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Neutrinos generated through solar fusion reactions travel effortlessly through the Sun’s dense core. Each specific fusion process creates neutrinos with distinctive signatures, potentially providing a method to examine the Sun’s internal structure. Multiple neutrino detection observatories on Earth are now capturing these solar particles, which can be analysed alongside reactor-produced neutrinos with the data eventually enabling researchers to construct a detailed map of the interior of the Sun.

The Sun is a massive sphere of hot plasma at the centre of our solar system and provides the light and heat to make life on Earth possible. Composed mostly of hydrogen and helium, it generates energy through nuclear fusion, converting hydrogen into helium in its core. This process releases an enormous amount of energy which we perceive as heat and light. The Sun’s surface, or photosphere, is around 5,500°C, while its core reaches over 15 million°C. It influences everything from our climate to space weather, sending out solar wind and occasional bursts of radiation known as solar flares. As an average middle-aged star, the Sun is about 4.6 billion years old and will (hopefully) continue burning for another 5 billion years before evolving into a red giant and eventually becoming a white dwarf.

This image shows our Sun during a period of high activity.

The standard solar model (SSM) is used to understand and predict the Sun’s internal structure and evolution, it’s how we work out what’s going on inside the Sun. It explains how, in the Sun’s core, different nuclear fusion reactions are constantly pumping out neutrinos – tiny, nearly massless particles that travel through almost anything. Each type of reaction creates neutrinos with their own properties. These neutrinos may help us to understand more about the interior of the Sun. Right now, we only know about its internal density structure from theoretical models based on the SSM, matched with what we can see on the Sun’s surface. The neutrinos may hold the information that will gives us more direct data about the solar interior. 

Chinese researchers are working on a new neutrino observatory called TRIDENT. They built an underwater simulator to develop their plan. Image Credit: TRIDENT

In a paper published by Peter B. Denton from the Brookhaven National Laboratory and Charles Gourley from Rensselaer Polytechnic Institute they show how solar neutrinos can help us to look inside the Sun and establish its density structure. In contrast, photons of light only tell us about the surface of the Sun as it is right now, and give us a little information about the Sun’s interior hundreds of thousands of years ago. This delay in photons exiting the Sun is because they bounce around the dense solar interior for centuries before escaping. Neutrinos on the other hand give us up to the minute information because they can zip straight through the Sun without getting stopped. 

It has long since been known that neutrinos change their flavour or type (electron neutrino, muon neutrino or tau neutrino) as they travel through matter and that depends on the local density. This is well documented as the Mikheyev-Smirnov-Wolfenstein effect and, by measuring the flux of the neutrino as observed at Earth, compared to unoscillating  predicted flux, the density where the neutrinos were produced can be calculated. Input is also required from independent measurements from neutrino oscillations  that have been created inside nuclear reactors. 

The team demonstrate that the approach does have its limitations  and that there are constraints on just how much density information can be gleaned from the SSM alone. Further data from projects like JUNO and DUNE are needed to further improve the solar internal density profile and give us a more realistic view of the internal workings of our local star.

Source : Determining the Density of the Sun with Neutrinos

The post Could Neutrinos Tell Us About the Inside of the Sun? appeared first on Universe Today.

Innovation is a history of someone trying to build a better mouse trap – or at least that’s how it’s described in business school. But what happens if someone tries to build a better version of something that isn’t even commonly used yet? Maybe we will soon find out, as NASA recently supported an effort to build a better type of solar sail as part of its Institute for Advanced Concepts (NIAC) program.

The project, called “The Ribbon” on its announcement page, is a novel take on a typical solar sail and is being developed by a company called TestGuild Engineering out of Boulder, which seems to be run by a sole proprietor known as Gyula Greschik, who also appears to be a researcher at UC Boulder. The Ribbon consists of a “film strip with a diffractive grating” that uses the same principle as a traditional solar sail to move – light pressure. 

