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As part of the Artemis Program, NASA intends to establish all the necessary infrastructure to create a “sustained program of lunar exploration and development.” This includes the Lunar Gateway, an orbiting habitat that will enable regular trips to and from the surface, and the Artemis Base Camp, which will permit astronauts to remain there for up to two months. Multiple space agencies are also planning on creating facilities that will take advantage of the “quiet nature” of the lunar environment, which includes high-resolution telescopes.

As part of this year’s NASA Innovative Advance Concepts (NIAC) Program, a team from NASA’s Goddard Space Flight Center has proposed a design for a lunar Long-Baseline Optical Imaging Interferometer (LBI) for imaging at visible and ultraviolet wavelengths. Known as the Artemis-enabled Stellar Imager (AeSI), this proposed array of multiple telescopes was selected for Phase I development. With a little luck, the AeSI array could be operating on the far side of the Moon, taking detailed images of stellar surfaces and their environments.

The proposal was made by Kenneth Carpenter and his colleagues at NASA Goddard Space Flight Center (GSFC). Carpenter is the Hubble Operations Project Scientist at GSFC and the ground system scientist for the Nancy Grace Roman Space Telescope (RST). As they note in their proposal, NASA’s return to the Moon offers several significant opportunities for him-impact scientific research. Not the least of these is the potential for creating observatories that take advantage of the “radio quiet” environment and extended periods of darkness on the far side of the Moon.

Artist’s illustration of a radio telescope inside a crater on the Moon. Credit: NASA/JPL-Caltech

Due to the tidally locked nature of its orbit, where one side of the Moon is always facing toward Earth, the Moon’s day/night cycle lasts for 14 days. This means a “lunar day” consists of two weeks of continuous sunlight, while a lunar night consists of two weeks of continuous darkness. At the same time, the Moon’s airless environment means that any observations by optical telescopes will not be subject to atmospheric interference. This makes the far side of the Moon a pristine environment for conducting high-resolution interferometric imaging, a method where multiple telescopes collect light to look for patterns of interference.

Astronomers extract data from these patterns to create a detailed picture of celestial objects that are difficult to resolve with conventional telescopes. This same technique allowed the Event Horizon Telescope (EHT), a global network of radio telescopes, to acquire the first image of a black hole ever taken. According to the team, a lunar interferometry array has immense scientific potential and could be built incrementally to limit construction costs:

“This can resolve the surfaces of stars, probe the inner accretion disks surrounding nascent stars and black holes, and begin the technical journey towards resolving surface features and weather patterns on the nearest exoplanets. A fully developed facility will be large and expensive, but it need not start that way. The technologies can be developed and tested with 2 or 3 small telescopes on short baselines. Once the technology is developed, baselines can be lengthened, larger telescopes can be inserted, and the number of telescopes can be increased. Each of these upgrades can be accomplished with minimal disruption to the rest of the system.”

Despite these advantages, the team notes how previous studies on interferometers in space concentrated on designs for free-flying arrays. This was largely due to the 2003-2005 NASA Vision Missions Studies that examined the trade-offs between free-flying space concepts and kilometer-sized interferometers built on the lunar surface. The study concluded that it was better to pursue space-based free-flyers, given the absence of pre-existing human infrastructure on the lunar surface that could provide power and regular maintenance.

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

However, with the Artemis Program, Carpenter and his team argue that this situation is now changing. With the completion of surface habitats, transportation, drilling, and power facilities planned for the coming years, now is a good time to investigate the possibility of building interferometers on the lunar surface. “Our study of a lunar surface-based interferometer will be a huge step forward to larger arrays on both the moon and free-flying in space, over a wide variety of wavelengths and science topics,” they write. “It will determine, given the current and anticipated state of our space technology and human exploration plans, whether it is better to pursue designs for the lunar surface or for deep space.”

They further envision that a lunar interferometer will lead to advancements in astrophysics, like the study of stellar magnetic activity, the nuclei of active galaxies, and the dynamics of cosmological phenomena on many scales. The design and construction of such a facility will address key engineering concerns, like the best way to incorporate variable-length optical lines, the best configurations for the telescopes, and the optimal mirror size for meeting both technical and scientific goals. They also hope to create a plan for maintaining and expanding the facility over time using a mix of human and robotic support.

