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Methane, a potent greenhouse gas, is converted to CO2 by microbes in tree bark, meaning trees are even better for the climate than we thought

When we take a break from exercise, it can feel like we quickly go back to square one. But this isn't the case, and there are various ways to minimise the decline

Today’s Jesus and Mo strip, called “Trump“, came with a short summary: “God wants you to stop projecting your own desires onto him.”

Clearly Mo is a Democrat!  But of course, anybody who wishes that Trump had been killed is morally off the rails, though I’ve heard that from a few people.

A brain circuit discovered in mice could explain why placebo treatments ease pain in people

If the idea of exercise is more attractive than the reality, you aren't alone. But there are ways to train your motivation and develop better habits

To keep long-term moon residents safe from harmful radiation, lunar bases will need to be built several metres under the surface or inside caves or lava tubes

Combining two neural networks has helped researchers predict potentially disastrous collapses in complex systems, such as financial crashes or power blackouts

Rehabilitation robots, first introduced in the 1990s, are just what they sound like – robotics used to aid in regaining function through rehabilitation following an injury. The idea sounds compelling, and the technology has been advancing steadily. But still we have to ask ourselves the question – do they actually help, and what is the evidence? A recent comprehensive meta-analysis and systematic […]

The post The Evidence for Rehabilitation Robots first appeared on Science-Based Medicine.

An orange layer on the tips of Komodo dragons’ teeth may give the enamel extra strength for ripping apart their prey

Researchers are calling for greater protection for basking sharks after a camera on a tagged shark recorded a collision for the first time

In an effort to understand ancient Neanderthal food preparation techniques, researchers butchered five wild birds using flint stone tools and roasted them

People generalize to form beliefs about a large language model's performance based on what they've seen from past interactions. When an LLM is misaligned with a person's beliefs, even an extremely capable model may fail unexpectedly when deployed in a real-world situation.

An international collaboration seeks to innovate the future of how a mechanical man's best friend interacts with its owner, using a combination of AI and edge computing called edge intelligence. The overarching project goal is to make the dog come 'alive' by adapting wearable-based sensing devices that can detect physiological and emotional stimuli inherent to one's personality and traits, such as introversions, or transient states, including pain and comfort levels.

Researchers have successfully made super-heavy element 116 using a beam of titanium-50. That milestone sets the team up to attempt making the heaviest element yet: 120.

Think about background radiation and most people immediately think of the cosmic background radiation and stories of pigeon excrement during its discovery. That’s for another day though. Turns out that the universe has several background radiations, such as infrared and even gravitational wave backgrounds. NASA’s New Horizons is far enough out of the Solar System now that it’s in the perfect place to measure the cosmic optical background (COB). Most of this light comes from the stars in galaxies, but astronomers have always wondered if there are other sources of light filling our night sky. New Horizons has an answer. No!

Ok lets talk pigeon excrement.  Back in 1965 two telecommunication engineers were exploring signal interference at the Bell Laboratory. Penzias and Wilson detected a faint ‘hum’ in all directions and initially put it down to pigeon excrement as they nested in the horn of the radio receiver. Instead, what they had discovered was the cosmic background radiation, the faint glow that permeates the entire universe and is the thermal radiation left over from the Big Bang. Studying it allows us to understand more about the Universe when it was 380,000 years old. 

The full-sky image of the temperature fluctuations (shown as color differences) in the cosmic microwave background, made from nine years of WMAP observations. These are the seeds of galaxies, from a time when the universe was under 400,000 years old. Credit: NASA/WMAP

In the late 80’s a different type of background radiation was detected; the infrared background radiation. It consists of the diffuse infrared glow that fills the universe coming from numerous sources throughout the history of the universe. It is mostly from thermal emissions from dust grains heated by stellar radiation. In addition to this is the gravity wave background although this has yet to be detected. 

