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The Arctic Ocean I trekked across 21 years ago is melting fast, becoming a potential shipping super-highway. That should worry us all, says the explorer and ocean conservationist

The amazing rise of RNA to delivering precise gene editing and its potential to unlock life's biggest secrets is told in The Catalyst by Nobel prizewinner Thomas Cech, who was a big part of the story

Of course the games should go after those who use performance-enhancing drugs to gain an advantage, but stamping out such abuses won't create a truly level playing field

In October 2022, the Fermi Gamma-ray Space Telescope and the Neil Gehrels Swift Observatory detected an extraordinarily powerful Gamma Ray Burst (GRB). It still stands as the Brightest Of All Time (BOAT), and astronomers have been curious about it ever since.

New research has uncovered more details in the burst. What do they tell us about these forceful explosions?

“When I first saw that signal, it gave me goosebumps.”

Maria Edvige Ravasio, Radboud University, Nijmegen, Netherlands

GRBs are the most powerful energetic events in the Universe, second only to the Big Bang. They’re brief yet powerful explosions that can release as much energy in a few seconds as the Sun will release in its billions of years of fusion. Astronomers don’t completely understand the mechanism behind them. They seem to come from the explosion of an extremely massive star or the merger of two extremely dense objects like neutron stars or black holes.

A GRB’s initial burst is called the prompt emission. While the prompt emissions themselves last anywhere from milliseconds to several hundred seconds, GRBs have afterglows that are much longer-lived and emitted in wavelengths longer than gamma rays: X-ray, ultraviolet, optical, infrared, microwave, and radio emissions. This means that astronomers can still study their source long after the gamma rays have disappeared.

When BOAT, aka GRB 221009A, was discovered, it was so powerful that it saturated Fermi’s detectors. That means astronomers weren’t able to observe some of the GRB’s most energetic moments.

In new research published in Science, astronomers say they’ve found another peak in GRB 221009A’s prompt emissions data. The research is “A mega–electron volt emission line in the spectrum of a gamma-ray burst.” The lead author is Maria Edvige Ravasio, a Post-doctoral Researcher in Astrophysics at Radboud University in Nijmegen, Netherlands. This peak is a new clue about what happens during a GRB.

“The physics of the prompt emission is poorly understood: The dominant form of energy in the relativistic jet is unknown, as is the nature of the radiative process responsible for producing the observed photons,” the authors write in their paper.

In their new research, the team used observations of the GRB and combined them with statistical models to identify new features. They divided the GRB into different time intervals and analyzed them separately and together. They focused on the parts of the prompt emission that weren’t the brightest. “We investigated the less bright portions of the prompt emission,” they write, and they avoided the portion of the signal that was saturated by the GRB’s extraordinary power.

This figure from the research shows some of the analysis. The horizontal axis shows the time since the GBM. GBM is the Gamma-ray Burst Monitor, an instrument on the Fermi Space Telescope that’s triggered by GRBs. The vertical axis shows the count rate, the blue line is the GRB’s light curve, and the numbered segments are the thirteen time intervals the researchers worked with. The grey area labelled BTI stands for Bad Timing Interval, excluded because the detector was saturated by the BOAT’s overwhelming energy. Image Credit: Ravasio et al. 2024.

“A few minutes after the BOAT erupted, Fermi’s Gamma-ray Burst Monitor recorded an unusual energy peak that caught our attention,” said Ravasio. “When I first saw that signal, it gave me goosebumps. Our analysis since then shows it to be the first high-confidence emission line ever seen in 50 years of studying GRBs.” A high-confidence emission line is a specific wavelength of light that’s unlikely to be noise. Like everything else about GRBs, the line was transient. It only lasted 40 seconds, but it’s still significant. It occurred about five minutes after the initial burst and peaked at 12 MeV (million electron volts). To put that into context, the light our eyes can sense, called visible light, ranges from only two to three eV.

This figure from the research shows some of the results. The left panel is for the 290 to 295-second interval, and the right panel is for the 300 to 320-second interval. These panels are dense with information, but the main takeaway is the peak shown with black dotted lines in both panels. “We find that the spectra at times 280 to 320 s after the GBM trigger contain a narrow emission feature at ~10 MeV,” the authors write. They used different models and methods to understand the data. SBPL stands for “smoothly-broken power law,” and Gaussian is another data handling method. Image Credit: Ravasio et al. 2024.

The newfound emission line is significant because of what happens to the energy emitted by GRBs. When powerful electromagnetic radiation collides with matter, it can be absorbed and then re-emitted at lower wavelengths. Depending on conditions, some wavelengths of light will be more prominent than others. Astronomers examine the light spectroscopically, and depending on the light that’s prominent or obscured, they can learn a lot about the chemistry of the matter that’s emitting the light. Some of the features in the spectrum can also reveal particle processes that are occurring. One of those processes is the annihilation of matter and anti-matter.

When astronomers studied the absorption and emission spectra from GRBs in the past, they couldn’t be certain that what they were seeing wasn’t noise. But this time, it’s different.

“We’ve determined that the odds this feature is just a noise fluctuation are less than one chance in half a billion.”

