Cosmic Teacup

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  • Re-analysis of Milky Way’s central supermassive black hole shows elongated structure

    Re-analysis of Milky Way’s central supermassive black hole shows elongated structure

    by National Astronomical Observatory of Japan

    October 25, 2024

    A research team led by Assistant Professor Makoto Miyoshi of the National Astronomical Observatory of Japan (NAOJ) has independently re-analysed observation data of the supermassive black hole at the centre of the Milky Way galaxy obtained and published by the international joint observation project Event Horizon Telescope (EHT). They found that the structure is slightly elongated in the east-west direction.

    This research, published in the Monthly Notices of the Royal Astronomical Society, takes a new look at the publicly available EHT data and demonstrates the scientific process in which the certainty of the answer increases as different researchers continue to examine and discuss a theory.

    The Milky Way galaxy, in which we live, contains more than 100 billion sun-like stars. There are countless such large galaxies in the universe, most of which are thought to have supermassive black holes at their centres with masses millions to billions of times that of the sun. The Milky Way galaxy also has a supermassive black hole at its centre, called Sagittarius A* (A star).

    The black hole swallows everything, including light, making it impossible to see the supermassive black hole itself, but analysis of stars circling the black hole at high speed indicates that Sagittarius A* has a mass approximately 4 million times that of the sun. By closely observing its surroundings, we can obtain clues to the nature of the invisible black hole.

    The EHT observed Sagittarius A* in 2017 with a network of eight ground-based radio telescopes using a technique known as radio interferometry to combine the results from the various telescopes. The results of these observations were published in 2022, including an image of a bright ring structure surrounding a central dark region, indicating the presence of a black hole.

    In contrast to typical photography, data from observations linking several widely separated radio telescopes contain many gaps in the completeness, so special algorithms are used to construct an image from the data. In this research, the team applied widely used traditional methods to EHT data, as opposed to the EHT’s own original analysis method.

    Miyoshi explains, “Our image is slightly elongated in the east-west direction, and the eastern half is brighter than the western half. We think this appearance means the accretion disk surrounding the black hole is rotating.”

    The EHT’s observational data and analysis methods are freely available, and many researchers have validated the results of EHT analysis. This research is also part of these regular verification activities.

    Radio interferometry connecting telescopes across the globe is a developing technology, and research on data analysis and image processing is ongoing, incorporating knowledge from statistics and other related disciplines.

    The structures presented in this research differ from the results of the EHT team, but both are plausible structures derived from the data using the respective methods. The EHT plays an important role in black hole research by soliciting independent verification and providing open data for verification.

    It is hoped that a more reliable picture of Sagittarius A* will emerge from active discussion by researchers based on improved analysis methods and data from follow-up observations conducted since 2018.

    Journal:

    Makoto Miyoshi et al, An independent hybrid imaging of Sgr A* from the data in EHT 2017 observations, Monthly Notices of the Royal Astronomical Society (2024).

    DOI: 10.1093/mnras/stae1158

    Image:

    Final image of Sgr A* obtained from our imaging process. Credit: Monthly Notices of the Royal Astronomical Society (2024). DOI: 10.1093/mnras/stae1158

  • Protecting the ELT from Earthquakes

    by Kate Green

    October 19, 2024

    The Extremely Large Telescope (ELT) in the Atacama Desert is equipped with sophisticated anti-seismic technology to ensure that it remains stable and operational even in the event of an earthquake. Since the region is seismically active, incorporating earthquake-resistant features is critical to protecting the telescope’s delicate instruments and optics. Here’s how this clever technology works:

    1. Base Isolation System:

    One of the key technologies used is base isolation, a system designed to decouple the telescope’s structure from ground motion during an earthquake. Here’s how it works:

    • Elastomeric Bearings: Large rubber and steel bearings are placed between the foundation and the telescope structure. These bearings can deform elastically during seismic activity, absorbing the earthquake’s energy and reducing the amount of shaking transmitted to the telescope.

    • Sliding Bearings: In some systems, sliding bearings are also used, allowing the structure to move slightly relative to the ground, which further reduces the impact of ground movement on the telescope.

    2. Dampers:

    In addition to base isolation, seismic dampers are installed to absorb the energy generated during an earthquake. These are specialized devices that:

    • Dissipate Vibrational Energy: Dampers convert the vibrational energy from the earthquake into heat, reducing the amount of movement the telescope experiences.

    • Shock Absorption: These devices provide a buffering effect, protecting both the mechanical and optical components from shocks.

    3. Structural Flexibility:

    The steel structure of the telescope dome is designed with flexibility in mind, meaning it can absorb and distribute seismic forces without cracking or deforming. The use of flexible joints and materials ensures that the structure bends rather than breaks, which helps protect the telescope’s sensitive optics.

    4. Automated Safety Systems:

    To further safeguard the telescope during seismic events, automated systems are in place to detect the onset of an earthquake. These systems may:

    • Shut Down Operations: Automatically stop observations and move the telescope into a “safe” position to prevent damage to the delicate instruments.

    • Secure Instruments: Lock down movable parts to minimize internal damage.

    Why It’s Crucial:

    Seismic protection is especially important because the ELT’s optics and adaptive systems require an incredibly high degree of precision. Even slight movements or distortions caused by seismic activity could affect the alignment of mirrors or damage equipment, impacting the telescope’s ability to capture high-resolution images.

    By combining these technologies, the ELT is built to withstand the region’s seismic challenges and continue its groundbreaking observations with minimal interruption.

    Video Credit: European Southern Observatory (ESO)

  • Observational study supports century-old theory that challenges the Big Bang

    Observational study supports century-old theory that challenges the Big Bang

    by Grant Guggisberg, Kansas State University

    September 11, 2024

    A Kansas State University engineer recently published results from an observational study in support of a century-old theory that directly challenges the validity of the Big Bang theory.

    Lior Shamir, associate professor of computer science, used imaging from a trio of telescopes and more than 30,000 galaxies to measure the redshift of galaxies based on their distance from Earth. Redshift is the change in the frequency of light waves that a galaxy emits, which astronomers use to gauge a galaxy’s speed.

    Shamir’s findings lend support to the century-old “tired light” theory instead of the Big Bang. The findings are published in the journal Particles.

