News Feeds

Thanks to nanoscale devices as small as human cells, researchers can create groundbreaking material properties, leading to smaller, faster, and more energy-efficient electronics. However, to fully unlock the potential of nanotechnology, addressing noise is crucial. A research team has taken a significant step toward unraveling fundamental constraints on noise, paving the way for future nanoelectronics.

Thanks to nanoscale devices as small as human cells, researchers can create groundbreaking material properties, leading to smaller, faster, and more energy-efficient electronics. However, to fully unlock the potential of nanotechnology, addressing noise is crucial. A research team has taken a significant step toward unraveling fundamental constraints on noise, paving the way for future nanoelectronics.

Physicists on the CMS experiment announce the most elaborate mass measurement of a particle that is notoriously difficult to study and has captivated the physics community for decades.

Understanding the relationship between plasticity of muddy soil and earth pressure can be crucial to maintaining tunnel stability and predicting ground behavior during earth pressure balance (EPB) shield tunnelling, a common underground excavation method. Researchers developed small-scale model experimentation combined with moving particle simulation-based computer-aided engineering analysis that reliably predicted soil's plasticity and its correlating factors without having to deal with the cost and time of on-ground field analysis.

Watching for changes in Mars' orbit over time could be new way to detect passing dark matter, according to researchers.

With the help of NASA's Hubble Space Telescope, an international team of scientists has found more black holes in the early universe than has previously been reported. The new result can help scientists understand how supermassive black holes were created.

Cultural values and traditions differ across the globe, but large language models (LLMs), used in text-generating programs such as ChatGPT, have a tendency to reflect values from English-speaking and Protestant European countries. A research team believes there is an easy way to solve that problem.

In a new paper, physicists argue that close observations of merging black hole pairs may unveil information about potential new particles.

In a new paper, physicists argue that close observations of merging black hole pairs may unveil information about potential new particles.

Van Gogh's brushstrokes in 'The Starry Night' create an illusion of sky movement so convincing it led researchers to wonder how closely it aligns with the physics of real skies. Marine sciences and fluid dynamics specialists analyzed the painting to uncover what they call the hidden turbulence in the artwork. They used brushstrokes to examine the shape, energy, and scaling of atmospheric characteristics of the otherwise invisible atmosphere and used the relative brightness of the varying paint colors as a stand-in for the kinetic energy of physical movement.

Billions of dollars of observatory spacecraft orbit around Earth or in the same orbit as our planet. When something wears out or goes wrong, it would be good to be able to fix those missions “in situ”. So far, only the Hubble Space Telescope (HST) has enjoyed regular visits for servicing. What if we could work on other telescopes “on orbit”? Such “fixit” missions to other facilities are the subject of a new NASA paper investigating optimal orbits and trajectories for making service calls on telescopes far beyond Earth.

Some of the most productive orbiting telescopes operate at the Sun-Earth Lagrange points L1 and L2. Currently, those positions afford us some very incredible science. What they can’t afford is easy access for repairs and servicing. That limits the expected lifetime of facilities such as JWST to about 10-15 years. In the future, more missions will be deployed a Lagrange points. These include the Nancy Grace Roman Telescope, ESA’s PLATO and ARIEL missions, and the Large Ultraviolet Optical Infrared Surveyor (LUVOIR).

Artist’s impression of the Nancy Grace Roman Space Telescope, named after NASA’s first Chief of Astronomy. This spacecraft will orbit at SEL2, far from Earth. Credits: NASA

These observatories need propellants for attitude thrusters to help them stay ‘in place’ during their observations. There’s only so much “gas” you can send along with these observatories. In addition, components wear out, as they did with HST. So, people are looking at ways to extend their lifetimes through servicing missions. If failing components can be replaced and propellant delivered, the lifetimes of these observatories should be extended quite a bit, giving astronomers more bang for the observational buck.

Planning Future Spacecraft Servicing Missions

Researchers at the Satellite Servicing Capability Office (SSCO) at the Goddard Space Flight Center (GSFC) investigated the possibilities for servicing missions to distant space telescopes. In a recently released paper, they focus on the feasibility of on-orbit refueling missions for space telescopes orbiting at Sun-Earth Lagrange 2 (SEL2).

There are many challenges. For one thing, present-day launch technologies are (at this writing) inadequate to do that kind of mission at such distances. Clearly, the technology has to advance for servicing visits to take place. In addition, it’s important to remember that current telescopes, such as Gaia and JWST, weren’t designed for such access. However, future telescopes can be fitted with servicing ports, etc. to enable servicing. Finally, there are the challenges of actually getting the servicing missions to the observatories.

