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Engineers have utilized quantum sensors to realize a groundbreaking variation of nuclear quadrupolar resonance (NQR) spectroscopy, a technique traditionally used to detect drugs and explosives or analyze pharmaceuticals. The new method is so precise that it can detect the NQR signals from individual atoms -- a feat once thought unattainable. This unprecedented sensitivity opens the door to breakthroughs in fields like drug development, where understanding molecular interactions at the atomic level is critical.

Researchers have developed a way of detecting circulating tumor cells in the bloodstream of pancreatic cancer and lung cancer patients.

Comet C/2024 G3 ATLAS may put on a quick show this month.

Comet G3 ATLAS on December 30th. Credit: Alan C. Tough

What ‘may’ be the best anticipated comet of 2025 is coming right up. Right now, there’s only one comet with real potential to reach naked eye visibility in 2025: Comet C/2024 G3 ATLAS. This comet reaches perihelion at 0.094 Astronomical Units (AU, 8.7 million miles or 14 million kilometers, interior to the orbit of Mercury) from the Sun on January 13th, and ‘may’ top -1st magnitude or brighter. At magnitude +4 in late December, Comet G3 ATLAS could become a fine object low in the dawn sky for southern hemisphere observers… if (a big ‘if) it holds together and performs as expected.

The comet actually produced an outburst over the first weekend of 2025, jumping from magnitude +4 to +1 (a sixteen-fold increase in brightness in a few short days). This could be a harbinger for good (or bad) things to come shortly.

“The comet has had an outburst in the last few days,” Nicolas Lefaudeux told Universe Today. “If the outburst is linked to disintegration, there would probably be nothing to see after perihelion. If the outburst is linked to new active areas or splitting of a large nucleus, the display could be much better than in the simulations.”

The prospects for the tail of Comet G3 ATLAS, around perihelion. Credit: Nicolas Lefaudeux

A recent International Astronomical Union Central Bureau for Astronomical Telegrams message suggests an optimistic peak of -3rd magnitude near perihelion post outburst, ‘if’ the comet holds together.

Comet G3 ATLAS low at dawn versus Mercury on January 11th. Credit: Starry Night. The Discovery

The comet was discovered by the Asteroid Terrestrial-Impact Last Alert System (ATLAS) survey as a +19th magnitude object in the southern hemisphere constellation Apus the Bee on the night of April 5th, 2024.

The orbital path for Comet G3 ATLAS through the inner solar system. Credit: NASA/JPL

The orbital period for this one is around 160,000 years. It’s unclear if Comet G3 ATLAS is a first-time visitor to the inner solar system, or a new denizen coming from the distant Oort Cloud. The last time the comet swung by the inner solar system (assuming it has done so in the past), wearing clothing was the hot new thing among our homo sapiens ancestors.

Comet G3 ATLAS from January 2nd. Credit: iTelescope/Tara Prystavski. Comet G3 at Perihelion: Perish or Prosper?

Prospects for seeing this comet will be tricky. Unlike last year’s Comet C/2023 A3 Tsuchinshan-ATLAS which unfurled a magnificent tail for its evening apparition, G3 ATLAS will be a timid one both before and after perihelion, as it departs our solar neighborhood hugging the southern horizon in the dusk sky.

Comet G3 ATLAS, post perihelion on January 15th at dusk. Credit: Starry Night.

A daytime comet could be in the offing if G3 ATLAS over-performs at perihelion… but it will be a challenging view, very near the Sun. Be sure to block the dangerous glare of the Sun fully out of view behind a building or structure if you attempt to spot the comet in daylight. Like A3 T-ATLAS, the joint NASA/ESA SOHO observatory will see the comet near perihelion crossing through its LASCO C3 viewer.

Comet G3 ATLAS versus SOHO through the month of January. Credit: Starry Night. Best Bets For Comet G3 ATLAS

Perihelion on Monday, January 13th, 2025 will see the comet just four degrees from the Sun. The comet also makes its closest approach to Earth at 0.938 AU distant on the same date. The comet ‘could’ reach -4th magnitude (about as bright as Venus) around the same time… if it manages to hold together at perihelion.

Here’s a recent remote telescope image of the comet taken from late December by Nick James:

Comet G3 ATLAS from December 15th. Credit: Nick James/BAA Comet Section/iTelescope.

Comet G3 ATLAS has been elusive thus far. The comet has been bashful, skimming just five degrees above the dawn horizon leading up to perihelion in early January for northern hemisphere observers. The comet reemerges low to the west after dusk, but again, folks up north only get a very brief view 5-10 degrees above the horizon at dusk, as the comet runs parallel with the horizon southward. As usually seems to be the case with comets, the southern hemisphere gets the better view.

Here’s a blow-by-blow of what to expect in the coming months from the comet. (Note that ‘passes near,’ denotes a conjunction of a degree or less):

January

6-Near the Lagoon Nebula (Messier 8)

7-Near the globular cluster (Messier 28)

8-Crosses the ecliptic plane northward

11-Enters SOHO LASCO C3 view

13-At perihelion, less than 5 degrees from the Sun

14-Crosses into the constellation Capricornus

15-Exits SOHO LASCO C3 view, and crosses the ecliptic plane southward

21-Nicks the corner of the constellation Microscopium

22-Crosses into the constellation Piscis Austrinus

The light curve for comet G3 ATLAS. Adapted from Seichii Yoshida’s Weekly Information About Bright Comets. February

1-May drop back down below +6th magnitude

6-Crosses into the constellation Grus

21-Nicks the corner of the constellation Sculptor

25-Crosses into the constellation Phoenix

March

March 1st: May drop back down below +10th magnitude.

