Perfectly functional spacecraft have to cease operations because they run out of propellant for stationkeeping. Now a Chinese satellite has demonstrated practical orbital refueling. The recently launched Shijian-25 satellite docked with the Beidou-3 G7 at geosynchronous orbit and transferred 142 kilograms of hydrazine, extending the communication satellite's lifespan by 8 years. China is planning to build a network of "space gas stations" to maintain its fleet.
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fraser@m.universetoday.com
@fraser@m.universetoday.com
A forum for discussing and organizing recreational softball and baseball games and leagues in the greater Halifax area.
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Perfectly functional spacecraft have to cease operations because they run out of propellant for stationkeeping. -
China's Tianwen-2 spacecraft recently arrived at the launch site for its upcoming May 2025 mission to asteroid Kamoʻoelewa.China's Tianwen-2 spacecraft recently arrived at the launch site for its upcoming May 2025 mission to asteroid Kamoʻoelewa. This mission will collect samples from the 40-100 meter asteroid and deliver them to Earth by 2027. Kamoʻoelewa is a small, "quasi-satellite" of Earth with an unusually rapid rotation rate. A team of astronomers put out a new paper describing their most recent observations of Kamoʻoelewa and the outstanding scientific questions.
Astrometry, orbit determination, and thermal inertia of the Tianwen-2 target asteroid (469219) Kamo`oalewa
Abstract page for arXiv paper 2502.13222: Astrometry, orbit determination, and thermal inertia of the Tianwen-2 target asteroid (469219) Kamo`oalewa
arXiv.org (arxiv.org)
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Unlike Earth, Venus lacks an internal dynamo and a planetwide magnetosphere that could protect any life from solar and cosmic radiation.Unlike Earth, Venus lacks an internal dynamo and a planetwide magnetosphere that could protect any life from solar and cosmic radiation. But it does have an extremely thick atmosphere. Planetary scientists recently simulated the atmosphere of Venus and calculated how much space radiation would penetrate down to the lower cloud deck. They found that the atmosphere is sufficiently thick to protect life at Venus's "habitable altitude" of 40–60 km.
The Venusian Chronicles
Abstract page for arXiv paper 2502.13371: The Venusian Chronicles
arXiv.org (arxiv.org)
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The Cosmic Horseshoe is a spectacular gravitational lens, in an almost perfect Einstein Ring.The Cosmic Horseshoe is a spectacular gravitational lens, in an almost perfect Einstein Ring. The enormous gravity of a foreground galaxy cluster is magnifying the light from a more distant galaxy into a circle around it. And now, astronomers have worked out that the galaxy cluster contains a supermassive black hole with 36 billion times the mass of the Sun, one of the most massive ever measured in the Universe.
Unveiling a 36 Billion Solar Mass Black Hole at the Centre of the Cosmic Horseshoe Gravitational Lens
Abstract page for arXiv paper 2502.13788: Unveiling a 36 Billion Solar Mass Black Hole at the Centre of the Cosmic Horseshoe Gravitational Lens
arXiv.org (arxiv.org)
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Until someone tells them otherwise, engineers at NASA are continuing to prepare for the upcoming Artemis II mission, where 4 astronauts will take an Apollo 8-style flight around the Moon in an Orion Capsule and return to Earth.Until someone tells them otherwise, engineers at NASA are continuing to prepare for the upcoming Artemis II mission, where 4 astronauts will take an Apollo 8-style flight around the Moon in an Orion Capsule and return to Earth. As part of this mission, technicians fully stacked the twin Space Launch System solid rocket boosters in the Vehicle Assembly Building. They started stacking the twin rockets in late November 2024, completing them on February 19th.
Artemis II Rocket Booster Stacking Complete - NASA
Engineers at NASA’s Kennedy Space Center in Florida completed stacking the twin SLS (Space Launch System) solid rocket boosters – seen in this Feb. 19, 2025,
NASA (www.nasa.gov)
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NASA astronomers have been continuing to evaluate the future orbits of asteroid 2024 YR4.NASA astronomers have been continuing to evaluate the future orbits of asteroid 2024 YR4. It was initially estimated to be around a 1.3% chance of impact; that number rose to 3.1% with further calculations and observations. Good news, the number is dropping again. Today the agency calculated that the chance of an impact is 0.28%, while the chance of an impact with the Moon rose to 1%. Future observations are planned with JWST, so stay tuned.
