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A quarter-century after its first observations of the full Crab Nebula, NASA’s Hubble Space Telescope has taken a fresh look at the supernova remnant. The result is an unparalleled, detailed look at the aftermath of a supernova and how it has evolved over Hubble’s long lifetime. A paper detailing the new Hubble observation was published in The Astrophysical Journal.

High in the Chilean Andes, at an altitude where the air is thin and the Sun is intense, a salt flat is hiding something remarkable. Locked inside ancient crystals of gypsum are the preserved remains of microscopic life, fossils of organisms that lived thousands of years ago, sitting alongside communities of microbes that are alive right now. Scientists studying this extraordinary place think it could be the closest thing on Earth to where life might once have existed on Mars.

Detecting gravitational waves has always demanded enormous machines; kilometre scale instruments capable of sensing distortions smaller than a proton. But a new theoretical study suggests the universe may have been leaving its calling card in the light emitted by individual atoms. If the idea holds up, the future of gravitational wave detection might not be sprawling observatories carved into the landscape, but something you could hold in the palm of your hand.

We've always thought that Tyrannosaurus rex was an unchallenged apex predator during the dying days of the dinosaurs. But a fresh look at controversial fossils has prompted palaeontology’s biggest-ever U-turn

CERN is working on building an antimatter delivery service. The project passed a big test by successfully transporting 92 antiprotons around a 4-kilometre loop of road

Heat shield design is one of the most critical aspects of missions that plan to either land on a planet’s (or moon’s) surface or return to our own. Spacecraft that have to survive the fiery, hypersonic plunge through an atmosphere require these systems. For decades, heat shields have been designed to slowly burn away in a process called ablation, which is intended to dissipate the incredible thermal energy or reentry. But, there’s another, less understood phenomenon that affects them too - spallation, where a heat shield sheds material in violent, unpredictable “bursts”. This second mode of destruction seems to be particularly prevalent in oxygen-deprived atmospheres, like that of Titan, where the Dragonfly helicopter plans to land in the not too distant future. A new paper published in Carbon from researchers at the University of Illinois Urbana-Champaign (UIUC) performed some tests showing just how different those heat shields might need to be.

Last year the inner solar system had an interstellar visitor – 3I/Atlas (which stands for the third interstellar object which was discovered by the Atlas telescope). The third ever of anything is by definition a rare event, and so this was scientifically exciting. The comet came into the inner solar system, passing close to Jupiter and Mars, but not to the Earth, went behind the sun, then emerged on its path away from the sun. It is now headed for the orbit of Jupiter and out of the solar system. At first 3I/Atlas displayed a number of minor anomalies. It was behaving sort of like a comet, but with some differences. This fits well, however, with the main hypothesis that it is an interstellar comet – so it’s a comet, but may have a different composition from comets that were formed in our own solar system. This is not almost certainly the case – the comet comes from the thick disc of the galaxy, likely from a low metallicity star system, and has likely been travelling through interstellar space for billions of years, possibly being even older than our own star.

Now that it is passing out of the solar system we can look at all the data that NASA collected and make some fairly confident conclusions. There are a lot of sources of information, but Wikipedia actually has a pretty good summary and list of references. In the end, 3I/Atlas behaved mostly like a typical comet. It formed a tail heading away from the sun, brightened as it got close, then faded away as it moved away from the sun. Spectral analysis found that the comet was unusually rich in carbon dioxide (CO2), with small amounts of water ice, water vapor, carbon monoxide (CO), and carbonyl sulfide (OCS). It also had small amounts of cyanide and nickel gas, which is common in comets from our own solar system. In other words – it is a comet. It did originate from a part of the sky that we had previously calculated would have fewer such interstellar objects, which either makes it especially rare or means that our calculations are off.

Every time we encounter a new interstellar object we gather more data about such objects – how frequent are they, where do they come from, and what is their nature. Right now we have just three data points. After the first one, Oumuamua, we had not idea how common they were because we had just one data point. Now we have enough instruments surveying the sky that we are better able to detect such objects, which are very fleeting. The question was – was Oumuamua a one-off, and we just got lucky to detect something that happens very rarely, or are such objects common. We now have three data points and can conclude that they are fairly common, and we should detect one every few years or so, perhaps even more often if we start looking more.