Om Sharan Salafiam co-author, INAF-Brera Observatory in Milan, Italy

“While some previous studies have reported possible evidence for absorption and emission features in other GRBs, subsequent scrutiny revealed that all of these could just be statistical fluctuations. What we see in the BOAT is different,” said coauthor Om Sharan Salafia at INAF-Brera Observatory in Milan, Italy. “We’ve determined that the odds this feature is just a noise fluctuation are less than one chance in half a billion.”

The researchers think that the emission line comes from gamma rays travelling at nearly the speed of light. Their most likely source is exotic: the annihilation of matter and anti-matter.

“When an electron and a positron collide, they annihilate, producing a pair of gamma rays with an energy of 0.511 MeV,” said coauthor Gor Oganesyan at Gran Sasso Science Institute and Gran Sasso National Laboratory in L’Aquila, Italy. “Because we’re looking into the jet, where matter is moving at near light speed, this emission becomes greatly blueshifted and pushed toward much higher energies.”

For the observed peak to reach the 12 MeV level, the electrons and positrons had to be moving at 99.9 % of the speed of light: 299,492,665 meters per second.

This artist’s illustration shows a jet of particles moving at nearly light speed emerging from a massive star. When the star ran out of fuel, it collapsed into a black hole. The black hole’s powerful gravity drew nearby matter toward it, and some of the matter was redirected into dual jets firing in opposite directions. We see a gamma-ray burst when one of these jets happens to point directly at Earth. Image Credit: NASA’s Goddard Space Flight Center Conceptual Image Lab

This emission line is a new window into the world of powerful GRBs.

“After decades of studying these incredible cosmic explosions, we still don’t understand the details of how these jets work,” said Elizabeth Hays, the Fermi project scientist at NASA’s Goddard Space Flight Center. “Finding clues like this remarkable emission line will help scientists investigate this extreme environment more deeply.” 

The post Astronomers Uncover New Details in the Brightest Gamma Ray Burst Ever Detected appeared first on Universe Today.

This link was sent to me by a despondent (and of course anonymous) New Zealander with the comment, “This is now unstoppable in NZ.”  It’s from the Times Higher Education site, and the authors are Mahdis Azarmandi and Sara Tolbert, both on the Faculty of Education of New Zealand’s University of Canterbury.

Click screenshot to read:

It’s fairly clear that by full “decolonization,” the authors propose a full disruption and subversion—yes, they use those words—of universities, with the ideal being to give the lands and waters back to the Māori people, as well as completely transforming college education into a program catering to the indigenous people.  I’ll give the authors’ intentions, and then show their “praxis” for decolonization. Excerpts are indented and bolding is mine.

As non-Indigenous scholars, we can engage in anticolonial and feminist practices that subvert the settler colonial university, but we cannot promise “decolonisation”, especially in a country such as New Zealand, where the effects of colonisation are ongoing and where, in the words of Indigenous climate activist India Logan-Riley, “land back, oceans back” is yet to be realised. Unless the university is fully engaged in land back, oceans back, decolonisation will be used by the settler colonial university to justify settler occupation of stolen land, water and knowledge (see “additional links”, below).

Rather than offer how-to tips for “decolonising the university”, we suggest a few points as a call for collective action to change things that are unjust ­– inside and outside the university. We argue that to engage in anticolonial, feminist practice, we must address the systems that produce violence and exploitation, not just in the scholarly aspect of our work but also within our own institutional and material conditions such as housing, jobs and access to health. Some of these points are taken from our forthcoming chapter “A manifesto for transdisciplinary (transgressive) feminist praxis in the Academy”.

It’s clear from these words that the authors, who are both non-indigenous, don’t want merely a cosmetic redo of universities, which they see as not only having stolen the land and water from the indigenous people, but also “produce violence and exploitation.” They mean what they say: they want a complete rethink and redo of how the country’s universities are run and what they teach.

Unless by “violence” the authors mean “offense”, the hyperbole is strong, especially since New Zealand’s government and universities are doing everything that can to create equity for the Māori. (Indigenous people constitute 16.5% of New Zealand, just ahead of the 15.1% Asian and well behind the 70% European people.)  One question underlying all this is whether the whole system has to be transformed to cater to the people who got to the islands first. But I’ll leave that aside and move on, because it’s worth seeing the reforms these two scholars suggest. There are six alterations of “praxis”:

1.) We can’t both love and change the university at the same time. We must actively engage in the disruption of oppressive, settler colonial and patriarchal practices. Learning from abolitionist struggles, we need to engage in non-reformist reform – that is, practices that improve the lives and conditions of those most marginalised (outside and inside the university) but that do not consolidate the power of the institution.

