Science

In a significant step toward creating a sustainable and circular economy, researchers have demonstrated that carbon nanotube (CNT) fibers can be fully recycled without any loss in their structure or properties. This discovery positions CNT fibers as a sustainable alternative to traditional materials like metals, polymers and the much larger carbon fibers, which are notoriously difficult to recycle.

A thorough analysis of market, technological, and supply chain outcomes for sodium-ion batteries finds that significant advances are needed before commercialization.

Scientists have come a step closer to understanding how collisionless shock waves -- found throughout the universe -- are able to accelerate particles to extreme speeds.

Scientists have taken a major step forwards in tackling one of the greatest abiding challenges in chemistry, by learning how to program the self-assembly of molecules in such a way that the end result is predictable and desirable. Their 'Malteser-like' molecules could one day have a suite of applications -- from highly sensitive and specific sensors, to next-gen, targeted drug delivery agents.

In order to recover valuable substances from CO2, it must be reduced in many individual steps. If electrocatalysis is used for this, many potentially different potential molecules are formed, which cannot necessarily be used. Biocatalysts, on the other hand, are selective and only produce one product -- but they are also very sensitive. An international research team has developed a hybrid catalysis cascade that makes use of the advantages of both processes.

Giving people better data about their energy use, plus some coaching, can help them substantially reduce their consumption and costs, according to a new study.

The process of updating deep learning/AI models when they face new tasks or must accommodate changes in data can have significant costs in terms of computational resources and energy consumption. Researchers have developed a novel method that predicts those costs, allowing users to make informed decisions about when to update AI models to improve AI sustainability.

The process of updating deep learning/AI models when they face new tasks or must accommodate changes in data can have significant costs in terms of computational resources and energy consumption. Researchers have developed a novel method that predicts those costs, allowing users to make informed decisions about when to update AI models to improve AI sustainability.

It's long been known that different positions on the football field fit different body types. A study led by the University of Kansas has gone beyond knowing that linemen are bigger with more body mass than receivers and tested a team of college football starters, finding differences in strength, power, jumping ability and more. The findings could help improve strength training designed to optimize performance for different types of players, researchers argue.

Astronomers observed flashes of X-rays coming from a supermassive black hole at a steadily increasing clip. The source could be the core of a dead star that's teetering at the black hole's edge.

A new study overcomes a key obstacle to switching commercial aircraft from their near-total reliance on fossil fuels to more sustainable aviation fuels. The study details a cost-effective method for producing ethylbenzene -- an additive that improves the functional characteristics of sustainable aviation fuels -- from polystyrene, a hard plastic used in many consumer goods.

A new study overcomes a key obstacle to switching commercial aircraft from their near-total reliance on fossil fuels to more sustainable aviation fuels. The study details a cost-effective method for producing ethylbenzene -- an additive that improves the functional characteristics of sustainable aviation fuels -- from polystyrene, a hard plastic used in many consumer goods.

The use of plastic has skyrocketed over the past decade. Recent statistics reveal that in 2021, each person in the European Union (EU) generated an average of 36 kg of plastic packaging waste.

Wood has been a mainstay of human machines and construction for millennia. Its physical properties offer capabilities that are unmatched by almost any synthetic replacements. However, it has only very rarely been used in space. That might change based on the results of a new test run by Japan’s Space Agency (JAXA). LignoSat, one of the world’s first wooden satellites, was deployed from the ISS in December. 

We previously reported on the satellites’ history and launch. Matt’s article here provides an in-depth look at LignoSat’s path to eventual deployment.

Now that LignoSat has officially been deployed, what is it trying to measure? Stress and strain are two big ones that go hand in hand with temperature. Wood can warp with temperature changes, and there is probably still some water left in the honoki magnolia wood panels used for LignoSat’s construction. Understanding those effects on the satellite’s structure is one of the metrics of LignoSat’s makers at the University of Kyoto.

LignoSat is one of three Cubesats being deployed in this photo.
Credit – NASA

The effect of radiation is another. Wood, though an organic substance, is typically housed under the protective umbrella of the ozone layer, protecting it from most of the Sun’s radiation. Several samples of different kinds of wood were exposed to the space environment outside the ISS to test for these effects. However, testing them in full force without shielding the ISS is another of LignoSat’s challenges.