    “In the 1920s, Edwin Hubble and George Lemaitre discovered that the more distant the galaxy is, the faster it moves away from Earth,” Shamir said. “That discovery led to the Big Bang theory, suggesting that the universe started to expand around 13.8 billion years ago. At around the same time, preeminent astronomer Fritz Zwicky proposed that galaxies that were more distant from Earth did not really move faster.”

    Zwicky’s contention was that the redshift observed from Earth is not because the galaxies move but because the light photons lose their energy as they travel through space. The longer the light travels, the more energy it loses, leading to the illusion that galaxies that are more distant from Earth also move faster.

    “The tired light theory was largely neglected, as astronomers adopted the Big Bang theory as the consensus model of the universe,” Shamir said. “But the confidence of some astronomers in the Big Bang theory started to weaken when the powerful James Webb Space Telescope saw first light.

    “The JWST provided deep images of the very early universe, but instead of showing an infant early universe as astronomers expected, it showed large and mature galaxies. If the Big Bang happened as scientists initially believed, these galaxies are older than the universe itself.”

    While new imaging casts doubt on the Big Bang, Shamir’s study used the constant rotational velocity of the Earth around the center of the Milky Way to examine the redshift of galaxies at the Milky Way’s galactic poles that move in different velocities relative to Earth and to test how the change in the redshift responds to the change in velocity.

    “The results showed that galaxies that rotate in the opposite direction relative to the Milky Way have lower redshift compared to galaxies that rotate in the same direction relative to the Milky Way,” Shamir said. “That difference reflects the motion of the Earth as it rotates with the Milky Way. But the results also showed that the difference in the redshift increased when the galaxies were more distant from Earth.

    “Because the rotational velocity of the Earth relative to the galaxies is constant, the reason for the difference can be the distance of the galaxies from Earth. That shows that the redshift of galaxies changes with the distance, which is what Zwicky predicted in his Tired Light theory.”

    Image:

    Northeastern University researchers have shown that our visible universe and invisible dark matter likely co-evolved from the time of the Big Bang. Credit: Pixabay/CC0 Public Domain

    Journal:

    Lior Shamir, An Empirical Consistent Redshift Bias: A Possible Direct Observation of Zwicky’s TL Theory, Particles (2024). DOI: 10.3390/particles7030041

  • NASA’s SpaceX Crew-8 mission Astronaut remains Hospitalised

    NASA’s SpaceX Crew-8 mission Astronaut remains Hospitalised

    by Kate Green

    October 25, 2024

    NASA recently announced that an Astronaut from the Crew-8 mission, who returned from completing a 235-day mission on October 25, is currently hospitalized following a routine medical check.

    The mission, which included NASA astronauts Matthew Dominick, Michael Barratt, and Jeanette Epps, along with Roscosmos cosmonaut Alexander Grebenki, had an uneventful re-entry and splashdown off Florida’s coast.

    After safely splashing down on Earth as part of NASA’s SpaceX Crew-8 mission Friday, a NASA astronaut experienced a medical issue. NASA stated that after initial evaluations were performed aboard the recovery ship, further medical assessments were undertaken as a precautionary measure.

    According to a statement from NASA, “”additional evaluation of the crew members was requested out of an abundance of caution.”

    NASA did not elaborate further.

    The latest update from NASA states that “three crew members have since been released, while one NASA astronaut remains under observation at Ascension Sacred Heart Pensacola as a precautionary measure.”

    The Agency continued to say that they “are grateful to Ascension Sacred Heart for its support during this time, and we are proud of our team for its quick action to ensure the safety of our crew members.”

    NASA has not specified the medical condition to respect the Astronaut’s privacy but has assured the public that they are in stable condition.

    NASA will provide additional information as it becomes available.

    Image: The SpaceX Dragon Endeavour spacecraft shortly after splashdown off the coast of Florida on October 25, 2024.

  • NASA’s Next-Gen Spacesuits: Where Fashion Meets Space!!

    NASA’s Next-Gen Spacesuits: Where Fashion Meets Space!!

    by Kate Green

    The collaboration between Axiom Space and Prada has unveiled the Axiom Extravehicular Mobility Unit (AxEMU) spacesuit, designed for NASA’s Artemis III mission. This next-gen spacesuit combines creativity with engineering, reflecting how partnerships between diverse industries can drive innovation in space exploration.

    Prada contributed its expertise in high-performance materials and advanced sewing techniques to enhance the suit’s outer-layer design, while Axiom Space integrated its technology for flexibility, safety, and functionality. The AxEMU suit is built to withstand the extreme environment of the lunar surface, including elevated temperatures and lunar dust, and it is scalable for use in low-Earth orbit. Notably, the suit’s design supports a wide range of astronaut sizes, from the first to the 99th percentile.

    The AxEMU is built on NASA’s Exploration Extravehicular Mobility Unit (xEMU) design, offering increased mobility, performance, and safety, with specialized features like regenerable CO2 scrubbing and cooling systems. The suit will allow astronauts to perform spacewalks for up to eight hours in the harsh lunar environment, including the permanently shadowed regions of the Moon’s south pole.

    Axiom Space and Prada’s collaboration marks a significant step forward in the commercialization of space, blending industry expertise to pioneer innovative solutions for space exploration. The spacesuit is set to undergo further testing, with critical design reviews expected in 2025.

    AXEMU DEVELOPMENT

    The AxEMU (Axiom Extravehicular Mobility Unit) is a next-generation spacesuit developed by Axiom Space, advancing NASA’s xEMU (Exploration Extravehicular Mobility Unit) design. It enhances flexibility, safety, and performance, crucial for the challenges of the lunar south pole, particularly during the Artemis III mission. The suit is designed to accommodate a broad range of astronaut body types (from the first to the 99th percentile) and endure the Moon’s extreme environments. It can operate in the coldest, permanently shadowed lunar regions for at least two hours and support eight-hour spacewalks.

    Key features of the AxEMU:

    • Multiple redundant systems and an onboard diagnostic system to ensure safety.

    • A regenerable CO2 scrubbing system and advanced cooling technology to remove excess heat.

    • Enhanced coatings on the helmet and visor for better visibility (in collaboration with Oakley).

    • Custom gloves designed in-house with advancements for comfort and usability.

