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Our neighbour, the Large Magellanic Cloud (LMC), is rich in gas and dust and hosts regions of extremely robust star formation. It contains about 700 open clusters, groups of gravitationally bound stars that all formed from the same giant molecular cloud. The clusters can contain thousands of stars, all emitting vibrant energy that lights up their surroundings.

One of these clusters is NGC 2040 in the constellation of Dorado, and the Gemini South Telescope captured its portrait.

NGC 2040 is noteworthy because it contains so many O-type and B-type stars. They’re hot, massive stars that tend to live fast and die young as explosive supernovae. The cluster contains more than a dozen of these stars.

There are two things at play in this image. Supernova explosions buffet the gas and dust and help shape the nebula while the young stars light it up. The explosions also create shock waves that compress the surrounding gas, leading to the formation of the next generation of stars.

A press release describes the nebula as a “Valentine’s Day rose.” What we’re really seeing is oxygen and hydrogen atoms energized by UV light from young stars and emitting light at different wavelengths. However, since it’s Valentine’s Day, we’ll concede to their more poetic description.

Human eyes can never see something like this naturally. The light spans wavelengths from the ultraviolet to the optical to the infrared. Instead, the Gemini South telescope captures the light at wavelengths beyond our range. The telescope employs filters to manage the light, showing us the deep red and orange colours from hydrogen and the light blue of oxygen. Bright white regions are abundant in both. It’s a nice partnership between telescope technology and human vision.

NGC 2024 is part of a larger structure called LH 88, one of the LMC’s largest star formation regions. The stars in the cluster are moving together, though they’re widely separated. They’re ensconced in gas and dust, some left behind by stars that have already exploded as supernovae. The gas and dust are further shaped by the strong stellar winds from so many young stars.

Our Sun likely formed in a cluster similar to NGC 2024. However, since that happened about five billion years ago, the stars have dispersed, and so have the gas and dust. There’s no more nebula.

The Hubble Space Telescope captured this image of NGC 2040 back in 2012 with its Wide Field Planetary Camera 2. Image Credit: ESA/Hubble, NASA and D. A Gouliermis. Acknowledgement: Flickr user Eedresha Sturdivant

It might not seem like it in our busy lives here on Earth’s surface, but this image tells a story we’re all wrapped up in: The cyclical nature of birth, death, and rebirth. When stars die and explode as supernovae, their material is expelled into space and taken up in the next round of star formation. And who knows, some of that material may be taken up in planet formation, maybe even rocky planets in the habitable zones of some of the new stars. Perhaps life will take root on one of those planets.

A zoom-in of the main image. Are planets forming in here somewhere? Rocky ones in habitable zones? Image Credit: International Gemini Observatory/NOIRLab/NSF/AURA
Image Processing: J. Miller & M. Rodriguez (International Gemini Observatory/NSF NOIRLab), T.A. Rector (University of Alaska Anchorage/NSF NOIRLab), M. Zamani (NSF NOIRLab)

Nothing lasts forever. Everything has a beginning and an end. One day, our Sun will become a red giant, Earth will be destroyed, and humanity may be destroyed with it. Though it’s a bleak proposition, it seems likely. But so is a kind of rebirth in a Universe that constantly recycles matter.

“Death is certain for one who has been born, and rebirth is inevitable for one who has died,” the Bhagavad Gita tells us. “Therefore, you should not lament over the inevitable.”

The post A Flaming Flower in the Large Magellanic Cloud appeared first on Universe Today.

New research on locomotion techniques that could be used in space exploration is constantly coming out. A lab from UCLA known as the Robotics and Mechanisms Laboratory (RoMeLa) is presenting a paper at the upcoming IEEE Aerospace Conference in March that details a unique system. The Space and Planetary Limbed Intelligent Tether Technology Exploration Robot (SPLITTER) consists of two miniaturized jumping robots tethered together.

Such a system might sound like a recipe for chaos and bring back memories of ladder ball games where no amount of control seems to make the tether go where you want it to. But, according to the paper, that system is actually quite stable, even in airless environments.

Mechanically, their system consists of two four-legged robots designed for jumping and tied together at their tops by a tether. Jumping is much more effective than “roving” on the surface of an asteroid because of all the jagged obstacles that need to be avoided. It is also more effective than flying since there is no atmosphere to push against in many space environments. Jumping robots, however, have been around for a while, but the real secret sauce is in the controls the RoMeLa team has developed.

Video describing some of the underlying tech of the SPLITTER robot.
Credit – Alvin Zhu YouTube Channel

The concept they used is called inertial morphing. In the case of SPLITTER, the robots “adjust inertia with changes in limb configurations and tether length,” according to lead author Yusuke Tanaka in an interview with TechXplore. The researchers turned to a technique called Model Predictive Control (MPC) to determine how each variable needs to be adjusted.

MPC is used in various industries and comes as advertised, with a model (i.e., a mathematical representation of the robots) and a prediction, which reflects what the software estimates will happen to the model next. With the model’s current state and expected next state, a controller can change the variables that affect the model’s state. Those changes will result in a stable flying path, allowing SPLITTER to soar through the skies, even without air. It also uses a physical phenomenon known as the Tennis Racket Theorem, which describes how an object can flip rotation around its intermediate axis while rotating around it. Most famously, this was demonstrated on the ISS with a t-handle. It looks chaotic, but the mathematics behind the motion are well-understood.

Implementing it in a tethered robotic system is another matter altogether, though. While SPLITTER is flying, it looks a lot like a bola used in ladder ball, except instead of round spheres on each end, it’s a robot body with four legs splayed out in different directions. The orientation of how those legs are spread out and the length of the tether connecting the two ends are the variables the MPC controls to stabilize its flight. SPLITTER can operate without heavy attitude control hardware, like reaction wheels or thrusters.