Observing and imaging the comet will be challenging, owing to two main factors: first, it will never really leave the low-contrast, twilight sky for northern hemisphere observers. Second, said quoted magnitude for a comet gets ‘smeared out’ over its apparent surface area, knocking the comet’s apparent brightness down a notch or two. We can hope that Comet G3 ATLAS is an over-performer in this regard. My strategy is to find high ground to observe from and the lowest, flattest horizon (like, say, the ocean as seen from a beach) that you can find, and sweep the horizon at low power with binoculars for the fuzzball of a comet.

Good luck and clear skies on this, the first comet quest of 2025.

The post Will Comet G3 ATLAS Perform at Perihelion? appeared first on Universe Today.

Throat vibrations made by people who find it difficult to speak, such as after a stroke, can be analysed by AI and used to create sentences

One powerful way to study the galaxies is to study individual stars. By looking at the ages, types, and distribution of stars in the Milky Way, we’ve captured a detailed snapshot of how our galaxy formed and evolved. The only problem with this approach is that we can only do this for a handful of galaxies. Even with the most powerful telescopes, we can only see individual stars in the Milky Way and nearby galaxies such as Andromeda. For galaxies billions of light years away, individual stars blur together, and the best we can do is observe the overall spectra of galaxies, not individual stars. But thanks to a chance alignment, we can now observe dozens of stars in a galaxy so distant we see it at a time when the Universe was half its present age.

The results are published in Nature Astronomy, and they focus on JWST observations of a cluster of galaxies known as Abell 370. This galactic cluster is famous because it acts as a gravitational lens for more distant galaxies behind it. You can see them as arcs of light in the image above. One prominent arc, highlighted in the image, is known as The Dragon. It is made up of the lensed and magnified images of several galaxies, the light of which has traveled 5 to 7 billion years to reach us.

The Dragon has been studied before using observations from the Hubble Space Telescope, and from these studies astronomers have been able to see a handful of blue supergiant stars, which are the largest and brightest main sequence stars. But identifying individual stars is notoriously difficult. In this new study, the team used JWST observations of The Dragon from 2022 and 2023. Since the Webb is capable of capturing high-resolution images in the infrared, it’s perfectly suited to study the spectra of redshifted stars in the cosmic middle age.

Individual stars identified in the Dragon arc in 2022 and 2023. Credit: Yoshinobu Fudamoto, et al

But even the Webb would be hard-pressed to identify more than a few bright stars within The Dragon, were it not for a second effect of gravitational lensing known as microlensing. Within the distant galaxy, two stars can line up just so, and the more distant star is gravitationally magnified for a short time, like a flare. This allows astronomers to study the spectra of the distant star. So a galaxy from 7 billion years ago is lensed into a bright arc of light by the Abell 370 cluster, and within that galaxy stars are further microlensed by a stellar alignment.

The team was able to identify more than 40 microlensing events, and was therefore able to capture the spectra of more than 40 individual stars in the distant galaxy. Based on the spectra, these stars are red supergiants similar to Betelgeuse. The study shows that microlensing events such as these are common, so we should be able to see lots more stars in this distant galaxy in the future.

We know a great deal about red supergiants in the Milky Way. Since they are dying stars, red giants play a significant role in enriching the available elements in a galaxy, which determines things such as the formation of stars and even life. But by studying these distant red giants, we will be able to see how they impacted the chemical diversity of younger galaxies. It could even help us understand what the Milky Way was like when the Sun and Earth began to form.

Reference: Yoshinobu Fudamoto, et al. “Identification of more than 40 gravitationally magnified stars in a galaxy at redshift 0.725.” Nature Astronomy (2025).

The post A Dragon Reveals Individual Stars From A Time When the Universe Was Half Its Present Age appeared first on Universe Today.

Many people decide to give up alcohol during January. But is this actually helpful in the long-term and are there better, easier ways to change our drinking habits, asks Ian Hamilton

Simulations suggest Pluto and its largest moon may have gently stuck together for a few hours before Charon settled into a stable orbit around the dwarf planet

A velvet ant sting is like “hot oil spilling over your hand” – now, scientists have identified molecules in its venom that let it deliver excruciating pain to a variety of other animals

The many-worlds interpretation of quantum mechanics invokes alternative realities to keep everything in balance. Has solving a century-old paradox now undermined their existence?

Getting a spacecraft to another star is a monumental challenge. However, that doesn’t stop people from working on it. The most visible groups currently doing so are Breakthrough Starshot and the Tau Zero Foundation, both of whom focus on a very particular type of propulsion-beamed power. A paper from the Chairman of Tau Zero’s board, Jeffrey Greason, and Gerrit Bruhaug, a physicist at Los Alamos National Laboratory who specializes in laser physics, takes a look at the physics of one such beaming technology – a relativistic electron beam – how it might be used to push a spacecraft to another star.

There are plenty of considerations when designing this type of mission. One of the biggest of them (literally) is how heavy the spacecraft is. Breakthrough Starshot focuses on a tiny design with gigantic solar “wings” that would allow them to ride a beam of light to Alpha Centauri. However, for practical purposes, a probe that small will be able to gather little to no actual information once it arrives there—it’s more of a feat of engineering rather than an actual scientific mission.

The paper, on the other hand, looks at probe sizes up to about 1000kg—about the size of the Voyager probes built in the 1970s. Obviously, with more advanced technology, it would be possible to fit a lot more sensors and controls on them than what those systems had. But pushing such a large probe with a beam requires another design consideration—what type of beam?