Finally, it will test for geomagnetic interference. Typical satellites are large metal boxes. In electrical engineering terms, we would call that a “Faraday cage,” named after Michael Faraday, the father of modern electrical engineering. Faraday cages are essential to keeping signals either inside or outside the cage and now allowing signals to pass either in or out. That’s why old-style radios used to have antennas that extended outside of their metal housings.

However, a wooden box doesn’t create a Faraday cage, so any electronics inside would be subjected to various geomagnetic interferences. LignoSat’s other job is to determine how severe those interferences are.

Example of the wood joinery technique used to construct the LignoSat, known as a Blind Miter Dovetail Joint.
Credit – Kyoto University

To be fair, the satellite isn’t entirely made of wood—it has aluminum frames and internal steel shafts holding the wood panels in place. However, it is still intended to burn up in Earth’s atmosphere upon reentry in around six months, steel struts and all.

Interestingly, LignoSat uses a traditional Japanese wood joinery technique that will allow the panels to flex during temperature changes, whereas metal fasteners would be much more restrictive and possibly damage the panels. If nothing else, it makes for a beautifully designed box, the outside of which looks more like home decoration than a satellite.

As LignoSat begins collecting data, researchers at the University of Kyoto are already working hard on LignoSat2. It’s scheduled to be launched in 2026, and it promises to add even more aesthetic appeal to the satellite industry while hopefully overcoming some of its technical challenges.

Learn More:
NASA – JAXA’s First Wooden Satellite Deploys from Space Station
UT – Japan Launches the First Wooden Satellite to Space
UT – Japan to Launch ‘Wooden Satellite’ in 2023
UT – Building a Satellite out of Wood? Use Magnolia

Lead Image:
Internal view of LignoSat’s structure shows the relationship among wooden panels, aluminum frames, and stainless-steel shafts.
Credit: Kyoto University

The post Astronauts Deploy the First Wooden Satellite into Orbit appeared first on Universe Today.

It’s easy to forget that, despite life having existed on Earth for billions of years and despite our relatively carefree existence from total destruction, throughout history there have been events that wiped out nearly everything! Fortunately for many life forms, they have the ability to go dormant and enter a state of reversible, reduced metabolic activity. In this state they are protected from decay and can survive long harsh periods where life would otherwise not survive. Is it just possible therefore that dormancy could also allow life to survive on other worlds like Mars or Venus? 

‘Life, don’t talk to me about life,’ were the utterances of Marvin the depressive robot on the Hitchhikers Guide to the Galaxy. Unlike Marvin, it seems humanity loves talking about and exploring the possibilities that life may exist elsewhere in the universe. A discussion about life is always tricky though as life could, conceivably come in such a strange form that we might not even recognise it as life. Typically if we talk about searching for alien life of any level of existence, we tend to consider life like that which we find here on planet Earth. After all, we have to start somewhere. 

With thousands of exoplanets discovered so far, astronomers are learning how different planets can be. What if intelligent alien civilizations arise on extremely different habitable worlds? Some civilizations could develop space exploration technologies, but others would be trapped underwater, under ice, or in enormous gravity wells. How could they escape? Image Credit: DALL-E

Exploring the diversity of life on Earth gives us an insight into what critters might be out there in similar environments. One such state that is surprisingly common across Earthly organisms is the ability to enter the state known as dormancy. The process protects an inactive organism and minimises the chances of extinction by preserving the critical bodily functions and shutting down all others, but just temporarily. In a paper recently published in The Royal Society Journals, Kevin D. Webster and Jay T. Lennon explore dormancy theory in consideration of its enabling life to flourish elsewhere in the cosmos. 

The duo first analysed the key activities that led to the evolution of intelligent life; the supply of chemical building blocks at the necessary rate to exceeded their decay and that some sort of compartmentalisation was needed for early primative life to offer protection between their cellular components and the environment. The sustained evolution of life from these early stages was susceptible to chance events but also error in DNA replications that may have brought a species to an evolutionary dead end. 