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The habitable zone is where planets could have liquid water on their surfaces, but not if they're actually habitable.The habitable zone is where planets could have liquid water on their surfaces, but not if they're actually habitable. In a new paper, astronomers propose a new way to map the inner edge of habitable zones by searching for sulfur dioxide (SO₂) in the atmospheres of exoplanets. If there's SO₂, this indicates that the planet doesn't have liquid water on its surface. Telescopes like Webb could scan planets for SO₂, creating a more accurate map of habitable zones.
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Io is the most volcanically active place in the Solar System, covered by hundreds of hotspots.Io is the most volcanically active place in the Solar System, covered by hundreds of hotspots. This outgassing of sulfur dioxide (SO₂) is released into space and becomes a tenuous atmosphere around the moon, but escapes into orbit around Jupiter, gets ionized, and forms a plasma torus around Jupiter. According to a new paper, Io is losing about a ton a second from its atmosphere to supply this torus, and not directly from volcanic eruptions.
Mass supply from Io to Jupiter's magnetosphere
Abstract page for arXiv paper 2403.13970: Mass supply from Io to Jupiter's magnetosphere
arXiv.org (arxiv.org)
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The Phoenix Cluster is a huge collection of galaxies 5.8 billion light-years away, which should have used up its available star-forming gas and dust long ago.The Phoenix Cluster is a huge collection of galaxies 5.8 billion light-years away, which should have used up its available star-forming gas and dust long ago. It should be "red and dead"; instead, it still has a surprising amount of active star formation at its central galaxy. Astronomers mapped the cluster with JWST and discovered that the outer galaxies are still pumping out gas, which is then being actively cooled and driven into the central region.
Study reveals the Phoenix galaxy cluster in the act of extreme cooling
New findings from NASA’s James Webb Space Telescope explain the Phoenix cluster’s mysterious starburst. Data confirm the cluster is actively cooling and able to generate a huge amount of stellar fuel on its own.
MIT News | Massachusetts Institute of Technology (news.mit.edu)
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Astronomers believe that most gamma-ray bursts are caused by giant stars exploding as supernovae and leaving behind a black hole remnant.Astronomers believe that most gamma-ray bursts are caused by giant stars exploding as supernovae and leaving behind a black hole remnant. But a recent burst in 2024 had some strange behaviors that don't match the standard model of black holes. In a recent paper, a team of astronomers proposed that something more interesting happened: a massive star collapsed to form a magnetar, which then had a phase transition to become a "strange star" made of strange quark matter.
Signature of strange star as the central engine of GRB 240529A
Abstract page for arXiv paper 2502.11511: Signature of strange star as the central engine of GRB 240529A
arXiv.org (arxiv.org)
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The Oort Cloud is a collection of ice objects surrounding the Solar System that extends halfway to the nearest star.The Oort Cloud is a collection of ice objects surrounding the Solar System that extends halfway to the nearest star. Although its structure is roughly spherical, astronomers have simulated long-term perturbations from the planets in the outer Solar System and discovered that this process should be driving objects outward, which are then focused by the Galactic tide into two arms that spiral outward from 1,000 to 10,000 AU.
A Spiral Structure in the Inner Oort Cloud
Abstract page for arXiv paper 2502.11252: A Spiral Structure in the Inner Oort Cloud
arXiv.org (arxiv.org)
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There have been reports of Unidentified Aerospace Phenomena (UAPs) for decades, but they've been anecdotal and often given a mundane explanation.There have been reports of Unidentified Aerospace Phenomena (UAPs) for decades, but they've been anecdotal and often given a mundane explanation. But some scientists have proposed a more serious scientific study of UAPs, with optical cameras, radar systems, and other instruments that could clear up misidentification or provide genuine scientific data. What would serious research into UAPs look like and what could scientists uncover?
The New Science of Unidentified Aerospace-Undersea Phenomena (UAP)
Abstract page for arXiv paper 2502.06794: The New Science of Unidentified Aerospace-Undersea Phenomena (UAP)
arXiv.org (arxiv.org)
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Astronomers have developed several versions of rotating liquid metal telescopes, which use the force of gravity and centripetal force to create a natural telescope lens.Astronomers have developed several versions of rotating liquid metal telescopes, which use the force of gravity and centripetal force to create a natural telescope lens. They work, but there's a downside: they can only point straight up, in the opposite direction of gravity. A new paper is investigating how electromagnets could work with magnetic fluids (ferrofluids) to shape the liquid into a spherical shape and give it more viewing angles.