By “most marginalized,” I presume they mean the Māori people, though later they pull others into the reformist tent. Note that their purpose is not education, but social reform—outside as well as inside the university.  There is not a word about what sort of education people will get, save that it’s going to be centered on indigenous “ways of knowing”:

2.) A crucial aspect of anticolonial praxis in the university is recognising and respecting Indigenous epistemologies and, where possible, engaging these as central to its curriculum while also peripheralising European and settler knowledge, which has been foundational in its formation. However, how and to what extent Indigenous knowledge should be in the university is not for non-Indigenous people to decide, but the way we act within our natural and knowledge environment must not be extractivist. We can and must resist extracting resources and knowledge from land, water and people. We need also remember that some knowledge is not ours to share; “sometimes the knowledge does not need to be moved out of the communities where it resides into the pages, websites and walls of the academic industrial complex” (Tolbert & Azarmandi, forthcoming). What anticolonial feminist praxis centres is being-in-relation (with place and people). We need to approach the incorporation of Indigenous knowledge with humility – there is a fine line between incorporation of Indigenous knowledge and cultural appropriation. What we can do is make space by disrupting disciplinary boundaries and challenging the limitations of academic disciplines that discourage collaboration and maintain competition.

Here we see that the “settler colonialists”—that is, able-bodied heterosexual males of European descent (see below)—should have no say in what passes for knowledge in the university. Indigenous knowledge must be central, and settler knowledge peripheral.  In practice, this means the Māorization of the entire curriculum, including science.

3.) We must build collaborative partnerships and alliances with other marginalised communities, acknowledging the intersections of colonialism, racism, sexism, homo-transphobia, ableism and other forms of oppression. Building genuine relationships and collaborative partnerships with Indigenous and marginalised communities is essential. If these relationships benefit scholars and the academy more than the community, chances are they are meant to further empower settler colonial regimes and not disrupt and decolonise them. Adapt feminist and collaborative writing practices; refuse symbolic service requests and instead strategise and work towards systemic change: unionise, organise for a living wage and improve institutional practices such as parental leave and access to healthcare and housing.

In the above they pull into their tent everyone considered marginalized, including the disabled, people of color, women, gay people, and trans people.  It’s not just that these people deserve equal rights and equal educational opportunities—something that nobody would oppose—but that they will also participate in overthrowing and subverting the violent and exploitative universities. As for parental leave, healthcare and the like, that is the responsibility not of the universities themselves, but of the New Zealand government, which funds the universities.

4.) Anticolonial praxis requires institutional transformation at all levels. This also means securing the right to education and making sure public universities exist and are supported. In the institution, we need to critically examine and restructure policies, procedures and practices that perpetuate settler colonial regimes of power. It involves addressing systemic barriers that maintain inequality, such as access to education, hiring practices, tenure and promotion criteria, curricular decisions and funding allocations. Resist symbolic change and cultural window dressing. Name it; make it explicit.

#4 is more of the same, expressing a deep animus towards the “settler colonial regimes of power”, something they never give examples of.  They also argue that “systemic barriers” (i.e., codified systems of bigotry) must be dismantled, although they give no examples of such barriers and I know of none.

5.) Anticolonial and feminist praxis requires constant self-reflection and a commitment to unlearning. It involves critically examining our own complicity within the settler colonial structures. Be mindful, however, that this reflective and personal work alone does not create change – and sometimes, as feminist scholar Sara Ahmed has illuminated, it can become another way of not doing things with words. Connect, resist and organise.

6.) Finally, we must dare to dream beyond the university. What if the university can’t be unsettled or decolonised? If we do unsettle or decolonise the institution, will it be recognisable once we are done? As la paperson (the avatar of K. Wayne Yang, an associate professor of ethnic studies at the University of California, San Diego) has written (and we cite in our forthcoming chapter), we should understand “the university as a machine that is the composite of many other [disloyal] machines” – ones that ‘break down and travel in unexpected lines of flight – flights that are at once enabled by the university yet irreverent of that mothership of a machine’. May we find each other…beyond the university, and unite in our irreverent lines of flight”.

Here the universities are seen as mere staging areas for society-wide transformation, something they implied when they said, “Building genuine relationships and collaborative partnerships with Indigenous and marginalised communities is essential. If these relationships benefit scholars and the academy more than the community, chances are they are meant to further empower settler colonial regimes and not disrupt and decolonise them.”

One gets the impression here that the writers would be happiest if all the Europeans (save the marginalized ones, like the gays or people of color, were heaved out of the country so it would revert to a system of Māori governance.  Now it’s true that the Māori were historically oppressed, but were also given the rights of “colonialist” settlers as well as the right to keep all their lands and properties by the 1840 Treaty of Waitangi. This treaty, which is ambiguous and wasn’t even signed by all the indigenous leaders, is a holy document in New Zealand, interpreted by locals to mean that they get most of everything (the fearful Europeans dare not say otherwise).

When you read something like this, you wonder about not only the philosophy of Times Higher Education, which decided to print what is largely an incoherent (and incorrect) set of assertions and accusations, but you also wonder about what will happen to New Zealand. The authors, after all, are “settler-colonialists”, calling for their own decimation.

What is happening in New Zealand—with all the many official attempts to create equity only serving to provoke tirades like the one above—is the world’s most far-reaching attempt at ideological capture of an entire country by the people who consider themselves entitled to run the whole country: the descendants of the original Polynesian settlers.  But the world has moved on, and who can deny that “settler colonialists”, by bringing with them their knowledge, medicines, free national healthcare, and inventions, have improved the lives of most people in New Zealand? It is not as if the arrival of people from elsewhere has been an unmitigated evil.