    • A life support system, pressure garments, and avionics integrated into the architecture.

    The AxEMU’s modular design allows it to be scalable and adaptable for various missions, whether on the lunar surface or in low-Earth orbit (LEO). Over the past two years, Axiom Space has iteratively improved the suit, conducting extensive testing, including underwater simulations at NASA’s Neutral Buoyancy Laboratory (NBL) and reduced gravity simulations at NASA’s Johnson Space Centre.

    Recently, the suit completed a pressurized simulation test with NASA, SpaceX, and Axiom Space, the first since the Apollo era. As the AxEMU approaches the final development stages, it will undergo further crewed tests at the NBL and integrated tests with Artemis Lunar Terrain Vehicle prototypes before the critical design review phase in 2025.

    Returning to the Lunar Surface

    The Axiom Extravehicular Mobility Unit (AxEMU) spacesuit represents a major leap forward for lunar exploration, providing astronauts with cutting-edge equipment to access, live, and work on the Moon. This next-generation spacesuit, developed by Axiom Space, offers enhanced flexibility and protection tailored to the Artemis III mission and beyond. It builds on NASA’s xEMU design, incorporating innovative technologies to improve mobility, safety, and the ability to perform scientific tasks.

    Key advancements of the AxEMU spacesuit:

    • Increased flexibility: Allows astronauts to move more naturally, improving their ability to explore the lunar surface.

    • Greater protection: Designed to withstand the Moon’s harsh conditions, including extreme temperatures, lunar dust, and the challenges of working in low-gravity environments.

    • Specialized tools: Equipped with tools to aid in exploration, enabling astronauts to conduct more extensive scientific research on the lunar surface.

    The suit’s modular and flexible design enables astronauts to cover more ground, access new regions, and expand the scope of scientific opportunities, particularly in the lunar south pole. This development marks a significant milestone for U.S. space leadership, supporting NASA’s vision of long-term lunar exploration and setting the stage for future missions that extend human presence deeper into the solar system.

    Axiom Space’s work on the AxEMU also highlights the evolving commercial role in space exploration, providing NASA with advanced, commercially developed human systems that help pave the way for the Artemis program’s future missions and beyond.

    A spacesuit for everyone

    The Axiom Space AxEMU spacesuit is a breakthrough in both design and functionality, tailored to meet the diverse needs of astronauts, space agencies, and commercial ventures. Its adjustable and versatile sizing accommodates a broad spectrum of body types, providing a customized fit that enhances both comfort and performance for astronauts during critical missions.

    Key Features:

    • Adjustable design: The AxEMU’s ability to fit a wide range of body types, from the first to 99th percentile, ensures that astronauts of varying sizes can operate effectively in space. This inclusivity sets a new standard for space missions.

    • Improved comfort: The suit is engineered to increase comfort, which is essential for long-duration spacewalks and other extravehicular activities, allowing astronauts to work efficiently without being hindered by their gear.

    Designed for Versatility:

    The AxEMU is a cost-effective multipurpose spacesuit, making it adaptable to various mission types, whether on the lunar surface or in low-Earth orbit (LEO). Its agile design meets the stringent demands of different environments with minimal modifications, offering:

    • Dust resistance: The suit is designed to withstand the challenges of the lunar surface, particularly the abrasive lunar dust.

    • Critical interfaces: Key features ensure safe and effective extravehicular activities (EVAs) in microgravity, making the AxEMU suitable for use in various space exploration contexts.

    By providing a spacesuit that is adaptable for multiple missions, the AxEMU advances space exploration capabilities while being efficient and cost-effective. This flexibility ensures that astronauts are equipped to perform tasks safely and effectively across a range of space environments.

    Designed for Every Mission

    The AxEMU is designed as a cost-effective, multipurpose spacesuit, engineered to adapt to a wide variety of missions with minimal modifications. This versatile design ensures that astronauts can safely and efficiently perform tasks in various challenging environments, from the dusty lunar surface to microgravity conditions in low-Earth orbit (LEO).

    Key Advantages:

    • Safety and agility: The AxEMU offers improved safety through advanced technology and increased agility, enabling astronauts to navigate complex terrains and perform tasks with ease.

    • Environmental resilience: It is built to endure the harsh, dusty conditions of the lunar surface, ensuring that astronauts can continue their operations without being impeded by lunar dust.

    • Critical interfaces: Designed to maintain crucial systems and connections, the suit supports safe and effective extravehicular activities (EVAs), allowing astronauts to operate seamlessly in microgravity environments.

    By incorporating innovative features that enhance mobility and reliability, the AxEMU provides an adaptable solution for a wide range of exploration needs, making it a versatile asset for current and future space missions.

    Safety

    The AxEMU spacesuit prioritizes safety and reliability by incorporating advancements based on lessons from legacy spacesuits, while integrating new technologies to ensure astronaut protection during missions. Its design centres around mitigating risks and eliminating single-point failures through the use of redundant components.

    Key Safety Features:

    • Redundant systems: The AxEMU’s architecture includes multiple layers of redundancy, meaning that if one system fails, backup components will take over to ensure continuous functionality, especially during critical operations like returning to the spacecraft.

    • Enhanced reliability: The suit incorporates state-of-the-art technology, such as advanced life support systems and materials that provide additional protection, ensuring astronauts can operate confidently in challenging environments.

    The architecture built around the astronaut ensures that every aspect of the suit is optimized to keep them safe, allowing for seamless operation even in the event of equipment malfunction. By focusing on redundancy and reliability, the AxEMU sets a new standard for safety in space exploration.

    Better Mobility

    The AxEMU spacesuit is designed to deliver superior mobility and agility, essential for astronauts operating in extreme environments. Recognizing that spacesuits must support astronauts in performing complex tasks, the AxEMU integrates a combination of soft and hard joints to significantly improve the range of motion.

    Key Mobility Enhancements:

    • Innovative joint design: The combination of flexible soft joints and durable hard joints allows for a greater range of motion, enabling astronauts to walk, bend, and manoeuvre on the Moon’s surface with ease. This ensures they can conduct precise geological and scientific tasks with minimal effort.

    • Optimized for exploration: The suit is tailored to allow astronauts to move more fluidly while walking or working, enhancing their ability to navigate the challenging lunar terrain.

