News Feeds

There is a region of the sky where astronomers fear to look. Filled with dark clouds of dust, it hides an unseen mass. A mass so large it is pulling the Milky Way and other galaxies toward it…

Okay, maybe that’s overdramatic, but it is true. The region is known as the Zone of Avoidance, and it happens to be in the general direction of the galactic center. Our view of the Universe isn’t as perfect as we’d like. The Sun is located within the galactic plane of the Milky Way, about 30,000 light-years from its center. So if we look to the north or south of the galactic plane, we get a pretty normal view of the cosmos. We can peer deep into the sky and see distant galaxies. But if we look toward the galactic center, we don’t have a clear view. Instead, we see a bunch of stars, gas, and dust. This is fine if you want to study stars, gas, and dust, but it means our view of the distant Universe is obscured in that direction. So if you want to make an unbiased view of the cosmos, you avoid that region, hence the term.

It’s also true that we’re being pulled in that direction. There happens to be a supercluster of galaxies that way, called the Great Attractor. We can map it out a bit by studying the relative motion of nearby galaxies, and we can observe X-rays from the supercluster, so we know it’s out there. But with all the gas and dust in the Zone of Avoidance, we can’t study it in the optical. One thing we know so far is that the Great Attractor actually consists of multiple clusters. The closest one is known as the Norma cluster, while a larger and more distant one is called the Vela supercluster. Still, there is much we don’t know about the region.

Fortunately, radio light can penetrate the dust of the Zone, so radio astronomers have tried to map the region. One downside is that radio telescopes often don’t have a large field of view, so it’s difficult to map the region. But a new work is making progress.

Observed galaxies within the Vela supercluster. Credit: Sambatriniaina H. A. Rajohnson, et al

The new study uses data from the MeerKAT array telescope in South Africa. MeerKAT is particularly sensitive to the radio emissions of neutral hydrogen, known as the HI or [21-centimeter line.](https://briankoberlein.com/blog/dark-line/) Since hydrogen is so abundant in the Universe, the distribution of hydrogen tells us the distribution of galaxies and clusters. The study mapped the region of the Zone in the direction of the Vela supercluster with enough resolution to distinguish individual pockets of neutral hydrogen, each surrounding a galaxy. In this way, the team was able to discover 719 galaxies within the Vela cluster. Less than a third of them had been known previously.

This was just the first detailed survey of the Vela supercluster by MeerKAT, and it shows the real power of this relatively new observatory. Future studies should give us an even better understanding of the zone astronomers so often avoid.

Reference: Sambatriniaina H. A. Rajohnson, et al. “Revealing hidden structures in the Zone of Avoidance — a blind MeerKAT HI Survey of the Vela Supercluster.” arXiv preprint arXiv:2411.07084 (2024).

The post Astronomers Defy the Zone of Avoidance to Find Hundreds of New Galaxies appeared first on Universe Today.

In today’s Jesus and Mo strip, called “reason,” the barmaid suggests that both Jesus and Mo are going to hell. I am puzzled; why would they? They are prophets and, in Jesus’s case, the son of God/God. 

Today we have photos from South Africa taken by reader Phil Frymire on a recent trip. Phil’s captions and IDs are indented, and you can enlarge his pictures by clicking on them.

Here are some more photos from an August trip to Timbavati and Mala Mala in South Africa that occurred at the same time as our host’s visit. I previously submitted some leopards, lions, elephants and rhinos. Rounding out the Big Five, here are some African buffalo (Syncerus caffer) along with some spotted hyenas (Crocuta Crocuta), Burchell’s zebras (Equus quagga burchellii) and Northern giraffes (Giraffa camelopardalis).