The diffractive grating is the key here – when the Ribbon is oriented towards the light from the Sun, the light effectively “pushes” it, just like a solar sail. But, in this case, the diffractive grating causes the force to be directed toward the “leading end” of the Ribbon. Importantly, it does this with no structure components at all – just the Ribbon itself.

Fraser discusses how awesome solar sails are.

If a payload is attached to the other end, eventually, the force being applied to the front will drag the back along with it. It might not happen immediately, but like an actual ribbon, eventually, the force will be transferred down to the payload. That would allow it to effectively tow the payload, much like a traditional solar sail.

This does have some unique advantages, including its ease of storability and potentially infinite scaling—longer ribbons would simply mean more force, much like a larger solar sail would also mean more force. In theory, at least, there is no limit to the scaling of how large you could make the Ribbon, though practically, eventually, you would hit the physical limits of the material you chose to make it out of.

TestGuild has some experience developing projects for NASA already. Back in 2017, it was given a Small Business Innovation Research grant to work on a type of deployable communications array that uses similar structural engineering techniques to the Ribbon. It’s unclear whether that project is still ongoing, but given the new interest from NASA on a completely separate use case with the same PI, it likely isn’t.

Fraser discusses the basic concept behind solar sails.

 Comparing the Ribbon’s use cases to those of more traditional solar sails will take a long time. NIAC Phase I typically takes about a year. In the press release announcing the project, Dr Greschik notes that most of this round will be focused on simulation and feasibility studies. Special emphasis is placed on how the Ribbon responds to small perturbations and what control system would be necessary to stabilize it. So, it may be some time before we see a giant Ribbon pulling a payload through space. However, new solar sail concepts always pop up, and this one could provide some inspiration for the next generation of designs, or it could see itself manifested one day.

Learn More:
Greschik & NASA – The Ribbon
UT – NASA’s Putting its Solar Sail Through its Paces
UT – Project Helianthus – a Solar Sail Driven Geomagnetic Storm Tracker
UT – Solar Sails Could Reach Mars in Just 26 Days

Lead Image:
Artist’s concept of the Ribbon.
Credit – NASA / Gyula Greschik

The post A Giant Ribbon Can Pull Payloads Along appeared first on Universe Today.

Scientists have come up with a lithium ion capacitor using electrodes produced from wood particles that are discarded as waste in sawmills. This biomass is both readily available and sustainable, inexpensive processes have been used to produce electrodes. The results reveal that the materials derived from biomass have excellent properties for obtaining eco friendly, cost-effective systems designed to store high-power energy.

Choreographer Wayne McGregor’s extraordinary new show, Deepstaria, is inspired by the marine life of the deep ocean

Golden-bellied capuchins are usually found in humid forests, but some populations appear to have adapted to life in drier habitats with the help of stone tools

Time and memory space are the two main constraints on what we can compute, and understanding their relationship is a key part of computational complexity research

Regular Mark Sturtevant has sent us a passel of insect and spider photos. Mark’s captions are indented, and you can enlarge his pictures by clicking on them.

I come with another set of pictures of arthropods. Mostly orb-weaver spiders, actually. The pictures were taken in various parks near where I live, which is in Michigan.

Let’s begin with the large bee shown in the first two pictures. I was rather puzzled about the identity of this bee. Although it resembles a bumble bee, it turns out to be a male Eastern Carpenter Bee, Xylocopa virginica. I don’t recall ever seeing a male foraging at flowers, but I do see them hovering around nest entrances. The females are commonly seen out foraging, and are easily recognized by their shiny black abdomen and large all-black head. Female carpenter bees are well known for boring large holes into soft wood, which they provision with pollen for their young in a series of stacked cells. In preparing for this post, I learned that these bees are often not solitary (I thought they were!), but instead the can form small social groups where their duties depend on their age which can be up to three years. Older females are dominant and they perform all duties and most of the egg laying. Younger females do less provisioning and egg laying while tending to guard the nest entrance, and the youngest females pretty much just eat provisions and provide no services. Although I carry multiple degrees in Entomology (it’s a long story), this hobby and posting in WEIT has taught me a lot about the lives of insects.

