Category: 7. Science

Topline

Just days after a nova appeared in the night sky, another joined it. V572 Velorum, in the constellation Vela, joins V462 Lupi in Lupus. Both are now visible to the naked eye to observers in the Southern Hemisphere and are currently shining millions of times brighter than usual. The remarkable coincidence — judged to be extremely rare by astronomers — has occurred as astronomers await the explosion of T Coronae Borealis (T CrB) in Corona Borealis, which is known to explode and shine brightly every 80 years or so.

Key Facts

How Rare Are Nova Explosions?

Astronomers estimate that between 20 and 50 novae occur each year in our galaxy, but most go undiscovered, according to NASA. Very few — typically zero — are visible to the naked eye. For two to appear at once is unprecedented. “This is without question an extremely rare event,” said Stephen O’Meara, an American astronomer, to Spaceweather.com. “I have yet to find an occurrence of two simultaneous nova appearing at the same time.”

Why V572 Velorum Is Getting Brighter

It’s thought that both V572 Velorum and V462 Lupi are both classical novas. A classical nova occurs when a white dwarf — the dense core of a collapsed sun-like star — is orbited by a larger star. According to NASA, the white dwarf’s gravity pulls hot hydrogen from its companion, which builds up and triggers a thermonuclear blast. Unlike supernovas, which obliterate stars, novas are recurring events that only affect the outer layer of a white dwarf. These outbursts can make the system millions of times brighter.

Novas Create Lithium (and The Solar System)

Lithium is used to make lithium batteries and lithium-ion batteries, as well as heat-resistant glass and ceramics and mood-altering chemicals. Most of the lithium in our solar system and the wider Milky Way galaxy comes from classical nova explosions like V572 Velorum and V462 Lupi, according to a paper published in 2020. The same researchers previously discovered that novas contributed to the molecular cloud that formed the solar system.

Further Reading

ForbesA ‘New Star’ Suddenly Got 3 Million Times Brighter — How To See ItBy Jamie CarterForbesA New Star Will Soon Appear — What To Know About T Coronae BorealisBy Jamie CarterForbesSee The First Jaw-Dropping Space Photos From Humanity’s Biggest-Ever CameraBy Jamie Carter

The aptly-named Bullet Cluster is a huge structure in deep space that formed from the merging of two massive galaxy clusters 3.8 billion lightyears away.

Now the James Webb Space Telescope has given scientists the clearest, most detailed look yet at the chaotic aftermath, including the location of the elusive dark matter hiding within it.

Solving just what dark matter is made of is one of the biggest goals in physics right now.

And Webb has given scientists an insight into how it’s distributed across this enormous region of space.

A crash course in cosmic cartography

The Bullet Cluster is not just two galaxy clusters colliding in slow-motion over billions of years, it’s also a physics lab for studying dark matter.

Dark matter is a mysterious substance that doesn’t emit or reflect light, but makes up most of the Universe’s mass.

Astronomers know it’s there because it’s the only way to account for the gravitational pull that’s holding galaxies together.

Counting up all the mass of visible matter in galaxies alone – stars, dust and gas – doesn’t reveal enough ‘stuff’ that could prevent a galaxy’s stars from flying outwards into space as the galaxy rotates.

There must be some extra, unseen matter holding the galaxy’s structure together. That unseens substance is known as ‘dark matter’.

A team of astronomers led by PhD student Sangjun Cha of Yonsei University have used Webb’s near-infrared vision to weigh and map the mass of the Bullet Cluster more accurately than ever before.

Their study, published in The Astrophysical Journal Letters, includes the most comprehensive gravitational lensing dataset of this region to date.

Seeing the invisible

We can’t directly see dark matter, but we can see its effects.

That’s where gravitational lensing comes in, a trick where massive objects like galaxy clusters bend and magnify the light from background galaxies.

It’s like watching light ripple across a pond, except in this case, the ripples are caused by dark matter warping spacetime.