Deoxyribonucleic acid (DNA) is the genetic material for all known life on Earth. DNA is a biopolymer consisting of a string of subunits. The subunits consist of nucleotide base pairs containing a purine (adenine A, or guanine G) and a pyrimidine (thymine T, or cytosine C). DNA can contain nucleotide base pairs in any order without its chemical properties changing. This property is rare in biopolymers, and makes it possible for DNA to encode genetic information in the sequence of its base pairs. This stability is due to the fact that each base pair contains phosphate groups (consisting of phosphorus and oxygen atoms) on the outside with a net negative charge. These repeated negative charges make DNA a polyelectrolyte. Computational genomics researcher Steven Benner has hypothesized that alien genetic material will also be a polyelectrolyte biopolymer, and that chemical tests could therefore be devised to detect alien genetic molecules. Credit: Zephyris

Despite the sequence of events that brought about evolution that shaped our history there were events that momentarily brought a pause to proceedings. There have been five extinction events since the formation of Earth and it is the ability to drive through these dark days that dormancy really comes into its own. 

Impactors strike during the reign of the dinosaurs (image credit: MasPix/devianart)

Dormancy is a state of reduced activity or metabolism that organisms enter to survive during periods of challenging environmental conditions, such as extreme temperatures or reduced levels of light. This survival mechanism is common in plants, seeds, and certain animals, enabling them to withstand harsh seasons or environments. For animals, dormancy may take the form of hibernation or estivation, where metabolic rates decrease to conserve energy until conditions improve.

Dormancy provides protection, allowing inactive organisms to survive during unfavourable conditions and resume activity once more better conditions return. It may not have just helped organisms to survive harsh seasons but may have protected life from extinction during catastrophic events. It seems that the ability for primitive organisms to evolve dormancy processes is quite simple. If this is the case then it is quite plausible that any organisms that evolved on other planets with less than favourable conditions could be in their dormant state and waiting for conditions to improve. 

Source : Dormancy in the origin, evolution and persistence of life on Earth

The post Dormancy Could Be One of the Keys to Life on Earth (and Beyond) appeared first on Universe Today.

Suzie Imber is a co-investigator for the BepiColombo mission, currently on its way to Mercury. She explains how it will cast new light on the planet's many oddities, including its awful space weather and the fact it appears to have shrunk

Suzie Imber is a co-investigator for the BepiColombo mission, currently on its way to Mercury. She explains how it will cast new light on the planet's many oddities, from its massive core to its epic solar storms

Regular pulses of X-ray radiation emanating from a supermassive black hole could be explained by a white dwarf star on the verge of falling in

Tonight (January 13th) offers a wonderful opportunity for all of us who love the night sky, and also for science teachers. For those living within the shaded region of Fig. 1, the planet Mars will disappear behind the Moon, somewhere between 9 and 10 pm Eastern (6 and 7 pm Pacific), before reappearing an hour later. Most easily enjoyed with binoculars. (And, umm, without clouds, which will be my own limitation, I believe…)

For everyone else, look up anyway! Mars and the Moon will appear very close together, a lovely pair.

Figure 1: the region of Earth’s surface where Mars will be seen to disappear behind the Moon. Elsewhere Mars and the Moon will appear very close together, itself a beautiful sight. Image from in-the-sky.org.

Why is this Cool?

“Occultations”, in which a planet or star disappears behind our Moon, are always cool. Normally, even though we know that the planets and the Moon move across the sky, we don’t get to actually see the motion. But here we can really watch the Moon close in on Mars — a way to visually experience the Moon’s motion around the Earth. You can see this minute by minute with the naked eye until Mars gets so close that the Moon’s brightness overwhelms it. Binoculars will allow you to see much more. With a small telescope, where you’ll see Mars as a small red disk, you can actually watch it gradually disappear as the Moon crosses in front of it. This takes less than a minute.

A particularly cool thing about this particular occultation is that it is happening at full Moon. Occultations like this can happen at any time of year or month, but when they happen at full Moon, it represents a very special geometry in the sky. In particular, it means that the Sun, Earth, Moon and Mars lie in almost a straight line, as shown (not to scale!!!) in Fig. 2.