Interstellar objects are a fairly new astronomical phenomenon, and what typically happens to new astronomical phenomena is that someone asks – could this be an alien artifact? So far the answer has been universally, no. The universe is a very big and complex place with lots of unusual phenomena. Historically speaking we have only just started to examine the cosmos, and are still encountering new phenomena on a regular basis. We have yet, however, to detect anything demonstrably, or even likely, alien. No one would be more excited than me if we discovered a genuine technosignature of an alien civilization. That is precisely why we have to be very careful before leaping to any such conclusions. But sure, ask the question, just don’t leap off the deep end.

What I mean by that is – do not make bad arguments to prop up an alien hypothesis, do not mystery-monger, do not truck in conspiracy theories, and do not draw undue attention to such speculation or present it as anything other than speculation. Every generation seems to have someone, sometimes with a scientific background, who does all of these things. The allure of the alien hypothesis is just too great. It is genuinely fascinating. It is the fast track to fame and attention. You can portray yourself as just being open-minded, brave enough to ask the tough questions, and criticize your colleagues for being closed-minded. Of course, like many things, this is a continuum. A little  is reasonable, more starts to get sketchy, and a lot makes you a crank.

An example of something which I consider to be in the sweet spot of good scientific exploration of the possibility of alien technosignatures is SETI. SETI essentially uses radioastronomy to survey for potential radio signals of alien origin. But they are not just doing this – they are also doing lots of ordinary good radio astronomy. But mixed in with their radio astronomy are methods to screen for signals that might be technosignatures. They are also extremely careful not to make any premature or overblown claims, and they are their own most dedicated skeptics.

At the other end of the spectrum, in my opinion, is Avi Loeb. He has seemed to make a career now out of mystery mongering anything unusual as a possible alien artifact. He claimed that all three interstellar objects might be alien craft. Why is he at the crank end of the spectrum? Because he elevated this possibility prematurely and with a series of really bad arguments, sometimes distorting the data or making bad calculations. He said that Oumuamua might be alien because it was coming close to the Earth, to observe it. He then argued that 3I/Atlas might be alien because it was not coming close to the Earth, to hide from us. He exaggerated its possible size, its apparent lack of a tail, its composition. He made a lot of the fact that the comet’s trajectory is close to the ecliptic, about 5 degrees off, committing a classic lottery fallacy argument. He calculated how likely this specific feature is, but only after knowing it, and did not adjust for all possible features that might be individually unlikely. He engaged in classic post-hoc reasoning. In the end, the predictions of NASA scientists all proved correct – 3I/Atlas is a comet, and displays all the features of a comet. Loeb attracted attention by saying 3I/Atlas might pivot toward the Earth once it emerges from behind the sun. When this prediction failed he did admit it was “most likely natural”, but is still emphasizing its apparent anomalies.

What he is doing is playing coy, which is a common strategy for those who are pushing fringe ideas but who are trying to seem reasonable. All along he said – the most likely explanation is that it is natural. But then follows up with – here are lots of (really bad) reasons why it is unusual and might be alien. This is a win-win for him – in the rare case that he turns out to be right, he is a genius and takes all the credit (keep in mind, if it were alien NASA would have found out all by themselves, with his prodding). If it turns out he is wrong, then he can claim he said all along it was likely to be natural. Either way he sucks up as much oxygen as possible from the media and distracts from the hard-working scientists at NASA doing good work. There is some great and interesting science here. The conclusion that this is almost certainly not an alien craft is a footnote at best, because there was never any good reason to hypothesize that it was.

Loeb is at it again (or still) with a recent post about a “mysterious” Mars cylinder (see the picture above the fold). This is also a common strategy of mystery mongers – comb through tons of data looking for anything unusual, then declare it a mystery. Again – looking for anomalies is a legitimate process of science. Blowing up apparent anomalies into a high-priority mystery is something that an attention-seeking crank would do. In this case others combed through NASA pictures from the Rover and then send it along to Loeb, so he is now a magnet for such things. And again – he admits this is most likely to be just a piece of debris from the Rover itself, or its landing, or whatever. There is now debris on Mars from all the spacecraft we have sent from Earth, so when we encounter a bit of what looks like ordinary debris, that is most likely what it is.