Famous video of the Tennis Racket Effect on the ISS.
Credit – Plasma Ben YouTube Channel

It also allows the system to perform other actions, like spelunking, where one robot is anchored firmly to the top of a cave system while the other rappels using the tether. Both robots only weigh about 10kg each on Earth, as well, which would make them even more agile on a world with smaller gravity like the Moon or an asteroid.

This isn’t the first robot system the RoMeLa lab designed for this purpose. They initially worked on a robot called the Spine-enhanced Climbing Autonomous Legged Exploration Robot) (SCALER), which had its limitations as they found the limbed climbing robot was too slow.

With SPLITTER, the research team thinks they have a better concept that can both traverse terrain faster and collect data that a robot tied to the ground would be unable to do. Unfortunately, for now, at least, SPLITTER is best described as a computer model, though some preliminary work has been done on the physics of MPC controlling a reaction wheel. Researchers at the lab intend to continue working on the concept, so maybe soon we’ll see a bola robot test jumping near Los Angeles.

Learn More:
TechXplore – Modular robot design uses tethered jumping for planetary exploration
Tanaka, Zhu, & Hong – Tethered Variable Inertial Attitude Control Mechanisms through a Modular Jumping Limbed Robot
UT – Miniaturized Jumping Robots Could Study An Asteroid’s Gravity
UT – A Jumping Robot Could Leap Over Enceladus’ Geysers

Lead Image:
Depiction of one SPLITTER robot descending into a crater while the other anchors on the rim.
Credit – Yusuke Tanaka, Alvin Zhu, & Dennis Hong

The post A Bola Robot Could Provide Stable Jumping Capability on Low-Gravity Bodies appeared first on Universe Today.

White dwarfs are the remnants of once brilliant main sequence stars like our Sun. They’re extremely dense and no longer perform any fusion. The light they radiate is from remnant heat only.

Astronomers have doubted that white dwarfs could host habitable planets, partly because of the tumultuous path they follow to become white dwarfs, but new research suggests otherwise.

White dwarfs are so small that their habitable zones would be equally as small. Their habitable zones could range from only 0.0005 to 0.02 AU from the star. At that range, any planets would be tidally locked. One side of the planet could suffer from the runaway greenhouse effect, while the other could be frigid. Another problem concerns the existence of any white dwarf planets themselves. There are indications that they exist, but their population is undefined.

There are about 10 billion white dwarfs (WDs) in the Milky Way, and new research in The Astrophysical Journal suggests that some of them could harbour life-supporting planets. The research is titled “Increased Surface Temperatures of Habitable White Dwarf Worlds Relative to Main-sequence Exoplanets.” The lead author is Aomawa Shields, associate professor of physics and astronomy at UC Irvine.

“These results suggest that the white dwarf stellar environment, once thought of as inhospitable to life, may present new avenues for exoplanet and astrobiology researchers to pursue.”

Aomawa Shields, lead author, UC Irvine

“Discoveries of giant planet candidates orbiting white dwarf (WD) stars and the demonstrated capabilities of the James Webb Space Telescope bring the possibility of detecting rocky planets in the habitable zones (HZs) of WDs into pertinent focus,” the authors write. If we do find more WD planets with the JWST or other telescopes, how likely is it that they’re habitable?

This research sought to find out by simulating two Earth-like aqua planets (ocean worlds) orbiting two different stars. They’re both tidally locked, follow circular orbits, and have Earth’s mass, atmospheric composition, and surface pressure. One is in the HZ of a main sequence star named Kepler-62, and the other is in the HZ of a hypothetical WD. Astronomers have already discovered large planets around WDs, so this simulation is based on real situations.

The researchers created synthetic spectra for both Kepler-62 and the white dwarf based on what is known about both. This image shows the spectral energy distribution of the modelled WD with an effective temperature of 5000 K (red) and a synthetic spectrum of Kepler-62 (4859 K, purple). Image Credit: Shields et al. 2025.

“While white dwarf stars may still give off some heat from residual nuclear activity in their outer layers, they no longer exhibit nuclear fusion at their cores. For this reason, not much consideration has been given to these stars’ ability to host habitable exoplanets,” lead author Shields said in a press release. “Our computer simulations suggest that if rocky planets exist in their orbits, these planets could have more habitable real estate on their surfaces than previously thought.”

Shields and her co-researchers used a 3D climate model to simulate planets around the stars. Both planets are tidally locked to their stars. Although both stars have similar effective temperatures, the results show that the planets’ climates differ considerably. The HZ around the white dwarf is much closer, meaning its planet is closer. That proximity means the planet had a higher surface temperature and a much faster rotation period, which is critical to the results.

“The synchronously rotating WD planet’s global mean surface temperature is 25 K higher than that of the synchronously rotating planet orbiting K62 due to its much faster (10 hr) rotation and orbital period,” the authors explain in their paper.

The simulated planet orbiting K62 had a much longer orbital period, which allowed a large mass of water vapour clouds to accumulate on the dayside. These clouds cooled more of the planet’s surface, subtracting habitable surface area. “The planet orbiting Kepler-62 has so much cloud cover that it cools off too much, sacrificing precious habitable surface area in the process,” Shields said.

“On the other hand, the planet orbiting the white dwarf is rotating so fast that it never has time to build up nearly as much cloud cover on its dayside, so it retains more heat, and that works in its favor,” Shields said.

The WD planet’s faster rotation circulated the atmosphere more effectively, avoiding the runaway greenhouse effect. “This ultrafast rotation generates strong zonal winds and meridional flux of zonal momentum, stretching out and homogenizing the scale of atmospheric circulation and preventing an equivalent buildup of thick, liquid water clouds on the dayside of the planet compared to the synchronous planet orbiting K62,” the paper states. The authors also explain that this transports heat from higher latitudes toward the equator and that this pattern is seen in other simulations of short-period planets.

