The Mermaid Nebula: A Star’s Violent Death, Still Glowing 10,000 Years Later - UNIVERSE

In a dark patch of sky in the constellation Centaurus, a ghostly figure drifts through space, pale blue and curved, vaguely human in silhouette. Astronomers call it the Mermaid Nebula. What it actually is, beneath that delicate appearance, is the aftermath of one of the most violent events in the universe.

A Supernova’s Signature

The Mermaid Nebula, also known as the Betta Fish Nebula, is part of the supernova remnant catalogued as G296.5+10.0. Around 10,000 years ago, a massive star at the end of its life collapsed and exploded as a supernova, releasing more energy in seconds than our Sun will emit over its entire 10-billion-year lifetime. What we see now is the still-expanding shell of gas and energy that explosion left behind, glowing as it plows into the surrounding interstellar medium.

The nebula sits a few thousand light-years from Earth. On astronomical scales, that makes it a relatively close neighbor, and close enough for dedicated amateur and professional telescopes to capture it in extraordinary detail.

Why It Glows in Blue and Red

The colors in the featured image are not decorative choices, they carry direct physical information about the nebula’s composition and energetics.

The striking blue comes from doubly ionized oxygen, known in spectroscopic notation as OIII. This occurs when oxygen atoms are stripped of two electrons by the intense radiation field produced by the shock wave from the original explosion. Doubly ionized oxygen is a classic tracer of high-energy astrophysical environments and appears frequently in planetary nebulae and supernova remnants photographed in narrowband light.

The deep red, meanwhile, is hydrogen-alpha emission, light released when electrons in hydrogen atoms drop from a higher to a lower energy state. Hydrogen is the most abundant element in the universe, and its characteristic red glow is a staple of emission nebulae across the galaxy.

Together, these two emission lines paint a picture of a highly energetic, chemically rich environment shaped by the shock waves radiating outward from the original stellar explosion.

The Ghost at the Center: A Radio-Quiet Pulsar

When a massive star collapses in a supernova, the core does not simply disappear. Under extreme gravitational pressure, protons and electrons are crushed together into neutrons, forming a neutron star, an object roughly the size of a city but containing more mass than the Sun. If that neutron star is spinning rapidly and emitting beams of radiation, it becomes a pulsar.

The Mermaid Nebula harbors just such an object. Its pulsar is young and peculiar, spinning approximately twice per second, which is fast for a neutron star of its age. What makes it unusual is that it is radio-quiet: unlike most known pulsars, which were originally discovered through their regular radio pulses, this one has not been detected at radio wavelengths. It has, however, been detected in X-rays, where neutron stars often shine brightly due to the extreme temperatures of their surfaces.

The pulsar does not appear in this image. It emits no confirmed visible light, so the beautiful blue and red structure we see is the nebula alone, the pulsar is there, somewhere near the center, invisible to optical telescopes.

The Image Itself

The photograph was produced through a collaboration between two astrophotographers: Sy Ming Wong handled the data acquisition, capturing the raw light from the nebula through narrowband filters over many hours of exposure. Guangyan Gao then processed that data, drawing out the delicate filamentary structure and color contrast that gives the Mermaid Nebula its unmistakable form. The image was selected as NASA’s Astronomy Picture of the Day on June 11, 2026, a recognition that places it among the finest astrophotography produced each day from around the world.

The bright stars scattered across the frame are not associated with the nebula. They are foreground objects, simply sharing the same line of sight from Earth.

Stardust in Slow Motion

There is something quietly profound about images like this one. The elements released in this supernova, oxygen, carbon, iron, and dozens of others forged in the dying star’s core, are now seeding interstellar space. Over millions of years, some of that material will be incorporated into new molecular clouds, new stars, and perhaps new planetary systems. The Mermaid Nebula is not just beautiful wreckage. It is a delivery mechanism for the raw materials of future worlds.

The Little Mermaid, in the old fairy tale, dissolves into seafoam. This one becomes stardust, and stardust, as it turns out, is far more durable.

Original APOD post: https://apod.nasa.gov/apod/ap260611.html
Image Credit & Copyright: Data acquisition: Sy Ming Wong; Processing: Guangyan Gao 

Source: The Mermaid Nebula: A Star’s Violent Death, Still Glowing 10,000 Years Later – Scents of Science  

Food waste beads could boost direct air capture by 10% to 50% - Energy & Green Tech - Hi Tech & Innovation

Still life featuring protein beads loaded with potassium hydroxide. The porous act as a sponge for CO₂. Credit: Mezzenga Lab / ETH Zurich

In order to stabilize global warming at less than 1.5°C in the long term, there is a need not only for a drastic reduction in greenhouse gas emissions but also for technologies to remove and store hundreds of billions of tons of carbon dioxide (CO₂) from the atmosphere. This is also the underlying basis of the scenarios set out in the latest Assessment Report from the Intergovernmental Panel on Climate Change (IPCC).