    • Ease of movement in microgravity: The increased agility not only benefits lunar surface missions but also improves astronauts’ ability to move around and translate while working in microgravity environments, such as space stations.

    By enhancing comfort and mobility, the AxEMU ensures that astronauts can perform their tasks more efficiently, reducing fatigue and enabling them to stay focused on exploration and scientific research. This advancement in design allows for safer, more productive extravehicular activities, crucial for the success of future space missions.

    Built Together

    The AxEMU spacesuit is a product of a truly collaborative effort, bringing together experts from diverse fields and industries. Each hardware component, fabric panel, and integrated system within the suit represents the combined knowledge and skills of individuals from various backgrounds—ranging from sewers and technicians to engineers, medical personnel, and more.

    This multidisciplinary approach ensures that every aspect of the suit is crafted with precision, reliability, and innovation, leveraging the best practices from each sector. By combining engineering expertise with innovative materials and production techniques, the AxEMU is not just a spacesuit, but a testament to the power of cross-industry collaboration.

    The development process has brought together people with a shared vision of advancing human exploration, creating a spacesuit designed to make history by enabling astronauts to safely walk on the Moon once again. This teamwork exemplifies the idea that groundbreaking achievements are built through the collective efforts of many, pushing the boundaries of space exploration.

    Built to last Generations

    The AxEMU spacesuit is designed with an agile, future-proof architecture, ensuring it meets the evolving needs of individual, commercial, and government space exploration customers. This adaptable design allows the suit to be tailored to a broad range of mission requirements, making it a versatile tool for various objectives in low-Earth orbit (LEO) and beyond.

    Key Features of Longevity:

    • Agile architecture: The suit’s core design is flexible and scalable, enabling it to accommodate a wide range of mission profiles and environmental conditions with minimal modifications.

    • On-orbit maintenance: The AxEMU can be maintained and repaired while in orbit, reducing the need for frequent resupply or costly replacements. This capability significantly lowers operational costs and extends the lifespan of the suit during long-duration missions.

    • Cost-efficiency: The long-lasting design of the AxEMU ensures that space agencies and commercial operators can rely on the suit for multiple missions, enhancing cost-effectiveness by minimizing the time and resources needed for upkeep.

    By focusing on durability and adaptability, the AxEMU is built to serve multiple generations of space exploration, supporting the future of low-Earth orbit operations, lunar missions, and even deeper space endeavours. This innovation ensures that the suit remains a vital tool in the continued expansion of human presence in space.

    Image: Shown here is the current white cover layer of the Axiom Extravehicular Mobility Unit (AxEMU) spacesuit prototype as it is tested in the Active Response Gravity Offload System (ARGOS) system at NASA’s Johnson Space Center. The person wearing it tests its use with different lunar geology tools.

    Image: The AxEMU spacesuit includes custom gloves made in-house featuring several advancements over the gloves currently in use.

    Image: The Axiom Extravehicular Mobility Unit (AxEMU) spacesuit includes a helmet with visor, lights, and HD camera.

    Image: The AxEMU suit will enable astronauts to perform a spacewalk for at least eight hours and it accommodates a wide range of crewmembers, including males and females from the first to 99th percentile (anthropomorphic sizing).

    Image: The single AxEMU architecture is evolvable, scalable and adaptable for missions on the lunar surface and in low-Earth orbit (LEO). The AxEMU has significant advancements in safety, mobility, sizing, and performance.

  • NASA / Boeing Starliner Saga Continues

    NASA / Boeing Starliner Saga Continues

    by Kate Green

    October 19, 2024

    NASA’s Starliner spacecraft, developed by Boeing, has faced several delays and technical issues, pushing its next crewed mission to the International Space Station (ISS) to no earlier than 2025.

    Here’s an overview of the situation and its impact on upcoming missions:

    Key Points:

    1. Starliner’s Crewed Mission Delayed:

      • Starliner’s next potential crewed mission to the ISS will occur no sooner than 2025. NASA is currently reviewing Boeing’s path to system certification following issues on the spacecraft’s first crewed test flight earlier this year.

      • The launch of the Crew Flight Test (CFT) on June 5, 2023, experienced propulsion problems during docking. While astronauts Butch Wilmore and Suni Williams reached the ISS safely, five out of 28 thrusters had issues, leading to repeated mission extensions.

    2. Troubleshooting and Delays:

      • Even after extensive ground and space testing, the propulsion issues weren’t fully resolved, prompting NASA to bring Starliner back autonomously on September 6, 2023.

      • Williams and Wilmore, originally expected to return on Starliner, will now return to Earth aboard SpaceX’s Crew Dragon capsule in February 2025 as part of the Crew-9 mission. Crew Dragon’s flexibility allowed for the mission to carry two astronauts instead of the usual four, making space for the Starliner crew.

    3. Certification Uncertainty:

      • NASA and Boeing are still working on determining if Starliner’s CFT mission was successful enough to meet certification requirements for future operational missions like Starliner-1.

      • If necessary, Starliner may require additional test flights with astronauts before being cleared for full operational use.

    4. Starliner’s Propulsion Issues:

      • The propulsion system issues seen in 2024 are not new. Starliner also faced similar problems during its two uncrewed test flights in 2019 and 2022, which NASA and Boeing believed were resolved before sending astronauts onboard.

    5. Upcoming Spaceflight Plans:

      • While Starliner is delayed, NASA’s partnership with SpaceX continues smoothly. SpaceX’s Crew-10 mission is scheduled to launch in February 2025, with a crew that includes NASA astronauts Anne McClain and Nichole Ayers, along with Takuya Onishi (JAXA) and Kirill Peskov (Roscosmos).

      • Crew-11 will follow no earlier than July 2025, though the crew for that mission has yet to be announced.

      • NASA astronauts Scott Tingle, Mike Fincke, and Canadian astronaut Joshua Kutryk are still assigned to Starliner-1, which was expected to fly in 2025. However, their status could change if Starliner requires additional test flights.

    Conclusion:

    Boeing’s Starliner spacecraft continues to face delays and challenges due to propulsion issues that have persisted over multiple flights. NASA is working with Boeing to determine if Starliner can be certified for regular crewed missions to the ISS.

