Tag Archives: emitting

Africa’s Forests Are Currently Emitting More CO2 Than They Absorb

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Congo’s rainforest ranks as the second largest globally

Güntaguni/Getty Images

Africa’s forests currently release more carbon dioxide than they can absorb, complicating global efforts to achieve net-zero emissions.

The continent’s forests and shrublands were once among the largest carbon sinks, contributing to 20% of all carbon dioxide absorption by plants. The Congo rainforest, the second largest in the world after the Amazon, is often termed the “lungs of Africa,” absorbing roughly 600 million tons of CO2 each year. Unfortunately, this vital ecosystem is diminishing due to logging and mining activities.

Recent research indicates that Africa’s forests lost an annual average of 106 million tonnes of biomass between 2011 and 2017, following a period of growth from 2007 to 2010. This loss translates to approximately 200 million tons of CO2 emissions annually, primarily linked to deforestation in the Congo. Heiko Balzter from the University of Leicester, UK, highlights this concerning trend.

“To lose tropical forests as a means of mitigating climate change means we must significantly reduce emissions from fossil fuel burning and strive for near-zero emissions,” he states.

Balzter and his team utilized satellite data to measure aspects like canopy color, water content, and height at selected locations to calculate biomass levels. These findings were compared to on-the-ground measurements, although such data are scarce in Africa.

However, Simon Lewis from University College London cautions that satellite technology cannot accurately identify tree species within a forest and fails to reliably estimate carbon absorption in forests with high biomass or emissions from those compromised by selective logging. For example, a dense hardwood like mahogany retains more carbon than a lighter wood like balsa of equivalent size.

“Deforestation rates in the Democratic Republic of Congo have surpassed those of the 2000s, a fact we cannot deny,” he asserts. “Nonetheless, it remains uncertain if this will significantly alter the carbon balance across the continent.”

The study also overlooks the wet peatlands that lie beneath much of the Congo rainforest. These peatlands absorb modest quantities of CO2 annually and sequester around 30 billion tonnes of ancient carbon.

In recent years, the Amazon rainforest, once a significant carbon sink, has emitted more CO2 than it absorbs. While deforestation in the Amazon is somewhat regulated, the situation is worsening in Congo.

In the Democratic Republic of Congo, impoverished farmers often clear rainforests for slash-and-burn agriculture, while many foreign-owned companies engage in illegal logging of valuable hardwoods such as African teak and coralwood.

During the recent COP30 climate summit in the Amazon, Brazil unveiled the Tropical Forests Forever Facility, a fund designed to provide investment returns to tropical nations at the rate of $4 per hectare of remaining forest. However, contributions to this fund have only reached $6.6 billion, a fraction of the $25 billion target.

Balzter believes this initiative could be more effective than carbon credits, which reward “avoided” emissions that often lack real value.

“It’s crucial to establish this tropical forest permanent facility swiftly if we intend to reverse the trend of increased carbon emissions from Africa’s tree biomass,” he emphasizes.

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Source: www.newscientist.com

Scientists Discover Largest Black Hole Flare Ever Recorded, Emitting 10 Trillion Solar Rays

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A supermassive black hole has violently consumed a massive star, resulting in a cosmic explosion that shone as brightly as 10 trillion suns, according to a recent study.

This event, referred to as a black hole flare, is believed to be the largest and most remote ever detected.

“This is genuinely a one-in-a-million occurrence,” stated Matthew Graham, a research professor of astronomy at the California Institute of Technology and the lead author of the study published Tuesday in Nature Astronomy.

Graham indicated that based on the explosion’s intensity and duration, a black hole flare is likely the explanation, but further studies will be necessary to validate this conclusion.

While it is common for black holes to devour nearby stars, gas, dust, and other materials, such significant flare events are exceptionally rare, according to Graham.

“This enormous flare is far more energetic than anything we’ve encountered previously,” he remarked, noting that the explosion’s peak luminosity was 30 times that of any black hole flare documented so far.

Its extreme intensity is partly due to the massive size of the celestial objects involved. The star that came too close to the black hole is estimated to possess at least 30 times the mass of the Sun, while the supermassive black hole and its surrounding matter disk are estimated to be 500 million times more massive than the Sun.

Graham mentioned that these powerful explosions have persisted for more than seven years and are likely still ongoing.