The simulations show that zonal winds are weaker on the K62 planet (left) than on the WD planet (right.) The WD planet’s more powerful winds create a more habitable planet. Image Credit: Shields et al. 2025

“We expect synchronous rotation of an exoplanet in the habitable zone of a normal star like Kepler-62 to create more cloud cover on the planet’s dayside, reflecting incoming radiation away from the planet’s surface,” Shields said. “That’s usually a good thing for planets orbiting close to the inner edge of their stars’ habitable zones, where they could stand to cool off a bit rather than lose their oceans to space in a runaway greenhouse. But for a planet orbiting squarely in the middle of the habitable zone, it’s not such a good idea.”

This figure shows surface temperatures on the K62 planet (left), which has a 155-day orbit, and the WD planet (right), which has a 0.44-day orbit. The planet orbiting K62 “shows a characteristic, oval-shaped temperature pattern,” the authors write. The hottest point is at the substellar point on the planet’s dayside, and a cold nightside. The WD planet has stretched-out scales of circulation across the planet. and midlatitude jets. The hottest surface temperatures are located in the midlatitude jets, which is similar to simulations of other short-period planets. Image Credit: Shields et al. 2025.

Fewer clouds on the dayside of WD planets, combined with a stronger greenhouse effect on the night side, would create warmer, more habitable conditions than on the Kepler-62 planet, despite the fact that WD energy outputs slowly decline over time. If these results hold up, they could be game-changing in our search for exoplanets in habitable zones.

“White dwarfs may, therefore, present amenable environments for life on planets formed within or migrated to their HZs, generating warmer surface environments than those of planets with main-sequence hosts to compensate for an ever-shrinking incident stellar flux,” the authors explain.

“These results suggest that the white dwarf stellar environment, once thought of as inhospitable to life, may present new avenues for exoplanet and astrobiology researchers to pursue,” Shields said.

What’s not clear is how many planets there are around WDs. The transition from a red giant to WD isn’t a peaceful process. When red giants expand, they engulf and destroy nearby planets. Our Sun will one day become a red giant, and it will engulf Mercury, Venus, and probably Earth. Maybe even Mars.

Artist’s impression of a red giant star. When red giants expand, they engulf and destroy nearby planets. Planets further away could migrate inwards and orbit the star when it’s a white dwarf. Image Credit: NASA/ Walt Feimer

These destroyed planets can form a debris disk around the white dwarf, from which a new generation of planets could emerge. Or planets further away from the red giant could survive and move closer to the star as it undergoes its changes. More research is needed to understand these possibilities.

“As it is likely that many of the planets orbiting WD progenitors will have been engulfed during the red giant phase, WD planets may be few within their systems and possibly orbiting alone in single-planet systems,” the authors write.

Our knowledge of exoplanet habitability is incomplete. Yet, it’s a critical issue in understanding the Universe and one of our biggest questions: Is there other life? We can’t answer the big one without a much better understanding of habitability and what conditions it exists in. The only way to gain that knowledge is with more powerful observations.

“As powerful observational capabilities to assess exoplanet atmospheres and astrobiology have come on line, such as those associated with the James Webb Space Telescope, we could be entering a new phase in which we’re studying an entirely new class of worlds around previously unconsidered stars.”

Press Release: UC Irvine astronomers gauge livability of exoplanets orbiting white dwarf stars

Research: Increased Surface Temperatures of Habitable White Dwarf Worlds Relative to Main-sequence Exoplanets

The post White Dwarfs Could Be More Habitable Than We Thought appeared first on Universe Today.

Throughout Earth's history, ice caps have been very rare, but a model of the past 420 million years suggests an explanation for why they sometimes form

We all know that asteroids are out there, that some of them come dangerously close to Earth, and that they’ve struck Earth before with catastrophic consequences. The recent discovery of asteroid 2024 YR4 reminds us of the persistent threat that asteroids present. There’s an organized effort to find dangerous space rocks and determine how far away they are and where their orbits will take them.

A team of scientists has developed a method that will help us more quickly determine an asteroid’s distance, a critical part of determining its orbit.

Our asteroid concern is centred on NEOs or Near-Earth Objects. These are asteroids whose closest approach to the Sun is less than 1.3 astronomical units (AU). (A small number of NEOs are comets.) There are more than 37,000 NEOs, and while potential impacts are rare, the results can be catastrophic. Considering what happened to the dinosaurs, there’s not much room for complacency or hubris.

Large asteroids in the Main Asteroid Belt (MAB) are easier to study. Their large sizes mean they produce a bigger signal when observed, and astronomers can more easily determine their orbits. However, the MAB holds many smaller asteroids around 100-200 meters. There could be hundreds of millions of them. They’re big enough to devastate entire cities if they strike Earth, and they’re more difficult to track. The first step in determining their orbits is determining their distances, which is challenging and takes time.

Recent research submitted to The Astronomical Journal presents a new method of determining asteroid distances in much less time. It’s titled “Measuring the Distances to Asteroids from One Observatory in One Night with Upcoming All-Sky Telescopes” and is available at arxiv.org. The lead author is Maryann Fernandes from the Department of Electrical and Computer Engineering at Duke University.

The Vera Rubin Observatory (VRO) should see its first light in July 2025. One of its scientific objectives is to find more small objects in the Solar System, including asteroids, by scanning the entire visible southern sky every few nights. If it moves and reflects light, the VRO has a good chance of spotting it. However, it won’t automatically determine the distance to asteroids.

The Vera Rubin Observatory is poised to begin observations in 2025. It could detect 130 Near Earth Objects each night. Image Credit: Rubin Observatory/NSF/AURA/B. Quint

“When asteroids are measured with short observation time windows, the dominant uncertainty in orbit construction is due to distance uncertainty to the NEO,” the authors of the new paper write. They claim their method can shorten the time it takes to determine an asteroid’s distance to one night of observations. It’s based on a technique called topocentric parallax.