Now we move on to orb-weaver spiders. There are many species in my area, and many members of this group stay hidden near their web by day. Some of them are cussedly hard to tell apart, but I do believe the first one is a Shamrock Orbweaver, Araneus trifolium. There are two other very similar species, but I rely on differences in the leg banding and markings under the abdomen to suggest this ID.

Next up is a Furrow Orbweaver, Larinioides cornutus. These common spiders are specialists in concealment since by day they usually stay in a tightly woven hide-away in a curled leaf.

The next two pictures are of Spotted Orbweavers, Neoscona crucifera. The first one really really impressed me since it managed to catch a large cicada.

The large and colorful garden spiders, or Argiopes, are always a favorite. These will sit out in the center of their web during the day. Although the other orb-weavers may be found anywhere, the Argiopes seem more patchy in distribution now-a-days, with only certain areas where they are common. The species shown here is the Banded Garden Spider, Argiope trifasciata.

Moving away from spiders, the next picture shows a Great Spreadwing Damselfly, Archilestes grandis, which is the largest damselfly in the U.S. That is not to say that it’s a large insect, but it is the size of a smallish dragonfly and so it is way bigger than all other damsels in the U.S. The linked picture will show you. This is originally a species from the southern portion of the country, but it has moved farther north and they are now common in a certain park near Ann Arbor. I go to this park every year or two with the specific goal of photographing this insect and of course whatever else may show up.

Bringing up the rear are pictures of grasshoppers. First is a mating pair of Differential Grasshoppers (Melanoplus differentialis). It was a little surprising that they could be coaxed onto my finger for this picture.

Some time ago I came across an internet meme that pointed out an amusing pareidolia with a grasshopper, which was that its sternum bore what looks like a lion face with sunglasses. I recognized that the species was a member of the spur-throated subfamily, Melanoplinae (See? My entomology degrees are useful), and the Differential ‘hopper and many other local species belong in it. So the last picture is of two spur-throated grasshoppers, and they each have the feline pattern. The one on the left is the Differential Grasshopper, and the right one is a Red-legged Grasshopper (M. femurrubrum). I expect that Jerry will especially like this last bit! [JAC: Cat faces!]

In closing, on occasion I am asked about the equipment that I use for photography. That really does not matter, although these pictures were generally taken with an old and very worn Canon crop sensor body (t5i), which is cheap these days, and a nice macro lens (Canon 100mm, f/2.8L), but there are less expensive macro lenses that are just as good or even better. If anyone would like to try this form of photography, however, I would suggest that they look into OM system cameras. OM cameras (formerly Olympus) have features that make them especially effective at macrophotography, and if I had a way to do it all over again I would not think twice about switching to that brand. Also, for what you get I believe they tend to be cheaper than other camera models. But it is hard to go wrong with cameras, and you can easily modify a regular lens to be used as a macro lens. What really matters, more than the choice of camera, is the diffuser on the external flash. That is a whole other subject that can take a lot of discussion. I lie awake at night worrying about whether my diffuser could be better.

NASA's newest space telescope will scan the entire sky in a range of near-infrared wavelengths to help astronomers better understand the evolution of the universe and search for promising spots for extraterrestrial life

Chemical rockets are loud, noisy and can only get us so far. If we want to reach another star system, we’ll need something better—either super energy-dense fuel to improve the efficiency of chemical rockets or a way to push spacecraft using beams of energy, like a photonic lightsail. A new paper looks at the pros and cons of lightsails, figures out the best setup to carry a small payload to another star while humans are still alive to see it, and checks out what materials might actually work for this kind of mission.

Interstellar travel, or journeying between stars, represents one of our most ambitious challenges. While current technology limits us to exploring the solar system, the dream of reaching distant star systems drives scientific innovation and imagination. Such journeys would require advanced propulsion systems, like nuclear fusion engines, solar sails, or theoretical concepts such as warp drives and wormholes (must resist any reference to Star Trek.) The immense distances between the stars present enormous challenges in terms of time, energy, and resource management. Shielding from radiation, life support and the psychological effects of isolation are among the challenges yet still, the pursuit of interstellar travel continues to inspire.