Illustration of OSAM-1 (bottom) grappling Landsat 7. This servicing mission concept was discontinued by NASA, but remains a good example of what’s needed to perform repairs and refueling to orbiting spacecraft. Credits: NASA

The Goddard team focused on this final issue by computing models of various launch and orbital solutions for such missions. Not only did they take into account the launch trajectories themselves, but also Sun-Earth-Lagrange point dynamics, plus the relative positions of observatories at SEL2. In addition, the team considered the stability of the observatories during and after rendezvous and attachment. All of these factors count when planning whether or not a servicing vehicle can be launched at a reasonable cost to extend the lifetime of the observatory enough to make the effort worth the time and expense.

Getting a Spacecraft Refuelling Mission Underway

The team created models for a theoretical mission for on-orbit fuelling at SEL2. That’s where JWST and Gaia are sitting, for example, along with WMAP, Planck, and others. The paper examines robotic refueling missions out to SEL2 for modeling purposes.

To do that, however, there must be an optimal trajectory for the robotic spacecraft to take out to SEL2. They need to be able to perform autonomous navigation to the correct point in space. Once at the target observatory, the refueling robot would then need to make a careful approach for its docking maneuvers. That requires on-orbit assessment of the target’s motion in space with respect to the Sun as well as its position in its SEL2 orbit. Docking itself can affect the observatory’s position and motion and the robot needs to take that into account, as well. The idea is to keep the observatory in the same position after docking.

However, the big question is: how do we get it out there inexpensively, fast, and safe?

The Goddard team primarily investigated the best and most efficient trajectories to get to SEL2. In particular, they looked at the best approaches to get to the Gaia spacecraft, which will run out of its propellant sometime in the next year. They also examined JWST as a possible target for such a mission. If such a mission was possible today, those observatories would gain years of “point and shoot” access to the Universe.

How to Get There

In their paper, the team looks at two approaches to the SEL2 refueling mission. One is a direct launch trajectory from Earth and the other is a spacecraft leaving from a geostationary transfer orbit (GTO). They assumed that the point of the mission was the fastest possible restoration of telescope operation. That dictates the shortest and safest possible trajectory along which the spacecraft can maintain constant thrust.

The Goddard team created a “forward design” approach for computing low-energy and low-thrust transfers from an Earth departure orbit to a space telescope orbiting the SEL2 point. Then they did the same for a servicing spacecraft leaving from a point in geostationary space. Essentially, either an Earth-departure or GTO-centric departure will work. Once the robotic servicing mission leaves Earth orbit, it travels at low thrust during a spiraling transit to SEL2. Once there, it does a rendezvous with the target, matches its motion in space, and then “locks on” to perform its delivery mission.

It’s important to remember that a launch from Earth or GTO is part of several solutions to SEL2 servicing missions. The team’s analysis resulted in a simplified process of generating possible orbits and trajectories for such activities. You can read the full text of their detailed analysis of the different trajectory solutions at the link below.

For More Information

Mission Design for Space Telescope Servicing at Sun-Earth L2
JWST Home Page
Gaia Telescope

The post There Could be a Way to Fix Spacecraft at L2, Like Webb and Gaia appeared first on Universe Today.

Maternity services need to educate parents-to-be on how pregnancy will affect their brain - their life could depend on it, says Helen Thomson

Echolocating bats can more easily find and pollinate long-stemmed flowers that stand out from the surrounding foliage, which may be why this floral trait evolved

Snoring is often viewed as harmless, at least to the snorer, but we are now uncovering its potentially serious effects on cardiovascular health. And finding ways to stop is surprisingly challenging

Astronomers have observed three types of black holes in the Universe. Stellar-mass black holes formed from the collapse of a massive star, intermediate mass black holes found in some star clusters, and supermassive black holes that lurk in the centers of galaxies. But there is a fourth type that remains hypothetical an unobserved. Known as primordial black holes, they are thought to have formed from tiny fluctuations in the hot and dense early cosmos. Since they wouldn’t have formed from stars or mergers, they could have a much smaller mass. And with small masses, primordial black holes would be tiny. Their event horizons would be smaller than an apple, perhaps as small as a grain of sand. You can see why they would be hard to find.

If they exist, these dustmote singularities would be a perfect candidate for dark matter. This is not a new idea. Observations of dark matter have ruled out stellar-mass black holes and even planet-mass ones, but they haven’t quite ruled out primordial black holes. So they are a possible explanation for dark matter, but how would we prove it? A new study on the arXiv tries to find out.