A resting buffalo:

A herd of buffalo. The male in the foreground has an impressive “boss” (the area where the horns grow together in the middle):

A “dagga boy” as Jerry’s guide Dan called them. Our guide Mike called them “retired”. These are old males that no longer travel with the herds. They will likely be taken by lions (but see the photo below). This one is accompanied by a red-billed oxpecker (Buphagus erythroryncha):

When we first encountered these lions at Mala Mala, they were walking with their left sides facing us. One of the females was limping pitifully. After we drove around for a better look, it became obvious why she was struggling. If you look carefully at the female on the right you will see a gaping, horrific wound on her right front leg running from the shoulder to the elbow. She never emerged from the bushes while we observed her so I couldn’t get a clear photo. Mike was very confident that the injury was caused by a buffalo horn. Predators fight for a meal, but prey fight for their life. Predators don’t always emerge from the fracas unscathed. Revenge of a dagga boy?:

Profile of a spotted hyena:

The same hyena intently staring at us:

Hyena with a black-backed jackal (Lupulella mesomelas) in the foreground:

The same hyena literally eating bone. The crushing sounds were very impressive:

A beautiful zebra:

Posing above a waterhole:

Why do zebras have stripes? Jerry mentioned in one of his posts that the scientific evidence supports the hypothesis that the stripes deter biting flies. I asked our guide Mike what he thought. He favored the idea that the stripes break up the body outline and confuse predators. He didn’t cite any scientific papers, but he did cite this view of a mother and foal:

Another mother and foal at a waterhole:

Four male giraffes:

Frontal view of a male showing the thick ossicones that they use in combat with other males:

Profile of a giraffe with an oxpecker on its neck:

When physicians spread medical misinformation, the potential harm to health is far greater than their direct patient care. And yet, in a recent study, medical boards rarely discipline physicians for spreading misinformation. The JAMA article looked at 3128 medical board disciplinary proceedings involving physicians. Spreading misinformation to the community was the least common reason, at 0.1%. Direct patient misinformation and inappropriate advertising […]

The post Physician Misinformation first appeared on Science-Based Medicine.

Global carbon emissions from fossil fuels have reached a record high in 2024, according to new research.

Completely artificial proteins that produce bioluminescence can serve as a non-invasive method for bioimaging, diagnostics, drug discovery, and more.

A team of archaeologists has excavated the earliest known ancient Maya salt works in southern Belize.

A new study has uncovered important behavior in the flow of electric current through quantum superconductors, potentially advancing the development of future technologies like quantum computing.

A new study has uncovered important behavior in the flow of electric current through quantum superconductors, potentially advancing the development of future technologies like quantum computing.

These miniature immune system models -- known as human immune organoids -- mimic the real-life environment where immune cells learn to recognize and attack harmful invaders and respond to vaccines. Not only are these organoids powerful new tools for studying and observing immune function in cancer, their use is likely to accelerate vaccine development, better predict disease treatment response for patients, and even speed up clinical trials.

The chances of intelligent life emerging in our Universe -- and in any hypothetical ones beyond it -- can be estimated by a new theoretical model which has echoes of the famous Drake Equation. This was the formula that American astronomer Dr Frank Drake came up with in the 1960s to calculate the number of detectable extraterrestrial civilizations in our Milky Way galaxy. More than 60 years on, astrophysicists have produced a different model which instead focuses on the conditions created by the acceleration of the Universe's expansion and the amount of stars formed.

Scientists point out that a coherent approach to understanding the threats posed by artificial intelligence is still elusive. They call for a complex systems perspective to better assess and mitigate these risks, particularly in light of long-term uncertainties and complex interactions between AI and society.

An annual accounting of CO2 emissions from burning fossil fuels and land use change finds no sign emissions will peak this year

Eurasian reed warblers don’t just get a sense of direction from Earth’s magnetic field – they can also calculate their coordinates on a mental map

Filmmakers love New Zealand. Its landscapes evoke other worlds, which explains why so much of The Lord of the Rings was filmed there. The country has everything from long, subtropical sandy beaches to active volcanoes.