Fraser discusses how we might get to Alpha Centauri.

Breakthrough Starshot is planning a laser beam, probably in the visible spectrum, that will push directly on light sails attached to the probe. However, given the current state of optical technology, this beam could only push effectively on the probe for around .1 AU of its journey, which totals more than 277,000 AU to Alpha Centauri. Even that minuscule amount of time might be enough to get a probe up to a respectable interstellar speed, but only if it’s tiny and the laser beam doesn’t fry it.

At most, the laser would need to be turned on for only a short period of time to accelerate the probe to its cruising speed. However, the authors of the paper take a different approach. Instead of providing power for only a brief period of time, why not do so over a longer period? This would allow more force to build up and allow a much beefier probe to travel at a respectable percentage of the speed of light. 

There are plenty of challenges with that kind of design as well. First would be beam spread—at distances more than 10 times the distance from the Sun to the EartSunhow would such a beam be coherent enough to provide any meaningful power? Most of the paper goes into detail about this, focusing on relativistic electron beams. This mission concept, known as Sunbeam, would use just such a beam.

Fraser discusses another interstellar probe – Project Dragonfly

Utilizing electrons traveling at such high speeds has a couple of advantages. First, it’s relatively easy to speed electrons up to around the speed of light—at least compared to other particles. However, since they all share the same negative charge, they will likely repel each other, diminishing the beam’s effective push.

That is not as much of an issue at relativistic speeds due to a phenomenon discovered in particle accelerators known as relativistic pinch. Essentially, due to the time dilation of traveling at relativistic speeds, there isn’t enough relative time experienced by the electrons to start pushing each other apart to any meaningful degree.

Calculations in the paper show that such a beam could provide power out to 100 or even 1000 AU, well past the point where any other known propulsion system would be able to have an impact. It also shows that, at the end of the beam powering period, a 1,000kg probe could be moving as fast as 10% of the speed of light – allowing it to reach Alpha Centauri in a little over 40 years.

Multi-stage ships could be the key to interstellar travel – as Fraser discusses.

There are plenty of challenges to overcome for that to happen, though – one of which is how to get that much power formed into a beam in the first place. The farther a probe is from the beam’s source, the more power is required to transmit the same force. Estimates range up to 19 gigaelectron volts for a probe out at 100 AU, a pretty high energy beam, though well within our technology grasp, as the Large Hadron Collider can form beams with orders of magnitude more energy.

To capture that energy in space, the authors suggest using a tool that doesn’t yet exist, but at least in theory could – a solar statite. This platform would sit above the Sun’s surface, using a combination of force from the push of light from the star and a magnetic field that uses the magnetic particles the Sun emits to keep it from falling into the Sun’s gravity well. It would sit as close as the Parker Solar Probe’s closest approach to the Sun, which means that, at least in theory, we can build materials to withstand that heat. 

The beam forming itself would happen behind a massive sun shield, which would allow it to operate in a relatively cool, stable environment and also be able to stay on station for the days to weeks required to push the 1000kg probe out as far as it would go. That is the reason for using a statute rather than an orbit—it could stay stationary relative to the probe and not have to worry about being occluded by the Earth or the Sun.

Fraser discusses interstellar travel with Avi Loeb, a Harvard professor and expert in interstellar travel.

All this so far is still in the realm of science fiction, which is why the authors met in the first place – on the ToughSF Discord server, where sci-fi enthusiasts congregate. But, at least in theory, it shows that it is possible to push a scientifically useful probe to Alpha Centauri within a human lifetime with minimal advances to existing technology.

Learn More:
Greason & Bruhaug – Sunbeam: Near-Sun Statites as Beam Platforms for Beam-Driven Rockets
UT – Researchers are Working on a Tractor Beam System for Space
UT – A Novel Propulsion System Would Hurl Hypervelocity Pellets at a Spacecraft to Speed it up
UT – A Concentrated Beam of Particles and Photons Could Push Us to Proxima Centauri

Lead Image:
Depiction of the electro beam statite used in the study.
Credit – Greason & Bruhaug

The post Pushing A Probe To Alpha Centauri Using A Relativistic Electron Beam appeared first on Universe Today.

How close are we to having fusion reactors actually sending electric power to the grid? This is a huge and complicated question, and one with massive implications for our civilization. I think we are still at the point where we cannot count on fusion reactors coming online anytime soon, but progress has been steady and in some ways we are getting tatalizingly close.

One company, Commonwealth Fusion Systems, claims it will have completed a fusion reactor capable of producing net energy by “the early 2030’s”. A working grid-scale fusion reactor within 10 years seems really optimistic, but there are reasons not to dismiss this claim entirely out of hand. After doing a deep dive my take is that the 2040’s or even 2050’s is a safer bet, but this may be the fusion design that crosses the finish line.

Let’s first give the background and reasons for optimism. I have written about fusion many times over the years. The basic idea is to fuse lighter elements into heavier elements, which is what fuels stars, in order to release excess energy. This process releases a lot of energy, much more than fission or any chemical process. In terms of just the physics, the best elements to fuse are one deuterium atom to one tritium atom, but deuterium to deuterium is also feasible. Other fusion elements are simply way outside our technological capability and so are not reasonable candidates.

There are also many reactor designs. Basically you have to squeeze the elements close together at high temperature so as to have a sufficiently high probability of fusion. Stars use gravitational confinement to achieve this condition at their cores. We cannot do that on Earth, so we use one of two basic methods – inertial confinement and magnetic confinement. Inertial confinement includes a variety of methods that squeeze hydrogen atoms together using inertia, usually from implosions. These methods have achieved ignition (burning plasma) but are not really a sustainable method of producing energy. Using laser inertial confinement, for example, destroys the container in the process.