The flare was initially detected in 2018 during a comprehensive sky survey using three ground-based telescopes. At the time, it was identified as a “particularly bright object,” but follow-up observations months later yielded little valuable data.

Consequently, black hole flares were mostly overlooked until 2023, when Graham and his team opted to revisit some intriguing findings from their earlier research. Astronomers have since managed to roughly ascertain the distance to this exceptionally bright object, and the results were astonishing.

“Suddenly, I thought, ‘Wow, this is actually quite far away,'” Graham explained. “And if it’s this far away and this bright, how much energy is it emitting? This is both unusual and intriguing.”

While the exact circumstances of the star’s demise remain unclear, Graham hypothesized that a cosmic collision might have nudged the star from its typical orbit around the black hole, leading to a close encounter.

This finding enhances our understanding of black hole behavior and evolution.

“Our perspective on supermassive black holes and their environments has dramatically transformed over the past five to ten years,” Graham stated. “We once pictured most galaxies in the universe with a supermassive black hole at the center, idly rumbling away. We now recognize it as a much more dynamic setting, and we are just beginning to explore its complexities.”

He noted that while the flares are gradually diminishing over time, they will remain detectable with ground-based telescopes for several more years.

Source: www.nbcnews.com

Microorganisms Emitting Methane Stabilize the Seabed

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Methane penetration refers to a submersible area around the globe where the natural gas you rely on for cooking and heating is known as methane that leaks from the seabed. These penetrations are commonly found in transitional regions where land meets the ocean, known as the continental margin. Methane originates from and is produced by organic matter, including dead plants and animals, that have been buried under layers of sediment for millions of years. Through pressure and heat from within the Earth, this organic matter can decompose into methane, which escapes from the seabed into the ocean.

This methane also serves as an energy source for various microscopic organisms, allowing it to fuel your stove. The microorganisms known as methanogenic bacteria or methanotrophs utilize methane as food through a process referred to as aerobic methane oxidation. These bacteria employ oxygen to extract energy from methane gas, akin to how humans extract energy from food, producing carbon dioxide and water as by-products.

When carbon dioxide interacts with water, it creates a weak acid known as carbonic acid. Carboxylic acids can dissolve calcium carbonate minerals that make up shells in organisms like corals, mussels, and clams. While methanotrophs produce carbon dioxide as waste, scientists remain uncertain about its role in corroding calcium carbonate in marine environments. Research has been conducted in laboratories, but not in natural marine settings until now.

A team of researchers from Germany investigated the corrosion of calcium carbonate associated with active methane along the continental margin off the west coast of Gabon, Congo, and Angola in Africa. They deployed limestone cubes measuring 10 cm (around 4 inches) high and 4 cm (approximately 4 inches) wide above the seabed near active methane sites, as well as on a mussel bed. The cubes were left on the seabed for 2.5 years before being retrieved.

Upon recovery, the researchers noted that cubes situated near the methane leak exhibited rough surfaces. Microscopic examination revealed small holes, termed microborings, likely created by microorganisms. In contrast, cubes placed farther from the methane leak showed no signs of such features. This led researchers to interpret these differences as evidence that microorganisms are responsible for the dissolution of limestone in areas of methane penetration.

To further analyze the role of methanotrophs in limestone dissolution, the team extracted DNA from microbial communities inhabiting the limestone cubes. They identified DNA from members of aerobic methane-oxidizing bacteria, particularly from the uncultured HYD24-01 clade. Previous studies have detected these microorganisms in other methane-rich locations, suggesting their potential for corroding limestone.

To corroborate their findings, the researchers also examined lipid molecules known as lipid biomarkers from microorganisms at the site. Scientists utilize lipid biomarkers to identify bacterial species and their energy sources. They discovered that the lipid biomarkers collected from the seabed sites matched the DNA results. Notably, they found an abundance of lipids from methanotrophs called NC16:1Ω7 among the limestone cubes. This led them to conclude that methanotrophs prominently represented the microbial communities linked to the microborings in the limestone.

The research team proposed that their findings provide concrete evidence that methane-consuming bacteria dissolve calcium carbonate rocks in areas of marine methane. They suggested that these bacteria acidify their environment by releasing carbon dioxide during methane oxidation. The released carbon dioxide combines with water to form carbonic acid, which decreases pH levels, dissolves limestone, and contributes to ocean acidification. They advocated for future research to delve into the specific mechanisms that these microorganisms utilize and to quantify the extent of microbial erosion’s contribution to marine acidification.


