 prototypes demonstrating functional flight capabilities, before the US F-47 is expected to fly in 2028, China has established a tangible temporal advantage which could translate into operational air dominance by 2030. China is not ahead of the US in deployed air superiority across the Pacific today. Rather, Beijing is positioned to potentially neutralize America’s traditional fighter jet advantage within a five-to-seven-year window through a combination of accelerated prototyping, rapid iterative development, integrated AI systems and a production capacity trajectory that dwarfs US acquisition timelines. This distinction matters profoundly for strategic assessment, as the threat is not present superiority but rather the elimination of a decisive advantage before the F-47 reaches operational maturity. China’s rapid progress on the J-36 and J-50 next-generation stealth fighter programs is prompting the US to accelerate development of the F-47 sixth-generation fighter and Collaborative Combat Aircraft (CCA) autonomous drone systems as Washington prepares for a potential Indo-Pacific conflict. Senior Pentagon leaders warned lawmakers, that preserving US air superiority is becoming increasingly critical as Beijing expands its capabilities in stealth aviation, long-range strike operations and AI-enabled warfare designed to challenge American power projection across the Pacific.

The release of the Pentagon’s 2025 China Military Power Report, contains language which will shape strategic planning across the Indo-Pacific for the remainder of this decade. The Department of Defense formally confirmed that the People’s Liberation Army Air Force (PLAAF) has successfully flight-tested two distinct sixth-generation fighter prototypes, designated tentatively as the Chengdu J-36 and Shenyang J-50. This acknowledgment is not merely an update to existing threat assessments; it represents an official recognition that the technological gap between American and Chinese air combat systems is narrowing at an “alarming” rate, to use the Pentagon’s own characterization. The strategic significance extends beyond hardware specifications. The J-36’s operational debut on December 26, 2024, occurred in a geopolitical context where the US remains locked in a protracted modernization cycle for its own sixth-generation initiative, the Next Generation Air Dominance (NGAD) program, with the Boeing F-47 not anticipated to conduct its maiden flight until 2028. This three-to-four-year gap in demonstrable flight testing creates a window of opportunity for Beijing to refine, test and potentially field limited numbers of sixth-generation aircraft while the US Air Force remains in the developmental phase. For a geopolitical analyst accustomed to assessing relative power trajectories, this temporal differential carries profound implications for the regional balance of power, particularly regarding Taiwan contingencies and freedom of navigation operations in the South China Sea. US Air Force’s FY2027 budget request prioritizes the rapid fielding of networked manned and unmanned combat aircraft capable of operating in highly contested environments while complicating Chinese targeting efforts. By combining sixth-generation fighters with autonomous CCAs, the Pentagon aims to increase combat mass, improve survivability and maintain operational dominance against increasingly sophisticated Chinese air and missile defense systems. 

The J-36’s physical architecture represents a radical departure from conventional fighter design philosophy. The aircraft features a tailless diamond-double-delta plateform, colloquially termed a “flying wing” configuration, distinguished by the absence of vertical and horizontal stabilizers. This design choice, replicated on the smaller J-50 variant, optimizes for all-aspect stealth signatures by eliminating the perpendicular surfaces which create radar reflections when aircraft are observed from angles other than head-on. Pentagon analysts note that this tailless configuration enables “ultra-long range” missions by reducing drag and the fuel expenditure required to sustain supersonic cruise across intercontinental distances. The next prototypes of the J-36, observable in satellite imagery from August 2025 and refined versions from October 2025 onward, demonstrate visible maturation in aerodynamic and propulsion integration. The most significant refinement involves the implementation of two-dimensional thrust-vectoring nozzles on all three engines, a capability which enhances pitch, yaw and roll control authority at high angles of attack while reducing the aerodynamic penalties associated with conventional control surfaces. Satellite reconnaissance also confirms the adoption of diverterless supersonic inlet (DSI) technology, which eliminates boundary-layer diverters and reduces structural complexity while maintaining optimal airflow pressure across all three engines throughout the flight envelope. These technical progressions, thrust vectoring, DSI geometry, refined landing gear architecture, are characteristic of an aircraft transitioning from proof-of-concept to an advanced flight-test phase where design trade-offs between stealth, performance, and operational utility are being systematically evaluated.