By far the best method, and the one favors by physics, is magnetic confinement. Here too there are many designs, but the one that is closest to the finish line (and the one used by CFS) is called a tokamak design. This is torus shaped in a specific way to control the flow of plasma just so to avoid any kind of turbulence that will prevent fusion.

In order to achieve the energies necessary to create sustained fusion you need really powerful magnetic fields, and the industry has essentially been building larger and larger tokamaks to achieve this. CFS has the advantage of being the first to design a reactor using the latest higher temperature superconductors (HTS), which really are a game changer for tokamaks. They allow for a smaller design with more powerful magnets using less energy. Without these HTS I don’t think there would even be a question of feasibility.

CFS is currently building a test facility called the SPARC reactor, which stands for the smallest possible ARC reactor, and ARC in turn stand for “affordable, robust, compact”. This is a test facility that will not be commercial. Meanwhile they are planning their first ARC reactor, which is grid commercial scale, in Virginia and which they claim will produce 400 Megawatts of power.

Reasons for optimism – the physics all seems to be good here. CFS was founded by engineers and scientists from MIT – essentially some of the best minds in fusion physics. They have mapped out the most viable path to commercial fusion, and the numbers all seem to add up.

Reasons for caution – they haven’t done it yet. This is not, at this point, so much a physics problem as an engineering problem. As they push to higher energies, and incorporate the mechanisms necessary to bleed off energy to heat water to run a turbine, they may run into problems they did not anticipate. They may hit a hurdle that will suddenly throw 10 or 20 years into the development process. Again, my take is that the 2035 timeline is if everything goes perfectly well. Any bumps in the road will keep adding years. This is a project at the very limits of our technology (as complex as going to the Moon), and delays are the rule, not the exception.

So – how close are they? The best so far is the JET tokamak reactor which produced 67% of net energy. That sounds close, but keep in mind, 100% is break even. Also – this is heat energy, not electricity. Modern fission reactors have about a 30% efficiency in converting heat to electricity, so that is a reasonable assumption. Also, this is fusion energy efficiency, not total energy. This is the energy that goes into the plasma, not the total energy to run the reactor.

The bottom line is that they probably need to increase their energy output by an order of magnitude or more in order to be commercially viable. Just producing a little bit of net energy is not enough. They need massive excess energy (meaning electricity) in order to justify the expense. So really we are no where near net total energy in any fusion design. CFS is hoping that their fancy new HTS magnets will get them there. They actually might – but until they do, it’s still just an informed hope.

I do hope that my pessimism, born of decades of overhyped premature tech promises, is overcalling it in this case. I hope these MIT plasma jocks can get it done, somewhere close to the promised timeline. The sooner the better, in terms of global warming. Let’s explore for a bit what this would mean.

Obviously the advantage of fusions reactors like the planned ARC design if it works is that it produces a lot of carbon-free energy. They can be plugged into existing connections to the grid, and produce stable predictable energy. They produce only low level nuclear waste. They also have a relatively small land footprint for energy produced. If the first ARC reactor works, we would need to build thousands around the world as fast as possible. If they are profitable, this will happen. But the industry can also be supported by targeted regulations. Such reactors could replace fossil fuel-based reactors, and then eventually fission reactors.

Once we develop viable fusion energy, it is very likely that this will become our primary energy source literally forever. At least for hundreds if not thousands or tens of thousands of years. It gets hard to predict technology that far out, but there are really no candidates for advanced energy sources that are better. Matter-antimatter theoretically could work, but why bother messing around with antimatter, which is hard to make and contain. The advantage is probably not enough to justify it. Other energy sources, like black holes, are theoretically and extremely exotic, perhaps something for millions of years advanced beyond where we are.

Even if some really advanced energy source becomes possible, fusion will likely remain in the sweet spot in terms of producing large amounts of energy cleanly and sustainable. Once we cross the line to being able to produce net total electricity with fusion, incremental advances in material science and the overall technology will just make fusion better. From that point forward all we really need to do is make fusion better. There will likely still be a role for distributed energy like solar, but fusion will replace all centralized large sources of power.

The post Plan To Build First Commercial Fusion Reactor first appeared on NeuroLogica Blog.

From carbon emissions to the share prize of videoconferencing firm Zoom, these graphs tell the story of how the covid-19 pandemic changed everything

From Cory Doctorow to Nnedi Okorafor and from fancy space opera to elegantly written visions of a flooded future world, there is plenty of great science fiction published this month

Deep sediments under Arctic lakes could release large amounts of carbon dioxide and methane, adding to the threat of runaway climate change

Smartphones, electric vehicles and wind turbines rely on environmentally destructive rare earth mining operations. Harnessing electric fields could make this mining more sustainable

A proponent of the Great Barrington Declaration is comparing rejection of its "natural herd immunity" approach to the pandemic to the rejection of Ignaz Semmelweis and his findings. It's a deceptive comparison beloved of all manner of scientific cranks.

The post The Semmelweis gambit: A red flag for defending bad science and quackery first appeared on Science-Based Medicine.

Between NASA, other space agencies, and the commercial space sector, there are some truly ambitious plans for humanity’s future in space. These plans envision the creation of permanent infrastructure on and around the Moon that will enable a permanent human presence there, complete with research, science, and commercial operations. They also call for the first crewed missions to Mars, followed by the creation of surface habitats that will allow for return visits. These plans present many challenges, ranging from logistical and technical issues to health and human safety.