Another hotly debated background is the cosmic optical background (COB), a diffuse light which originates from stars and galaxies and spans the whole of the visible spectrum. There has been gathering momentum in its study however with observations from Hubble Space Telescope and the Spitzer Infrared Telescope. The studies however revealed that a large contribution to a general background optical glow come from faint unresolved galaxies. The study of the COB allows us to explore the total energy output of the universe, about galaxy and star formation across the history of the cosmos. 

The detection of the COB is a challenging one however with Earth based instruments or even those in Earth orbit plagued by interference. The zodiacal light for example is the result of sunlight scattered by interplanetary dust, it is dominant in the inner solar system  and makes studies of the COB difficult. The New Horizon probe is ideally positioned out beyond the orbit of Pluto over 8 billion kilometres away from interference. On board New Horizons is the LORRI (Long Range Reconnaissance Imager) camera which was identified as an ideal platform to begin a search. 

The New Horizons instrument payload that is currently doing planetary science, heliospheric measurements, and astrophysical observations. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

Using images from the LORRI camera, a team of astronomers led by Marc Postman from the Space Telescope Science Institute attempted to measure the COB over the range 0.4 to 0.9 micrometers. The images were from high galactic latitudes to ensure no diffuse light from the Milky Way or scattered light from bright stars. Isolating the COB contribution to the total sky brightness levels required digitally subtracting the scattered light from bright stars and galaxies and from faint stars within the field that were fainter than that detectable by LORRI. Interestingly, the results showed that, based on the estimated galaxy counts in the sampled regions the COB is the result of light from all the galaxies within our observable region of the universe.

Source : New Synoptic Observations of the Cosmic Optical Background with New Horizons

The post New Horizons Measures the Background Light of the Universe appeared first on Universe Today.

The prospect of actually resolving the event horizon of black holes feels like the stuff of science fiction yet it is a reality. Already the Event Horizon Telescope (EHT) has resolved the horizon of the black holes at the centre of the Milky Way and M87. A team of astronomers are now looking to the next generation of the EHT which will work at multiple frequencies with more telescopes than EHT. A new paper suggests it may even be possible to capture the ring where light goes into orbit around the black hole at the centre of the Milky Way. 

Black holes are strange objects that are the powerhouses of many galactic phenomenon. They have a complex anatomy with a singularity at the centre, a point of infinite density where gravity is so intense that the laws of physics cease to work. Surrounding the singularity is the event horizon, the boundary beyond which, nothing, not even light can escape. Just outside the event horizon is the photon ring and it is here that light is bent into a circular orbit around the singularity. Further out than this is the accretion disk but the focus of the next generation Event Horizon Telescope will be the photon ring. 

The Event Horizon Telescope name is a little misleading for it is not one telescope but a global network of radio telescopes that work together to act as a virtual Earth-sized radio telescope. The technology that makes this happen is known as interferometry where the telescopes are all connected together. The very long baseline of the telescope or put more simply the fact it is virtually VERY big means it has incredible resolution capabilities allowing it to capture the event horizon around Sagittarius A at the centre of the Milky Way and also of the black hole at centre of M87.

The ALMA array in Chile. Once ALMA was added to the Event Horizon Telescope, it increased the EHT’s power by a factor of 10. Image: ALMA (ESO/NAOJ/NRAO), O. Dessibourg

The EHT was launched in 2009 but now attention is turning to the next generation. The addition of ten new dishes and a whole host of new technology will transform EHT. Modern high-speed data transfer protocols will speed up transfer times and the addition of new dishes and technology will mean EHT will be able to observe at 86, 230 and 345 GHz simultaneously. This allows for the utilisation of frequency phase transfer techniques where lower frequency data can be used to supplement higher frequency. Using this will mean integration times of minutes at 345 GHz rather than seconds opening up a whole universe of new observations such as, the photon rings of black holes. 