I think the person who sent me this screed is right: this movement is unstoppable, and it’s going to ruin New Zealand.  Apparently the Luxon government is either ignoring this stuff or doesn’t care to stop it.  Soon it will be too late, if it isn’t already.

I pity New Zealanders who want to get a good college education in the face of people like Drs. Azarmandi and Tolbert, whose program will sink New Zealand to the bottom of the academic ranking of comparable countries.

People with body dysmorphic disorder seem to have altered activity in a brain pathway involved in attention and recognition, which may explain why they overly focus on aspects of their appearance

Fossils found 50 and 100 years ago seemed to pinpoint the moment humanity emerged – but defining a human has turned out to be far trickier than we thought

Fossils found 50 and 100 years ago seemed to pinpoint the moment humanity emerged – but defining a human has turned out to be far trickier than we thought

A hypothetical question: You are one of the moderators of the next Presidential debate. (We’re not sure if there will be one, though there surely must.)  What question(s) would you most like to ask both candidates together, as well as either one separately. Since Harris hasn’t yet chosen a running mate, we’ll leave out VP questions, though if you want to say what you’d ask Vance, fire away.  Be hard on them!

But here’s one question I’d ask both candidates. A version of this was asked in 2007 among the Republican Presidential candidates, with three out of the ten candidates said they didn’t “believe in evolution.” Here’s the video of that:

So here’s what I’d ask both Trump and Harris:

Do you accept that evolution is true? Why or why not?

That’s a touchstone about whether they’d accept established scientific “truth.” If you don’t buy that, then you’re oblivious to evidence. I’m sure Harris would say “yes”, but don’t know what Trump would say.  But I’d also like to know if they know the evidence.

Here’s what I’d ask Trump (two questions):

You still maintain that the last Presidential election was rigged, with illegal votes counted in a way that made you lose.  If you lost this time, would you still say the same thing?

(This is to determine whether he’d still foment insurrection if he lost.)

As lagniappe, I’d ask him this:

You recently said this: 

“You got to get out and vote. In four years, you don’t have to vote again. We’ll have it fixed so good, you’re not going to have to vote.” 

And you’re sticking by that statement. Could you explain exactly what you meant by it? 

And here are two questions I’d ask Harris:

What do you think you accomplished on your own as Vice-President, as opposed to simply assenting to what Biden accomplished? I am referring to what you actually did to make America progress, as opposed to what you were supposed to do). 

I thought of one more:

You are hoping that you will win the Presidency by reinstalling Roe v. Wade as the law of the land. How, exactly, would you accomplish this if at least one house of Congress was majority Republican?

Both of those questions for Harris are designed to make her think on her feet as opposed to her custom of simply repeating a question as if it were an answer.

Put your questions below. Remember, you aren’t supposed to show partisan bias here, but to draw out the candidates, for that’s what debate moderators are supposed to do.

When giant solar storms hit Earth, they trigger beautiful auroral displays high in Earth’s atmosphere. There’s a dark side to this solar activity, though. The “space weather” it sets off also threatens our technology. The potential for damage is why we need highly accurate predictions of just when these storms will impact our planet’s magnetosphere.

To figure that out, scientists in England went to the source: specific places on the Sun where these storms erupt. Those outbursts are called “coronal mass ejections” (CMEs). They’re huge explosions of magnetically charged particles and gases from the Sun. They travel through space and hit whatever is in their way, including planets.

When that cloud of charged particles hits our magnetic field, it sets off a chain reaction of events. Of course, it creates beautiful auroral displays—northern and southern lights that dance in the skies. But, they also slam into and can damage orbiting satellites, including all our telecommunications and navigation systems for planes, boats, and trains. The danger is even greater for astronauts aboard orbiting space stations. That’s because radiation is a constant threat to human life. On Earth, those storms can cause huge circulating electrical currents that can damage electric power grids. The damage to technology just ripples across the planet.

This is why satellite operators and others want more accurate predictions of just when a space weather event triggered by a CME will hit us. To figure that out, solar physicists have to look back at the Sun and the sequence of events that cause CMEs.

Active region outbursts that cause solar storms. Studying the Solar Active Regions

CMEs emanate from active regions on the Sun. These are places with very strong magnetic fields. The magnetic field lines form loops that get twisted and eventually, they break. When that happens, there’s a huge outburst of material—the CME. Typically, they travel out from the Sun at anywhere from 100 km/sec to 3,000 km/sec. That large uncertainty makes it tough to predict when the solar cloud will hit Earth.

Steps in the creation of a CME, showing the root cause of solar storms. Courtesy Temmer, et al. CC BY 4.0.

Science teams led by Aberystwyth University solar physicist Harshita Ghandhi, focused on the height above the Sun where the magnetic field becomes unstable. They call it the “critical height” and it can help scientists predict the speed and arrival time of a coronal mass ejection.

“By measuring how the strength of the magnetic field decreases with height, we can determine this critical height,” said Gandhi. “This data can then be used along with a geometric model which is used to track the true speed of CMEs in three dimensions, rather than just two, which is essential for precise predictions.”