According to US command, the FY2027 defense budget focuses on rapidly integrating the F-47 with autonomous drone wingmen and space-enabled combat networks capable of operating in heavily contested environments. The Pentagon sees the combination of sixth-generation fighters and CCAs (Collaborative Combat Aircraft) as critical to countering emerging Chinese combat aircraft, while strengthening the survivability, operational reach and combat mass of US air forces across the Pacific theater. Weaponization capabilities present a particularly stark contrast to fifth-generation designs. The J-36’s main internal weapons bay measures approximately 7.6 meters in length, supplemented by side bays for smaller ordnance, creating a total internal volume substantially greater than the F-22 Raptor’s weapons carriage capacity. This volumetric advantage enables the integration of the PL-17 beyond-visual-range air-to-air missile, a system with a reported range exceeding 400 km's and equipped with a multimode seeker combining active radar and passive infrared guidance. By contrast, the F-22 cannot internally carry weapons of comparable range due to bay capacity constraints, necessitating external carriage that compromises stealth, a fundamental design limitation which translates into tactical disadvantage in the opening phase of air combat. The integration of AI and autonomous systems represents perhaps the most consequential difference between the J-36 and its fifth-generation predecessors. The Pentagon specifically notes that the J-36 is designed as a command node within a networked family of systems, managing autonomous “loyal wingman” uncrewed combat aerial vehicles (UCAVs) through data-link architecture and AI-driven sensor fusion algorithms. This represents not a modification to existing fighter doctrine but rather a wholesale reconceptualization of air warfare where the manned aircraft becomes a hub for coordinating multiple autonomous platforms, with AI systems processing sensor data at machine speeds and recommending tactical responses beyond human reaction capabilities. 

Understanding China’s acceleration toward sixth-generation fighter development requires tracing the trajectory of Chinese aerospace capabilities over the past two decades. The PLAAF’s traditional reliance on Russian airframes and engines, reflected in the licensed production of Su-27 and Su-30 variants throughout the 1990s and 2000s, created a persistent technological dependency which constrained indigenous development. However, the 2011 unveiling of the Chengdu J-20 Mighty Dragon fifth-generation stealth fighter marked a strategic turning point. While early assessments questioned the maturity of J-20 systems and the quality of Chinese stealth technologies, subsequent refinements and the integration of indigenous engines transformed the platform into a credible peer competitor. The acceleration occurred alongside a fundamental shift in China’s aircraft engine development. The WS-10 turbofan, despite early reliability challenges, achieved operational maturity in its WS-10C variant by the early 2020s, enabling China to reduce its dependence on the Russian AL-31 engine for J-20 production. 

By 2025, Chinese academic institutions had completed ground and altitude testing of adaptive cycle engine (ACE) prototypes, technology specifically designed to overcome thrust degradation at extreme altitudes and speeds, positioning China’s propulsion systems at the technological frontier. This engine development trajectory is not incidental to the J-36 program; it is foundational. The presence of different engines simultaneously increases mechanical complexity and weight but confers substantial operational advantages in terms of thrust vectoring capability, redundancy and the power generation capacity necessary to operate advanced sensor fusion systems and directed-energy weapons, the defining characteristics of sixth-generation air combat. A major shift in US airpower strategy required to counter China’s growing military capabilities across the Indo-Pacific theater through distributed, networked and highly survivable air operations. Air Force leaders emphasized before Congress that the F-47 and CCA programs are designed to operate together as a single combat architecture rather than separate acquisition efforts. The FY2027 request significantly increases investment in Research, Development, Test & Evaluation (RDT&E), accelerating engineering, systems integration and flight-test preparation for the F-47 while advancing autonomous combat drone capabilities intended to multiply operational effectiveness in contested battle space environments.

The centerpiece of the modernization effort is the F-47, now officially emerging as the core combat aircraft within the US Air Force’s Next Generation Air Dominance (NGAD) program. Unlike previous fighter generations, F-47 is being developed as a command-and-control combat aircraft capable of coordinating multiple unmanned aerial systems during combat operations. This approach fundamentally changes the structure of future air warfare by distributing sensors, weapons and electronic warfare functions across manned and unmanned assets. The strategy's operational logic is closely tied to the evolving threat environment facing US forces. China’s continued progress with the J-36 and J-50 stealth fighter programs is viewed inside the Pentagon as evidence that Beijing is rapidly narrowing the technological gap in advanced combat aviation. Chinese military modernization efforts increasingly combine stealth aircraft, long-range precision-strike systems, advanced integrated air-defense networks and AI-supported operational concepts to challenge traditional US air superiority advantages. Relative to Boeing’s F-47, boasting Mach 2+, 1,600+ km radius, adaptive propulsion, laser armaments and unmatched sensor fusion, the J-50 rivals kinematics and stealth quantum while J-36 overwhelms in volumetric ordnance, potentially outpacing US timelines through China’s voracious iteration, thereby fracturing Indo-Pacific aerial hegemony with precocious parity. 