Another challenge is coordinating operations across the lunar surface with those in orbit and back at Earth, which requires a system of standardized time. In a recent study, a team of NASA researchers developed a new system of lunar time for all lunar assets and those in cis-lunar space. They recommend that this system’s foundation be relativistic time transformations, known more generally as “time dilation.” Such a system will allow for coordination and effective timekeeping on the Moon by addressing discrepancies caused by gravitational potential differences and relative motion.

The study was conducted by Slava G. Turyshev, James G. Williams, Dale H. Boggs, and Ryan S. Park, four research scientists from NASA’s Jet Propulsion Laboratory (JPL). The preprint of their paper, “Relativistic Time Transformations Between the Solar System Barycenter, Earth, and Moon,” recently appeared online and is currently being reviewed for publication in the journal Physical Review D.

In this illustration, NASA’s Orion spacecraft approaches the Gateway in lunar orbit. Credits: NASA

Relativistic time transformations (RTT), as predicted by Lorentz Transformations and Einstein’s Special Theory of Relativity (SR), describe how the passage of time slows for the observer as their reference frame accelerates. When Einstein extended SR to account for gravity with his theory of General Relativity (GR), he established how acceleration and gravity are essentially the same and that the flow of time changes depending on the strength of the gravitational field. This presents a challenge for space exploration, where spacecraft operating beyond Earth are subject to acceleration, microgravity, and lower gravity.

As Turyshev told Universe Today via email, RTT will become a major consideration as humans begin operating on the Moon for extended periods of time:

“[RTT] account for how time flows differently depending on gravitational potential and motion. For example, clocks on the Moon tick slightly faster than those on Earth due to the weaker gravitational pull experienced at the Moon’s surface. Though these differences are small—on the order of microseconds per day—they become significant when coordinating space missions, where even a tiny timing error can translate to large positional inaccuracies or communication delays. In space exploration, precise timing is critical. Various time scales serve different roles, depending on the frame of reference.”

In their paper, the team identified three major timescales that come into play. They include:

• Terrestrial Time (TT): this timescale is used for Earth-based systems, representing time at mean sea level with corrections for Earth’s gravitational potential.
• Barycentric Coordinate Time (TCB): the time coordinate in the Barycentric Celestial Reference System (BCRS), centered at the Solar System barycenter. TCB accounts for relativistic effects due to both gravitational potentials and the motion of bodies relative to the barycenter, making it essential for high-precision modeling of celestial mechanics and dynamics.
• Barycentric Dynamical Time (TDB): derived from TCB but adjusted to run at the same average rate as Terrestrial Time (TT), this adjustment prevents a long-term secular drift relative to TT, ensuring that ephemerides remain consistent with Earth-based observations over long periods.

Illustration of NASA astronauts on the lunar South Pole. Mission ideas we see today have at least some heritage from the early days of the Space Age. Credit: NASA

“Relativistic corrections link these time scales, ensuring consistent timekeeping for spacecraft navigation, planetary ephemerides, and communication,” added Turyshev. “Without such corrections, spacecraft trajectories and mission timings would quickly become unreliable, even at relatively short distances.”

NASA’s Artemis Program includes multiple elements operating in cislunar space and on the lunar surface around the south pole region. These include the orbiting Lunar Gateway, multiple Human Landing Systems (HLSs), and the Artemis Base Camp – which will consist of the Lunar Terrain Vehicle (LTV), the Habitable Mobility Platform (HMP), and the Foundation Surface Habitat (FSH). In addition, the ESA plans to create its Moon Village, consisting of multiple transportation, power, and in-situ resource utilization (ISRU) elements.

China and Russia also have plans for a lunar habitat around the Moon’s south pole region, known as the International Lunar Research Station (ILRS). Based on multiple statements, this station could include a surface element (possibly in a lava tube), an orbital element, and other elements similar to the Artemis Base Camp and Moon Village. These will be followed and paralleled by commercial space interests, which could include harvesting, mining, and even tourism. And, of course, these operations must remain in contact with mission control as the Moon orbits the Earth.

As lunar exploration accelerates, says Turyshev, defining a dedicated Lunar Time (LT) scale and a Luni-centric Coordinate Reference System (LCRS) becomes increasingly important. Hence, he and his colleagues developed a TL scale to ensure precise timekeeping for activities on and around the Moon. Their approach involves applying relativistic principles used for Earth and adapting them to the Moon’s environment, including:

1. Weaker gravity on the Moon leads to a faster tick rate for lunar clocks than Earth clocks.
2. The Moon’s motion around Earth and the Sun introduces periodic time variations.
3. Local gravitational anomalies, known as mascons, subtly influence the Moon’s gravitational field and, thus, the flow of time.

Habitats grouped on the rim of a lunar crater, known as the Moon Village. Credit: ESA

“Our results show that lunar time drifts ahead of Earth time by about 56 microseconds per day, with additional periodic variations caused by the Moon’s orbit,” said Turyshev. “These periodic oscillations have an amplitude of around 0.47 microseconds, occurring over a period of approximately 27.55 days.”