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Some astrophysicists theorize that there are primordial black holes, leftover from the formation of the universe.Some astrophysicists theorize that there are primordial black holes, leftover from the formation of the universe. These could have a fraction of the mass of stellar and supermassive black holes and could even be a partial explanation for dark matter. In a new paper, a researcher investigates what would happen to the human body if one of these black holes passed through a person. How much mass, speed and gravity would be dangerous?
Gravitational Effects of a Small Primordial Black Hole Passing Through the Human Body
Abstract page for arXiv paper 2502.09734: Gravitational Effects of a Small Primordial Black Hole Passing Through the Human Body
arXiv.org (arxiv.org)
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Biologists have identified a series of "hard steps" on the long journey from abiogenesis to the modern technological civilization of humanity, such as the evolution of multi-cellular organisms or language.Biologists have identified a series of "hard steps" on the long journey from abiogenesis to the modern technological civilization of humanity, such as the evolution of multi-cellular organisms or language. A new paper suggests all those steps weren't actually that hard or improbable and might have been an inevitable outcome of life's interactions with its environment. Key evolutionary states were possible when the global environment reached certain milestones.
Does planetary evolution favor human-like life? Study ups odds we’re not alone | Penn State University
Humanity may not be extraordinary but rather the natural evolutionary outcome for our planet and likely others, according to a new model developed by researchers at Penn State for how intelligent life developed on Earth.
(www.psu.edu)
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There have been several missions to Mars, slowly building up the case that the Red Planet was once warmer, wetter, and more habitable.There have been several missions to Mars, slowly building up the case that the Red Planet was once warmer, wetter, and more habitable. To find evidence of past and even current microbial life will require new experiments, instruments, and techniques. In a new paper, researchers propose that Deception Island in Antarctica is one of the best places on Earth to practice for the exploration of Mars. More than 30 sites on the island correspond to places on Mars.
The potential of Deception Island, Antarctica, as a multifunctional Martian analogue of astrobiological interest | International Journal of Astrobiology | Cambridge Core
The potential of Deception Island, Antarctica, as a multifunctional Martian analogue of astrobiological interest - Volume 24
Cambridge Core (www.cambridge.org)
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Mars dust is a big problem for solar-powered spacecraft on Mars, covering their panels and choking off their source of sunlight.Mars dust is a big problem for solar-powered spacecraft on Mars, covering their panels and choking off their source of sunlight. But what impact will it have on humans? In a new paper, researchers studied the potential health impact of Martian dust on future astronauts and found the particles were very small and could easily penetrate the lungs. It's electrostatic, magnetic, and highly oxidative, which means it can cause a variety of lung damage and respiratory issues.
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When human astronauts make the trip to Mars, they'll be spending months in deep space in both legs of the journey, exposed to the direct radiation of space.When human astronauts make the trip to Mars, they'll be spending months in deep space in both legs of the journey, exposed to the direct radiation of space. NASA's recent Artemis 1 mission was only a few weeks, but it has given researchers a baseline to estimate what the potential radiation load astronauts could expect to receive on a Mars journey. These data confirmed previous models of radiation estimates and provided some surprises about shielding strategies.
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Astronomers working with the Zwicky Transient Facility have released a new catalogue of 3,628 Type Ia supernovae.Astronomers working with the Zwicky Transient Facility have released a new catalogue of 3,628 Type Ia supernovae. This class of exploding star is valuable because they explode at a fixed brightness, allowing astronomers to calculate their distance and measure the expansion of the Universe, the influence of dark energy, and other cosmological data. The Facility is finding nearly four new Type Ia supernovae every night, doubling the known number in two and a half years.
“Game changing” release of Type Ia Supernovae data may hold key to the history of the Universe - Lancaster University
Information relating to “Game changing” release of Type Ia Supernovae data may hold key to the history of the Universe
Lancaster University (www.lancaster.ac.uk)
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White dwarf stars are formed when a sun-like star dies, puffing out its outer layers and leaving behind its exposed stellar core.White dwarf stars are formed when a sun-like star dies, puffing out its outer layers and leaving behind its exposed stellar core. This process is violent and should be the end of habitability in a system, but new simulations show that might not be true. Researchers compared the climates of hypothetical exoplanets orbiting white dwarfs. They found that rocky planets in orbit could be more habitable than previously thought.
UC Irvine astronomers gauge livability of exoplanets orbiting white dwarf stars
Computer model comparison reveals rotational factors contributing to habitability
UC Irvine News (news.uci.edu)