The country’s otherworldliness extends into its atmosphere, where a cloud nicknamed the “Taieri Pet” forms when conditions are right.

The Taieri Pet is a lenticular cloud, a stationary type of cloud that forms in certain circumstances. They form in the troposphere when the wind blows over an obstacle, typically a mountain range. There are three types: altocumulus standing lenticular (ACSL), stratocumulus standing lenticular (SCSL), and cirrocumulus standing lenticular (CCSL). Each type forms at a different altitude.

When the wind is forced to move up and over an obstacle, it creates a lower-pressure zone on the leeward side. As the wind moves, it creates standing waves. If conditions are right, these waves become visible when the moisture condenses.

The Taieri Pet forms over New Zealand’s Rock and Pillar Range in the Strath-Taieri region of Otago on New Zealand’s South Island.

The Otago region on New Zealand’s South Island is home to the Taieri Pet. Image Credit: Peetel, (Creative Commons Attribution-Share Alike 4.0 International.)

The cloud is a common feature near the town of Middlemarch. It’s mentioned in newspapers as far back as the 1890s. Locals sometimes took Taieri Pet’s appearance as a signal that a storm was coming.

This page is from the Otago Witness, Issue 2226, 29 October 1896. It describes the Taieri Pet as “our old prognosticator,” because it forms before a wind storm. Image Credit: No Known Copyright.

The Operational Land Image (OLI) on Landsat 8 captured this stunning image of the Taieri Pet in September. Landsat 8 follows a polar orbit that allows it to observe the entire surface of the Earth every 16 days.

This zoomed-in image shows the cloud and the surface in more detail. The image shows the Macraes Mine, New Zealand’s largest gold mine. Image Credit: NASA/Lauren Dauphin; USGS

The Landsat satellites have been monitoring Earth for over 50 years from their orbit 705 km above us. The images and data are widely used by scientists, but they’re also beautiful portraits of our extraordinary, once-in-a-solar-system planet.

Anybody can enjoy the Landsat galleries, found here.

The post An Otherworldly Cloud Over New Zealand appeared first on Universe Today.

The theory goes that black holes accrete material, often from nearby stars. However the theory also suggests there is a limit to how big a black hole can grow due to accretion and certainly shouldn’t be as large as they are seen to be in the early Universe. Black holes it seems, are fighting back and don’t care about those limits! A recent study shows that supermassive black holes are growing at rates that defy the limits of current theory. Astronomers just need to figure out how they’re doing it! 

Black holes usually form from the collapse of a massive star. The origin of their larger cousins, the supermassive black holes found at the centre of most galaxies, remains a mystery. Theories suggest they grew over billions of years by consuming stars, gas and maybe even other black holes. Others suggest they formed from the primordial conditions of the early Universe or maybe from dense clusters of hot young early stars. The immense gravity from them plays a significant part in shaping stellar formation and the evolution of their host galaxy. If a supermassive black hole is actively accreting material, they are often seen as quasars, extremely luminous objects that are visible across million, even billions of light years. 

Illustration of a powerful black hole and its magnetic field. Credit: L. Calçada/ESO

A recent discovery by a team of astronomers revealed a low-mass supermassive black hole that was devouring material at an extreme rate. The black hole is at a distance that means we are seeing light as it was 1.5 billion years after the Big Bang. This means we can learn about the processes that govern these objects when the Universe was a lot younger. 

The black hole known as LID-568 was detected by a team of astronomers led by the International Gemini Observatory/NSF NOIRLab astronomer Hyewon Suh. It was detected in images from the James Webb Space Telescope following on from assessment of galaxies from the Chandra X-ray Observatory’s COSMOS legacy survey. The galaxies observed are bright X-ray sources but not visible in optical or near-infrared surveys. The team used JWST’s NIRSpec instrument that is capable of getting a spectrum off each individual pixel in its field of view. 