“With Webb’s observations, we carefully measured the mass of the Bullet Cluster with the largest lensing dataset to date, from the galaxy clusters’ cores all the way out to their outskirts,” says Sangjun Cha.

“Webb’s images dramatically improve what we can measure in this scene, including pinpointing the position of invisible particles known as dark matter,” says Kyle Finner, a study co-author and an assistant scientist at IPAC at Caltech in Pasadena, California.

Tracing the stars between galaxies

The team measured thousands of galaxies in Webb’s images to accurately ‘weigh’ visible and invisible mass in the galaxy clusters.

And they mapped and measured the light emitted by stars no longer bound to individual galaxies, known as intracluster stars.

Their findings are persuasive:. “We confirmed that the intracluster light can be a reliable tracer of dark matter, even in a highly dynamic environment like the Bullet Cluster,” Cha says.

What’s more, if these stars are bound to cluster’s dark matter, the team say it could get easier to refine what they know about dark matter.

In the new map of the Bullet Cluster, an image from Webb’s NIRCam (Near-Infrared Camera) is overlaid with data from NASA’s Chandra X-ray Observatory.

It shows hot gas in pink, including the bullet shape on the right side of the image.

Refined measurements of the dark matter, calculated by the team using Webb, are shown in blue.

Viewed as a whole, the new measurements refine the map of mass spread across the Bullet Cluster.

And this is revealing the history of the clusters involved in the merger.

For example, the galaxy cluster on the left of the image has an asymmetric, elongated area of mass along the left edge of the blue region.

This, say the team, is a clue pointing to previous mergers in that cluster.

A dark, mysterious giant

The team’s study shows that dark matter isn’t just invisible, it’s eerily quiet.

Their observations confirm it doesn’t interact much, if at all, with itself. Or, as the study puts it: “dark matter shows no signs of significant self-interaction”.

“As the galaxy clusters collided, their gas was dragged out and left behind, which the X-rays confirm,” Finner says.

Webb’s observations show dark matter still lines up with the galaxies, and wasn’t dragged away.

The bullet that shot twice

The dark matter map also suggests the Bullet Cluster may have gone through more than one dramatic collision.

That mass clump on the left could be the fingerprint of an earlier, or later, collision involving the larger cluster.

“A more complicated scenario would lead to a huge asymmetric elongation like we see on the left,” says James Jee, co-author and professor at Yonsei University.

What’s next?

The team say they’ve only uncovered part of the story.

“It’s like looking at the head of a giant,” says Jee. “Webb’s initial images allow us to extrapolate how heavy the whole ‘giant’ is, but we’ll need future observations of the giant’s whole ‘body’ for precise measurements.”

Enter the Nancy Grace Roman Space Telescope, scheduled to launch by May 2027, which will also give researchers expansive near-infrared images of the Universe.

“From NASA’s Nancy Grace Roman Space Telescope, which is set to launch by May 2027. “”With Roman, we will have complete mass estimates of the entire Bullet Cluster, which would allow us to recreate the actual collision on computers,” Finner says.

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A new technology that uses clinical MRI machines to image metabolic activity in the brain could give researchers and clinicians unique insight into brain function and disease, researchers at the University of Illinois Urbana-Champaign report. The non-invasive, high-resolution metabolic imaging of the whole brain revealed differences in metabolic activity and neurotransmitter levels among brain regions; found metabolic alterations in brain tumors; and mapped and characterized multiple sclerosis lesions — with patients only spending minutes in an MRI scanner.

Led by Zhi-Pei Liang, a professor of electrical and computer engineering and a member of the Beckman Institute for Advanced Science and Technology at the U. of I., the team reported its findings in the journal Nature Biomedical Engineering.

“Understanding the brain, how it works and what goes wrong when it is injured or diseased is considered one of the most exciting and challenging scientific endeavors of our time,” Liang said. “MRI has played major roles in unlocking the mysteries of the brain over the past four decades. Our new technology adds another dimension to MRI’s capability for brain imaging: visualization of brain metabolism and detection of metabolic alterations associated with brain diseases.”