• The Moon is full because it is fully lit from our perspective, which means that it must lie almost directly behind the Earth relative to the Sun. [If it were precisely behind it, then it would be in Earth’s shadow, leading to a lunar eclipse; instead it is slightly offset, as it is at most full Moons.]
• And when the Moon covers Mars from our perspective, that must mean Mars lies almost directly behind the Moon relative to the Earth.

So all four objects must lie nearly in a line, a relatively rare coincidence.

Figure 2: (Distances and sizes not to scale!!) For a full Moon to block our sight of Mars, it must be that the Sun, Earth, Moon and Mars lie nearly in a line, so that the night side of the Earth sees the Moon and Mars as both fully lit and in the same location in the sky. This is quite rare. What Does This Occultation Teach Us?

Aside from the two things I’ve already mentioned — that an occultation is an opportunity to see the Moon’s motion, and that an occultation at full Moon implies the geometry of Fig. 2 — what else can we learn from this event, considered both on its own and in the context of others like it?

Distances and Sizes

Let’s start with one very simple thing: Mars is obviously farther from Earth than is the Moon, since it passes behind it. In fact, the Moon has occultations with all the planets, and all of them disappear behind the Moon instead of passing in front of it. This is why it has been understood for millennia that the Moon is closer to Earth than any of the planets.

Less obvious is that the map in Fig. 1 teaches us the size of the Moon. That’s because the width of the band where the Moon-Mars meeting is visible is approximately the diameter of the Moon. Why is that? Simple geometry. I’ve explained this here.

“Oppositions” and Orbital Periods

The moment when Mars is closest to Earth and brightest in the sky is approximately when the Sun, Earth and Mars lie in a straight line, known as “opposition”. Fig. 2 implies that an occultation of a planet at full Moon can only occur at or around that planet’s opposition. And indeed, while today’s occultation occurs on January 13th, Mars’ opposition occurs on January 15th.

Oppositions are very interesting for another reason; you can use them to learn a planet’s year. Mars’ most recent oppositions (and the next ones) are given in Fig. 3. You notice they occur about 25-26 months apart — just a bit more than two years.

Figure 3: A list of Martian oppositions (when Mars lies exactly opposite the Sun from Earth’s perspective, as in Fig. 2) showing they occur a bit more than two years apart. From nakedeyeplanets.com. [The different size and brightness of Mars from one opposition to the next reflects that the planetary orbits are not perfect circles.]

This, in turn, implies something interesting, but not instantly obvious: the time between Martian oppositions tells us that a Martian year is slightly less than two Earth years. Why?

Fig. 4 shows what would happen if (a) a Martian year (the time Mars takes to orbit the Sun) were exactly twice as long as an Earth year, and (b) both orbits were perfect circles around the Sun. Then the time between oppositions would be exactly two Earth years.

Figure 4: If Mars (red) took exactly twice as long to orbit the Sun (orange) as does Earth (blue), then an opposition (top left) would occur every two Earth years (bottom). Because oppositions occur slightly more than 24 months apart, we learn that Mars’ orbit of the Sun — its year — is slightly less than twice Earth’s year. (Yes, that’s right!) Oppositions for Jupiter and Saturn occur more often because their years are even longer.

But neither (a) nor (b) is exactly true. In fact a Martian year is 687 days, slightly less than two Earth years, whereas the time between oppositions is slightly more than two Earth years. Why? It takes a bit of thought, and is explained in detail here (for solar conjuctions rather than oppositions, but the argument is identical.)

The Planets, Sun and Moon are In a Line — Always!

And finally, one more thing about occultations of planets by the Moon: they happen for all the planets, and they actually happen pretty often, though some are much harder to observe than others. Here is a partial list, showing occultations of all planets [except Neptune is not listed for some unknown reason], as well as occultations of a few bright stars, in our current period. Why are these events so common?

Well (although the news media seems not to be aware of it!) the Moon and the planets are always laid out roughly in a (curved) line across the sky, though not all are visible at the same time. Since the Moon crosses the whole sky once a month, the chance of it passing in front of a planet is not particularly small!