Studies of the supermassive black hole at the centre of M87 and Sagittarius A suggest a magnetically arrested accretion disk. In this accretion model, the accretion disk forms a series of irregular spiral streams and a vertical magnetic field, which is split into separate field lines, pokes through the accretion plane. As the disk rotates the material spirals inward, dragging the field lines and twist them around the axis of rotation leading to the formation of jets. These magnetically arrested disks exhibit symmetrically polarised synchrotron emissions which were used by a team of astronomers to study the detectability of the photon ring using next generation EHT.

M87 and the jet streaming away from its central supermassive black hole. Credits: NASA, ESA and the Hubble Heritage Team (STScI/AURA); Acknowledgment: P. Cote (Herzberg Institute of Astrophysics) and E. Baltz (Stanford University)

The paper authored by Kaitlyn M. Shavelle and Daniel C. M. Palumbo from the Princeton University and Harvard & Smithsonian (respectively) show through simulations that the planned enhancements to the EHT are likely to enable the detection of photon rings. In the analyses of the enhancements they find that the higher sensitivity of the new EHT will likely be more critical than better processing techniques in the detection of the photon ring.

Source : Prospects for the Detection of the Sgr A* Photon Ring with next-generation Event Horizon Telescope Polarimetry

The post Next Generation Event Horizon Telescope To Unlock Mysteries of Black Holes appeared first on Universe Today.

A prototype device harvests drinking water from the atmosphere, even in arid places.

A method that helped create two atoms of the rare, super-heavy element livermorium may pave the way towards making the hypothetical element 120

Researchers working at the forefront of an emerging photovoltaic (PV) technology are thinking ahead about how to scale, deploy, and design future solar panels to be easily recyclable. Solar panels made of perovskites may eventually play an important role amid global decarbonization efforts to reduce greenhouse gas emissions. As the technology emerges from the testing stages, it is a perfect time to think critically about how best to design the solar panels to minimize their impact on the environment decades from now.

The field of extrasolar planet studies has grown exponentially in the past twenty years. Thanks to missions like Kepler, the Transiting Exoplanet Survey Satellite (TESS), and other dedicated observatories, astronomers have confirmed 5,690 exoplanets in 4,243 star systems. With so many planets and systems available for study, scientists have been forced to reconsider many previously-held notions about planet formation and evolution and what conditions are necessary for life. In the latter case, scientists have been rethinking the concept of the Circumsolar Habitable Zone (CHZ).

By definition, a CHZ is the region around a star where an orbiting planet would be warm enough to maintain liquid water on its surface. As stars evolve with time, their radiance and heat will increase or decrease depending on their mass, altering the boundaries of the CHZ. In a recent study, a team of astronomers from the Italian National Institute of Astrophysics (INAF) considered how the evolution of stars affects their ultraviolet emissions. Since UV light seems important for the emergence of life as we know it, they considered how the evolution of a star’s Ultraviolet Habitable Zone (UHZ) and its CHZ could be intertwined.

The research team was led by Riccardo Spinelli, an INAF researcher from the Palermo Astronomical Observatory. He was joined by astronomers from the National Institute of Nuclear Physics (INFN), the University of Insubria, and the Astronomical Observatory of Brera. Their paper, “The time evolution of the ultraviolet habitable zone,” recently appeared in the Monthly Notices of the Royal Astronomical Society: Letters.

This infographic compares the orbit of the planet around Proxima Centauri (Proxima b) with the same region of the Solar System. Credit: ESO

As Spinelli told Universe Today via email, the UHZ is the annular region around a star where a planet receives enough UV radiation to trigger the formation of RNA precursors but not so much that it destroys biomolecules. “This zone primarily depends on the star’s UV luminosity, which decreases over time,” he said. “As a result, the UV habitable zone is farther from the star during the early stages of the star’s evolution and gradually moves closer to the star as time progresses.”