The Gemini North telescope on the summit of Mauna Kea (Gemini Observatory/AURA)

The study allowed the team to make the rather unexpected discovery of immense flows of gas out from the region around the centre of the black hole.  Suh and team could infer from this that a significant fraction of the growth of LID-568  may well have occurred in one single rapid accretion event. They calculated that it must be feeding on matter at a rate which is 40 times the Eddington limit. The limit relates to the maximum luminosity it can achieve acknowledging there is a balance between the outward force of radiation and the inward force of gravity. When the two forces balance, it is known as hydrostatic equilibrium. If an object exceeds the limit then an immense outward force will result in it losing mass. When the luminosity of LID-568 was calculated it was much higher then should be theoretically possible. 

The discovery provides an excellent opportunity for astronomers to study black holes in the early Universe and in particular those that challenge the Eddington limit theory. It would however suggest that the outflows of energy are acting to release energy that has built up during extreme accretion periods. Follow up observations are required. 

Source : NSF NOIRLab Astronomers Discover the Fastest-Feeding Black Hole in the Early Universe

The post Early Black Holes Fed 40x Faster than Should Be Possible appeared first on Universe Today.

Eventually, every stellar civilization will have to migrate to a different star. The habitable zone around all stars changes as they age. If long-lived technological civilizations are even plausible in our Universe, migration will be necessary, eventually.

Could Extraterrestrial Intelligences (ETIs) use stars themselves as stellar engines in their migrations?

In broad terms, a stellar engine uses a star to generate work. A simple example is solar panels, which use the Sun’s radiation to generate electricity that we use to perform work. But the scaled-up idea is to use the star to produce thrust. That thrust could be used to move the star itself. An ETI capable of doing that would be a Type II civilization on the Kardashev Scale.

To most of us, it seems like a wildly improbable idea. But who knows what’s out there? If an ETI can survive long enough, it may become a Type II civ.

The stellar engine idea dates back to science fiction author Olaf Stapledon. A couple of decades after Stapledon, astronomer Fritz Zwicky also discussed manipulating stars with advanced technology, even turning them into spacecraft. In the decades since, the idea has persisted, and other researchers have delved into it. In 1988, Leonid Shakdov developed the first detailed stellar engine model called the Shakdov Thruster.

In new research, Clement Vidal, from Vrije Universiteit in Brussels, Belgium, examines how an advanced civilization could use a binary star as a stellar engine. The paper is titled “The Spider Stellar Engine: a Fully Steerable Extraterrestrial Design?”

“Since about half the stars in our galaxy are in binary systems where life might develop too, we introduce a model of a binary stellar engine,” Vidal writes. “We apply the model to candidate systems, spider pulsars, which are binary stars composed of one millisecond pulsar and a very low-mass companion star that is heavily irradiated by the pulsar wind.”

Vidal is concerned with stellar engine technosignatures. Research has focused on hypervelocity stars as potential stellar engine technosignatures because they’re easily observable. Other researchers have also proposed other stellar engine concepts, but according to Vidal, they’re “poorly linked to observable technosignatures. ”

Vidal’s main goal in this work is to determine what types of technosignatures a binary stellar engine would emit. He discusses what potential signatures might be emitted by acceleration, deceleration, steering, and maneuvers such as gravitational assists or captures. However, unlike some other researchers, he focuses on a specific type of binary system: spider pulsars, which are a subclass of binary millisecond pulsars.

Pulsars are what remains of some massive stars. At the end of their lives, some massive stars collapse to form neutron stars. When these neutron stars spin rapidly, they produce beams of radiation from their poles. If the radiation is aimed at Earth, then we can observe the pulses of energy. These pulses have exquisitely precise timing, and astronomers use them to determine cosmic distances.

A spider pulsar is a pulsar with a companion, usually a red dwarf, a brown dwarf, or even a planetary-mass object. They’re called spider pulsars because it’s as if the pulsar spins a web of powerful beams of radiation that strips away the companion’s mass, eventually destroying it.