Topocentric parallax is based on the rotation of the Earth. In a 2022 paper by some of the same researchers, the authors wrote that “Topocentric parallax comes from the diversity of the observatory positions with respect to the center of the Earth in an inertial reference frame. Observations from multiple observatories or a single observatory can measure parallax because the Earth rotates.”

In the two years since that paper, the researchers have refined their method. The research expands on previous algorithms and tests the technique using both synthetic data and real-world observations.

“In this paper, we further develop and evaluate this technique to recover distances in as quickly as a single night,” the authors write in the new paper. “We first test the technique on synthetic data of 19 different asteroids ranging from ~ 0.05 AU to ~ 2.4 AU.”

The figure below shows the results of the test with synthetic data. Each asteroid was observed six times in one night, and two different equations were employed to process the data.

This figure shows the measured and true distances to 19 asteroids as part of the method’s test. In this test, each asteroid was observed six times in one night. The top shows Measured distance (AU) versus True distance (AU) for all 19 asteroids considered in this analysis. Each panel is based on a separate equation that can be employed in the method. “We see the fit from Eq. 1 for the group of asteroids yielding precise distances with relatively good agreement with true distances,” the authors write. Image Credit: Fernandes et al. 2025.

The researchers also tested their method by taking 15 observations of each asteroid over five nights (3 per night). In this test, Equation 1 performed poorly, while Equation 2 performed well.

This scenario featured 15 observations taken over 5 nights, with three observations per night. Equation 1 produces poor distance agreement, while with Equation 2, the distance recovery improves. Image Credit: Fernandes et al. 2025.

Of course, the distance to the asteroid affected the accuracy of the measurements. The closer the object was, the more precise the measurement was. The paper notes that the method was able to recover distances “with uncertainties as low as the ~ 1.3% level for more nearby objects (about 0.3 AU or less) assuming typical astrometric uncertainties.”

After these tests with synthetic data, the team acquired their own single-night observations of two asteroids using a different algorithm. The real observations produced a less precise result, but it was still a meaningful improvement. The authors explain that they were able to recover distances “to the 3% level.”

So, what do all these tests, equations, and algorithms boil down to?

When we hear of an asteroid that could potentially strike Earth in a few years, people can wonder why the situation is so uncertain. Shouldn’t we know if an asteroid is heading straight for us? Trying to determine the orbit of these small rocks from tens of millions of km away is extremely difficult. An AU is almost 150 million km (93 million miles). 2024 YR, the latest asteroid of concern, is only 40 to 90 metres (130 to 300 ft) in diameter. Those numbers illustrate the problem.

If this method can improve the accuracy of our distance measurements and do it based on a single night of observations, that’s a big improvement.

The technique can be applied to data generated by the Vera Rubin Observatory and the Argus Array. According to the authors, “distances to NEOs on the scale of ~ 0.5 AU can be constrained to below the percent level within a single night.” As the study shows, the accuracy of those measurements from a single-site observatory depends heavily on the spacing between individual observations. If multiple observatories at different sites are used on the same night, the accuracy increases.

The Argus Array is a planned astronomical survey instrument that will be unique in its ability to observe the entire visible sky simultaneously. It will consist of 900 small telescopes, each with its own camera. It’s currently under construction, but its location isn’t being publicized. The researchers say their method can work with Argus’ data. Image Credit: Argus Array

Though larger asteroids, like the one that wiped out the dinosaurs, tend to remain stable in the main asteroid belt, smaller asteroids are more easily perturbed and can become part of the NEO population. An impact from a smaller asteroid might not spell the end of civilization, but it can still be extremely destructive.

Anything humanity can do to understand the asteroid threat is wise. Many asteroids have struck Earth in the past, and it’s only a matter of time before another one comes our way. If we can see it coming in advance, we can try to do something about it.

Research: Measuring the Distances to Asteroids from One Observatory in One Night with Upcoming All-Sky
Telescopes

The post Dramatically Decreasing the Time it Takes to Measure Asteroid Distances appeared first on Universe Today.

Over time, batteries break down. Studying this process in-depth with imaging techniques may help us improve the lifespan of batteries.

Asteroids that orbit close to the Earth inevitably cause us some anxiety due to the even remote possibility of a collision. But their proximity also offers ample opportunities to learn more about the universe. Ryugu, a 900-meter diameter asteroid in the Apollo belt, has recently proven useful in our search for signs of life's precursors elsewhere in our Solar System. A team of researchers has found evidence of salt minerals in samples recovered from Ryugu during the initial phase of Japan's Hayabusa2 mission.

A unique dataset of Type Ia Supernovae being released today could change how cosmologists measure the expansion history of the Universe.

A survey of adults found most had low trust in their health care system to use artificial intelligence responsibly or to make sure an AI tool would not harm them.

As more satellites, telescopes, and other spacecraft are built to be repairable, it will take reliable trajectories for service spacecraft to reach them safely. Researchers are developing a methodology that will allow multiple CubeSats to act as servicing agents to assemble or repair a space telescope. Their method minimizes fuel consumption, guarantees that servicing agents never come closer to each other than 5 meters, and can be used to solve pathway guidance problems that aren't space related.

A remarkable discovery appeared in the journal Science in 2010.  Felisa Wolfe-Simon and her colleagues reported finding, in California’s salty Mono Lake, a bacterium that could substitute arsenic for phosphorus in its metabolism.  This was stunning, as phosphorus was thought to be an essential constituent of many biological macromolecules, including proteins and DNA—the latter using phosphorus as part of its backbone.  (The bacterium was, by the way, named GFAJ-1, standing for “Give Felisa a job,” as she was apparently looking for a permanent academic position.)

At any rate, this was huge news, and implied, to many, including hype-promoting journalists, that if life could thrive on arsenic, perhaps the chances of life on other planets was higher than we thought. Wolfe-Simon herself implied that perhaps there was a “shadow biosphere,” on Earth, including organisms that we didn’t know of because their biochemistry was so different from that of life we knew.