Conventional MRI provides high-resolution, detailed imaging of brain structures. Functional MRI maps brain activity by detecting changes in blood flow and blood oxygenation level, which are closely linked to neural activity. However, they cannot provide information on the metabolic activity in the brain, which is important for understanding function and disease, said postdoctoral researcher Yibo Zhao, the first author of the paper.

“Metabolic and physiological changes often occur before structural and functional abnormalities are visible on conventional MRI and fMRI images,” Zhao said. “Metabolic imaging, therefore, can lead to early diagnosis and intervention of brain diseases.”

Both MRI and fMRI techniques are based on magnetic resonance signals from water molecules. The new technology measures signals from brain metabolites and neurotransmitters as well as water molecules, a technique known as magnetic resonance spectroscopic imaging. These MRSI images can provide significant new insights into brain function and disease processes, and could improve sensitivity and specificity for the detection and diagnosis of brain diseases, Zhao said.

Other attempts at MRSI have been bogged down by the lengthy times required to capture the images and high levels of noise obscuring the signals from neurotransmitters. The new technique addresses both challenges.

“Our technology overcomes several long-standing technical barriers to fast high-resolution metabolic imaging by synergistically integrating ultrafast data acquisition with physics-based machine learning methods for data processing,” Liang said. With the new MRSI technology, the Illinois team cut the time required for a whole brain scan to 12 and a half minutes.

The researchers tested their MRSI technique on several populations. In healthy subjects, the researchers found and mapped varying metabolic and neurotransmitter activity across different brain regions, indicating that such activity is not universal. In patients with brain tumors, the researchers found metabolic alterations, such as elevated choline and lactate, in tumors of different grades — even when the tumors appeared identical on clinical MRI images. In subjects with multiple sclerosis, the technique detected molecular changes associated with neuroinflammatory response and reduced neuronal activity up to 70 days before changes become visible on clinical MRI images, the researchers report.

The researchers foresee potential for broad clinical use of their technique: By tracking metabolic changes over time, clinicians can assess the effectiveness of treatments for neurological conditions, Liang said. Metabolic information also can be used to tailor treatments to individual patients based on their unique metabolic profiles.

“High-resolution whole-brain metabolic imaging has significant clinical potential,” said Liang, who began his career in the lab of the late Illinois professor Paul Lauterbur, recipient of the Nobel Prize for developing MRI technology. “Paul envisioned this exciting possibility and the general approach, but it has been very difficult to achieve his dream of fast high-resolution metabolic imaging in the clinical setting.

“As healthcare is moving towards personalized, predictive and precision medicine, this high-speed, high-resolution technology can provide a timely and effective tool to address an urgent unmet need for noninvasive metabolic imaging in clinical applications.”

Reference: Zhao Y, Li Y, Jin W, et al. Ultrafast J-resolved magnetic resonance spectroscopic imaging for high-resolution metabolic brain imaging. Nat Biomed Eng. 2025. doi: 10.1038/s41551-025-01418-4

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Topline

The Northern Lights may be visible in the U.S. overnight on Wednesday and Thursday just as the Milky Way appears in the night sky. The delayed arrival of a coronal mass ejection traveling towards Earth may cause a geomagnetic storm, according to the latest forecast by the National Oceanic and Atmospheric Administration’s Space Weather Prediction Center. It follows a false alarm on July 1-2, but also notable displays of aurora in northern U.S. states in recent weeks.

Key Facts

Where To See The Northern Lights

NOAA’s aurora viewlines indicate potential aurora displays are possible in northern U.S. states and Canada. U.S. states that may see aurora include (northerly parts of) Washington, northern Idaho, Montana, Wyoming, North Dakota, South Dakota, Minnesota, Wisconsin, Michigan, Iowa, New York, Vermont, New Hampshire and Maine. In the U.S., regions close to the Canadian border will have the highest chance.