Beyond that, the anticipated benefits include technical advances that will enable a UV-optical interferometer and space-based missions capable of imaging black holes (similar to the EHT), searching for biosignatures, and directly imaging rocky exoplanets around other stars. Carpenter and his colleagues also anticipate that the creation of a major facility on the Moon, in conjunction with the Artemis Program’s human exploration goals, will generate tremendous public interest and engagement:

“Finally, this effort will make people dream again – and remember that we can do great things, even in [the] face of difficult times. Our study will help keep the focus on the grandeur of the Universe and what humans can do if they work hard together. Our project will excite generations of future Science, Technology, Engineering, Art, and Mathematics (STEAM) workers, who will be inspired by this bold vision.”

Further Reading: NASA

The post NASA Wants to Put a Massive Telescope on the Moon appeared first on Universe Today.

According to my go-to source, the Oxford English Dictionary, “civil disobedience is defined this way:

Rebellion of the populace against a governing power; (in later use) spec. refusal to obey the laws, commands, etc., of a government or authority as part of an organized, non-violent political protest or campaign.

The three key aspects here involve deliberately breaking the law, doing it as part of a “political protest or campaign”, and doing it in a peaceful, nonviolent way. But I would add potential effectiveness: the actions must aim at achieving political results, and do so in a way that could reach those results.

The archetypal examples of civil disobedience that met these four criteria are the nonviolent protests of Gandhi and the Indian people that led the British to “quit India” in 1947, and the American civil rights actions of the 1960s that led to the nation-changing civil rights acts of 1964 and 1965.

Gandhi, of course, was one inspiration for Martin Luther King, Jr., who adopted Gandhi’s methods of nonviolent resistance. These were epitomized in his “Salt March” of 1930, which began when Gandhi led protestors on a three-week, 200-mile march to the sea, where Gandhi picked up a lump of salty mud, which was converted into salt. This violated the onerous “salt tax” that the British imposed on Indians buying the produce. Below is the moment that changed India; the caption is “Mahatma Gandhi at Dandi Beach 6 April 1930. Standing behind him is his second son Manilal Gandhi and Mithuben Petit.”

This civil disobedience launched an India-wide resistance movement, and a peaceful one, which played a major role in India gaining its independence in 1947.  Civil disobedience is best used as a way of changing people’s minds. And the Salt Resistance kindled similar protests across India, promoted other resistance, and eventually changed the mind of the British rulers. Here’s a video:

 

To quote Wikipedia:

The Salt Satyagraha campaign was based upon Gandhi’s principles of non-violent protest called satyagraha, which he loosely translated as “truth-force” Literally, it is formed from the Sanskrit words satya, “truth”, and agraha, “insistence”. In early 1920 the Indian National Congress chose satyagraha as their main tactic for winning Indian sovereignty and self-rule from British rule and appointed Gandhi to organise the campaign. Gandhi chose the 1882 British Salt Act as the first target of satyagraha. The Salt March to Dandi, and the beating by the colonial police of hundreds of nonviolent protesters in Dharasana, which received worldwide news coverage, demonstrated the effective use of civil disobedience as a technique for fighting against social and political injustice. The satyagraha teachings of Gandhi and the March to Dandi had a significant influence on American activists Martin Luther King Jr., James Bevel, and others during the Civil Rights Movement for civil rights for African Americans and other minority groups in the 1960s. The march was the most significant organised challenge to British authority since the Non-cooperation movement of 1920–22, and directly followed the Purna Swaraj declaration of sovereignty and self-rule by the Indian National Congress on 26 January 1930 by celebrating Independence Day.  It gained worldwide attention which gave impetus to the Indian independence movement and started the nationwide Civil Disobedience Movement which continued until 1934 in Gujarat.

A key principle of satyagraha is that the protest must be peaceful, and the protestors must take what punishment is dished out. One must, according to Gandhi, “Suffer the anger of the opponent” without retaliating.  (As you see above, that happened: Gandhis and thousands of other protestors were beaten and arrested.

When adopted by the American Civil Rights Movement, these principles were adopted wholesale. Rosa Parks protested an unjust segregation law and was arrested for peacefully sitting in the front of a bus and refusing to move.  The blacks and whites who demonstrated together at the Woolworth lunch counter sit-ins in Mississippi and North Carolina were peacefullyt protesting an immoral segregation law, and, as the video shows below, the protestors were jeered, pushed, and had food dumped over them, but did not resist.