To derive these transformations, Turyshev and his team relied on high-precision data from NASA’s Gravity Recovery and Interior Laboratory (GRAIL) mission, twin satellites that studied the Moon between 2011 and 2021. In addition to mapping the lunar surface, the twin satellites also mapped the Moon’s gravitational field in fine detail. This was combined with measurements made by Lunar Laser Ranging (LLR) experiments, which measure the Earth-Moon distance with millimeter-level precision. Said Turyshev:

“Using this data, we modeled the Moon’s gravitational potential and orbital dynamics, ensuring sub-nanosecond accuracy in the resulting time transformations. Key constants were introduced to describe the transformations, analogous to those used for Earth-based time systems. The most critical of these constraints are:

• LL, which represents the average rate of time transformation between the Moon’s center and its surface, compensating for the combined gravitational and rotational potential at the selenoid level.
• LM, analogous to LB for Earth, compensates for the average rate in time transformation between Barycentric Coordinate Time (TCB) and Lunar Time (TL).
• LH, representing the long-time average of the Moon’s total orbital energy in its motion around the solar system barycenter. It defines the rate difference between TCB and the luni-centric coordinate system time (TCL) and includes contributions from gravitational interactions with the Sun and planets.
• LEM, which represents the long-time average of the Moon’s total orbital energy in its motion around Earth, as observed from the Geocentric Celestial Reference System (GCRS).
• PEM, which accounts for periodic relativistic corrections arising from the Moon’s elliptical orbit and gravitational perturbations by the Sun and planets, resulting in time-dependent oscillations.

“These transformations form the basis of our highly accurate lunar timekeeping system, which is crucial for future mission planning and operations.”

Visualization of the ILRS, from the CNSA Guide to Partnership (June 2021). Credit: CNSA

As Turyshev and his colleagues establish in their paper, there are many reasons why creating a unified lunar time system is essential for mission success. These include:

1. Precision Navigation and Landing: With numerous missions targeting the lunar surface, from orbiters to landers and rovers, synchronized timekeeping will ensure precise positioning and reduce the risk of errors during critical mission phases.
2. Seamless Communication: Coordinating activities between Earth, orbiters, and lunar bases requires consistent time synchronization to avoid communication delays and ensure the correct ordering of data transmission.
3. Collaborative Science: A common time standard enables multiple missions—conducted by different space agencies and organizations—to share and compare data accurately, supporting large-scale studies of lunar geology, seismic activity, and gravitational anomalies.
4. Autonomous Operations: As lunar missions grow in complexity and duration, a dedicated lunar time system will allow bases and spacecraft to operate independently from Earth, reducing dependence on Earth-based timekeeping during periods when Earth is not visible. 

New systems of timekeeping are one of many adaptations that humanity must make to become an interplanetary species. A coordinated system of lunar time will become increasingly important as humanity’s presence on the Moon grows and becomes permanent in this century. Similar measures will need to be taken once regular crewed missions to Mars begin, and those efforts have already begun in earnest! Check out Mars Coordinated Time (MCT) and the Darian Calendar to learn more.

Further Reading: arXiv

The post If We Want to Live on Other Worlds, We're Going to Need New Clocks appeared first on Universe Today.

I’ve often said that if I could have been any rock star, it would have been Stephen Stills. Well, make that any American rock star, for if I could chose one musician from around the world, it would be Paul McCartney. Both men were incredibly handsome, a prerequisite for my fantasy, but more important, both were immensely talented, able to write great songs, sing wonderfully, and play a number of instruments with dexterity. It’s just that McCartney produce a greater variety of music, and overall better music, than did Stills.

But Stills, who celebrated his 80th birthday on January 3, remains underrated. His greatest years were with Buffalo Springfield, as well as with Crosby, Nash (and somtimes Neil Young), but I will put up a few songs that he wrote and played on his own or with other groups.

First comes one of my favorite Stills songs, “4 + 20,” which did appear on a CS&N album, but is solely the work of Stills. He was indeed 24 when he wrote it, a remarkable achievement for someone that young. I loved it so much that I taught myself to play it back when I played acoustic guitar and did three-finger picking. Wikipedia says this:

Stills stated: “It’s about an 84-year-old poverty stricken man who started and finished with nothing.” However, the lyrics state that the narrator was born 24 years ago, making him about a year younger than Stills was when the song was recorded.

. . . . Stills recorded the song in one take and planned to use it on his upcoming debut solo album, but when his bandmates heard it, they implored him to use it on the Déjà Vu album. He planned to have bandmates David Crosby and Graham Nash sing harmony parts, but they refused. “They told me they wouldn’t touch it,” said Stills. “So it always stood alone.” On the highly-collaborative Déjà Vu album, “4 + 20” stands out as the only song which was both written and performed solo by one member of the band, justified by Crosby who recalled “We just said, ‘It’s too damn good, we’re not touching it.”)

Here he sings and plays it on the Dick Cavett show, and you might recognize Joni Mitchell beside him as well as David Crosby sitting nearby.  The lyrics are slightly different from the recorded version (here), as Stills seems to forget the one line: “And he wasn’t into selling door to door.”

In this part of his life, Stills was also into wearing ponchos.

“Do for the others” is remarkable in that the entire song—all the vocals and instrumentation—was performed by Stills. (he also wrote it). It’s from his first solo album, the 1970 Stephen Stills. All that Wikipedia says about it is this:

“Do For the Others” was written for David Crosby about the death of his girlfriend Christine Hinton.

Below we have the song “It doesn’t matter” from the 1972 Manassas album, by a group in which he shared guitar leads with former Byrd Chris Hillman.  I wanted to put up a live version of another great song from that album, “So begins the task,” but I couldn’t find a live version. You can hear the recorded version here.

The song is clearly about a lost love, and that love is apparently Judy Collins, with whom Stills had a torrid relationship. One site says this:

[Stills] wrote the song about his breakup with Judy Collins; that same lost romance was fodder for “Suite: Judy Blue Eyes” and “You Don’t Have to Cry.” “So Begins the Task” is believed the first song Stills wrote about/for Collins.