When To See The Northern Lights

When and where aurora is visible is uncertain until a turbulent solar wind is detected by NASA’s DSCOVR and ACE satellites. Orbiting the sun from around a million miles from Earth, they give a roughly 30-minute warning of aurora displays after measuring the solar wind’s speed and magnetic intensity. Check NOAA’s 30-minute forecast or use the Glendale App for up-to-the-minute forecasts. Be prepared to fail — it may take multiple trips to finally see aurora, as displays can be unpredictable.

The Milky Way In June

Early July is a great time to see the Milky Way. Although it’s visible from the Northern Hemisphere all year, its bright core only becomes visible in the southern sky after dark from late May through September. The bright core is the center of the galaxy, home to a dense concentration of stars, star clusters and nebulae. You’ll need to be away from light pollution to see it.

Further Reading

ForbesBootid Meteor Shower: How To See ‘Shooting Stars’ On FridayBy Jamie CarterForbesA Comet 85 Miles Wide Is Erupting In The Solar System — What To KnowBy Jamie CarterForbesNASA Urges Public To Leave The City As Milky Way Appears — 15 Places To GoBy Jamie Carter

The study, published in Royal Society Open Science, found chlorothalonil – one of the world’s most extensively used fungicides – severely impacts insect reproduction and survival, even at the lowest levels routinely detected on food.

“Even the very lowest concentration has a huge impact on the reproduction of the flies that we tested,” says lead author Darshika Dissawa, a PhD candidate from Macquarie’s School of Natural Sciences.

“This can have a big knock-on population impact over time because it affects both male and female fertility.”

The researchers exposed fruit flies (Drosophila melanogaster) to chlorothalonil levels matching those typically found in produce from cranberries to wine grapes. Even at the lowest dose, flies showed a 37 percent drop in egg production compared with unexposed individuals.

Chlorothalonil is a widely applied broad-spectrum fungicide in American agriculture, used on crops like:

• Tomatoes
• Potatoes
• Peanuts
• Corn
• Turfgrass (e.g., golf courses)
• Fruits such as peaches, strawberries, and melons

Supervising author Associate Professor Fleur Ponton says the dramatic decline was unexpected.

“We expected the effect to increase far more gradually with higher amounts. But we found that even a very small amount can have a strong negative effect,” Associate Professor Ponton says.

Although banned in the European Union, chlorothalonil is extensively applied to Australian crops including orchards and vineyards, often preventatively when no disease is present.

The findings add to mounting evidence of global insect population decline, with some regions reporting drops exceeding 75 percent in recent decades.

“We need bees and flies and other beneficial insects for pollination, and we think this is an important problem for pollinator populations,” Associate Professor Ponton says.

The research highlights a critical knowledge gap in pesticide regulation, with fewer than 25 scientific papers examining chlorothalonil’s effects on insects despite its widespread use.

The researchers recommend more sustainable practices, including reduced application frequency to allow insect population recovery between treatments.

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The new weather satellite Meteosat Third Generation Sounder-1 (MTG-S1) lifted off on board a Falcon 9 rocket from the US company SpaceX on Tuesday. It is expected to provide more precise weather forecasting.

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An instrument for monitoring air pollution was also launched into space together with the satellite from the Kennedy Space Centre in Florida. The European Space Agency (Esa) announced that the launch had been successful.

The spacecraft, developed by Esa on behalf of weather satellite operator Eumetsat, will “revolutionise weather forecasting and climate observation in Europe”, said Tobias Guggenmoser from Esa. As an Eumetsat member, Switzerland will also utilise the satellite’s data.

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Swiss satellite tech to improve weather forecasting from space

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Aug 23, 2018


The Aeolus satellite, which is carrying Swiss technology, will measure winds around the globe.