Artistic rendition of an interstellar spacecraft traveling near the speed of light. Credit: Made with ChatGPT

A new paper authored by a team led by Jadon Y. Lin from the University of Sydney explores one possible technology that may get, if not us then our technology, to the stars. They explore the principles of lightsail technology and how the application of photons of light could drive spacecraft the immense distances. Starting with the desired outcome, the team use a computational method which starts with a desired outcome and work backwards to get the best solution to achieve it. 

DALL-E illustration of a light sail

Just what is the problem. Travelling even relatively short distances among the stars, such as to Proxima Centauri ‘just’ 4.2 light years away, a spacecraft would need to travel at over 10% the speed of light to get there in a human lifetime! That’s approximately 30,000 km per second when our fastest probe has only achieved 194 kilometres per second! We need to go faster! According to the Tsiolkovsky rocket equation, chemical propulsion to accelerate a single proton to that speed would require more fuel than the entire observable universe! That means any spacecraft aiming for such enormous speeds needs an external source of momentum and energy. Enter light sail technology which could, according to recent research propel a probe to Proxima Centauri in just 21 years!

This image of the sky around the bright star Alpha Centauri AB also shows the much fainter red dwarf star, Proxima Centauri, the closest star to our Solar System. New research shows that material from Alpha Centauri has reached our Solar System, mostly in the form of tiny rocks. Image Credit: Digitized Sky Survey 2. Acknowledgement: Davide De Martin/Mahdi Zamani

Fundamental to the success of a functional lightsail for interstellar travel hinges on finding the right materials and fabrication methods for the sail itself. There are some promising options available such as silica, silicon nitride and molybdenum disulfide although their full properties in ultra-thin membranes have still to be tested. The team conclude that molybdenum disulfide is currently the best contender but further testing is needed. Shifting the focus to design, the traditional sail shapes show potential but the paper concludes that they are outperformed by nano-structured designs like diffraction gratings, which optimise propulsion, thermal control, and stability. 

Sadly interstellar lightsails might yet take decades to become a reality. The technology isn’t quite there yet, not just in material science but progress is needed in areas like metalenses and high-powered lasers too. We have already seen light sails used successfully in space but, as interest develops and technology advances, slowly, interstellar spacecraft designs may at least one day becoming a reality. 

Source : Photonic Lightsails: Fast and Stable Propulsion for Interstellar Travel

The post Photonic Lightsails are our Best Shot at Reaching Another Star appeared first on Universe Today.

In this passage from Dengue Boy, the latest read for the New Scientist Book Club, we get an insight into life for Michel Nieva’s mosquito protagonist – and the drowned future world she inhabits

Any satellite sent to space must be able to deal with the battle with Earth’s gravitational pull, withstanding the harsh conditions of launch before reaching the zero-gravity environment it was designed for. But what if we could send raw materials into orbit and build the satellite there instead? DARPA (the Defence Advanced Research Projects Agency) has formed partnerships with a number of universities to develop 3D printing technology and in-orbit assembly of satellite components. It’s recently put out a new request for proposals to explore biological growth mechanisms in space – the exciting prospect of living organisms that can increase in size, develop structures, and repair themselves.

Satellite launches from Earth began on October 4, 1957, when the Soviet Union successfully launched Sputnik 1, the world’s first artificial satellite. It marked the beginning of the space age and was followed by the U.S. launch of Explorer 1 in 1958. Over the decades that followed, advancements in rocketry culminated in the development of Saturn V capable of delivering humans to the Moon. The 1960s and 1970s saw the rise of communication, weather, and reconnaissance satellites and with the advent of reusable spacecraft like the Space Shuttle in the 1980s space became more economical. 