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Source: sciworthy.com

Starlink Satellites Emitting Radio Signals That May Disrupt Astronomy

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A new batch of Starlink satellites deployed via Falcon 9 Rocket

SpaceX

Astronomers have raised concerns that SpaceX’s Starlink satellites emit radio waves that may jeopardize their ability to observe and comprehend the early universe.

With thousands of Starlink satellites in orbit offering worldwide internet coverage, astronomers worry that radio emissions from these satellites could interfere with sensitive telescopes monitoring distant and faint radio waves. Although SpaceX has collaborated with astronomers to minimize this disruption by disabling transmission beams while passing over significant telescopes, these measures seem insufficient.

Steven Tingay from Curtin University, Australia, along with his team, is currently tracking signals from nearly 2,000 Starlink satellites using prototype telescopes at the Square Kilometer Array-low Observatory (SKA-low). This future network of over 100,000 interconnected telescopes is designed to investigate the early universe, but researchers have found that Starlink signals could jeopardize their goals by affecting a third of the data gathered at numerous frequencies.

Additionally, they found that the satellites transmit signals in two frequency bands protected for radio astronomy by the International Telecommunications Union (ITU), which should not be utilized for Starlink transmissions. Yet, these satellite emissions are deemed unintentional. The leaked signals are 10,000 times stronger than the faint radio emissions from the neutral hydrogen clouds that existed when the first stars began to form, and which astronomers wish to study to decode the early universe.

“The signal strength from these unintended emissions can rival some of the brightest natural radio sources in the sky,” Tingay explains. “It’s akin to taking the strongest sauces in the sky, adding even more artificial ones, and causing significant interference, especially in experiments that target super sensitivity.”

Tingay suggests that the emissions likely arise from onboard electronics inadvertently transmitting signals through satellite antennas. He notes that while such leaks are not technically illegal, as ITU regulations only cover intentional emissions, the discourse about how to regulate these types of emissions is starting at the ITU, which has withheld comment.

Dylan Grigg, another researcher from Curtin University, emphasizes, “The optimal approach to mitigate these unintended emissions is for satellites to either reduce or eliminate them. From the operator’s perspective, it’s beneficial that there are existing mitigation strategies in satellites, which SpaceX has already implemented for optical astronomy.” Starlink has adjusted its satellites to minimize light reflection to reduce visual interference.

A spokesperson for SKA-LOW remarked, “These findings align with our previous studies, but additional research is necessary to fully grasp the impact on low-frequency observations.”

Grigg and Tingay have shared their findings with SpaceX, stating that the company is open to discussions on strategies to decrease emissions. SpaceX has not commented on the matter.

If SpaceX cannot devise a solution, researchers may need to introduce algorithmic strategies to filter out contaminated radio waves. However, Tingay pointed out that such methods are still in their early development phases and might require more computational resources than are currently needed for basic processing of the astronomical signals of interest.

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Source: www.newscientist.com

Radio Waves and X-ray Emitting Stars: A New Perspective from Our Galaxy

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Askap J1832-0911 – Likely a magnetar or a highly magnetized white dwarf star – emits radio signals and X-ray pulses for 2 minutes every 44 minutes. Paper published in Nature.

A combination of radio, X-ray, and infrared radiation in the field of ASKAP J1832-0911. Image credit: Wang et al., doi: 10.1038/S41586-025-09077-W.

Askap J1832-0911 is situated roughly 15,000 light-years away from Earth in Scutum.

This star was identified by astronomers utilizing the Australian ASKAP Radio telescope.

It belongs to a category known as long-term radio transients, first detected in 2022, characterized by variations in radio wave intensity over several minutes.

This duration is thousands of times greater than the regular fluctuations observed in pulsars. It’s a neutron star that spins rapidly, emitting signals multiple times per second.

“Askap J1832-0911 follows a 44-minute cycle of radio wave intensity, placing it in the realm of long-term radio transients,” stated Dr. Ziteng Wang, an astronomer at Curtin University’s node at the International Centre for Radio Astronomical Research (ICRAR).

Using NASA’s Chandra X-Ray Observatory, researchers noted that ASKAP J1832 also exhibited regular variations in X-ray emissions every 44 minutes.

This marks the first discovery of an X-ray signal in long-term radio transients.