The team found a very strong relationship between the critical height of the CME as it gets started and its true speed as it moves out. “This insight allows us to predict the CME’s speed and, consequently, its arrival time on Earth, even before the CME has fully erupted,” Ghandhi said.

Knowing the actual speed of the CME to a higher degree of accuracy will let solar physicists predict when it will hit Earth. That, in turn, will allow satellite operators, grid owners, space agencies, and others to prepare for the action and protect their assets. “Understanding and using the critical height in our forecasts improves our ability to warn about incoming CMEs, helping to protect the technology that our modern lives depend on,” Gandhi pointed out.

Solar Storms and the Damage They Cause

Our Sun goes through periods where it is more “outbursty” than others. Some of the strongest solar storms occur during the solar maximum part of the Sun’s 11-year sunspot cycle. That’s not to say they don’t occur at other times. Whenever they happen, however, they can cause a lot of damage. One famous storm occurred on March 13, 1989. It was a combo of two CMEs that lifted off the Sun on March 10th and March 12th. They stirred up currents low in Earth’s atmosphere at the same time they triggered auroral displays. At the time, power grids were not necessarily “hardened” against such events. As a result, the Hydro-Quebec power grid shut down and suffered tremendous damage. The power was out for days across eastern Canada and parts of the United States.

Sensitive to solar activity? Power grids on the ground are vulnerable to interruptions from space weather caused by solar storms. (AP Photo/Smithsonian)

Another huge storm hit around Halloween in 2003. It affected satellite systems, cut off communications, some power systems shut down, and people around the world saw a dazzling display of aurorae. In space, the SOHO solar satellite shut down briefly. Astronauts onboard the ISS had to take shelter in a safe place aboard the station.

Today, we’re in another cycle of heightened solar activity. We’ve already seen strong storms in May of 2024, and more will surely occur. So far they haven’t caused much damage, and they’ve given us some lovely auroral displays. Luckily, advanced research on these solar storms has helped technology operators and space agencies “harden” their systems. However, there’s only so much they can do to protect their assets. Having highly accurate advance predictions of just when a CME will impact our planet is a big step forward. At the very least, these operators will be able to reposition satellites, strengthen their power grids and other communications technology, and give astronauts in space advance warning. In future years, when we have people on the Moon or on their way to Mars, such predictions will help keep them safe, too.

For More Information

New Dawn For Space Storm Alerts Could Help Shield Earth’s Tech
A 21st-Century View of the March 1989 Magnetic Storm

The post Predicting Solar Storms Before They Leave the Sun appeared first on Universe Today.

Today’s Jesus and Mo strip, called “choice,”  came with a question, “What’s your favorite verse in the Qur’an?”

Mo’s upset because the Qur’an states that Jesus wasn’t killed on the cross, but ascended alive to heaven, hauled up to be with God.  This shows that both religions can’t be true, but of course they can both be false.

Meanwhile the barmaid has a bit of fun.

Permanently shadowed regions on the moon are the perfect spots for preserving deep-frozen organisms, although questions remain about how easy it would be to access them

We’re right at the end of the queue, but I’m leaving on Saturday so hold onto your good wildlife photos until I return at the beginning of September. Today we have some photos from Damon Williford in Texas. His notes and IDs are indented, and you can enlarge the photos by clicking on them:

Here are a few more bird photos from the central Gulf Coast of Texas taken during the spring of this year.

The Laughing Gull (Leucophaeus atricilla) is the only species of gull that breeds along the U.S. Gulf Coast. The individual pictured is an adult in full breeding plumage, which begins to develop in February and March and starts to disappear in mid- summer:

Herring Gull (Larus argentatus) is one of the three species of gulls that regularly spend the winter in Texas. This individual was an immature bird possibly transitioning between second- and third-year plumages:

 The Ring-billed Gull (Larus delawarensis) is another gull that winters regularly in Texas:

The Royal Tern (Thalasseus maximus) is one of seven species of terns that breed in the Gulf of Mexico region. It is also one of the most common terns on the Texas coast, and the second largest species of tern in the area: only the Caspian Tern (Hydroprogne caspia) exceeds it in size. The Royal tern pictured has already transitioned to non-breeding plumage, which involves the loss of most of the black plumage on the crown so that it looks like aging punk rocker suffering from a receding hairline:

Black skimmers (Rynchops niger) are regular breeding birds on the Texas coast:

Brown Pelicans (Pelecanus occidentalis):

Snowy Egrets (Egretta thula) are one of the most common species of herons in Texas. It is also one those species (others include the Laughing Gull and Brown Pelican) that I photograph frequently because Snowy Egrets are abundant and are not overly skittish, allowing me to get close. The one in the photo was so intent on catching breakfast that it came very close to where I was standing on a jetty overlooking a salt marsh:

Another Snowy Egret chasing down its own breakfast:

A pair of White Ibises (Eudocimus albus) at a freshwater marsh on the San Bernard National Wildlife Refuge:

Over the last few decades there has been a steady infiltration of acupuncture into Western mainstream medicine. It is not unreasonable to conclude that acupuncture’s journey from an exotic Eastern practice to a fringe treatment to mainstream acceptance has been complete. Knowledgeable proponents of science based medicine (SBM) who remain skeptical of acupuncture now find themselves on the fringe. How did this […]

The post Acupuncture and Evidence Based Medicine first appeared on Science-Based Medicine.