    In the meantime, SpaceX’s Crew Dragon remains the primary vehicle for transporting astronauts to and from the space station, ensuring continuous operations on the ISS while Starliner’s future is assessed.

    Image:

    Boeing’s Starliner Crew Flight Test capsule landing on September 6, 2024. (Image credit: NASA TV)

  • Increasing Space Debris – Are there solutions?

    Increasing Space Debris – Are there solutions?

    by Kate Green

    October 19, 2024

    The Disney-Pixar movie WALL-E (2008) offers an interesting, if not entirely realistic, portrayal of Earth’s future, including a representation of space debris. While the film primarily focuses on environmental degradation, its depiction of space junk hints at real-world issues related to space debris and human neglect of sustainability.

    The real life growing issue of space debris, or space junk, is a significant challenge for the future of space exploration and satellite operations. As more nations and companies launch satellites and missions into Earth’s orbit, the risk of collisions and disruptions increases.

    Why is Space Debris a Problem?

    Space debris includes defunct satellites, spent rocket stages, fragments from collisions, and other non-functional objects in Earth’s orbit. These range from large objects to tiny paint flecks, but even small debris traveling at high velocities (up to 28,000 km/h) can cause severe damage.

    As of October 2024, over 36,000 pieces of debris larger than 10 cm are tracked, but millions of smaller, untracked particles also pose dangers. Collisions between debris and operational spacecraft could lead to a Kessler syndrome, where the density of objects in low Earth orbit (LEO) reaches a point that leads to cascading collisions, rendering orbits unusable for satellites or space missions, trapping humanity on Earth much like in WALL-E.

    Space debris threatens active satellites, the International Space Station (ISS), and future space missions. It also endangers human spaceflight and critical infrastructure like communication and weather satellites.

    Proposed Solutions to the Space Debris Problem

    Active Debris Removal (ADR)

    ADR involves removing large debris objects before they cause collisions. Several concepts are being developed:

    • Space tugs: Satellites equipped with robotic arms or nets could capture and deorbit large debris.

    • Harpoons and nets: Special satellites can harpoon or net debris, dragging it into Earth’s atmosphere to burn up.

    • Lasers: Ground-based or satellite-based lasers could “nudge” debris by altering its orbit slightly, causing it to deorbit and burn up in the atmosphere over time.

    A real life example is the European Space Agency’s (ESA) ClearSpace-1 mission, planned for 2026, which aims to capture and de-orbit a large piece of space debris (a rocket component) using a robotic arm.

    Debris Mitigation

    The reduction in the creation of new debris is crucial with mitigation strategies including:

    • End-of-life protocols: Satellites should be designed to either deorbit themselves or move to a graveyard orbit at the end of their operational life. This is already a regulatory requirement for some missions.

    • Design improvements: Satellites and rockets should minimize the shedding of parts during launch and operations, and be made of materials that degrade more quickly in orbit.

    An example of this is the UN’s Outer Space Treaty and Inter-Agency Space Debris Coordination Committee (IADC)  which recommends guidelines for minimizing debris, though enforcement is challenging.

    International Cooperation and Policy

    • International treaties: Coordinated international policies and agreements will be necessary to enforce space debris regulations, ensuring that all countries follow best practices for debris mitigation and removal.

    • Debris-tracking networks: Nations must work together to enhance global tracking systems. This includes sharing data about debris objects and possible collisions.

    Organizations like the UN Office for Outer Space Affairs (UNOOSA) work to foster international dialogue on space sustainability – but again, not all countries and private / commercial companies are willing to participate.

    Space Traffic Management (STM)

    Just as air traffic control manages airplanes, STM aims to manage and monitor objects in space. By tracking large debris, space agencies can prevent collisions and ensure the safety of space missions. However, as the number of objects in orbit grows, this task becomes more challenging, emphasizing the need for active debris removal and better space traffic management.

    • Real-time tracking: Enhanced debris tracking and collision-avoidance systems could help prevent potential collisions between satellites and debris.

    • Autonomous systems: AI-powered systems onboard satellites could automatically adjust orbits when on a collision course with debris.

    • Tracking Objects Larger than 10 cm: Pieces of debris larger than 10 cm are considered large enough to be tracked with ground-based radar and optical telescopes. Space agencies such as NASA and ESA (European Space Agency) keep continuous track of these objects. Private organizations like the U.S. Space Surveillance Network (SSN) and LeoLabs also track debris and offer collision avoidance services for satellite operators.

    • Catalogued Objects: There are currently over 36,000 pieces of debris larger than 10 cm orbiting Earth that are being tracked. These include defunct satellites, spent rocket stages, and fragments from collisions or disintegration events.

    • Avoidance Manoeuvres: When larger pieces of tracked debris come close to active satellites or the International Space Station (ISS), operators are alerted and sometimes perform avoidance manoeuvres to prevent collisions.

    • Objects Between 1 and 10 cm: Although objects between 1 and 10 cm are harder to track, they are still dangerous. These are often detected using radar, but their precise orbits may not always be catalogued. The number of objects in this size range is estimated to be much higher, in the hundreds of thousands.

    • Smaller Debris: Even smaller debris (under 1 cm) poses risks, especially to spacecraft and Astronauts, though these are too small to track individually. Shielding techniques are used to protect spacecraft from these tiny, high-velocity objects.

    Recycling and Repurposing in Space

    • In-orbit recycling: A future possibility could involve missions that collect debris and repurpose materials in space for manufacturing. This would help clear orbits and provide resources for constructing spacecraft or stations without launching materials from Earth.

    • On-orbit servicing: Some companies are developing satellites that can extend the life of other satellites by refueling or repairing them, preventing them from becoming debris.

    Another private company example is that of Northrop Grumman’s Mission Extension Vehicle (MEV) that successfully extended the life of a communications satellite, showcasing the potential of on-orbit servicing.

    The Path Forward

    While Disney’s WALL-E is an animated science fiction film, its portrayal of space debris serves as a cautionary tale. It highlights the importance of addressing real-world environmental and space sustainability issues before they spiral out of control. It reflects a growing awareness of the need for responsible space exploration, better debris management, and sustainable living on Earth.

    Innovative solutions are being developed with the challenge being implementing these solutions globally and at scale. Active removal efforts combined with strong mitigation policies, technological advances, and international cooperation offer the most promising paths to maintaining a sustainable space environment for future generations.