“Astronomers have observed countless celestial bodies through various telescopes and have never encountered anything behaving like this,” Dr. Wang remarked.

“It’s exhilarating to witness such new stellar phenomena.”

Through Chandra and the SKA Pathfinder, scientists found that Askap J1832-0911 experienced a significant reduction in both X-ray and radio wave signals over a six-month period.

Besides the long-term changes, the combination of 44-minute cycles in X-rays and radio waves differs from observations made in the Milky Way galaxy.

The authors are currently competing to determine whether Askap J1832-0911 truly represents long-term radio transients and if its unusual behavior can shed light on the origins of such objects.

Dr. Nanda Lea, an astronomer at the Institute of Space Sciences in Barcelona, Spain, commented:

“No exact match has been found so far, but some models fit better than others.”

It’s improbable that ASKAP J1832-0911 is simply a pulsar or neutron star drawn from a companion star, as its properties do not align with the typical signal strengths of these celestial objects.

Some characteristics might be attributed to neutron stars with exceptionally strong magnetic fields, known as magnetars, which are over 500,000 years old.

However, other aspects, such as its bright and variable radio emissions, make it challenging to categorize this as an aged magnetar.

In the sky, ASKAP J1832-0911 appears to be situated among debris from a supernova, which commonly contains neutron stars formed during such events.

Nevertheless, the team concluded that this proximity is likely coincidental and that the two entities are not associated with one another, suggesting that neither may host neutron stars.

They deduced that while isolated white dwarfs don’t account for the data, white dwarfs with companion stars might.

But such a scenario would necessitate the strongest known magnetic fields in white dwarfs within our galaxy.

“We continue to seek clues about this object and look for similar entities,” said Dr. Tong Bao, an astronomer at the Osservatorio Astronomico in Italy’s National Institute of Astronomy (INAF).

“Discovering mysteries like this is not frustrating; rather, it’s what makes science thrilling!”

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Z. Wang et al. Detection of X-ray radiation from bright long-term radio transients. Nature Published online on May 28, 2025. doi:10.1038/s41586-025-09077-W

Source: www.sci.news

Rare Titan Arum blooms in Kew Gardens emitting scent of rotten flesh

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June 18th, Corpse Flowers at Kew Gardens

Sebstian Kettley/RBG Cue

This gorgeous, but smelly, corpse flower bloomed on June 18th. Royal Botanic Gardens, KewIn London however it tends to be only for a short period, lasting only 24 to 36 hours.

Corpse Flower (Amorphophallus titanium) also known as Titan Aramgets its name from the foul smell it gives off, resembling rotting meat, which is so strong it can be heard for hundreds of metres. The smell is produced to attract rare pollinating insects, such as flesh flies and carrion beetles, to the short-lived flowers, and must be strong enough to do its job during the short period the plant is in flower, because the plant may not flower again for many years.

Strictly speaking, this up to 3 metre tall plant isn’t one flower, but many. The inner inflorescence, or spadix, emerges from a purple, pleated collar called a bract and looks like a yellow obelisk. The inflorescence, or cluster of flowers, lies in the protected area between the bract and the spadix.

If you happen to see and smell it, the smell may not be what you expect: it can change during the flower’s short lifespan and can smell like rotting flesh, as well as pleasant excrement or warm garbage.

This rare plant is endemic to the rainforests of the Indonesian island of Sumatra, but is cultivated in many botanical gardens around the world for its beauty and the crowds it attracts when it blooms. The first time it is known to flower outside of Sumatra was in 1889 at Kew Botanical Gardens.

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Source: www.newscientist.com

Astronomers find record-breaking slowest rotating neutron star emitting radio waves

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Neutron stars typically spin quickly, taking just a few seconds or even a fraction of a second to complete one revolution around their axis, but one neutron star labeled ASKAP J1935+2148 bucks this rule, emitting radio signals at a relatively slow interval of 53.8 minutes.

Artist's impression of a neutron star. Image courtesy of Sci.News.

“We're used to extreme examples when studying radio-emitting neutron stars, so the discovery of such a compact star that is still emitting radio waves despite rotating slowly was unexpected,” said Professor Ben Stappers, from the University of Manchester.

“This new generation of radio telescopes demonstrates that pushing the boundaries of our search space will reveal surprises that will shake up our understanding.”