If this video disappears, see it here.

The most iconic instances of civil disobedience that provoked violence by authorities, leading to sympathy for the protestors and eventually ending in the changing the laws, were the marches and civil protests in Birmingham and Selma, Alabama in 1963 and 1965, respectively, which led to the Civil Rights Act of 1964 and the Voting Rights Acts of 1965. Two videos:

“Bloody Sunday” in Selma: March 7, 1965:

The sight of peaceful protestors, both black and white, being attacked by dogs, drenched by fire hoses, run down by horses, and battered with billy clubs—all this was too much for America, and bent the moral arc upwards. It was the visuals, and the knowledge that the protestors were peaceful, yet protesting unjust laws and getting injured for their actions—all this horrified viewers. It’s one thing to read about it, but another to see it.  And in the end, this led to the greatest advance in civil rights in a century.

Protests like this one below are not peaceful. While the painting wasn’t damaged, the walls were, and we had simple vandalism.

NEW – Climate radicals attack the Mona Lisa painting in the Louvre Museum, Paris.pic.twitter.com/OP3AGiNe0W

— Disclose.tv (@disclosetv) January 28, 2024

From the NYT report:

Two protesters from an environmental group hurled pumpkin-colored soup on the Mona Lisa at the Louvre museum in Paris on Sunday, splashing the bulletproof glass that protects the most famous painting in the world, but not apparently damaging the work itself.

As the customary crowd around the 16th-century painting by Leonardo da Vinci gasped in shock, the protesters, two young women, followed up their attack by passing under a barrier and standing on either side of the artwork, hands raised in an apparent salute.

“What is more important? Art or the right to have a healthy and sustainable food system?” the activists said, speaking in French. “Our agricultural system is sick.” They were led away by Louvre security guards.

It was not immediately clear how the women got the soup through the elaborate security system at the museum, which borders the Seine and contains a vast art and archaeological collection spanning civilizations and centuries.

One of the women removed her jacket to reveal the words Riposte Alimentaire, or Food Response, on a white T-shirt. Riposte Alimentaire is part of a coalition of protest groups known as the A22 movement. They include Extinction Rebellion and Just Stop Oil, the group that poured tomato soup over Vincent Van Gogh’s Sunflowers at the National Gallery in London in 2022.

Does this help the cause of climate change? I doubt it. You might say it does because it calls attention to the problem, but I’m guessing that most of the people who saw this were angry at the protestors and not inclined to take a more salubrious view towards the idea that humans are changing the climate.  This is not only not civil disobedience, but, in my view, ineffective and immature.  Why, then, are they doing it? Your guess is as good as mine.

What about blocking traffic, bridge, and tunnels? This is the speciality of pro-Palestinian demonstrators; an example from Los Angeles is below.

Does this help the protestors accomplish their aims, which is either to bring peace in the Middle East, often to erase Israel and extend Palestine “from the river to the sea”? I doubt it: those whose cars are blocked may be more aware of the protests, but I don’t think they’ll become more sympathetic to the Palestinian cause.  But maybe I’m wrong. Maybe impressionable young people, who are ignorant of history but impressed by the loud, aggressive demonstrations of those favoring Palestine, will come to favor their cause. After all, it is the young who most take the side of Hamas (or Palestine) in the Hamas/Israel war.

At any rate, this is the new form of civil disobedience, although the protestors don’t willingly take punishment. Often there is  no punishment: when pro-Palestinian protestors illegally blocked the University of Chicago’s administration building, or, last Friday, did a lie-in in the Pret a Manger campus food-and-coffee shot, blocking entry, the University police stood by and did nothing.  Protestors here were arrested last year for conducting a sit-in in the admissions office, but the charges were dropped. (I am prevented from learning if the University will exercise its own sanctions for violating university regulations.)

This is the new form of civil disobedience in which protestors publicize a cause, violate regulations and laws, but face little or no punishment. And often they resist punishment or feel that they don’t deserve it. Publicity may be all they want, but it seems to me that political protest must go beyond publicizing a cause, but, to paraphrase Karl Marx, must have a chance of changing the world.

Do these protestors actually accomplish the kind of change they want?  I’ll leave it to the readers to discuss the issue, and I would appreciate hearing as many readers’ takes as possible.