Searching for Earth 2.0 has been an obsession of almost all exoplanet hunters since the discipline’s dawn a few decades ago. Since then, they’ve had plenty of technological breakthroughs help them in their quest, but so far, none of them have been capable of providing the clear-cut image needed to prove the existence of an exo-Earth. However, some of those technologies are undoubtedly getting closer, and one of the most interesting is utilizing a system called a multi-grated vector vortex coronagraph (mgVVC). Researchers funded by ESA think it may hold the optical properties to enable space-based telescopes like the Habitable Worlds Observatory (HWO) to finally capture the holy grail of exoplanet hunting – and it may be ready for prime time as early as next year.

That’s the timeline provided by the project team for the Substantiating Unique Patterned Polarization-sensitive Polymer Photonics for Research of Exoplanets with Space-based Systems (SUPPPPRESS) project, based out of Leiden University. ESA funded the project in October 2023 and plans to run for two years. For those two years, its primary focus will be building and testing a mgVVC designed to eliminate one of the biggest challenges related to its implementation—polarization leakage.

To understand why that’s a problem, it’s best first to understand what a vector vortex coronagraph is. A standard coronagraph uses some optical mask or physical disk to block out a star’s light. This allows the light from that star’s exoplanets to shine directly onto its optical system, allowing even relatively standard optics to make out details of the planet, like whether it has water in its atmosphere.

Fraser interviews coronagraph expert Dr. Lucie Leboulleux

A vector vortex coronagraph uses a type of liquid crystal mask that shifts the phase of the starlight, essentially eliminating it. However, light from objects slightly off the mask’s axis, such as an exoplanet, isn’t affected by the phase shift, allowing it to pass through directly to the accompanying telescope’s detector. 

Polarization leakage happens because of manufacturing defects in the liquid crystal mask used by VVCs. These could result from alignment errors, deformities in the liquid crystals, or stress or strain on the mask. Ironically, the way to fix this might be to make more masks.

The concept of a multi-grated vector vortex coronagraph is to layer multiple masks on each other. Since many of the defects are created in the manufacturing process, they should be unique to each individual mask, and as such, they shouldn’t stack but cancel each other out when placed in series with one another. And the more grates there are, the more effective this solution is. According to the paper, a single-grated VVC could capture light from an exoplanet that is about 10,000 times dimmer than its host star. In contrast, a triple-grated VVC would be capable of capturing light from exoplanets that are 10 billion times dimmer than their stars.

Nancy Grace Roman is another mission planned with an amazing coronagraph, as Fraser discusses here.

That level of contrast is what would be needed to find a true exo-Earth. But the research team isn’t quite there yet. As part of a recent paper, the SUPPPPRESS project team did some modeling, built some preliminary prototypes, and performed some testing using JPL’s In-Air Coronagraphic Testbed and the University of Arizona’s Space Coronagraph Optical Bench. Results were promising, though they “highlighted the need for further refinements,” according to the paper. Each prototype test showed some errors in the mgVVC design, including the ominous-sounding “dark-hole regions” and the slightly less dire-sounding “uniform speckle field.” 

These hurdles aren’t impossible to overcome, and further testing is ongoing at the THD2 test bed in Paris – as long as the researchers aren’t distracted by all the sports going on around them. They did pass a preliminary design review in April of this year and plan to wrap up the next round of testing by December.

If continued testing and development go as planned, the researchers at the University of Leiden could provide one of the critical components for HWO by the time it is ready to move to the manufacturing phase. But even if it isn’t used on that mission, given this system’s impressive optical characteristics, it will undoubtedly be used somewhere.

Learn More:
Laginja et al – Prototyping liquid-crystal coronagraphs for exo-Earth imaging
UT – The Search for the Perfect Coronagraph to Find Earth 2.0
UT – Webb Directly Images a Jupiter-Like Planet
UT – Suppressing Starlight: How to Find Other Earths

Lead Image:
This artist’s concept features one of multiple initial possible design options for NASA’s Habitable Worlds Observatory.
Credits: NASA’s Goddard Space Flight Center Conceptual Image Lab

The post How to SUPPPPRESS Light From a Star That Is Ten Billion Times Brighter Than Its Habitable Exoplanet appeared first on Universe Today.

Near-Earth space is an orbiting junkyard of space debris. Everything from old rocket parts and pieces of dead satellites to cameras and tools floats in orbit. None of it serves a useful function any longer, but it does threaten other spacecraft. In fact, some missions have been damaged by this orbital debris and the problem will get worse as we launch more missions to space.

So, it makes sense to remove the existing space junk, but how to do that? A company in Japan called Astroscale is working with the Japan Aerospace Agency (JAXA) to figure that out.