  • First results from the Axion Dark-Matter Birefringent Cavity experiment establish a new technique for axion se

    First results from the Axion Dark-Matter Birefringent Cavity experiment establish a new technique for axion se

    by Kate Green

    October 20, 2024

    MIT researchers recently published the first results of an experiment aimed at detecting axion dark matter by exploring axion-induced birefringence of electromagnetic waves. Although no axion signals were observed, the findings, published in Physical Review Letters, introduced a new method for axion searches. This approach uses a tuneable optical cavity, allowing researchers to adjust the experimental parameters and expand the range of possible axion masses they can probe. This marks a significant advancement in the search for axions, hypothetical particles thought to be a key component of dark matter.

    Evan Hall, a research scientist at MIT’s LIGO lab, explained that the experiment was first proposed in 2019 through a collaboration between their lab and the MIT Center for Theoretical Physics. The team was exploring new approaches to search for the axion, a hypothetical dark matter particle.

    “Any observable interaction between axions and standard matter is expected to be very faint. We realized that the problem of trying to find a faint signal was a very similar problem to the detection of gravitational waves, which is another kind of very faint kind of signal detected only recently” Hall stated.

    After extensive theoretical discussions, Evan Hall and his colleagues recognized that the lasers and optical instruments used in LIGO’s gravitational wave detection could be adapted for axion searches. This led to the development of the Axion Dark-Matter Birefringent Cavity (ADBC) experiment, which began collecting data in 2022. The experiment repurposes LIGO’s technology to probe for faint signals that could reveal the existence of axions, a type of hypothetical dark matter particle.

    “We wanted to demonstrate experimentally how to use these tools to pull off an axion search,” explained Hall. “Light comes in two polarizations—horizontal and vertical. Axions, if they exist, are expected to convert one polarization into the other. In our lab, we use a laser to generate vertically polarized light, and we look for any hint that axions have converted some of that light into the horizontal polarization.”

    The ADBC experiment’s detector is composed of four mirrors arranged in an optical cavity, a structure designed to trap and recirculate light. This cavity allows laser-generated light beams to bounce thousands of times, significantly amplifying any faint signals that could be caused by axions. This design enhances the experiment’s ability to detect the subtle interactions expected from these hypothetical dark matter particles.

    In the early stages of the experiment, Hall and his team used the ADBC detector to search for axions with masses around 50 neV (about 10–40 grams). Interestingly, a research group in the United Kingdom has been conducting similar searches for axions, focusing on those with masses around 2 neV, using equipment comparable to that used at MIT. This highlights the growing global interest in axion searches, with different teams probing various mass ranges to uncover these elusive dark matter particles.

    “Our work showed that this new kind of cavity can be tuned to widen the range of possible axion masses that can be searched over,” said Swadha Pandey, fourth year Ph.D. student at MIT. “Specifically, we showed that the cavity can be tuned by adjusting the angles of its four mirrors. Tunability is an important criterion for making the apparatus useful for dark matter searches. Since nobody knows what the axion mass might be, we need to search over a wide range of possible masses.”

    The initial results from the ADBC experiment have placed important constraints on the potential coupling between axion-like particles and photons. While axions have not been detected yet, these findings lay the groundwork for future research, showing that optical cavities can be an effective tool for searching for these hypothetical dark matter particles. This work could inspire further experiments and refinements in the search for axions, bringing researchers closer to their potential experimental discovery.

    “Having shown that this method can work over a broad range of axion masses, the next step would be to build a larger, more sensitive experiment,” added Pandey. “Such an experiment would use more laser light, so that there are more photons interacting with the axions, and the experiment would be larger, to increase the time that the photons can interact with the axions. Automation of the tuning mechanism and clever designs for mirror coatings are also essential for scanning across the entire available range of axion masses.”

    Journal:

    Swadha Pandey et al, First Results from the Axion Dark-Matter Birefringent Cavity (ADBC) Experiment, Physical Review Letters (2024).

    DOI: 10.1103/PhysRevLett.133.111003

    Image:

    Experimental setup at MIT, picture by Swadha Pandey. Our four-mirror detector is housed inside two steel vacuum chambers connected by a pipe. The platform in front of the near vacuum chamber supports optics that direct laser light into and out of the chamber. Credit: Pandey, Hall and Evans.

    Image:

    Experimental setup: bow-tie cavity with A, D, B, C mirrors. ^𝑠-polarized pump field from a 1064 nm Nd:YAG laser enters the cavity at mirror A and is locked to the cavity using a Pound-Drever-Hall lock. ^𝑝-polarized sidebands generated by an axionlike particle (ALP) at the cavity splitting frequency 𝜔𝑎=𝜔sp are resonant in the cavity. Heterodyne readout is performed using pump and signal field transmitted at mirror C. Credit: Physical Review Letters (2024). DOI: 10.1103/PhysRevLett.133.111003

  • Cloudspotting on Mars Project

    Cloudspotting on Mars Project

    by Zooniverse

    October 30, 2024

    Get ready to explore the skies of Mars: we’re thrilled to launch Cloudspotting on Mars: Shapes!

    In this fun new project, you’ll help us identify and map different types of Martian clouds using data from NASA’s MAVEN mission. Dive into the Red Planet’s atmosphere, spot icy clouds, and help scientists unlock the mysteries of Martian weather patterns!

    The MAVEN spacecraft has been snapping stunning images for years, and we need your help to sort through them. Your discoveries will be part of a cool cloud library that will help scientists better understand Mars’ ever-changing atmosphere.

    Join the adventure and start cloudspotting today—visit: https://www.zooniverse.org/projects/matteocrismani/cloudspotting-on-mars-shapes

    Has this new NASA citizen science project sparked your interest? Consider subscribing to our NASA-Zooniverse email list to receive updates and news regarding broader NASA citizen science projects and efforts.

    If interested, please follow these instructions to sign up:

    1. Log in to your Zooniverse account.

    2. Visit https://www.zooniverse.org/settings/email

    3. Click the checkbox under “Zooniverse partner email preferences” to sign up for periodic email updates from NASA.

  • Axions: leading candidate for dark matter or not?