In the early days of telescopic astronomy, you could only focus on one small region of the sky at a time. Careful observations had to be done by hand, and so much of the breakthrough work centered around a particular object in the sky. A nebula or galaxy, quasar or pulsar. But over the years we’ve been able to build telescopes capable of capturing a wide patch of sky all at once, and with automation, we can now map the entire sky. Early sky surveys took years to complete, but many modern sky surveys can look for changes on the order of weeks or days. This ability to watch for changes across the sky is changing the way we do astronomy, and it is beginning to yield some interesting results. As a case in point, an infrared sky survey is revealing hidden stars we hadn’t noticed before.

In a series of papers published in the Monthly Notices of the Royal Astronomical Society, the authors have analyzed data from a decade-long survey called the Visible and Infrared Survey Telescope (VISTA). VISTA allows astronomers to keep an eye on hundreds of millions of stars at infrared wavelengths. In these works, the team combed through the observations to focus on about 200 stars that showed the most dramatic shifts in brightness. These transient changes are important because they can reveal the subtle dynamics of stars.

Artist’s impression of an eruption in the disc of matter around a newborn star. Credit: Philip Lucas/University of Hertfordshire

One goal of the studies was to look for very young stars. Stars in the earliest moments of transition toward becoming true fusion-powered stars. And within their selected stars they found 32 erupting protostars. All of them experienced a rapid increase of at least a factor of 40, and some brightened as much as a factor of 300. The outbursts lasted for months or years, and they seem to occur within the disk of matter surrounding the young stars. Based on the dynamics, these bursts can accelerate the growth of young stars, but they could also make it more difficult for planets to form. They refer to these turbulent protostars as squalling newborns.

The team also found a surprise. Deep within the center of our galaxy, they found 21 red giant stars with dramatic brightness changes. They turned out to be a new type of red giant known as old smokers. The center of our galaxy is rich with heavy elements, so these red giants have a high metalicity. As they age, they can cast off clouds of dust that can obscure the star for a time. So the star temporarily fades from view and then re-brightens as the clouds disperse. This discovery could change our understanding of how heavy elements are released into the galaxy to be used by new stars.

Reference: Lucas, P W, et al. “The most variable VVV sources: eruptive protostars, dipping giants in the nuclear disc and others.” Monthly Notices of the Royal Astronomical Society 582.2 (2024): 1789–1822.

Reference: Guo, Zhen, et al. “Spectroscopic confirmation of high-amplitude eruptive YSOs and dipping giants from the VVV survey.” Monthly Notices of the Royal Astronomical Society 582.2 (2024): 1769–1788.

Reference: Peña, Carlos Conteras, et al. “On the incidence of episodic accretion in Class I YSOs from VVV.” Monthly Notices of the Royal Astronomical Society 582.2 (2024): 1823–1840.

Reference: Guo, Zhen, et al. “Multiwavelength detection of an ongoing FUOr-type outburst on a low-mass YSO.” Monthly Notices of the Royal Astronomical Society 582.2 (2024): L115–L122.

The post New Types of Hidden Stars Seen for the First Time appeared first on Universe Today.

This morning I was surprised to read this headline in the NYT (click to read, or find it archived here). A halt in fighting for weeks?

Here’s the gist of the “deal” as the NYT reports it:

American-led negotiators are edging closer to an agreement in which Israel would suspend its war in Gaza for about two months in exchange for the release of more than 100 hostages still held by Hamas, a deal that could be sealed in the next two weeks and would transform the conflict consuming the region.

Negotiators have developed a written draft agreement merging proposals offered by Israel and Hamas in the last 10 days into a basic framework that will be the subject of talks in Paris on Sunday. While there are still important disagreements to be worked out, negotiators are cautiously optimistic that a final accord is within reach, according to U.S. officials who insisted on anonymity to discuss sensitive talks.

President Biden spoke by phone separately Friday with the leaders of Egypt and Qatar, who have served as intermediaries with Hamas, to narrow the remaining differences. He is also sending his C.I.A. director, William J. Burns, to Paris for Sunday’s talks with Israeli, Egyptian and Qatari officials. If Mr. Burns makes enough progress, Mr. Biden may then send his Middle East coordinator, Brett McGurk, who just returned to Washington, back to the region to help finalize the agreement.