“Suite: Judy Blue Eyes” is one of Stills’s best songs, sung on the 1969 album “Crosby, Stills & Nash” (original recording here). But here are CS&N doing it live, and it’s a very good version, showing the harmony that made the group famous (they first sang together at a party at Joni Mitchell’s home in 1968).

Here’s a translation of the Spanish lyrics at the song’s end:

How happy it makes me to think of Cuba,
the smiles of the Caribbean Sea,
Sunny sky has no blood, and how sad that
I’m not able to go
Oh go, oh go go

What a great tribute to Judy!

Finally, Blonde in the Bleachers,” an underrated song by Joni Mitchell from her great 1972 album “For the Roses.” On this song Stills plays the bass and drums.  The two never had a romance, but did work together a few times.  My theory (which is mine) is that Mitchell wrote the song about Stills and his groupies.

The Atlantic has waded into perilous waters by publishing what turns out to be quite a good article about transgender women competing in athletics against biological women. The fact that this liberal and prestigious magazine even writes about the issue is, to me, a good sign: a sign that the issue needs discussing.  And I’m glad to see that the author, staff writer Helen Lewis, concludes with a solution that is virtually identical to mine.

To read her piece, click below, or find it archived here.

Lewis begins by citing recent controversies involving transgender women competing—and winning—against biological women. They include the now well-known story of Lia Thomas, who will swim no more against women, as well as the San Jose State women’s volleyball team, which included what seemed to be a trans woman (they won’t publicly admit it, but most team members do). This story isn’t as well known:

In September, the San Jose State co-captain Brooke Slusser and the associate coach Melissa Batie-Smoose went public with their concerns about their own team’s trans player. “Safety is being taken away from women,” Batie-Smoose later told Fox News. “Fair play is taken away from women.” Both women told Quillette that they believed players and coaches were being pressured not to make a fuss. The next month, Liilii told me, she and her Nevada teammates voted, 16–1, to boycott their next match against San Jose State. The Nevada players were not alone: Teams from Boise State, the University of Wyoming, Southern Utah, and Utah State also forfeited games rather than face the trans player.

 

San Jose State kept competing despite all that—and despite a lawsuit aimed at barring the school from the Mountain West Conference postseason tournament in Las Vegas in November. (The lawsuit failed, and the team finished second in the finals.) The season ended in acrimony. “I will not sugarcoat our reality for the last two months,” San Jose State’s head coach, Todd Kress, said in a statement after the tournament. “Each forfeiture announcement unleashed appalling, hateful messages individuals chose to send directly to our student-athletes, our coaching staff, and many associated with our program.” Afterward, seven of the team’s athletes requested to enter the transfer portal. The disputed player, who is a senior, will not compete again.

 

The problem is, as the references below show, trans women who go through male puberty retain substantial athletic advantages over biological women, even if testosterone suppressors are used to try to equalize the categories.  But the suppressors don’t do that, for somebody who goes through male puberty develops the musculature, bone density, grip strength, and other indices of athletic success that give them pronounced advantages over natal women (equestrian sports may be an exception).  And this advantage appears to last for years—perhaps forever.

Well, why not allow trans women to compete who have transitioned before puberty? The problem is that there are almost none of these, for male puberty occurs some time between ages 9 and 14, and that is simply too young for adolescent males to decide to take hormones and/or have surgery to develop something closer to a woman’s body. If future research shows that transitioning at a very young age makes females athletically equal on average to natal females, then we can reassess. But existing data show that trans women, or some with disorders of sex determination, have an innate athletic advantage over women, and thus shouldn’t be competing in women’s sports.

Republicans have made hay of this, of course, and if you polled Democrats versus Republicans over whether trans women should compete against natal women in sports, Republicans would say “no” at a higher rate. But just because this view is more pervasive in the GOP doesn’t mean it’s wrong. In fact, Democrats themselves are starting to realize that such competition is unfair:

Greater awareness of Thomas and other trans athletes in women’s sports did not translate into greater approval. If anything, the opposite occurred: In 2021, 55 percent of Democrats supported transgender athletes competing in the team of their chosen gender, according to Gallup. Two years later, however, that number had fallen to 47 percent. Overall, nearly seven out of 10 Americans now think athletes should compete in the category of their birth sex.

Nevertheless, the Biden Administration’s early executive order prohibiting discrimination on the basis of gender identity implied that this would also hold for sports participation. Now, as Lewis notes, Biden has backed off on this construal of the order, perhaps because the wokeness of Harris and Biden (the subject of GOP attack ads) may have played a role in their November defeat.

Regardless, as I’ve learned in the past week or so, those who say that “trans women are women” will accept no exceptions to that mantra: trans women are to have every perquisite of natal women, including sports participation.  But, unlike gay rights, trans rights conflict with the rights of other groups far more often (I can’t think of any case in which gay rights conflict with other people’s rights, except for those cases of religious people asked to make cakes for gay weddings). The last sentence in Lewis’s paragraph below is telling (I’ve bolded it):

“People like to say that it’s a complicated issue, and I don’t actually think it is … It all boils down to: Do you actually think that trans women and intersex women are real women—and are really female or not?” the transgender cyclist Veronica Ivy told The Daily Show’s Trevor Noah in 2022. “It’s an extreme indignity to say, ‘I believe you’re a woman, except for sport.’” She added that the enforcement of traditional categories was about “protecting the fragile, weak cis white woman from the rest of us.” Noah’s studio audience in New York heartily applauded Ivy’s words. Sports was only one part of a seamless whole: If you believed, as good liberals did, that trans women were women, no carve-outs were justifiable.