The publicity attending this discovery was huge: NASA held a press conference in which Simon was the only one of the dozen authors to appear. Simon also gave a TED talk on this subject, and in 2011 Time Magazine named her one of “Time’s 100 people,” supposedly the most influential group in the world.

The problem, which emerged pretty rapidly, is that this discovery was wrong. The research was sloppy, the reviewers apparently didn’t have the proper expertise to review the paper, and researchers who did have the expertise began pointing out the discovery’s flaws, first online and then in a series of eight critiques published in Science. As Wikipedia notes,

 If correct, this would be the only known organism to be capable of replacing phosphorus in its DNA and other vital biochemical functions.[14][15][16] The Science publication and an hour-long December 2, 2010 NASA news conference were publicized and led to “wild speculations on the Web about extraterrestrial life”.[17] Wolfe-Simon was the only one of the paper’s authors at that news conference.[18] The news conference was promptly met with criticism by scientists and journalists.[19] In the following month, Wolfe-Simon (and her co-authors and NASA) responded to criticisms through an online FAQ and an exclusive interview with a Science reporter, but also announced they would not respond further outside scientific peer-review.[20][21] In April 2011 Time magazine named Wolfe-Simon one of that year’s Time 100 people.[22][23]

The Science article “A Bacterium That Can Grow by Using Arsenic Instead of Phosphorus” appeared in the June 3, 2011 print version of Science;[1] it had remained on the “Publication ahead of print” ScienceXpress page for six months after acceptance for publication. However, Rosemary Redfield and other researchers from the University of British Columbia and Princeton University performed studies in which they used a variety of different techniques to investigate the presence of arsenic in the DNA of GFAJ-1 and published their results in early 2012. The group found no detectable arsenic in the DNA of the bacterium. In addition, they found that arsenate did not help the strain grow when phosphate was limited, further suggesting that arsenate does not replace the role of phosphate.[24][25]

Following the publication of the articles challenging the conclusions of the original Science article first describing GFAJ-1, the website Retraction Watch argued that the original article should be retracted because of misrepresentation of critical data.[26][27] In October 2024, Science editor Holden Thorp notified the article’s authors of its intention to retract, arguing that, whereas formerly only misconduct justified retraction, current practice allows it for unreliablity.[22]

I wrote about the controversy at the time; see my several posts here.  Simon et al. apparently were dead wrong.  This was first revealed byblog posts by Rosie Redfield (who later published a critique in the literature) and followed by eight critiques in Science about the Wolfe-Simon et al, paper, and two failed attempts to replicate their results, both of which failed. Wolfe-Simon did not get her coveted job and, as the new NYT article below reports, she now spends her time making music on the oboe, and working part-time on bacteria that apparently can use the Earth’s magnetic field to navigate.

Now the NYT has revisited the controversy on its 15th anniversary, and has published a long and remarkable article that does its best to exculpate Wolfe-Simon and demonize her critic. As the headline below implies, she further “changed science forever.”  That’s wrong. Why do they do this? Greg Mayer has two theories, which are his, and I’ll mention them below.

Click below to read the NYT article by Sarah Scoles, which is also archived here.

The article is remarkably soft on Wolfe-Simon, downplaying the scientific sloppiness of her theme and making her into kind of heroine who was unfairly attacked by a social-media mob They don’t mention microbiologist Rosie Redfield, a prime critic responsible for pointing out the errors of Wolfe-Simon et al., though one link goes to her.  The article implies, as I said, that “her discovery” (it was a group of people!) nevertheless changed science forever, for it was critiqued on social media (something that the NYT implies is bad), and from then on science has been vetted, even before papers are formally published, by non-scientists or scientists who publish their criticisms on social media, including blogs. This, claims author Scoles, has affected science so it’s never been the same.

Scoles is wrong and grossly exaggerates the situation.  Papers were criticized on social media long before Wolfe-Simon’s, but hers received special attention solely because not only was it a remarkable phenomenon, one hard to believe, but also because the authors gave it huge hype, helped along by the press. Remarkable results deserve remarkable attention. And, in the end, the problems with the Wolfe-Simon paper and the failure to replicate it found their way into the scientific literature, so that nobody now believes that there was an arsenic-using bacterium.  This is the way science is supposed to work, and in this case it did work. A sloppy and incorrect report was corrected.

Now others, including Science‘s editor Holden Thorp, as well as David Sanders in the Retraction Watch article below from 2020, feel that Wolfe-Simon et al. paper should be retracted.  I disagree. Retraction, if it’s used for anything, should be reserved for papers that were duplicitous, containing fake data or false assertions.  Wolfe-Simon et al. simply produced an incorrect and poorly reviewed paper, but there was no cheating. The paper should stay, and its simply met the fate of many papers that were wrong (remember, at least two Nobel Prizes have been given for sloppy and incorrect science). It is an object lesson on how wonky results get fixed.

Click below to read this Retraction Watch article from 2021, or see the more recent article here.

The question remains: why did the NYT paint a misleading picture of Felisa Wolfe-Simon, of her detractors, and of the scientific process? Why did they go so easy on her, making her into a heroine who was unfairly mobbed—to the point where she could not find an academic job.  Greg Mayer suggested two theories:

1.) Greg notes that because the article “makes her out as a victim”, it plays into the “victim narrative” of scientists who were treated unfairly (she was a woman, too, which feeds into that narrative).  And newspapers love victim narratives.

2.) Greg also wrote,  “The article seems in line with the Times’s embrace of woo: another example of credulous reporting of outlandish claims, a la their recent UFO coverage.”

I’m going to let Greg dilate on these theories, which are his, below, so come back to this post later on today to see what he says. I agree with him in the main, and we both agree that Wolfe-Simon’s paper should NOT be retracted.

Addendum by Greg Mayer.