On July 15 and 16th, Astroscale maneuvered a demonstration satellite called ADRAS-J into place around its target. Its goal was to do a “Fly-around observation” of a rocket upper stage that launched the Greenhouse Gases Observing Satellite (GOSAT) in 2009. ADRAS-J was launched earlier this year on a trajectory to chase down space debris. The early July portion of the mission saw ADRAS-J fly around the object and get high-quality images of the object. In addition, it took data about the rocket motor’s motion in space (including its orbital parameters) and assessed its condition. The effort was successful and the teams captured great images of the motor from every angle.

More images of the target object of space debris from ADRAS-J on July 16th. Courtesy Astroscale/JAXA.

The maneuvers ADRAS-J made are technically challenging, requiring fine guidance control of the ADRAS-J module. Luckily, the target object was fairly easy to approach and move around. In on-orbit maneuvers like this one, it’s important to control the relative position and attitude of the servicer unit (ADRAS-J). Such control allows it to move around the object and zero in on specific parts for further work. The rocket motor was fairly stable. However, not all bits of space junk are as stable as the rocket motor targeted for this experiment.

Challenges to Working with Space Debris

Given the huge collection of space junk out there, not everything is going to be easy to capture. Future “clean-up efforts” could involve so-called “non-cooperative targets” whose motions are more chaotic, or are dangerous to approach. Those could be very challenging. So, it’s important to have the detailed shape and surface reflectance of the real target object. For most pieces of space junk that information isn’t readily available.

For example, it’s also useful to know the changing visibility of the target object, and the influence of earth-reflected light, which disturbs the navigation sensor (the so-called Earth background problem in non-cooperative relative navigation). These add to the complexity of the mission. That’s because the servicer spacecraft must overcome those challenges for relative navigation while achieving highly accurate relative six-degree-of-freedom control around the target.

The ADRAS-J mission is part of the “Commercial Remove of Debris Demonstration” initiative from JAXA to acquire and test debris removal in space. If it’s successful, that should help clear up space for future missions leaving Earth. Astroscale Japan, Inc. will continue to operate ADRAS-J and will carry out “Astroscale missions” to further test the hardware and maneuvering capabilities.

The next step will be to perform a “Mission termination service”. That involves the transfer of a target piece of space junk to a safe orbit. This will be done in cooperation with JAXA, which has already provided extensive technical advice, testing facilities, and other activities supporting ADRAS-J’s development and operation.

Fly-around images in sequence. Courtesy Astroscale/JAXA. Why Clean Up Space Junk?

Tens of thousands of artificial objects orbit above Earth. That includes more than 5,000 operating satellites, plus space stations, and Starlinks, and other stuff shot into orbit since the late 1950s. Eventually, as the old adage says, “what goes up must come down.” In fact, some of it does come back to Earth, which also poses a safety issue.

In the case of dead rocket motors and other nonworking pieces of space junk, not only will they come down to Earth, but they get in the way of spacecraft launches. That includes crewed launches carrying astronauts to the space stations, the Moon, and beyond.

The danger isn’t just that a collision will hurt somebody in space or on the ground. Tiny pieces of space junk can knock holes in solar panels and instruments. Bits of dust and paint flecks and other materials literally “sandblast” spacecraft on the way up. Space shuttles showed a lot of this damage. All this space debris began littering our spaceways starting with the first launches in the late 1950s. The materials are tracked by the North American Aerospace Defense Command (NORAD), and their catalogs include details of all the objects including satellites, weapons, fairings, upper stages, cameras, tools, and other pieces of debris from satellites destroyed by collisions and other actions.

It makes sense to clean up the junk that doesn’t fall back to Earth (and hopefully burn up in the atmosphere). That’s why JAXA and other agencies are looking at proactive ways to approach, apprehend, and safely store the debris (or deorbit it to vaporize, if possible). The first steps with ADRAS-J are proofs of concept that should lead to a larger clean-up job and a safer near-Earth environment for future missions.

For More Information

CRD2 Phase I / ADRAS-J Update: Fly-Around Observation Images of Space Debris Released
ESA: about Space Debris

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Tulip trees have a structure that is somewhere between hardwood and softwood – called "midwood" – which could increase their ability to store carbon  

I have always found Mariana’s Trench fascinating, it’s like an alien world right on our doorstep. Any visitor to the oceans or seas of our planet will hopefully get to see fish flitting around and whilst they can survive in this alien underwater world they still need oxygen to survive. Breathing in oxygen is a familiar experience to us, we inflate our lungs and suck air into them to keep us topped up with life giving oxygen. Fish are different, they get their oxygen as water flows over their gills. Water is full of oxygen which at the surface comes from the atmosphere or plants. But deep down, thousands of meters beneath the surface, it is not so easy. Now a team of scientists think that potato-sized chunks of metal called nodules act like natural batteries, interacting with the water and putting oxygen into the deep water of the ocean. 

Thanks to robotic underwater explorers the sight of life teeming around thermal vents on the bottom of the deep ocean is not unusual. At those depths, no sunlight can penetrate to facilitate photosynthesis in plants. Somehow though, oxygen is present in the dark, deep regions of the ocean and its the rocks that a team of scientists led by Andrew Sweetman have been exploring.

A Three-dimensional cross-section of the hydrothermal system in the Chicxulub impact crater and its seafloor vents. The system has the potential for harboring microbial life. Illustration by Victor O. Leshyk for the Lunar and Planetary Institute.