By comparison, the J-36 program achieved observable first flight within what appears to be a compressed development timeline, raising questions about Chinese engineering methodology, the extent of technology transfer from existing fifth-generation programs, or the possibility that development timelines in official records understate actual program maturity. The Pentagon assessment also highlights an asymmetry in force-structure goals. Current US acquisition plans envision approximately 185 F-47 aircraft over the coming two decades, a reduction from earlier procurement targets of 200 airframes. Chinese production capacity, by contrast, demonstrates unprecedented scale. The J-36 and J-50 programs remain highly classified, but Western defense analysts believe both aircraft are intended to support future Chinese air-dominance operations with enhanced stealth characteristics, extended operational range, advanced networking and potentially autonomous teaming capabilities. Collaborative Combat Aircraft are intended to solve the growing survivability challenge by dramatically increasing combat mass while reducing vulnerability. Instead of relying solely on traditional fighter formations, the Air Force plans to deploy autonomous unmanned aerial vehicles alongside the F-47, enabling missions to be distributed across a larger number of interconnected combat systems. These unmanned systems can carry additional missiles, electronic warfare payloads, intelligence sensors, or decoys, creating multiple simultaneous targeting dilemmas for enemy forces.

Air Force officials believe this distributed combat architecture will complicate adversary targeting calculations by forcing opponents to engage a far larger and less predictable force package. Enemy air-defense systems will face increased difficulty distinguishing between high-value crewed combat aircraft and lower-cost autonomous systems designed to absorb risk, conduct deception operations, or overwhelm defensive networks through sheer operational density. Beijing has credibly positioned itself to achieve technological parity or dominance in the near future, a shift that would represent not a continuation of existing capabilities but rather a fundamental rebalancing of regional power dynamics. The threat is not current superiority but rather the elimination of a longstanding advantage within a compressed timeframe. The J-36’s operational deployment, occurring before the F-47’s maturation, creates a temporal asymmetry that works decisively in China’s favor. This is not a matter of technological inevitability or Chinese exceptionalism; rather, it reflects deliberate strategic choices by Beijing to compress development timelines through rapid prototyping, centralized decision-making and production scaling that the US cannot quickly replicate. For policymakers and strategists, the implication is clear: the operational window for addressing this emerging asymmetry closes within five to seven years. 

Options include accelerating the F-47 program beyond current timelines (politically and technically challenging), deploying interim sixth-generation demonstrations to the Indo-Pacific (the military’s current strategy), or accepting the temporary dominance of Chinese sixth-generation systems and planning contingencies accordingly. The Pentagon’s acknowledgment of the J-36 program is not a recognition that the battle is lost but rather a warning that the tempo of competition has accelerated beyond the pace at which American defense acquisition traditionally operates. The coming half-decade will determine whether the US can reconstitute its air superiority advantage before China’s numerical and technological advantages become irreversible. For pilots accustomed to traditional dogfighting paradigms, this shift toward network-centric, AI-augmented combat introduces operational domains where human decision-making becomes a constraint rather than an advantage. The emphasis on combat mass also signals an important doctrinal evolution within the US Air Force. For decades, American airpower relied heavily on maintaining technological superiority through fewer, more advanced combat aircraft. The F-47 and CCA concept instead combines advanced technology with scalable force density, seeking to ensure that the Air Force can generate both quality and quantity against adversaries capable of fielding large missile inventories and sophisticated integrated defenses. The emergence of China’s J-36 and J-50 programs is therefore not only influencing US procurement priorities but also reshaping future American air combat doctrine. The Pentagon’s evolving strategy now centers on highly connected combat ecosystems where crewed sixth-generation fighters operate alongside autonomous drone formations, supported by resilient space-based networks which can survive in electronically contested, missile-saturated environments. Thee narrowing technological gap cannot be attributed to any single factor but rather emerges from a constellation of structural advantages that China has systematically cultivated over the past fifteen years. 

Current Chinese operational planning assumes air superiority achieved through saturating strikes by ballistic and cruise missiles, followed by massed fighter operations against degraded Taiwanese defenses. A J-36-equipped PLAAF would shift this calculus toward a more sophisticated air dominance strategy. The numerical asymmetry compounds this technical gap: if China deploys several hundred J-36s by 2035 while the US fields fewer than 100 F-47s operational combat aircraft, the qualitative advantage associated with superior stealth and AI integration could be overwhelmed by quantitative Chinese preponderance. This is precisely the scenario which prompted the Pentagon to characterize the technological gap narrowing as occurring at an “alarming” rate, not because the J-36 is inherently superior to the F-47, but because the timing of deployment introduces a window wherein America’s air superiority advantages are neutralized before their replacement systems achieve operational maturity.

Muhammad (Peace be upon him) Name