My first suggestion is actually the “scientist as hero” narrative, which portrays the lone scientist as struggling against an entrenched orthodoxy that tries to suppress their discoveries. For some discussion of the narrative, its faults, but also its upside, see this post by Andrew Gelman and the links within it. The media love this narrative– sometimes it’s even true! That the “hero scientist” becomes a “victim” is even better– now you’re Galileo! It doesn’t hurt if the victim seems to be opposed by heartless male editors like Holden Thorpe; it helps if you neglect to mention that some of the most incisive criticisms were by another female scientist. But as someone once said, you can’t wrap yourself in the cloak of Galileo merely because orthodoxy opposes you: you must also be right. Getting a sympathetic reassessment in the Times also fits well with the initial strategy of maximum media attention (NASA press conference, TED talk, Glamour, Time, Wall Street Journal, etc.) as a way to advance one’s career, and with the general approach to science of the media, including the Times.

The second suggestion, which is not mutually exclusive, is that the article follows the Times recent attraction to woo, like astrology and UFOs. A lot of elite media have gotten in on the latter– see Andrew Gelman again, especially here. He points out that the media seem to think they are being skeptical of elites and authority when purveying this stuff, but while doubting authority, they gullibly accept anything else they’re told. (There’s a very similar strain in RFK Jr.’s approach to science.) But, as Gelman notes, extreme skepticism bleeds into credulity.

My friend Phil Ward at UC Davis found this reference and called it to my attention. It’s from the Philosophical Transactions of the Royal Society (B), and access is free (click on title below).  The pdf with the numbered references is here.

The paper is about how the evolution of two different types of gametes (“anisogamy”: a requirement for the origin of biological sexes) can originate from isogamy (same-sized gametes) under certain conditions. It is a theoretical paper, and I haven’t read it closely as I’m math-averse. However, what’s of interest is the first paragraph of the paper, which reviews the literature on anisogamy.  That paragraph states that anisogamy (ergo biological sex) has originated independently in many groups of eukaryotes (organisms with true cells).  I’ve put that first paragraph below and have bolded the relevant part. I’ve also linked to each group so you can see what they are.  The numbers lead to the references, which I have not checked.

Multicellular organisms typically produce gametes of two distinct size classes: larger eggs and smaller sperm. This dimorphism—known as ‘anisogamy’—is a remarkable case of convergent evolution. It has arisen independently in multiple distantly related eukaryotic lineages, including in animals [1]; dikaryotic fungi [2]; various groups of green algae, including the ancestors of land plants [3,4]; red algae [5]; brown algae [6,7]; yellow-green algae (Xanthophyceae: Vaucheria) [8]; diatoms [9]; oomycetes [10]; dinoflagellates [11]; apicomplexans [12]; and parabasalids (Trichonympha) [13]. By contrast, the gametes of most unicellular and some multicellular eukaryotes are isogamous, with a unimodal distribution of gamete sizes. Anisogamy is often taken as the defining difference between ‘male’ and ‘female’ sexual strategies: males produce only sperm; females produce only eggs; and hermaphrodites have the potential to produce both gamete types, either simultaneously or at different life stages. Isogamous species lack sexes by this definition. However, their gametes can often be classified into two, or occasionally more, ‘mating types’, such that fertilization only occurs between gametes of unlike types [2,14–16].

If you add up these groups, you get at least 11 evolutionarily independent origins of anisogamy: the production of “larger eggs and smaller sperm.”  The independence is probably inferred via a “cladistic” method by looking at the family trees of these groups, seeing that the ancestors were either asexual or isogamous, and noting that anisogamy appeared on a later-appearing derived branch.

If the authors are indeed correct, then what we have here is a remarkable example of evolutionary convergence: eleven separate groups independently evolving binary sex with large eggs and small sperm.  There are of course evolutionary theories showing why an ancestral condition of sex with equal-size gametes would split into a derived condition with two sizes of gametes, but that is a theoretical result.  Here we see that this has actually happened in nature nearly a dozen times, so the theories may hold some water.

I’ll add one thing. Not only has anisogamous sex apparently evolved eleven times independently, but, even in the one group of animals the determinants of sex—the features that trigger the development of two types of animals producing different-sized gametes—have also evolved independently. Luana and I pointed this out in our paper, “The ideological subversion of biology” (bolding is mine):

We can see the stability of the two-sex condition by realizing that what triggers the development of males versus females varies widely across species (Bachtrog et al. 2014). Different sexes can be based on different chromosomes and their genes (e.g., XX vs. XY in humans, ZW vs. ZZ in birds, individuals with like chromosomes being female in mammals and male in birds); different rearing temperatures (crocodiles and turtles); whether you have a full or half set of chromosomes (bees); whether you encounter a female (marine worms); and a host of other social, genetic, and environmental factors. Natural selection has independently produced diverse pathways to generate the sexes, but at the end there are just two destinations: males and females. And so we have an evolved and objectively recognized dichotomy—not an arbitrary spectrum of sexes.

Now I’m not smart or diligent enough to figure out why once there are two sexes—which is the case in animals, and must thus have been true in our common ancestor)—how you can evolutionarily traverse from one determinant of sex (say a gene on a chromosome) to something like temperature-dependent sex determination or social sex determination (e.g. the famous clownfish, used by miscreants to claim that there are more than two sexes).  It’s a mystery waiting to be solved.  But so even here, in one group, we have convergent evolution—of the factors that cause the two sexes to diverge.

I find all this fascinating, and it shows the power of Orgel’s Second Rule: “evolution is cleverer than you are.”

Crops don't generally thrive in desert-like ground, but 1000 years ago farmers in Israel utilised refuse such as ash and bones to turn sand into fertile land

Please send in your wildlife photos! Do I have to beg? Very well, then, I’m begging.

Today we have some photos by ecologist Susan Harrison: mostly birds but two mammals and one astronomy picture. Her captions are indented, and you can enlarge the photos by clicking on them.

More miscellany of early 2025

It’s been a turbulent time at work and a slow time for birdwatching, so it’s challenging to come up any wildlife photos, let alone ones with a theme.   But here are a few more random sights from around Davis, California in January – early February 2025.