Read more: Swiss satellite tech to improve weather forecasting from space

The infrared sounder will collect data on temperature, humidity and trace gases at an altitude of around 36,000 kilometres. This can help to recognise and predict rapidly developing and potentially dangerous weather patterns. “By recording 1,700 infrared channels every half hour, we can slice the sky into layers (…) so that meteorologists can see exactly what is happening at every altitude,” explained Guggenmoser.

The satellite, whose main contractor is the company OHB Bremen, is a major step forward for Esa. Europe previously only had imagers, which are satellites with imaging instruments, but not sounders with spectroscopic instruments for geostationary weather satellites.

More precise warnings, more protection, less damage

Before MTG-S1 lifted off into space, an imager from the satellite series had already been launched into space. Another is due to follow next year to complete the constellation. Together, these three instruments should be able to see the formation of thunderstorms before clouds even form and thus provide more precise storm warnings. The hope is that communities will be able to better prepare for severe storms in the future, resulting in less damage and fewer deaths.

The newly launched missile also carries the Sentinel-4 satellite of the Copernicus Atmospheric Monitoring Service (CAMS) for monitoring air quality. The instrument analyses the composition of the atmosphere, for example with regard to ozone and nitrogen dioxide, and is intended to provide more precise information on air pollution in Europe. Switzerland does not use the data from the Copernicus satellite as it is not a member.

Translated from German by DeepL/jdp

NASA is exploring the properties of a metal alloy that shrinks as it is heated, as boffins in its Astrophysics Division think it may be needed if the planned Habitable Worlds Observatory (HBO) is to succeed.

Readers doubtless know that metals expand when heated. As explained in a NASA blog post that’s a problem for space telescopes because if their components warm and expand it can mean that the shape of their mirrors change in ways that make it harder to conduct observations.

NASA has already developed materials that compensate for those effects and used them in the James Webb Space Telescope and in the Nancy Grace Roman Space Telescope that the aerospace agency intends to launch in 2027.

The HBO, NASA’s next space ‘scope project after the Nancy Grace Roman, will need even more resilient materials.

To understand why, the post explains how to observe exoplanets.

“As light passes through a planet’s atmosphere or is reflected or emitted from a planet’s surface, telescopes can measure the intensity and spectra (i.e., ‘color’) of the light, and can detect various shifts in the light caused by gases in the planetary atmosphere. By analyzing these patterns, scientists can determine the types of gases in the exoplanet’s atmosphere.”

Observing those shifts is no easy matter, “because the exoplanets appear very near their host stars when we observe them, and the starlight is one billion times brighter than the light from an Earth-size exoplanet.”

That means the Habitable Worlds Observatory “will need a contrast ratio of one to one billion (1:1,000,000,000).”

To achieve that contrast ratio, the HBO will need to be 1,000 times more stable than the James Webb telescope.

Which is why NASA scientists and a company called ALLVAR are investigating a “negative thermal expansion” (NTE) alloy that shrinks when heated.

According to NASA’s post, “A 1-meter-long piece of this NTE alloy will shrink 0.003 mm for every 1° C increase in temperature.”

“Because it shrinks when other materials expand, ALLVAR Alloy 30 can be used to strategically compensate for the expansion and contraction of other materials,” NASA’s post states.

Tests have delivered promising results: ALLVAR apparently built a test mirror mounted on struts of a titanium alloy that expands when heated and struts made with Alloy 30. Both alloys performed as expected, with Alloy 30 offsetting the expansion in the titanium alloy to produce a stable mirror.

NASA thinks the tests also showed Alloy 30 “enabled enhanced passive thermal switch performance and has been used to remove the detrimental effects of temperature changes on bolted joints and infrared optics.”

Space boffins are therefore considering how to use Alloy 30 in many other space scenarios.

You might want to consider using it, too, as NASA wrote “ALLVAR developed washers and spacers are now commercially available to maintain consistent preloads across extreme temperature ranges in both space and terrestrial environments.” ®

Little luck or skill is needed to find them: scientists believe that there are more dinosaur eggs here than at any other place on Earth. 