Artist’s impression of a so-called “Black Widow” pulsar PSR B1957+20 (seen in the background) through the cloud of gas enveloping its brown dwarf star companion. Credit: Dr. Mark A. Garlick; Dunlap Institute for Astronomy & Astrophysics, University of Toronto

Vidal’s paper describes the payload as a pulsar with about 1.8 solar masses and the propellant as its low-mass companion star with between 0.01 and 0.7 solar masses.

In essence, the gravitationally bound binary system is the vehicle, and the smaller companion star is the propellant. The spider pulsar generates thrust by expelling propellant out of the gravitational system, and the propellant is the matter stripped from the companion.

The binary pair orbits a common center of gravity. The idea behind this binary stellar engine (BSE) is that as they orbit, the pulsar’s radiation strikes the companion or propellant star. A close binary is more effective because the closer the pulsar is to the propellant, the more thrust is generated. The assumption is that a Type II civilization would have the technology to moderate this thrust to serve their purposes by timing the radiation and heating the outer layers of the propellant star with X-ray or gamma radiation.

To decelerate, the BSE would produce active thrust in the opposite direction of travel. It could also use a passive magnetic sail deployed from the pulsar to transfer momentum to the interstellar medium.

The BSE steers by selectively evaporating the star during different orbital phases. “To choose a direction, it suffices to evaporate the companion star once per orbit, at a specific orbital phase, in order to create consistent thrust in one direction,” Vidal explains.

The top panels show the BSE in different configurations, with the top being the direction of travel. (a) The BSE is in acceleration mode. (b) the BSE is steering to the left. (c) the BSE is decelerating. (d) is a side view that shows changes in the orbital plane by asymmetric heating of the companion, which creates a lifting
force in relation to the orbital plane. The binary separation is not to scale. Image Credit: Vidal et al. 2024.

These various maneuvers and manipulations with the BSE would emit technosignatures. Have astronomers observed any candidate BSEs in the Milky Way? Possibly.

“Could our galaxy host a kind of fully steerable binary stellar engine that we proposed? This is a plausible hypothesis in the context of the stellivore hypothesis, which reinterprets some observed accreting binary stars as advanced civilizations feeding on stars,” Vidal writes.

A stellivore is a hypothesized type of civilization first proposed by Vidal that has the technology to consume its home star via accretion. They use the star’s energy to sustain their existence. Vidal writes that rather than consume the energy, they could use it to migrate to a more favourable location in the galaxy.

“For most of its time, a stellivore civilization would eat its home star via accretion. However, energy is never eternal, and instead of eating its star until the end and dying, a stellivore civilization would use its low-mass companion star as fuel not to be accreted but to be evaporated in order to create thrust and travel towards a nearby star,” Vidal explains.

This brings us to spider pulsars. Rather than accreting material, a spider pulsar appears to be evaporating its propellant companion.

There are two types of spider pulsars: Black Widows and Redblacks. The distinction is in the mass of the companion. In a black widow (BW), the companion is less than 0.1 stellar masses. In a redblack, the companion is between 0.1 and 0.7 stellar masses. Spider pulsars are different from other pulsar binaries because they evaporate their companions rather than accrete them. When pulsars accrete too much material, they can form black holes. Spider pulsars don’t tempt the same fate. Vidal calls these spider stellar engines (SSEs) rather than binary stellar engines (BSEs).

The panels in this figure show PSR J1959+2048, the original Black Widow pulsar. Left: the BW pulsar (in blue) is plotted in the RA-DEC plane, and its proper motion vector is displayed until it reaches a close encounter with a target star, in orange. Middle: a Chandra X-ray view of the BW pulsar, displaying a comet-like tail; the candidate target star is also visible in the bottom right (visualization with ESASky). Right: The composite image on the right shows the X-ray tail (in red/white) and a bow shock visible in the optical (green). Credit: X-ray: NASA/CXC/ASTRON/B. Stappers et al.; Optical: AAO/J.Bland-Hawthorn & H. Jones.