The Sputnik spacecraft stunned the world when it was launched into orbit on Oct. 4th, 1954. Credit: NASA

One of the biggest challenges facing agencies launching space satellites is the challenge of size and weight. The bigger and heavier it is, the more expensive it is to launch. DARPA’s 2022 NOM4D program aims to solve this by sending lightweight materials to space for on-site construction, rather than build them before launch. This innovative approach enables building much larger, more mass-efficient structures into orbit that would perhaps otherwise be impossible to launch fully assembled. The idea opens new possibilities for optimised designs that aren’t limited by launch vehicle dimensions and lifting capability. 

The partnerships established by DAPRA include Caltech (the California Institute of Technology) and the University of Illinois Urbana-Champaign have already demonstrated wonderful advances in the first two phases. They are now continuing phase 3 with launch companies to undergo in-space testing of the assembly process. In many ways though, the concept is not new, the ISS for example has been built in orbit over many decades, it’s the first time however that the approach is being used for smaller satellites. 

International Space Station. Credit: NASA

The Caltech experiment will operate independently in orbit without human interaction once deployed. It’s going to be fascinating to watch this momentous test. On-board cameras will provide live monitoring of the construction process as an autonomous robot assembles lightweight composite fibre tubes into a circular truss 1.4 meters in diameter, representing an antenna structure. It’s a little bit like popular children’s toys like K’Nex but of course, a little more advanced. 

If successful, the technology could be scaled up to eventually construct space-based antennas exceeding 100 meters in diameter, transforming space exploration with enhanced communicating and monitoring capabilities. It goes much further than this though. DARPA is now exploring the possibility of “growing” large biological structures in space too. 

Recent advances in metabolic engineering, knowledge of extremophile organisms and developments in tunable materials like hydrogels are making space grown organic structures a tantalising possibility. It aims to DAPRA have put out a request for proposals to explore the concept. These biologically manufactured structures could enable projects that are impractical with traditional methods with dreams of space elevator tethers, orbital debris capture nets and expandable commercial space station modules perhaps not so far from being a reality. By harnessing biological growth in the unique conditions of space, entirely new construction possibilities may become feasible. Just imagine!

Source : DARPA demos will test novel tech for building future large structures in space and Large Bio-Mechanical Space Structures

The post DARPA Wants to Build Structures in Orbit, Without Needing a Launch from Earth appeared first on Universe Today.

Michel Nieva, the author of the latest read for the New Scientist Book Club, Dengue Boy, on his story of a drowned, pandemic-struck future Earth – and his unusual protagonist

The many doctors who are just now realizing that misinformation wasn't "COVID hysteria nonsense" have a lot of catching up to do to understand how the forces they've legitimized the led to this moment.

The post Welcome to the Resistance UCSF Doctors first appeared on Science-Based Medicine.

NASA’s asteroid-studying spacecraft Lucy captured an image of its next flyby target, the asteroid Donaldjohanson. On April 20th, the spacecraft will pass within 960 km of the small, main belt asteroid. It will keep imaging it for the next two months as part of its optical navigation program.

Donaldjohanson is an unwieldy name for an asteroid, but it’s fitting. Donald Johanson is an American paleoanthropologist who discovered an important australopithecine skeleton in Ethiopia’s Afar Triangle in 1974. The female hominin skeleton showed that bipedal walking developed before larger brain sizes, an important discovery in human evolution. She was named Lucy.

NASA named their asteroid-studying mission Lucy because it also seeks to uncover clues about our origins. Instead of ancient skeletal remains, Lucy will study asteroids, which are like fossils of planet formation.

During its 12-year mission, Lucy will visit eight asteroids. Two are in the main belt, and six are Jupiter trojans. Asteroid Donaldjohanson is a main-belt, carbonaceous C-type asteroid—the most common variety—about 4 km in diameter and is Lucy’s first target. It’s not one of the mission’s primary scientific targets. Instead, the flyby will give Lucy mission personnel an opportunity to test and calibrate the spacecraft’s navigation system and instruments.