    Axions: leading candidate for dark matter or not?

    by Kate Green

    October 19, 2024

    A collaborative team of physicists from the universities of Amsterdam, Princeton, and Oxford has recently published findings suggesting that extremely light particles known as axions may form large clouds around neutron stars. These axions offer a potential explanation for dark matter, a phenomenon that has long eluded cosmologists. Importantly, the research indicates that these axion clouds might be observable with existing telescopes.

    Background on Axions

    1. Previous Research:

      • The team previously explored axions that escape neutron stars, investigating how they could lead to observable signals when converted into light under certain conditions.

    2. Current Focus:

      • The latest research shifts attention to axions that do not escape the gravitational pull of neutron stars, focusing on those captured and retained by the star’s immense gravity.

    Formation of Axion Clouds

    1. Capturing Axions:

      • Over time, axions that are gravitationally bound to neutron stars accumulate, gradually forming a dense, hazy cloud around the star.

    2. Observational Potential:

      • The formation of these axion clouds raises intriguing questions for astronomers and physicists alike. The existence of such clouds could lead to observable phenomena that might provide insights into both axion physics and the nature of dark matter.

    Why Study Axion Clouds?

    1. Exploration of Dark Matter:

      • Understanding axion clouds could help elucidate the properties and behaviours of dark matter, contributing to a more comprehensive understanding of the universe’s composition.

    2. Observable Signals:

      • The clouds may produce detectable signals that can be studied using current astronomical instruments, enabling researchers to test theories regarding axions and dark matter.

    3. Link to Neutron Stars:

      • Neutron stars represent extreme environments, making them ideal laboratories for studying the fundamental interactions of particles like axions. Observing these clouds could yield valuable data about the physics governing both neutron stars and potential dark matter candidates.

    The study of axion clouds around neutron stars presents a promising avenue for advancing our understanding of dark matter. By focusing on the axions retained by these stars, physicists aim to uncover observable signals that may confirm the existence of axions and provide critical insights into the nature of the universe. This research exemplifies the interconnectedness of particle physics, astrophysics, and cosmology, as scientists strive to unravel one of the most profound mysteries of modern physics.

    Axions: From soap to dark matter

    Introduction to Axions

    1. Understanding Common Particles:

    • Many people are familiar with protons, neutrons, electrons, and photons—fundamental particles that constitute the matter around us. In contrast, axions are less known and remain a theoretical entity.

    1. Hypothetical Nature:

    • Axions are currently only a hypothetical type of particle; no experimental evidence has yet confirmed their existence. Their conception emerged from the need to address theoretical inconsistencies within particle physics.

    Origin and Naming

    1. Naming and Historical Context:

    • Proposed in the 1970s, the term “axion” was inspired by a brand of soap, reflecting its role in “cleaning up” theoretical problems concerning the strong interactions of particles like the neutron.

    1. Theoretical Framework:

    • In particular, axions were introduced as part of the solution to the strong CP problem, which involves the apparent absence of certain types of symmetry violations in strong interactions. Their introduction aimed to reconcile theoretical predictions with observed phenomena.

    Characteristics of Axions

    1. Hypothetical Nature:

    • Despite being a compelling theoretical candidate, axions have not yet been detected. They are predicted to be extremely light—much lighter than protons, neutrons, or electrons—making them difficult to observe directly in laboratory experiments.

    1. Weak Interactions:

    • Axions are theorized to have very weak interactions with other particles, meaning that even if they do exist, they would be challenging to detect with existing experimental setups. This property makes them intriguing candidates for dark matter.

    Axions and Dark Matter

    If axions exist, they could potentially account for a significant portion of the universe’s dark matter due to their ability to cluster and exert gravitational influence on galaxies and cosmic structures.

    1. Dark Matter Overview:

    • Approximately 85% of the universe’s matter content is thought to be “dark matter,” which interacts with normal matter primarily through gravitational forces. This dark matter does not emit, absorb, or reflect light, making it invisible and detectable only through its gravitational effects on visible matter, such as galaxies and galaxy clusters.

    1. Detection Challenges:

    • The notion that axions could contribute to dark matter has gained traction, as they may account for the unseen mass influencing the universe’s structure and behaviour.

    • Despite the theoretical implications, dark matter interactions with normal matter are presumed to be minimal, making it exceptionally difficult to detect.

    The axion remains one of the most intriguing candidates for solving the dark matter mystery, bridging gaps between fundamental physics and the cosmos. Thus, the quest to detect axions continues, with physicists exploring innovative experimental approaches to uncover the nature of dark matter and the universe’s composition. If proven to exist, axions could illuminate our understanding of the universe and provide answers to some of the most profound questions in modern physics. The theoretical possibility that axions could be a key component of dark matter emphasizes the intricate connections between particle physics, cosmology, and our understanding of the universe.

    Neutron stars as magnifying glasses

    The concept of neutron stars acting as “magnifying glasses” for axions is a fascinating approach to addressing the challenge of detecting these elusive particles.

    Here is a deeper dive into how this works and its implications for axion research:

    The Axion-Photon Conversion Mechanism

    1. Electric and Magnetic Fields:

    • Axions are hypothesized to have the ability to convert into photons (light particles) when subjected to electric and magnetic fields. This conversion is a crucial aspect of their potential detectability.

    • However, the interaction strength between axions and photons is expected to be extremely weak, meaning that the amount of light produced from axions under typical conditions would be minimal.

    1. Conditions in Neutron Stars:

    • Neutron stars provide a unique environment due to their extreme density and strong gravitational fields. These stars are typically around 12 to 15 kilometres in radius but contain masses similar to that of the Sun, creating immense pressure and temperature.

    • The magnetic fields around neutron stars can be billions of times stronger than those on Earth, offering an ideal setting for the mass production of axions. Under these conditions, the density of axions could become substantial enough to enhance the likelihood of photon production.

    The Potential for Observable Signals

    1. Enhanced Signal Detection:

    • The dense clouds of axions formed around neutron stars increase the chance of axion-photon conversion events, leading to potentially observable signals.

    • If a significant number of axions can convert into photons due to the extreme magnetic fields present in neutron stars, it may produce a detectable light signature that astronomers can observe.