Previous researchers have studied the original BW, and Vidal writes, “… the 3D motion of the system appears to be nearly aligned with the spin axis of the MSP.” This fits in with the SSE interpretation because this perfect alignment is necessary to produce maximum thrust. A stellivore civilization would have a destination in mind, and Vidal says that he’s found a potential destination for the original Black Widow pulsar. He says that the pulsar will reach this target star in about 420 years while also acknowledging the uncertainty in this determination.

PSR J1959+2048, the original BW, also modulates itself, which could be interpreted as steering. However, it also displays other characteristics and moderation that call into question the ‘steering’ interpretation.

Ultimately, Vidal’s SSE may have a shorter duty cycle than other proposed stellar engines, limiting its usefulness. However, it has advantages in steering over others. “Transposing it on a smaller scale, it might also be an inspirational design for advanced propulsion solutions, or for planetary defence purposes such
as deflecting asteroids,” Vidal writes.

The idea may seem preposterous to some, but that’s incidental. Many ideas in history seemed preposterous until they weren’t.

Vidal isn’t claiming that we’re seeing the technosignatures of stellar engines. He’s arguing that it’s worth pursuing the idea of observing them. He sees these candidates and predictions of what their signals might look like as clues and as starting points for further investigation.

“Spider pulsars thus offer observable stellar engine technosignature candidates, with decades of data, active studies that discover, model and monitor these dazzling systems,” he concludes.

The post A Spider Stellar Engine Could Move Binary Stars Halfway Across a Galaxy appeared first on Universe Today.

Samantha Harvey has won the UK's top fiction prize for a novel that takes place over 24 hours on the International Space Station

AI and Google Street View have created 'digital twins' of living trees in North American cities – part of a huge simulation that could help make urban tree planting and trimming decisions

https://traffic.libsyn.com/secure/sciencesalon/mss484_Ben_Westhoff_2024_11_12.mp3 Download MP3

In 2023, 107,543 Americans died from an overdose—over 75 thousand of those overdosed from fentanyl. This is almost double the number of people who died in car accidents or from gun homicides that year.

Fentanyl has been cut into heroin for years, but now is often mixed into meth and cocaine, fueling rising death counts for those drugs, a troubling development, considering that Americans are much more likely to try meth and cocaine than heroin.

In Canada, the numbers are similarly astronomical, and fentanyl deaths have marched upward in Australia and many European countries as well. Ten years ago, fentanyl and its analogues overtook heroin to become the deadliest drug in Sweden.

“Fentanyl is the game changer,” Special Agent in Charge James Hunt of the US Drug Enforcement Administration (DEA) told Vice News. “It’s the most dangerous substance in the history of drug tracking. Heroin and cocaine pale in comparison to how dangerous fentanyl is.”

Ben Westhoff is a best-selling investigative journalist focused on drugs, culture, and poverty. His book Fentanyl, Inc.: How Rogue Chemists Created the Deadliest Wave of the Opioid Epidemic is the bombshell first book about fentanyl. Since its publication, Westhoff has advised top government officials on the fentanyl crisis, including from the White House Office of National Drug Control Policy, U.S. Senate and House of Representatives, the U.S. embassy in Beijing, and the U.S. State Department.

His new book Little Brother: Love, Tragedy, and My Search for the Truth tells the story of his relationship with Jorell Cleveland, his longtime mentee in the Big Brothers Big Sisters program. When Jorell was murdered at age 19, and the case went cold, Ben used his skills as an investigative journalist to find the killer. It’s a three-year investigation set in the northern suburbs of St. Louis that uncovers a heartbreaking cycle of poverty, poor education, drug trafficking, and violence. Follow him at benwesthoff.substack.com and benwesthoff.com.

If you enjoy the podcast, please show your support by making a $5 or $10 monthly donation.