Overwintering Snow Geese (Anser caerulescens):

American Beaver (Castor canadensis) in the local stream:

Mountain Bluebird (Sialis curricucoides), an uncommon overwintering bird around here, hunting crickets in a plowed field:

Merlin (Falco columbarius), distinguished from the similar-sized American Kestrel by having a white eyebrow instead of a black mustache (as birders call the vertical facial stripe):

American Kestrel (Falco sparverius) for comparison:

Miniature goats (Capra hircus), seemingly puzzled that the human is looking up into trees rather than bringing them carrots:

Horned Larks (Eremophila alpestris), which always look to me like they’re searching for someone’s lost keys:

American Avocets (Recurvirostra americana), in which females have more upcurved bills than males, possibly giving them different feeding niches:

Killdeer (Charadrius vociferus), inexorably drawn to stony surfaces like gravel roads and railroad beds:

Cinnamon Teal (Spatula cyanoptera) pairing up, Northern Shoveler (Spatula clypeata), and a rear-end view of a Northern Pintail (Anas acuta):

Mixed ducks flying away, as they are—sadly but for good reason—very shy of humans:

Savannah Sparrow (Passerculus sandwichensis), a drab little bird with not much to fear from a human:

And finally, though I’m no celestial photographer, the Moon being approached by Mars:

A new look at fossils from the Cambrian Period around 500 million years ago has revealed that some of the earliest animals spent time on mudflats that were sometimes exposed to the air – a find that could rewrite the story of when life first left the oceans

It’s a familiar sight to see astronauts on board ISS on exercise equipment to minimise muscle and bone loss from weightlessness. A new study suggests that jumping workouts could help astronauts prevent cartilage damage during long missions to the Moon and Mars. They found that the knee cartilage in mice seems to grow stronger after jumping exercises, potentially counteracting the effects of low gravity on joint health. If effective in humans, this approach could be included in pre-flight routines or adapted for space missions.

In space, astronauts experience significant loss of bone and muscle mass due to microgravity. Without Earth’s gravitational pull, bones lose density, increasing fracture risk, while muscles, especially in the lower body and spine, weaken from reduced use. This deterioration can impair mobility when back on Earth and effect overall health. To combat this, astronauts follow rigorous exercise routines, including resistance and cardiovascular training, to maintain strength and bone integrity. 

ESA astronaut Alexander Gerst gets a workout on the Advanced Resistive Exercise Device (ARED). Credit: NASA

The next obvious step as we reach out into the Solar System is the red planet Mars. Heading that far out into space will demand long periods of time in space since its a 9 month journey there. Permanent bases on the Moon too will test our physiology to its limits so managing the slow degradation is a big challenge to space agencies. A paper published by lead author Marco Chiaberge from the John Hopkins University has explored the knee joints of mice and how their cartilage grows thicker if they jump! They suggest astronauts should embed jumping activities into their exercise regiment. 

Mars seen before, left, and during, right, a global dust storm in 2001. Credit: NASA/JPL/MSSS

Cartilage cushions the joints between bones and decreases friction allowing for pain free movement. Unlike many other tissues in the body, cartilage does not regenerate as quickly so it is important to protect it. Prolonged periods of inactivity, even from bed rest but especially long duration space flight can accelerate the degradation. It’s also been shown that radiation from space can accelerate the effect too. 

To maintain a strong healthy body, astronauts spend a lot of time, up to 2 hours a day running on treadmills. This has previously shown to slow the breakdown of cartilage but the new study has shown that jumping based movements is particularly effective. T

The team of researchers found that, over a nine week program of reduced movement, mice experienced a 14% reduction in cartilage thickness in joints. Other mice performed jumping movements three times a week and their cartilage was found to be show a 26% increase compared to a control group of mice. Compared to the group that had restricted movement, the jumping mice had 110% thicker cartilage. The study also showed that jumping activities increased bone strength too with the jumping mice having a 15% higher density than the control.

An interesting piece of research but further work is needed to see whether jumping would herald in the same benefits to humans but the study is promising. If so, then jumping exercises are likely to be a part of pre-flight and inflight exercise programs for astronauts. It is likely that for this to be a reality in the micro-gravitational environment, astronauts will be attached to strong elasticated material to simulate the pull of gravity. 

Source : Jumping Workouts Could Help Astronauts on the Moon and Mars, Study in Mice Suggests.

The post Should Astronauts Add Jumping to their Workout Routine? appeared first on Universe Today.

My younger self, seeing that title – AI Powered Bionic Arm – would definitely feel as if the future had arrived, and in many ways it has. This is not the bionic arm of the 1970s TV show, however. That level of tech is probably closer to the 2070s than the 1970s. But we are still making impressive advances in brain-machine interface technology and robotics, to the point that we can replace missing limbs with serviceable robotic replacements.

In this video Sarah De Lagarde discusses her experience as the first person with an AI powered bionic arm. This represents a nice advance in this technology, and we are just scratching the surface. Let’s review where we are with this technology and how artificial intelligence can play an important role.

There are different ways to control robotics – you can have preprogrammed movements (with or without sensory feedback), AI can control the movements in real time, you can have a human operator, through some kind of interface including motion capture, or you can use a brain-machine interface of some sort. For robotic prosthetic limbs obviously the user needs to be able to control them in real time, and we want that experience to feel as natural as possible.

The options for robotic prosthetics include direct connection to the brain, which can be from a variety of electrodes. They can be deep brain electrodes, brain surface, scalp surface, or even stents inside the veins of the brain (stentrodes). All have their advantages and disadvantages. Brain surface and deep brain have the best resolution, but they are the most invasive. Scalp surface is the least invasive, but has the lowest resolution. Stentrodes may, for now, be the best compromise, until we develop more biocompatible and durable brain electrodes.