The production of oxygen by plants is well understood. Light is captured by a pigment known as chlorophyll where it is then converted into chemical energy and stored in the glucose. During photosynthesis, carbon dioxide from air and water from soil are combined in a series of chemical reactions to produce glucose and oxygen that we use to breathe. This oxygen from the plants plays a role in maintaining levels in the atmosphere and the oceans and seas. The study challenges this somewhat simplified explanation. 

The team focussed on measuring how much oxygen was being consumed by organisms in the depths of the ocean. Water sampled from the deep showed a surprising rise in oxygen levels instead of an anticipated decline. The study was repeated a few years later from the same location in a study commissioned by a mining company. Again they saw a rise in oxygen levels. Clearly something in the deep ocean was creating oxygen, but what?

Lab tests ruled out the possibility of microbes but the region being studied was peppered with lumps of rock known as polymetallic nodules. The nodules are known to form when manganese and cobalt precipitate out of water and form around shells. The nodules where theorised to be the source of the oxygen but the mechanism was not understood. 

The answer came when Sweetman heard a reporter calling the nodules ‘a battery in a rock’. Putting batteries in saltwater results in bubbles of hydrogen and oxygen which is the result of a process known as electrolysis. The team measured the voltage on the nodules and found just one of them to be 0.95 volts – a little lower than the required 1.5 volts for saltwater driven electrolysis but the team were onto something, suspecting multiple rocks could cluster together to increase voltage. 

The discovery of rocks on the bottom of the ocean generating oxygen is fascinating on its own but it has profound impacts on the search for life elsewhere in the universe. We have already discovered ice covered water worlds among the moons around some of the outer planets. It’s likely there will be others in planetary systems around other stars. If these worlds are common then it is quite likely that oxygen is being released through electrolysis from similar metallic nodules and perhaps, supporting entire ecosystems.  

Source : Evidence of dark oxygen production at the abyssal seafloor

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Computers benefit greatly from being connected to the internet, so we might ask: What good is a quantum computer without a quantum internet?

The origins of the Moon have been the cause of many a scientific debate over the years but more recently we seem to have settled on a consensus. That a Mars-sized object crashed into Earth billions of years ago, with the debris coalescing into the Moon. The newly formed Moon drifted slowly away from Earth over the following eons but a new study suggests some surprising nuances to the accepted model. 

According to current theory, the Moon formed around 4.5 billion years ago, shortly after the Solar System’s birth. It began with a massive collision between the early Earth and a Mars-sized protoplanet called Theia. The impact sent debris into orbit around the Earth which eventually coalesced to create the Moon. There is plenty of evidence to support this theory chiefly the composition of Earth’s mantle and lunar rocks.

Artist’s impression of the early Solar System, where collision between particles in an accretion disc led to the formation of planetesimals and eventually planets. Those early particles brought primitive minerals to each world. Credit: NASA/JPL-Caltech

The majority of the debris cloud settled back down on the Earth, a large proportion formed the Moon but some of it was ejected from the Earth-Moon system. In the paper recently authored by Stephen Lepp and his team from the University of Nevada they explored the dynamics of the material ejected from the impact. 

Shortly after the Moon formed it was orbiting Earth at a distance about 5% of its current value (average distance – 384,400km) but slowly, due to tidal effects between Earth and Moon it drifted away to its current altitude. Its surface was largely molten magma which gradually cooled and solidified forming the familiar crust, mantle and core that we see today. Heavy bombardment scarred the lunar surface with impact basins and craters and volcanic activity led to the slow formation of the lunar maria. 

The orbit of the Moon around the Earth has settled into a slightly elliptical one with an eccentricity of 0.0549. It is not a perfect circle and moves from 364,397km to 406,731km from Earth. The system wasn’t so stable in the early days of the Earth-Moon system and the particles in the accreting Moon had more erratic journeys. 

The Moon on August 24, 2023, with the eQuinox 2 telescope by Unistellar. Credit: Nancy Atkinson.

One of the terms that describes evolving orbits is nodal precession (where the orbital intersections slowly move around the orbit). There are two types and the first relates to where particles in an orbit slowly precess about the angular momentum vector of the Earth-Moon system. The other occurs around highly eccentric binary systems when the inclination of the orbiting object is large. The particle precesses about the binary eccentricity vector. Taking into account the Earth and orbits of particles in the debris cloud as the Moon started to form, such orbits described would be unstable.

The team showed that of all the possible orbits of particles, those in polar orbits were the most stable. They went further and showed that they existed around the Earth-Moon binary system after the Moon formed. As the separation of the Earth and Moon slowly increased through tidal interactions the region of space where polar orbits could exist decreased. Today, with the Moon at its current distance from Earth, there are no stable polar orbits since the nodal precession driven by the Sun is dominant

The team conclude that the presence of polar orbiting material can drive eccentricity growth of a binary system like the Earth and Moon. If a significant amount of material found its way into a polar orbit then the eccentricity of the Earth-Moon system would have increased.  

Source : Polar orbits around the newly formed Earth-Moon binary system

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