    1. Types of Signals:

    • Continuous Emission: During the neutron star’s active phase, a steady emission of light could be produced as axions convert to photons. This signal may be detectable over long periods.

    • Transient Events: A dramatic one-time burst of light could occur at the end of a neutron star’s life, potentially offering a clear and unique signal that could be studied in detail.

    Broader Implications for Axion Research

    Testing Dark Matter Theories:

    • Observing these axion-induced signals would provide valuable data that could either support or challenge current models of dark matter. If axions are confirmed to exist and are observed through these mechanisms, it would significantly advance our understanding of the universe’s composition.

    Increased Collaboration:

    • The study of axions in neutron stars could lead to cross-disciplinary collaborations between astrophysicists, particle physicists, and experimental scientists as they work together to develop and deploy observational strategies.

    Future Research Directions:

    • Continued theoretical and computational modelling will be essential to refine predictions about axion clouds and their potential signals. Additionally, the development of new observational techniques and technologies will enhance the search for these elusive particles.

    Neutron stars, with their extreme conditions, present a promising avenue for detecting axions and addressing fundamental questions about dark matter. By leveraging the unique properties of these stellar remnants, researchers are better positioned to uncover new physics and enhance our understanding of the universe. The potential to observe axion-induced light from neutron stars not only offers hope for confirming the existence of these hypothetical particles but also for unravelling the mysteries of dark matter that have puzzled scientists for decades.

    The ones that stay behind

    The authors’ research marks a significant advancement in our understanding of axions, particularly focusing on those that are captured by neutron stars rather than escaping into space. Here is a detailed breakdown of their findings and implications:

    Key Findings

    1. Axion Capture:

    • The study shifts the focus from axions that escape neutron stars to those that are gravitationally bound to them. These captured axions, despite their extremely low mass and weak interactions, can accumulate around the neutron star over millions of years.

    1. Formation of Axion Clouds:

    • The authors argue that axion clouds should exist around most neutron stars due to their gravitational pull, leading to the formation of dense axion clouds. These clouds may be significantly denser—potentially up to twenty orders of magnitude—than local dark matter densities, presenting a unique opportunity for observation.

    1. Observational Signatures

    • The dense axion clouds around neutron stars could produce various observable signals, primarily:

      • Continuous Signals: Emitted over extended periods during the neutron star’s lifetime, providing a steady light source for telescopes to detect.

      • One-Time Bursts: Occurring at the end of a neutron star’s life when it ceases its electromagnetic emissions. This burst could serve as a distinct signal for axion detection.

    Implications for Axion Research

    1. Research Opportunities

    • The presence of axion clouds around neutron stars creates exciting avenues for research. These clouds can be studied to probe the properties and interactions of axions, contributing to our understanding of dark matter and fundamental particle physics.

    1. Utilization of Existing Telescopes:

    • The potential for detection using existing radio telescopes is significant, as it allows for immediate observational efforts without the need for new, complex instrumentation. This accessibility could expedite the search for evidence of axions.

    1. Understanding Neutron Star Dynamics:

    • The formation and characteristics of axion clouds could also provide insights into the dynamics and evolution of neutron stars, enriching our knowledge of stellar physics.

    The authors’ focus on axion clouds around neutron stars opens up a promising frontier in astrophysics. By studying these clouds, researchers may not only advance our understanding of axions as a candidate for dark matter but also enhance the broader understanding of neutron star physics and cosmic structure. The potential to observe distinct signals from axion clouds could lead to groundbreaking discoveries, making this a highly impactful area of research in the ongoing quest to unravel the mysteries of the universe.

    What is next?

    The next steps in the study of axion clouds around neutron stars are multifaceted and aim to deepen our understanding of both axions and neutron stars themselves. Here are some key directions for future research:

    1. Search for Axion Clouds

    • Observational Campaigns: The primary focus will be on conducting thorough searches for axion clouds using existing radio telescopes and observatories. Scientists will look for the predicted signals associated with axion emissions, both continuous and one-time bursts, to confirm their existence.

    1. Theoretical Investigations

    • Dynamics of Neutron Stars: One of the authors is already working on exploring how the presence of axion clouds could influence the dynamics of neutron stars. Understanding these interactions could provide insights into the internal structure and evolution of these dense objects.

    1. Numerical Modelling

    • Refining Predictions: More numerical modelling of axion clouds is essential to provide accurate predictions of their formation, behaviour, and the resulting observational signatures. This modelling will help researchers identify specific parameters to focus on during observations.

    1. Binaries and Axion Clouds

    • Studying Binaries: Many neutron stars exist in binary systems, either with another neutron star or with a black hole. Investigating how axion clouds behave in these environments will be critical. Researchers will need to understand how the dynamics of axion clouds might change in these complex systems and what unique signals they could produce.

    1. Cross-Disciplinary Collaborations

    • Integrative Research: As the study of axions intersects with various fields—particle physics, astrophysics, plasma physics, and observational astronomy—collaborations among experts in these disciplines will be important. This integrative approach can lead to new methodologies and enhance the overall understanding of dark matter and fundamental physics.

    1. Future Theoretical Developments

    • Exploring Alternative Scenarios: Researchers might explore alternative theories and scenarios involving axions and their potential role in the broader context of cosmology, dark matter, and the evolution of the universe.

    The exciting prospect of discovering axion clouds represents a significant step in understanding dark matter and the fundamental forces governing the universe. By establishing a comprehensive research agenda focused on both observational and theoretical advancements, scientists hope to illuminate the mysteries surrounding these elusive particles and their implications for astrophysics. As this field progresses, it may reveal profound insights into the nature of matter and the structure of the cosmos.

    Journal:

    Dion Noordhuis et al, Axion Clouds around Neutron Stars, Physical Review X (2024). DOI: 10.1103/PhysRevX.14.041015

    Image:

    An axion cloud around a neutron star. While some axions escape the star’s gravitational pull, many remain bound to the star and over a long period of time form a cloud surrounding it. The interaction with the neutron star’s strong magnetic field causes some axions to convert into photons – light that we can eventually detect with our telescopes on Earth. Credit: University of Amsterdam

    Image:

    Overview of the four stages characterizing the formation and evolution of axion clouds around neutron stars. Credit: Physical Review X (2024). DOI: 10.1103/PhysRevX.14.041015