You can also control a robotic prosthetic without a direct brain connection, using surviving muscles as the interface. That is the method used in De Lagarde’s prosthetic. The advantage here is that you don’t need wires in the brain. Electrodes from the robotic limb connect to existing muscles which the user can contract voluntarily. The muscles themselves are not moving anything, but they generate a sizable electrical impulse which can activate the robotic limb. The user then has to learn to control the robotic limb by activating different sequences of muscle contractions.

At first this method of control requires a lot of concentration. I think a good analogy, one used by De Lagarde, is to think of controlling a virtual character in a video game. At first, you need to concentrate on the correct sequence of keys to hit to get the character to do what you want. But after a while you don’t have to think about the keystrokes. You just think about what you want the character to do and your fingers automatically (it seems) go to the correct keys or manipulate the mouse appropriately. The cognitive burden decreases and your control increases. This is the learning phase of controlling any robotic prosthetic.

As the technology develops researchers learned that providing sensory feedback is a huge help to this process. When the user uses the limb it can provide haptic feedback, such as vibrations, that correspond to the movement. Users report this is an extremely helpful feature. It allows for superior and more natural control, and allows them to control the limb without having to look directly at it. Sensory feedback closes the usual feedback loop of natural motor control.

And that is where the technology has gotten to, with continued incremental advances. But now we can add AI to the mix. What roll does that potentially play? As the user learns to contract the correct muscles in order to get the robotic limb to do what they want, AI connected to the limb itself can learn to recognize the user behavior and better predict what movements they want. The learning curve is now bidirectional.

De Lagarde reports that the primary benefit of the AI learning to interpret her movements better is a decrease in the lag time between her wanting to move and the robotic limb moving. At first the delay could be 10 seconds, which is forever if all you want to do is close your fist. But now the delay is imperceptible, with the limb moving essentially in real time. The limb does not feel like her natural limb. She still feels like it is a tool that she can use. But that tool is getting more and more useful and easy to use.

AI may be the perfect tool for brain-machine interface in general, and again in a bidirectional way. What AI is very good at is looking at tons of noisy data and finding patterns. This can help us interpret brain signals, even from low-res scalp electrodes, meaning that by training on the brain waves from one user an AI can learn to interpret what the brain waves mean in terms of brain activity and user intention. Further, AI can help interpret the user’s attempts at controlling a device or communicating with a BMI. This can dramatically reduce the extensive training period that BMIs often require, getting months of user training down to days. It can also improve the quality of the ultimate control achieved, and reduce the cognitive burden of the user.

We are already past the point of having usable robotic prosthetic limbs controlled by the user. The technology is also advancing nicely and quite rapidly, and AI is just providing another layer to the tech that fuels more incremental advances. It’s still hard to say how long it will take to get to the Bionic Man level of technology, but it’s easy to predict better and better artificial limbs.

The post AI Powered Bionic Arm first appeared on NeuroLogica Blog.

One of the basic principles of cosmology is the Cosmological Principle. It states that, no matter where you go in the Universe, it will always be broadly the same. Given that we have only explored our own Solar System there is currently no empirical way to measure this. A new study proposes that we can test the Cosmological Principle using weak gravitational lensing. The team suggests that measuring tiny distortions in light as it passes through the lenses, it may just be possible to find out  if there are differences in density far away. 

The Cosmological Principle is a fundamental assumption stating that the universe is homogeneous on a large scale. In other words regardless of location or direction, the universe appears uniform and it underpins many cosmological models, including the Big Bang theory. Taking the assumption that physical laws apply consistently everywhere makes calculations and predictions about the universe’s structure and evolution far simpler, but research has been testing its validity by searching for potential anomalies.

This illustration shows the “arrow of time” from the Big Bang to the present cosmological epoch. Credit: NASA

A paper has been published by a team of astrophysicists, led by James Adam from the University of Western Cape in South Africa and explains that the Standard Model of Cosmology predicts the Universe has no centre and has no preferred directions (isotropy.) The paper, which was published in the Journal of Cosmology and Astroparticle Physics, articulates a new way to test the isotropy of the Universe using the Euclid space telescope.

The Euclid telescope is a European Space Agency mission to explore dark matter and dark energy. It was launched in 2023 and maps the positions and movements of billions of galaxies. It’s using this instrument that the team hope to search for variations in the structure of the Universe that might challenge the Cosmological Principle. 

Artist impression of the Euclid mission in space. Credit: ESA

Previous studies have found such anomalies before but there are conflicting measurements of the expansion rate of the Universe, in the microwave background radiation and in various cosmological data. Further independent observations are required though, providing more data to see if the observations were the result of measurement errors. 

The team explore using weak gravitational lenses, which occur when matter sits between us and a distant galaxy, slightly bending the galaxies light. Analysis of this distortion can be separated into two components; E-mode shear (caused by the distribution of matter in an isotropic and homogenous Universe) and B-mode shear which is weak and would not appear in an isotropic Universe at large scale. 

If the team can detect large scale B-modes this in itself wouldn’t be enough to confirm the anisotropies since the measurements are tiny and prone to measurement errors. To confirm, and finally test the Cosmological Principles, E-mode shear needs to be detected as well. Such discovery and correlation of E-mode and B-mode shear would suggest the expansion of the Universe is anisotropic. 

Ahead of the Euclid observations, the team simulated the effects of an anisotropic universe expansion on a computer. They were able to use the model to describe the effect of the weak gravitational force and predict that Euclid data would be sufficient to complete the study. 

Source : Does the universe behave the same way everywhere? Gravitational lenses could help us find out

The post Do We Live in a Special Part of the Universe? Here’s How to Find Out appeared first on Universe Today.

For more than 40 years, Jonathan McDowell has tirelessly catalogued the space industry. Now he is planning to retire, and looking to pass on his extensive collection of knowledge

A UK start-up is producing dyes made by bacteria and yeast rather than fossil fuel-derived chemicals, which could help clothes manufacturers cut energy use and pollution