The area, closed to the public, is nicknamed “Eggs en Provence”, due to its proximity to the southeastern city of Aix en Provence. 

“There’s no other place like it,” explained Thierry Tortosa, a palaeontologist and conservationist at the Sainte Victoire Nature Reserve. 

“You only need to look down to find fragments. We’re literally walking on eggshells here.” 

Around 1,000 eggs, some of them as big as 30 centimetres (12 inches) in diameter, have been found here in recent years in an area measuring less than a hectare -– a mere dot on a reserve that will span 280 hectares once it is doubled in size by 2026 to prevent pillaging. 

“We reckon we’ve got about one egg per square metre (11 square feet). So there are thousands, possibly millions, here,” Tortosa told AFP. 

“Eggs” is not in the business of competing with other archaeological sites -– even though Tortosa finds the “world record” of 17,000 dinosaur eggs discovered in Heyuan, China, in 1996 vaguely amusing. 

“We’re not looking to dig them up because we’re in a nature reserve and we can’t just alter the landscape. We wait until they’re uncovered by erosion,” he said. 

“Besides, we don’t have enough space to store them all. We just take those that are of interest from a palaeontology point of view.” 

– Holy Grail –

Despite the plethora of eggs on site, the scientists still have mysteries to solve. 

Those fossils found so far have all been empty, either because they were not fertilised or because the chick hatched and waddled off. 

“Until we find embryos inside -– that’s the Holy Grail — we won’t know what kind of dinosaur laid them. All we know is that they were herbivores because they’re round,” said Tortosa. 

Fossilised dinosaur embryos are rarer than hen’s teeth.  

Palaeontologists discovered a tiny fossilised Oviraptorosaur that was at least 66 million years old in Ganzhou, China, around the year 2000. 

But Tortosa remains optimistic that “Eggs” holds its own Baby Yingliang.

“Never say never. In the nine years that I’ve been here, we’ve discovered a load of stuff we never thought we’d find.” 

Which is why experts come once a year to search a new part of the reserve. The location is always kept secret to deter pillagers.

When AFP visited, six scientists were crouched under camouflage netting in a valley lost in the Provencal scrub, scraping over a few square metres of clay-limestone earth, first with chisels, then with pointy-tipped scribers.  

“There’s always something magical — like being a child again — when you find an egg or a fossilised bone,” specialist Severine Berton told AFP. 

– Unique –

Their “best” finds -– among the thousands they have dug up — include a small femur and a 30-centimetre-long tibia-fibula. They are thought to come from a Rhabdodon or a Titanosaur — huge herbivores who roamed the region.

In the Cretaceous period (89-66 million years BCE), the Provencal countryside’s then-flooded plains and silty-clayey soils offered ideal conditions for dinosaurs to graze and nest, and perfect conditions to conserve the eggs for millennia. 

The region, which stretched from what is now Spain to the Massif Central mountains of central France formed an island that was home to several dinosaur species found nowhere else in the world.

Alongside the endemic herbivores were carnivores such as the Arcovenator and the Variraptor, a relative of the Velociraptor of Jurassic Park fame. 

In 1846, French palaeontologist Philippe Matheron found the world’s first fossilised dinosaur egg in Rognac, around 30 kilometres from Eggs.

Since then, museums from across the world have dispatched people to Provence on egg hunts. Everyone, it seems, wants a bit of the omelette. 

Despite efforts to stop pillaging, problems persist, such as when a wildfire uncovered a lot of fossils in 1989 and “everyone came egg collecting”, Tortosa said. 

Five years later the site was designated a national geological nature reserve, closed to the public — the highest level of protection available. 

The regional authorities are now mulling over ways to develop “palaeontology tourism”, a move Tortosa applauds. 

“France is the only country in the world that doesn’t know how to promote its dinosaurs,” Tortosa said.

“Any other place would set up an entire museum just to show off a single tooth.”

dac/so/ol/gil/bc