As astronomers have known for some time, CHZs are also subject to evolution, owing to changes in the star’s luminosity and heat output, which increase or decrease over time depending on the mass of the star. Addressing the interaction of these two habitable zones could shed light on which exoplanets are most likely to be “potentially habitable” for life as we know it. As Spinelli explained:

“We still do not know precisely how life originated on Earth, but we have some clues suggesting that ultraviolet (UV) radiation may have played a crucial role. Experimental studies, such as the one conducted by Paul Rimmer and John Sutherland in 2018, provide significant insights. In their experiment, Rimmer and Sutherland exposed hydrogen cyanide and hydrogen sulfite ions in water to UV light and discovered that this exposure efficiently triggered the formation of RNA precursors.

“Without UV light, the same mixture resulted in an inert compound that could not form the building blocks of life. Furthermore, RNA demonstrates a resistance to damage from UV radiation, indicating that it likely formed in a UV-rich environment. Indeed, UV radiation was one of the most abundant sources of chemical-free energy on the surface of the early Earth, suggesting it might have played a crucial role in the emergence of life.”

For their purposes, Spinelli and his colleagues sought to determine if (and for how long) the CHZ and the UVZ would overlap – thus facilitating the emergence of life. To this end, the team analyzed data from NASA’s Swift Ultraviolet/Optical Telescope (UVOT) to measure the current UV luminosity of stars with exoplanets that reside in the “classical” HZ. They then consulted data from NASA’s Galaxy Evolution Explorer (GALEX), an orbiting space telescope that has been observing galaxies up to 10 billion years away in the UV wavelength.

Illustration of the Trappist-1 system. Credit: NASA/JPL-Caltech

From GALEX, they incorporated how moving groups of young stars evolve in terms of their near-UV luminosity. “To estimate the evolution in time of the ultraviolet habitable zone, we used the results obtained by Richey-Yowell et al. 2023,” said Spinelli. “In this work, the authors derived an average UV luminosity evolution for each type of star. In our work, we reconstructed the evolution of the UV brightness of stars hosting planets in the classical habitable zone by combining the average evolution derived by Richey-Yowell et al. 2023 and the measurements carried out with the Swift Telescope.”

From this, they determined there is an overlap between the evolution of CHZs and UHZs. These results were especially significant for M-type (red dwarf) stars, where many rocky planets have been found orbiting within their CHZs. Previous research, which includes a 2023 paper by Spinelli and many of the same colleagues, has suggested that M-dwarf stars are not currently receiving near-UV radiation to support the prebiotic chemistry necessary for the emergence of life. However, their conclusions in this latest paper contradicted their previous findings. Said Spinelli:

“We assert that, when examining the evolution of NUV luminosity in M-dwarfs, most of these cool stars are indeed capable of emitting an appropriate amount of NUV photons during the first 1–2 billion yr of their lifetimes to trigger the formation of important building blocks of life. Our results suggest that the conditions for the onset of life (according to the specific prebiotic pathway we consider) may be or may have been common in the Galaxy. Indeed, in this work, we demonstrated that an intersection between the classical habitable zone and the ultraviolet habitable zone could exist (or could have existed) around all stars of our sample at different stages of their life, with the exceptions of the coolest M-dwarfs (temperature less than 2800 K, notably Trappist-1 and Teegarden’s star).”

While they may be a bit of a letdown for those hoping to find life on some of TRAPPIST-1s seven rocky planets, it bodes well for other M-type stars hosting rocky planets in their HZs. This includes the closest exoplanet to the Solar System (Proxima b), Ross 128 b, Luyten b, Gliese 667 Cc, and Gliese 180 b, all of which are within 40 light-years of Earth. These findings could have significant implications for exoplanet and astrobiology studies, which have been transitioning from discovery to characterization in recent years.

These fields will benefit from next-generation telescopes like Webb, the Nancy Grace Roman Space Telescope, and ground-based observatories that will enable Direct Imaging studies of exoplanets.

Further Reading: MNRAS

The post The Ultraviolet Habitable Zone Sets a Time Limit on the Formation of Life appeared first on Universe Today.