For years, research groups and startups have therefore been working on ways to remove CO₂ directly from the air—a process known as "direct air capture." The company Climeworks, which was founded as an ETH spin-off in 2009, is one of the world's first commercial providers of DAC. To this day, however, the direct removal of CO₂ from the air remains an energy-intensive and expensive process.

Porous protein beads bind carbon dioxide

In a study published in the journal PNAS, researchers present a promising new approach to DAC. A group led by materials scientist Raffaele Mezzenga, a professor at the Department of Health Sciences and Technology at ETH Zurich, uses whey and byproducts from tofu production for CO₂ absorption.

Dairy and tofu production generate large quantities of protein-containing solutions, only a small part of which is reprocessed in food production—the remainder goes to waste. From this waste, the researchers isolate proteins that they use to form long, threadlike chains known as amyloid fibrils.

They then load these fibrils with potassium hydroxide and process them into beads with a diameter of between half and one centimeter. "The resulting material is like a sponge that can absorb large quantities of CO₂ via the potassium hydroxide," Mezzenga explains.

When the porous beads are exposed to ambient air, the potassium hydroxide reacts with CO₂ to form hydrogen carbonate, a salt of carbonic acid. This process removes the CO₂ from the air. "In our tests with ambient air, we were able to extract 97 milligrams of CO₂ with one gram of material," explains Zhou Dong, a postdoc in Mezzenga's group and lead author of the study.

This is a very high rate, he says, and 10% to 50% greater than the capacity of conventional DAC methods. Dong assumes that, with 1 kilogram (2.2 pounds) of protein beads, it would theoretically be possible to bind and isolate 100 grams (3.5 ounces) of CO₂ per process cycle.

Technique for a circular economy

Conventional DAC methods generally use heat and negative pressure to release the carbon dioxide from the absorption material again. This is necessary in order to then store the CO₂ or convert it into other materials, thereby removing it from the atmosphere on a long-term basis. However, this process requires a great deal of energy, which is why DAC generally only makes sense nowadays—in terms of both energy and economics—where large amounts of renewable energy are available.

This is another area in which the researchers in Mezzenga's team are taking a different approach: In order to release the carbon dioxide from the protein beads again, the beads are alternately sprayed with a mild acid and base for around 10 minutes at room temperature. This breaks the chemical bonds so that the CO₂ can be isolated.

The acid, base and beads can then be reused. "The synthetic materials that are used to capture CO₂ today decompose quickly," says Dong. "By contrast, our protein beads remain stable for a long time." In the lab, the researchers tested 30 cycles of CO₂ adsorption and release without observing significant losses of efficiency.

Mezzenga assumes that the material would nevertheless need to be replaced after a few thousand cycles due to a decrease in adsorption capacity. However, the protein beads could then be used as fertilizer in agriculture or converted into biofuel, the researcher explains. The beads are made up entirely of organic material, he says, and are readily degradable—meaning that the system could therefore become part of a circular economy.

"The materials we use for this process are nontoxic and are food-grade," Mezzenga points out. In a life cycle analysis, the researchers show that their method generates less environmental pollution across the entire life cycle than other DAC methods.

Expected to be cheaper than other capture methods

Further tests are needed to reveal whether the technology is scalable for practical use and whether the high CO₂-absorption capacity will remain intact on a larger scale. For the recently published study, the researchers tested the method in a controlled laboratory environment with a few grams of protein beads, binding and isolating around 50 grams (1.8 ounces) of CO₂.

Mezzenga is optimistic. He has been working with amyloid fibrils for nearly 20 years and is well acquainted with the material. In the past, he has used it to develop biodegradable alternatives to plastics as well as techniques for water purification.

"We're confident that the technology is scalable," he says. According to Mezzenga, the spray system used to separate the CO₂ from the protein beads is geared toward existing techniques that are already used in industry. Postdoc Zhou Dong will now further examine the question of scalability.

Although the researchers have yet to make an exact calculation of the costs per captured ton of CO₂, Mezzenga expects them to be significantly lower than with conventional DAC.

"Our technology is cheaper and more sustainable because it requires little energy and is based on a widely available waste product," he says. "That could be a game changer for the future of removing CO₂ from the air." 

Provided by ETH Zurich 

by ETH Zurich

edited by Sadie Harley, reviewed by Robert Egan 

Source: Food waste beads could boost direct air capture by 10% to 50%