“Both leaders affirmed that a hostage deal is central to establishing a prolonged humanitarian pause in the fighting and ensure additional lifesaving humanitarian assistance reaches civilians in need throughout Gaza,” the White House said in a statement Friday night summarizing the president’s conversation with Sheikh Mohammed bin Abdulrahman al-Thani, Qatar’s prime minister. “They underscored the urgency of the situation and welcomed the close cooperation among their teams to advance recent discussions.”

In a statement in Israel on Saturday, Prime Minister Benjamin Netanyahu reaffirmed his commitment to securing the release of those hostages who were not freed as part of a more limited agreement in November. “As of today, we have returned 110 of our hostages and we are committed to returning all of them home,” he said. “We are dealing with this and we are doing so around the clock, including now.”

. . . The deal now coming together would be more expansive in scope than the previous one, officials say. In the first phase, fighting would stop for about 30 days while women, elderly and wounded hostages were released by Hamas. During that period, the two sides would work out details of a second phase that would suspend military operations for roughly another 30 days in exchange for Israeli soldiers and male civilians being held. The ratio of Palestinians to be released from Israeli prisons is still to be negotiated but that is viewed as a solvable issue. The deal would also allow for more humanitarian aid into Gaza.

I found this report dubious for several reasons. First, I don’t believe that Israel would suspend action in Gaza for two months, as that would give Hamas a huge opportunity to revive itself. Second, Netanyahu’s statement is hardly expressive of someone looking for a compromise, but a simple assertion that Israel is working to get the hostages released.  Third, the hostages would not all be released at once, but in dribs and drabs. That is not something that’s propitious, especially because of condition #4: Palestinian terrorists in Israeli prisons are also to be released. And I’m very distressed that no deal has ever been proposed to let all the hostages go at once. There are about 120, but I suspect that about 20 of them are dead.  The International Court of Justice stipulated release of all the hostages now, but of course Hamas won’t do it and the world is hardly even mentioning that.  The UN in particular, which created the International Court of Justice and elects its 15 judges, should be pressuring Hamas and Palestine hard on the hostage issue. If Israel does obey the ICJ’s stipulations, then Palestine and Hamas should as well.

And then, when I read the website below, which gives opinions expressed in Israeli news, I became even more dubious.

The two paragraphs below, in informal language, are from Balkonic, a website that translate Israeli news from Hebrew into Polish. According to Malgorzata, it has been an almost totally reliable source of information, and the translator makes corrections when he/she is wrong.  This time the translator said what’s below in Polish, and I’ve used Google translate to put it into English. It’s jargon, but that’s the way this informal website is written.

and again some fake news from the new york times, which reports, that ‘there is progress towards the release of all the kidnapped in exchange for a 2-month break in the war’… of course, in Israel they deny this information…

2 months yeah… I’m not saying that it would be total surrender to Hamas, practically the end wars and Hamas rearming at a rapid pace, but it is clear that Hamas would leave a few kidnapped people as a human shield and a bargaining chip… what normal-thinking Israeli can believe in such nonsense…

Now that doesn’t give sources, which is why I’m also taking Balkonic with a grain of salt. However, my suggestion is to take the NYT report with many grains of salt, and not start thinking that a cease-fire and hostage release are at hand.

We do not yet know how, where, or why life first appeared on our planet. Part of the difficulty is that “life” has no strict, universally agreed-upon definition.

Normally this is not an issue, as the vast majority of life is most definitely alive, and only biologists interested in the extreme edges – viruses, prions, and the like – need to worry about precise classifications. But to study the origins of life we must, by necessity, examine a process that takes non-living matter and fundamentally changes it. Presumably this process happened in stages, with fits and starts along the way, and so the line between uncoordinated chemical reactions and the beginnings of vibrancy must be blurred.

It’s helpful here to present at least a simple working definition of life, not to rewrite the biology textbooks, but so that at least we can properly frame the discussion of life’s origins. And for those purposes a simple statement will suffice: life is that which is subject to Darwinian evolution. That is, life experiences natural selection, that unceasing pressure that chooses traits and characteristics to pass down to a new generation through the simple virtue of their survivability. If the trait contributes in some way, even circuitously, to the survivability of an organism and its ability to reproduce, it persists. All else is discarded (or, at best, gets carried unceremoniously along for the ride).

Earth is the only known place in the solar system, in the galaxy, in the entire universe where Darwinian evolution takes place.

To succeed at evolution and separate itself from mere chemical reactions, life must do three things. First, it must somehow store information, such as the encoding for various processes, traits, and characteristics. This way the successful traits can pass from one generation to another.