Observational constraints on primordial black holes over various mass ranges. Credit: M. Cirelli (2016)

The authors begin by noting that if dark matter really is composed of primordial black holes, then they must be clustered around regular matter in the way dark matter does. There must be a halo of tiny black holes surrounding the Milky Way, and there must be primordial black holes scattered throughout our solar system. The gravitational pull of these tiny black holes should therefore affect the motion of planets, asteroids, and comets in detectable ways. Previous searches turned up nothing, but the authors wanted to know whether the effect would be significant enough to observe with our current technology.

So they ran several computer simulations to calculate the size of the effect. Since the gravitational pull of a single black hole would be tiny, the team looked at how nearby encounters would shift the orbits of solar system bodies. We describe orbital motion by ephemerides tables, so they used simulations to determine how the ephemerides would change over time. What they found was that even if we took a decade’s worth of ephemerides observations, the effect of primordial black holes would be an order of magnitude smaller than the limits of observation. In other words, even if primordial black holes exist their effect is way too tiny to observe in our solar system.

While the result is a bit disappointing, it does contradict a few studies that argue current observations rule out primordial black holes as dark matter. Though they are an unlikely solution to this cosmic mystery, they are still in the game.

Reference: Thoss, Valentin, and Andreas Burkert. “Primordial Black Holes in the Solar System.” arXiv preprint arXiv:2409.04518 (2024).

The post Could We Find Primordial Black Holes in the Solar System? appeared first on Universe Today.

Saturn is well known for its ring system and many recognise that the planets Jupiter, Uranus and Neptune also have rings. Did Earth ever have rings though? A team of researchers suggests that a worldwide collection of impact craters points to the existence of a ring around Earth millions of years ago. It’s possible that Earth captured and destroyed an asteroid that passed too close 466 million years ago. The asteroids torn up debris orbited the Earth as a ring and then the individual chunks entered the atmosphere, landed on the surface and produced the craters observed today. 

Seeing the rings of Saturn against an inky black sky are the very things that grabbed my attention as a ten year old boy. Since then I have been fascinated by all things space. The rings of Saturn, and Jupiter, Uranus and Neptune are made up of a collection of lumps of ice and rock all orbiting around the host planet in the same way our Moon orbits around the Earth. Collectively, and from a distance, they look like a complex system of rings. 

This NASA Hubble Space Telescope photo of Saturn reveals the planet’s cloud bands and a phenomenon called ring spokes. NASA, ESA, STScI, Amy Simon (NASA-GSFC)

The origin of the rings of the giant gas planets has been the cause of many debates over the decades. The most likely explanation is that the rings formed from the remains of moons or other celestial bodies that wondered a  little too close. The intense gravitational force from the planets tore the objects apart in a process known as tidal disruption. 

In a paper published by Andrew G. Tomkins and a team of researchers they suggest Earth too may have had its own rings in the past. Interactions between Earth and material from within our Solar System has been clearly evident. The Arizona crater and the Chicxulub impact event have left their scars on our planet but in the last 540 million years there was an increase in cratering events. Recorded in limestone deposits around the world are higher levels of chondrite (stony) meteorites and micrometeorite debris. At the same time there seems to have been an increase in seismic and tsunami activity although the correlation between the two is not confirmed. 

Barringer Crater, also known as Meteor Crater, in Arizona. This crater was formed around 50,000 years ago by the impact of a nickel-iron meteorite. Near the top of the image, the visitors center, complete with tour buses on the parking lot, provides a sense of scale. Credit: National Map Seamless Viewer/US Geological Service

The increase in meteoric material in limestone has been suggested as being caused by a general increase in asteroid dust across the inner Solar System but an interesting alternative theory has been suggested by Tomkins and his team. They propose instead that a large chondrite asteroid experienced a near-miss with Earth around 466 million years ago. If the object passed within the Roche limit of Earth, then Earth’s gravitational field will be strong enough to stop any smaller object from being held together by gravity. It would therefore break-up and lead to the formation of a debris ring.

The team investigated the impact sites of the 21 meteorite impacts known to coincide with the increase in meteorite activity in the Ordovician period. They then calculated the probability that the identified impact points resulted from randomly distributed impact events. This would be the likely cause of all the impactors came from the asteroid belt scenario. Instead the team concluded that the impact structure were located near to the equator as would be the case if they came from a single body that broke up in orbit. The resultant decay of the ring particles would have lasted several tens of millions of years before finally settling in the limestone records for future researchers to unearth. 