But Loeb is saying that NASA should turn the rover around and travel a few days to go back and take a closer look at this debris. NASA has not responded or commented to Loeb’s statement. This is actually a good operational definition of making too much of an apparent anomaly. Thinking that such anomalies, even when they are likely mundane, should take high priority and redirect our limited resources away from other scientific priorities, is worse than grabbing attention. It is trying to commandeer precious public resources to go on your own wild-goose chases, not because it is good science, but because it serves your own personal agenda.  NASA is perfectly capable of determining the proper priorities for their own rover. They don’t have to go chasing after every piece of space junk because Loeb is trying to grab attention and justify his own dubious professional existence.

The post What Happened to Comet 3I/Atlas first appeared on NeuroLogica Blog.

Physicists are grappling with how the increasing presence of AI will change the nature of their profession

Astronomers have finally cracked a decades-old mystery about red giant stars—how material from their deep interiors makes its way to the surface. Using cutting-edge supercomputer simulations, researchers discovered that stellar rotation plays a powerful role in mixing elements across a previously unexplained barrier inside the star.

Astronomers have finally cracked a decades-old mystery about red giant stars—how material from their deep interiors makes its way to the surface. Using cutting-edge supercomputer simulations, researchers discovered that stellar rotation plays a powerful role in mixing elements across a previously unexplained barrier inside the star.

As the science fiction author publishes the latest novel in his Children of Time series, Children of Strife, he talks to Alison Flood about mantis shrimp, the pleasures of sci-fi and why empathy is so important in his writing

Are we evolving to be more stupid? Humans have a relatively high genetic mutation rate, which has been thought to be driving down our physical and mental fitness – but columnist Michael Le Page finds these mutations aren’t the health risk some make them out to be

Supplying some much-needed skepticism to an episode of the BBC podcast Uncanny.

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Scientists have turned simple glass into a powerful quantum communication device that could safeguard data against future quantum attacks. The chip combines stability, speed, and versatility—handling both ultra-secure encryption and record-breaking random number generation in one compact system.

Scientists have found a clever way to supercharge ultra-thin semiconductors by reshaping the space beneath them rather than altering the material itself. By placing a single-atom-thick layer of tungsten disulfide over tiny air cavities carved into a crystal, they created miniature “light traps” that dramatically boost brightness and optical effects—up to 20 times stronger emission and 25 times stronger nonlinear signals. These hollow structures, called Mie voids, concentrate light exactly where the material sits, overcoming a major limitation of atomically thin devices.

Scientists have found a clever way to supercharge ultra-thin semiconductors by reshaping the space beneath them rather than altering the material itself. By placing a single-atom-thick layer of tungsten disulfide over tiny air cavities carved into a crystal, they created miniature “light traps” that dramatically boost brightness and optical effects—up to 20 times stronger emission and 25 times stronger nonlinear signals. These hollow structures, called Mie voids, concentrate light exactly where the material sits, overcoming a major limitation of atomically thin devices.

Foams have long baffled scientists because liquid drains from them far sooner than theory predicts. New research shows the reason: the bubbles don’t stay put—they rearrange, opening pathways for liquid to escape. The key factor is the pressure needed to shift bubbles, not just push liquid through them. This insight reshapes how we understand foams and could improve everyday products.

For the first time, scientists have reconstructed the full history of a galaxy outside the Milky Way using chemical clues. By analyzing oxygen across NGC 1365 and comparing it with simulations, they traced its growth over 12 billion years. The findings show how its core formed early while its outer regions were built through repeated mergers. This new approach could transform how astronomers study galaxy evolution.

When we think of asteroids, we almost immediately think of giant rocks bouncing around like the iconic chase scene in Empire Strikes Back, and we often hear how they are remnants from the birth of the solar system. While the asteroids that comprise the Main Asteroid Belt of our solar system are not only spread far apart from each other, they are also not all made of rock. One asteroid approximately the size of the State of Massachusetts called 16 Psyche is made of metal, which planetary scientists hypothesize could be the remnants of a protoplanet’s core that didn’t build into a full-fledged planet. But how did such a unique asteroid form?

What happens in a protoplanetary disk to create planetesimals around a star? We know the general story -- the material begins to clump together and eventually grows from dust grains to rocky bodies capable of sticking together to make planets. But, how does that dust begin the aggregation journey? That's what a research team from the Switzerland wanted to know. So, they did experiments aboard parabolic micro-gravity flights to find an answer.