Second, life must self-replicate. It must be able to make reasonably accurate copies of its own molecular structure, so that the information contained within itself has the chance to become a new generation, changed and altered based on its survivability.

Lastly, life must catalyze reactions. It must affect its own environment, whether for movement, or to acquire or store energy, or grow new structures, or all the many wonderful activities that life does on a daily basis.

By interacting with its environment, making copies of itself, and storing information (like how to interact with the environment and make copies of itself), life can evolve, growing in complexity and specialization over geologic time, from humble molecules to conscious minds capable of peering into its own shrouded origins.

In the modern era, with billions of years of practice behind it, life on Earth has evolved a dizzying array of chemical and molecular machines to propagate itself – a menagerie so complex and interconnected that we do not yet fully understand it. But a basic picture has emerged. Put exceedingly simply (for I would hate for you to mistake me for a biologist), life accomplishes these tasks with a triad of molecular tools.

One is the DNA, which through its genetic code stores information using combinations of just four molecules: adenine, guanine, cytosine, and thymine. The raw ability of DNA to store massive amounts of information is nothing short of a miracle; our own digital system of 1’s and 0’s (invented because it’s much simpler to tell if a circuit is on or off than some stage in-between) is the closest comparison we can make to DNA’s information density. Natural languages don’t even earn a place on the chart.

The second component is RNA, which is intriguingly similar to DNA but with two subtle, but significant, differences: RNA swaps out thymine for uracil in its codebase, and contains the sugar ribose, which is one oxygen atom short of the deoxyribose of DNA. RNA also stores information but, again speaking only in generalities, has the main job of reading the chemical instructions stored in the DNA and using that to manufacture the last member of the triad, proteins.

“Proteins” is a generic catch-all term for the almost uncountable varieties of molecular machines that do stuff: they snip apart molecules, bind them back together, manufacture new ones, hold structures together, become structures themselves, move important molecules from one place to another, transform energy from one form to another, and so on.

Proteins have one additional function: they perform the job of unraveling DNA and making copies of it. Thus the triad completes all the functions of life: DNA stores information, RNA uses that information to manufacture proteins, and the proteins interact with the environment and perform the self-replication of DNA. This cycle allows living organisms to experience the gift of evolution.

And this cycle is, as I said, gloriously complex and obviously the result of billions of years of fine-tuning and refinement. The interconnected nature of DNA, RNA, and proteins means that it could not have sprung up ab initio from the primordial ooze, because if only one component is missing then the whole system falls apart – a three-legged table with one missing cannot stand.

The post The Improbable Origins of Life on Earth appeared first on Universe Today.

Sensible Medicine doctors often utter the words "do an RCT". So why are their readers so ignorant about RCTs?

The post Why Are Sensible Medicine Doctors Indifferent to the Nonsense Comments of Sensible Medicine Commentators? As Instructed, I Consider the Dualities of Interest and Motivating Biases. first appeared on Science-Based Medicine.

The James Webb Space Telescope, a collaborative effort between NASA, the ESA, and the Canadian Space Agency (CSA), has revealed some stunning new images of the Universe. These images have not only been the clearest and most details views of the cosmos; they’ve also led to new insight into cosmological phenomena. The latest image, acquired by Webb‘s Mid-InfraRed Instrument (MIRI), is of the star-forming nebula N79, located about 160,000 light-years away in the Large Magellanic Cloud (LMC). The image features a bright young star and the nebula’s glowing clouds of dust and gas from which new stars form.

The image above is centered on one of the three giant molecular cloud complexes – dubbed N79 South (S1) – a region dominated by interstellar atomic hydrogen that is ionized. The star is identifiable as the brightest spot in the image, surrounded by six large spokes of light that cross the image. The processed image uses many different colors to indicate different infrared wavelengths, with near-infrared light (7.7-10 microns) shown in blue, while mid-infrared wavelengths (10, 15, and 21 microns) are shown in cyan, yellow, and red (respectively).

The Tarantula Nebula as seen by the James Webb Space Telescope. Credit: NASA/ESA/CSA/STScI/Webb ERO Production Team.