Source : Evidence suggesting that earth had a ring in the Ordovician

The post Earth Might Have Had Rings Half a Billion Years Ago appeared first on Universe Today.

In 2022, physicists were excited by hints that something was wrong with our understanding of the universe - but new results have put that in doubt

In my book, which I will now shamelessly promote – The Skeptics’ Guide to the Future – my coauthors and I discuss the incredible potential of information-based technologies. As we increasingly transition to digital technology, we can leverage the increasing power of computer hardware and software. This is not just increasing linearly, but geometrically. Further, there are technologies that make other technologies more information-based or digital, such as 3D printing. The physical world and the virtual world are merging.

With current technology this is perhaps most profound when it comes to genetics. The genetic code of life is essentially a digital technology. Efficient gene-editing tools, like CRISPR, give us increasing control over the genetic code. Arguably two of the most dramatic science and technology news stories over the last decade have been advances in gene editing and advances in artificial intelligence (AI). These two technologies also work well together – the genome is a large complex system of interacting information, and AI tools excel at dealing with large complex systems of interacting information. This is definitely a “you got chocolate in my peanut butter” situation.

A recent paper nicely illustrates the synergistic power of these two technologies – Interpreting cis-regulatory interactions from large-scale deep neural networks. Let’s break it down.

Cis-regulatory interactions refer to several regulatory functions of non-coding DNA. Coding DNA, which is contained within genes (genes contain both coding and non-coding elements) directly code for amino acids which are assembled into polypeptides and then folded into functional proteins. Remember the ATCG four letter base code, with three bases coding for a specific amino acid (or coding function, like a stop signal). This is coding DNA. Noncoding DAN regulates how coding DNA is transcribed into proteins.

There are, for example, promoter sequences, which are necessary for transcription in eukaryotes. There are also enhancer sequences which increase transcription, and silencer sequences which decrease transcription. Interactions among these various regulatory segments control how much of which proteins any particular cell will make, while responding dynamically to its metabolic and environmental needs. It is a horrifically complex system, as one might imagine.

CRISPR gives us the ability to not only change the coding sequence of a gene (or remote or splice in entire genes), it can also be used to alter regulation of gene expression. It can reversibly turn off, and then back on again, the transcription of a gene. But doing so messes with this complex systems of regulatory sequences, so the more we understand about it, the better. Also, we are discovering that there are genetic diseases that do not involve mutations of coding DNA but of regulatory DNA. So again, the more we understand about the regulatory system, the better we will be able to study and eventually treat diseases of gene expression regulation.

This is a perfect job for AI, and in this case specifically, deep neural networks (DNN). The problem with conventional research into a massive and complex system like the human genome (or any genome) is that the number of individual experiments you would need to do in order to address even a single question can be vast. You would need the resources of laboratory time, personnel and money to do thousands of individual experiments. Or – we could let AI do those experiments virtually, at a tiny fraction of the cost and time. This is exactly the tool that the researchers have developed. They write:

“Here we present cis-regulatory element model explanations (CREME), an in silico perturbation toolkit that interprets the rules of gene regulation learned by a genomic DNN. Applying CREME to Enformer, a state-of-the-art DNN, we identify cis-regulatory elements that enhance or silence gene expression and characterize their complex interactions.”

Essentially this is a two-step process. Enformer is a DNN that plows through tons of data to learn the rules of gene regulation. The problem with some of these AIs, however, is that they spit out answers but not necessarily the steps that led to the answers. This is the so-called “black box” problem of some AIs. But genetics researchers want to know the steps – they want to know the individual regulatory elements that Enformer identified as the building blocks for the overall rules the produce. That is what CREME does – it looks at the rule output of Enformer and reverse engineers the cis-regulatory elements.

The combination essentially allows genetics researchers to run thousands of virtual experiments in silico to build a picture of cis-regulatory elements and interactions that make up the web of rules that control gene expression. This is great example of how AI can potentially dramatically increase the pace of scientific research. It also highlights how genetics is perhaps ideally suited to reap the benefits of AI-enhanced research, because it is already an inherently digital science.

This is perhaps the sweat spot for AI-enhanced scientific research – look through billions of potential targets and tell me which 2 or 3 I should focus on. This also applies to drug research and material science, where the number of permutations – the potential space – of possible solutions is incredibly vast. For many types of research, AI is condensing down months or years of research into hours or days of processing time.