At the end of their lives, massive stars use up all their fuel and undergo a spectacular explosion called a supernova.

What remains is a stellar remnant called a neutron star, which consists of trillions of neutrons packed into an extremely dense sphere with a mass 1.4 times that of the Sun, packed into a radius of just 10 km.

Astronomers detected an unexpected radio signal from ASKAP J1935+2148 that traveled about 16,000 light-years to Earth.

The nature of its radio emission and the rate of change of its rotation period suggest that it is a neutron star, but further study is needed to confirm what this object is.

“This discovery relied on the complementary capabilities of the ASKAP and MeerKAT telescopes, combined with our ability to probe these objects on timescales of minutes, and examine how their radiation changes from second to second,” said Dr Kaustubh Rajwade, an astronomer at the University of Oxford.

“Such synergies can shed new light on how these compact objects evolve.”

ASKAP J1935+2148 was detected by CSIRO's ASKAP radio telescope in the Wadjari Yamatji region of Western Australia.

“What's interesting is that this object exhibits three different radiation states, each with completely different properties to the others,” said Dr Manisha Caleb, an astronomer at the University of Sydney.

“The MeerKAT radio telescope in South Africa played a key role in distinguishing between these states.”

“If the signals had not come from the same point in the sky, it would be hard to believe that it was the same object producing these different signals.”

“Until the arrival of these new telescopes, the dynamic radio sky was relatively unexplored,” said Professor Tara Murphy, from the University of Sydney.

“Now we can look deeply and frequently see a variety of unusual phenomena.”

“These events give us insight into how physics works in extreme environments.”

This discovery paper In the journal Natural Astronomy.

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M. Caleb othersA radio transient phenomenon in which the radiation state switches with a period of 54 minutes. Nat AstronPublished online June 5, 2024; doi: 10.1038/s41550-024-02277-w

Source: www.sci.news

Spiral Galaxies Emitting “Forbidden” Emissions

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This image from the Hubble Space Telescope shows MCG-01-24-014. It is a spiral galaxy with an active galactic nucleus located 275 million light-years away and is classified as a Type 2 Seyfert galaxy. Seyfert galaxies are often closer to Earth than quasars and are distinguished by their unique spectra, especially the “forbidden” emission of type 2 Seyferts.Credit: ESA/Hubble & NASA, C. Kilpatrick

this swirl hubble space telescope This image shows a bright spiral galaxy known as MCG-01-24-014, located about 275 million light-years from Earth. MCG-01-24-014 is called an active galaxy because, in addition to being a well-defined spiral galaxy, it has a very energetic core known as an active galactic nucleus (AGN) .

More specifically, it is classified as a Type 2 Seyfert galaxy. Seyfert galaxies are home to one of the most common subclasses of AGNs, along with quasars. The exact classification of AGNs is nuanced, but Seyfert galaxies tend to be relatively nearby where the host galaxy can be clearly detected alongside the central AGN, whereas quasars are always very distant AGNs and their Its incredible brightness exceeds that of its host galaxy.

Understanding Seyfert galaxies and their spectra

Both Seyfert galaxies and quasars have further subclasses. For Seyfert galaxies, the main subcategories are type 1 and type 2. They are distinguished from each other by their spectra (the pattern created when light is split into its constituent wavelengths). The spectral lines emitted by Type 2 Seyfert galaxies are particularly associated with certain so-called “forbidden” emissions.

To understand why synchrotron radiation from galaxies is thought to be forbidden, it helps to understand why the spectrum exists in the first place. Spectra look the way they do because certain atoms and molecules absorb and emit light very reliably at very specific wavelengths.

The reason is quantum physics. Electrons (tiny particles orbiting the nucleus of atoms and molecules) can only exist at very specific energies, so electrons can only lose or gain very specific amounts of energy. These very specific amounts of energy correspond to specific wavelengths of light that are absorbed or emitted.

Discharge prohibition phenomenon

Forbidden emission lines are therefore spectral emission lines that should not exist according to certain rules of quantum physics. However, quantum physics is complex, and some of the rules used to predict quantum physics use assumptions that are appropriate for laboratory conditions on Earth.

Under these rules, this release is “prohibited” and ignored because it is unlikely. But in space, in the midst of incredibly energetic galactic nuclei, those assumptions no longer apply, and “forbidden” light has a chance to shine towards us.

Source: scitechdaily.com