Why are they roughly in a line? This is because the Sun and its planets lie roughly in a disk, with the Earth-Moon system also oriented in roughly the same disk. A disk, seen from someone sitting inside it, look like a line that goes across the sky… or rather, a huge circle that goes round the Earth.

To get a sense of how this works, look at Fig. 5. It shows a flat disk, seen from three perspectives (left to right): first head on, then obliquely (where it appears as an ellipse), and finally from the side (where it appears as a line segment.) The closer we come to the disk, the larger it will appear — and thus the longer the line segment will appear in side view. If we actually enter the disk from the side, the line segment will appear to wrap all the way around us, as a circle that we sit within.

Figure 5: A disk, seen from three perspectives: (left) face on, (center) obliquely, and (right) from the side, where it appears as a line segment. The closer we approach the disk the longer, the line segment. If we actually enter the disk, the line segment will wrap all the way around us, and will appear as a circle that surrounds us. Upon the sky, that circle will appear as a curved line (not necessarily overhead) from one horizon to the other, before passing underneath us.

Specifically for the planets, this means the following. Most planetary systems with a single star have the star at the near-center and planets orbiting in near-circles, with all the orbits roughly in a disk around the star. This is shown in Fig. 6. Just as in Fig. 5, when the star and planets are viewed obliquely, their orbits form an ellipse; and when they are viewed from the side, their orbits form a line segment, as a result of which the planets lie in a line. When we enter the planetary disk, so that some planets sit farther from the Sun than we do, then this line becomes a circle that wraps around us. That circle is the ecliptic, and all the planets and the Sun always lie close to it.

Fig. 6: (Left) Planets (colored dots) orbiting a central star (orange) along orbits (black circles) that lie in a plane. (Center) the same system viewed obliquely. (Right) The same system viewed from the side, in which case the planets and the star always lie in a straight line. (See also Fig. 5.) Viewed from one of the inner planets, the other planets and the star would seem to lie on a circle wrapping around the planet, and thus on a line across the night sky.

Reversing the logic, the fact that we observe that the planets and Sun lie on a curved line across the sky teaches us that the planetary orbits lie in a disk. This, too, has been known for millennia, long before humans understood that the planets orbit the Sun, not the Earth.

(This is also true of our galaxy, the Milky Way, in which the Sun is just one of nearly a trillion stars. The fact that the Milky Way always forms a cloudy band across the sky provides evidence that our galaxy is in the shape of a disk, probably somewhat like this one.)

The Mysteries of the Moon

But why does the Moon also lie on the ecliptic? That is, since the Moon orbits the Earth and not the Sun, why does its orbit have to lie in the same disk as the planets all do?

This isn’t obvious at all! (Indeed it was once seen as evidence that the planets and Sun must, like the Moon, all orbit the Earth.) But today we know this orientation of the Moon’s orbit is not inevitable. The moons of the planet Uranus, for instance, don’t follow this pattern; they and Uranus’ rings orbit in the plane of Uranus’ equator, tipped almost perpendicular to the plane of planetary orbits.

Well, the fact that the Moon’s orbit is almost in the same plane as the planets’ orbits — and that of Earth’s equator — is telling us something important about Earth’s history and about how the Moon came to be. The current leading explanation for the Moon’s origin is that the current Earth and Moon were born from the collision of two planets. Those planets would have been traveling in the same plane as all the others, and if they suffered a glancing blow within that plane, then the debris from the collision would also have been mostly in that plane. As the debris coalesced to form the Earth and Moon we know, they would have ended up orbiting each other, and spinning around their axes, in roughly this very same plane. (Note: This is a consequence of the conservation of angular momentum.)

This story potentially explains the orientation of the Moon’s orbit, as well as many other strange things about the Earth-Moon system. But evidence in favor of this explanation is still not overwhelmingly strong, and so we should consider this as an important question that astronomy has yet to fully settle.

So occultations, oppositions, and their near-simultaneous occurrence have a great deal to teach us and our students. Let’s not miss the opportunity!

Trees dating back almost 6000 years have come to scientists' attention due to ice melting in the Rocky mountains, offering a "time capsule" into the past