This image depicts the two areas where most of the asteroids in the Solar System are found: the asteroid belt between Mars and Jupiter and the Trojans, two groups of asteroids moving ahead of and following Jupiter in its orbit around the Sun. Image Credit: NASA

The animation below blinks between images captured by Lucy on Feb. 20th and 22nd. It shows the perceived motion of Donaldjohanson relative to the background stars as the spacecraft rapidly approaches the asteroid.

via GIPHY

The flyby is like a practice run before Lucy visits the Jupiter trojans. These asteroids are clusters of rock and ice that never coalesced into planets when the Solar System formed. These are the “fossils of planet formation,” the most well-preserved evidence from the days of Solar System formation.

Currently, Donaldjohanson is 70 million km away and will remain a tiny point of light for weeks. Only on the day of the encounter will the spacecraft’s cameras capture any detail on the asteroid’s surface. In the images above, the dim asteroid still stands out from the dimmer stars of the constellation Sextans. Lucy’s high-resolution L’LORRI instrument, the Long Lucy LOng Range Reconnaissance Imager, captured the images.

Lucy is following a unique flight pattern. It’s essentially a long figure-eight.

Illustration of the Lucy spacecraft’s orbit around Jupiter, which will allow it to study its Trojan population. Though the image lists 6 flybys, the spacecraft will visit 8 asteroids. One of the listed ones is a binary, and the spacecraft already encountered the asteroid Dinkinesh. Image Credit: SwRI

Even this early in its mission, Lucy has delivered some surprising results. In November 2023, it flew past asteroid 152830 Dinkinesh. The flyby was intended as a test for the spacecraft’s braking system, but instead, it revealed that Dinkinesh has a small satellite. Closer observations showed that the satellite is actually a contact binary, which means it’s composed of two connected bodies. This was a valuable insight into asteroids.

These two images from Lucy show the asteroid Dinkinesh and its satellite Selam. The first image (L) shows Selam just coming into view behind Dinkinesh. The second image (R) reveals that Selam is actually two objects, a contact binary. Image Credits: By NASA/Goddard/SwRI/Johns Hopkins APL/NOIRLab – Public Domain, https://commons.wikimedia.org/w/index.php?curid=139996127

There are surprising discoveries in every mission, and Lucy is no exception. As it makes its way through its list of targets, it will almost certainly show us some surprises.

The Trojans are difficult to study from a distance. They’re a long way away. Scientists aren’t certain how many there are; there may be as many Trojans as there are main-belt asteroids. The Trojans exhibit a wide variety of compositions and characteristics, which could indicate that they came from different parts of the Solar System. By studying the Trojans in all their diversity, Lucy will hopefully help scientists reconstruct their origins and how they were captured by Jupiter.

The Solar System has a long history and we’ve only just become a part of it. Some of the clues to our origins are out there among the battered rocks of the asteroid belt and the Jupiter Trojans. Lucy will give us our best look at the Trojans. Who knows what it might reveal?

• Press Release: NASA’s Lucy Spacecraft Takes Its 1st Images of Asteroid Donaldjohanson
• Press Release: NASA Lucy Images Reveal Asteroid Dinkinesh to be Surprisingly Complex
• ASU Institute of Human Origins: Lucy’s Story

The post Lucy Sees its Next Target: Asteroid Donaldjohanson appeared first on Universe Today.

A research team has developed a way for self-driving vehicles to share their knowledge about road conditions indirectly, making it possible for each vehicle to learn from the experiences of others even when they rarely meet on the road.

A research team has developed a way for self-driving vehicles to share their knowledge about road conditions indirectly, making it possible for each vehicle to learn from the experiences of others even when they rarely meet on the road.

Scientists demonstrate a new quantum chip architecture for suppressing errors using a type of qubit known as a cat qubit.

Scientists demonstrate a new quantum chip architecture for suppressing errors using a type of qubit known as a cat qubit.

Scientists have revealed how quantum interference and symmetry dictate molecular behavior in collisions with gold surfaces, offering new insights into molecular interactions. The findings can have important implications for chemistry and materials science.

Scientists have revealed how quantum interference and symmetry dictate molecular behavior in collisions with gold surfaces, offering new insights into molecular interactions. The findings can have important implications for chemistry and materials science.