Many women and men think otherwise, as do I. But the carve-outs, as I see them, are very few. Still, if you’re a extremist gender ideologue, they are impermissible.

Democrat Seth Moulton’s breaking ranks from the Biden-ish gender ideology may have been a telling moment, as it made it acceptable for Democrats to discuss the issue in public, though many, including the FFRF, appear to still think the issue shouldn’t be discussed, much less raised. Moulton still got savaged, of course, which reflects poorly on his fellow Democrats:

After the 2024 election, a handful of Democrats broke ranks. “I have two little girls,” Representative Seth Moulton of Massachusetts told The New York Times. “I don’t want them getting run over on a playing field by a male or formerly male athlete.” His campaign manager subsequently resigned, protesters gathered outside one of his offices, and he was rebuked by the state’s Democratic governor. But many of Moulton’s fellow Democrats were notably silent. “Asked for comment on Mr. Moulton’s remarks, each of the 10 other members of the state’s congressional delegation, all Democrats, declined to comment or did not immediately respond,” the Times reported. Further evidence that a taboo had been broken came on the Friday before Christmas. The White House abandoned its proposed rule change forbidding blanket bans on trans athletes after 150,000 public responses, acknowledging that the incoming Trump administration will set its own rules.

Lewis is too good a writer not to give her own opinion after weighing the controversy. At the end, she suggests the “empathic compromise” given below, and I must say that I agree with almost every word of it:

In my view, the way forward lies in an empathetic compromise, one that broadly respects transgender Americans’ sense of their own identity—for example, in the use of chosen names and pronouns—while acknowledging that in some areas, biology really matters. Many sports organizations have established a protected female category, reserved for those who have not experienced the advantages conferred by male puberty, alongside an open one available to men, trans women, trans men taking testosterone supplements, and nonbinary athletes of either sex. Unlike Veronica Ivy, many voters who support laws protecting trans people from housing and employment discrimination don’t see trans rights as an all-or-nothing deal; in fact, a few limited carve-outs on the basis of biological sex might increase acceptance of gender-nonconforming people overall.

Not everything has to be an entrenched battle of red versus blue: As more and more Democrats realize that they shouldn’t have built their defense of trans people on the sand of sex denialism, Republicans should have the grace to take the win on sports and disown the inflammatory rhetoric of agitators such as Representative Nancy Mace, who responded to the election of the first trans member of Congress by deploying anti-trans slurs. As the second Trump administration begins, the lesson from the college-volleyball rebellion is that institutions cannot impose progressive values by fiat. Attempts at social change will not survive without the underlying work of persuasion.

My only beef with the above is that it may be dangerous to trans men or “nonbinary athletes of either sex” to compete against biological men, as the greater strength of the latter could be dangerous. This is probably why World Rugby, as well as the International Rugby League, have banned the participation of transgender women in international competitions, presumably because although they are biological men, suppressing testosterone could reduce their ability to withstand injury in this heavy-contact sport.

The athletic effects of testosterone suppression in males:

An opinion piece by Robyn Blumner in Skeptical Inquirer cites references I’ve mentioned before, showing that testosterone suppression isn’t a way to equalize the athletic performance of transgender women and natal women. As she writes:

If we eliminated sex categories for most sports, there would rarely be female winners. For natal women to be able to compete in a way that gives them a fair chance at victories, there have to be sex segregated sports.

The question then becomes whether that advantage can be mitigated through testosterone suppression. That is a matter of scientific inquiry, and the longitudinal biomedical findings to date suggest that “the effects of testosterone suppression in male adulthood have very little impact” on physiological outcomes such as muscle strength, muscle mass, or lean body mass, according to a paper titled “When Ideology Trumps Science” by six international leading researchers (Devine et al. 2022). They cite a cross-sectional study from 2022 that measured the performance of transgender women and found the “advantage may be maintained after 14 years of testosterone suppression.” (For a thorough vetting of the subject, read “Transgender Women in the Female Category of Sport: Perspectives on Testosterone Suppression and Performance Advantage” by researchers Emma Hilton and Tommy Lundberg, published in the journal Sports Medicine [Hilton and Lundberg 2021].)

References:

Devine, Cathy, Emma Hilton, Leslie Howe, et al. 2022. When ideology trumps science: A response to the Canadian Centre for Ethics in Sport’s Review on Transwomen Athletes in the Female Category. idrottsforum.org (November 29).

Hilton, Emma N., and Tommy R. Lundberg. 2021. Transgender women in the female category of sport: Perspectives on testosterone suppression and performance advantage. Sports Medicine 51(2): 199–214.

Today is Sunday, and so we are blessed with another batch of photos by biologist John Avise, who is sending butterflies now. John’s comments and IDs are indented, and you can enlarge his photos by clicking on them.

Butterflies in North America, Part 5 

This week continues my many-part series on butterflies that I’ve photographed in North America.  I’m continuing to go down my list of species in alphabetical order by common name.

Clouded Skipper (Lerema accius):

Clouded Skipper underwing:

Clouded Sulphur (Colias philodice):

Clouded Sulphur underwing:

Cloudless Sulphur (Phoebis sennae):

Common Buckeye (Junonia coenia), dark version:

Common Buckeye, light version:

Common Buckeye underwing:

Common Wood-Nymph (Cercyonis pegala):

Compton Tortoiseshell (Nymphalis vaualbum):

Coral Hairstreak (Satyrium titus):

Dainty Sulphur (Nathalis iole):