For genetics these two technologies (AI and gene-editing such as, but not limited to, CRISPR) combine to give us incredible knowledge and control over the literal code of life. It still takes a lot of time to translate this into specific practical applications, but they are coming. We already, for example, have approved therapies for genetic diseases, like sickle cell, that previously had no treatments that could alter their course. More is coming.

This field is getting so powerful, in fact, that we are discussing the ethics of potential applications. I understand why people might be a little freaked out at the prospect of tinkering with life at its most fundamental level. We need a regulatory framework that allows us to reap the immense benefits without unleashing unintended consequences, which can be similarly immense. For now this largely means that we don’t mess with the germ line, and that anything a company wishes to put out into the world has to be individually approved. But like many technologies, as both AI and genetic manipulation gets cheaper, easier, and more powerful, the challenge will be maintaining effective regulation as the tech proliferates.

For now, at least, we can remain focused on ethical biomedical research. I expect in the next 5-20 years we will see not only increasing knowledge of genetics, but specific medical applications. There is still a lot of low hanging fruit to be picked.

The post The Potential of AI + CRISPR first appeared on NeuroLogica Blog.

A ring of asteroid debris could have orbited Earth for tens of millions of years, and perhaps even have altered the planet's climate

The Moon has inspired poets and artists, musicians and playwrights. The sight of our one and only Moon is familiar to anyone that has ever glanced up at the night time (and sometimes day time sky!) Every so often though, our Moon (note the use of capital ‘M’)is joined by a small asteroid that wanders too close. Astronomers have detected an 11-metre wide asteroid that has the snappy name 2024 PT5 and it came within 567,000 kilometres of Earth and will become a temporary satellite from 29 September until 25 November when it will leave our system. 

Planets, comets, satellites and asteroids are the main constituents of our Solar System, plus of course, the Sun. The asteroids are small rocky objects that orbit the Sun with the majority in orbits between Mars and Jupiter. These remnants of the early Solar System come in a wide range of sizes from those measuring just a few centimetres to others measuring hundreds of kilometres. They have no atmosphere and are usually irregular in shape. 

The asteroid Dimorphos was captured by NASA’s DART mission just two seconds before the spacecraft struck its surface on Sept. 26, 2022. Observations of the asteroid before and after impact suggest it is a loosely packed “rubble pile” object. Credit: NASA/JHUAPL

Asteroids that pass within 1.3 astronomical units (one astronomical unit is the average distance between the Sun and Earth) are typically referred to as near-earth objects (NEOs.) Their proximity to Earth means they may – if not immediately – pose a potential impact threat to Earth. Most NEO’s pass by harmlessly on each orbit but they are tracked for future threats. The study of this family of asteroids helps us to understand about the formation of the Solar System. 

On occasions, Earth can capture asteroids from the NEO group and for a short period, pull them into an orbit. These temporary captures can be very short lived not even lasting for an entire orbit before returning to their regular trajectory.  Others like 2006RH120 remained in orbit around Earth for a year, while some have been captured for more than a year. These mini-moon events have even turned out to be pieces of space junk like one identified in 2020 which turned out to be a rocket booster from the launch of Surveyor 2 in 1966!

This 1964 photograph shows a Centaur upper-stage rocket before being mated to an Atlas booster. A similar Centaur was used during the launch of Surveyor 2 two years later. Credit: NASA

Asteroid 2024 PT5 is a NEO that was discovered on 7 August 2024 by ATLAS, the Asteroid Terrestrial-impact Last Alert System. It measures 11 metres across and can approach within 1 million kilometres of Earth in an orbit whose path resembles a horseshoe shape. This complex type of orbit occurs when a smaller object orbits a relatively larger object. In the case of 2024 PT5, the gravitational attraction of Earth changes the shape of the asteroids elliptical orbit. The horseshoe shape is only evident when the orbit of the asteroid is mapped relative to both the Sun and the Earth.

The dynamics of the two objects means that for a period of 56 days from 29 September to 25 November, 2024 PT5 will officially orbit the Earth although it is only classed as a ‘temporary captured flyby.’ It will only perform one single orbit however before it returns to its usual heliocentric, Sun centred orbit. This won’t be the only time though as it is predicted to return again in 2055. 

Don’t get too excited about seeing it though. The object will be far too faint to be seen with the naked eye, even beyond the visual range of amateur telescopes. It is however possible for experienced amateur astronomers to capture images of the asteroid using astronomical imaging techniques.

Source : A Two-month Mini-moon: 2024 PT5 Captured by Earth from September to November

The post Earth Will Have a Tiny New Mini-Moon for a Few Months appeared first on Universe Today.