This N79 nebula spans over 500 parsecs (1,630 light-years) in the largely unexplored southwest region of the LMC and is often regarded as the younger sibling to the Tarantula Nebula (aka. 30 Doradus). This nebula was imaged recently by Webb (see above), where combined light from varying wavelengths created a detailed image revealing many interesting features (like star-forming regions astronomers were not expecting to find). However, research suggests that for the past 500,000 years, N79 has had star formation efficiency more than twice that of the Tarantula Nebula.

Several other bright objects can be seen in the cloud, which are stars in the early stages of formation (aka. protostars) shown in great detail as layers of colorful wisps. Thanks to Webb‘s ability to capture longer and shorter wavelengths of infrared light, these latest image provides insight into the nebula’s star forming regions. Since shorter wavelengths are absorbed or scattered by dust grains, mid-infrared light reveals what is happening deeper inside the clouds (which include some young protostars). The image shows a distinct “starburst” pattern surrounding a bright object.

This is known as a “diffraction spike,” an artifact only visible around very bright and compact objects that arises from the design of a telescope’s mirrors. In this case, the six diffraction spikes extending from the center are due to the hexagonal symmetry of Webb’s eighteen primary mirror segments. Astronomers are particularly interested in star-forming regions because their chemical composition resembles that of nebulas observed when the Universe was only a few billion years old.

Unlike nebulae in the Milky Way today, star formation was at its peak during this time, producing particularly massive stars with low concentrations of metal and short-lived by current standards. By taking details images from N79 and similar nebulae, astronomers can compare and contrast star-formation rates to deep observations of distant galaxies in the early Universe.

Webb images of early galaxies shaped like surfboards and pool noodles. Credit: NASA/ESA/CSA

These latest observations by Webb are part of a program to study the evolution of circumstellar discs and envelopes around stars in formation over a wide range of mass and evolutionary stages. Webb‘s sensitivity will allow astronomers for the first time, to detect these planet-forming disks around stars of similar mass to that of our Sun and at distances comparable to that of the LMC (around 160,000 light-years). This will shed light on how planetary systems like our own formed and evolved, potentially providing clues as to where life may have also emerged in our galaxy.

Further Reading: ESA

The post New Webb Image of a Massive Star Forming Complex appeared first on Universe Today.

Caturday felids are back, and I have a bunch of material for future posts (I assume that some readers are ailurophiles).

First, from Funny And Cute Cat’s Life, cats doing stuff better than humans do. 10½ minutes of fun, with plenty o’ kittens! I like the two cats who like being repeatedly thrown on a bed.  Also climbing kitten at 9:46.

***************

In this post, Emily Stewart, the business and finance correspondenct for Vox, who apparently doesn’t really like cats, tries to answer the title question.

First, her view of cats:

I am not a cat person. Whenever friends ask why I don’t have one — after all, I am a single woman in her 30s — my response is always the same: There’s too big a risk your cat hates you. Cat owners’ stories are basically, “Oh my God, you won’t believe what Fluffy just did! So cute!” And then they tell you about something objectively destructive and, occasionally, gross. Even if your cat likes you, it’s sometimes distant and perhaps kind of an asshole — most cats are. It’s not a bad thing, really. (See: Grumpy Cat, a cultural icon.) They’re semi-wild animals we have as pets, which is a whole separate complicated issue on its own. The main expectation you can have of a cat is that you can’t have a lot of expectations.

Seriously? “Most cats are perhaps kind of an asshole?”  No, animals can’t really be “assholes” in the human sense. Here Stewart shows she doesn’t really understand cats. Yes, they are wilder than dogs, and she grudgingly admits that this could be a good thing, but the other good thing is that they’re like people: you can’t count on them to behave the same way all the time (that’s what d*gs are for).  Anyway, Ms. Stewart answer the question in an oddball way: she decides to go to a cat show.  The them of the piece is whether the author’s friend Donna’s cat, a black Persian named Vincenzo, is a “good cat”. Donna shows Vincenzo at cat shows.

“The whole question of cats is less about the cat and more about the human. A cat is going to be a cat, and they’re very funny and affectionate,” says Ella Cerón, an author, friend, and owner of two black cats — Holly and Olive — when I tell her via text that I’m working on this story. “You as a person also have to understand that there are things in this life you cannot control, and one of those things is a cat.”

What even makes a “good” cat? Do we want them to be loving? Aloof? Friendly? Beautiful? Strong? Or is the idea mainly for them to catch critters? Are they supposed to bend to our will, or are we supposed to bend to theirs?. . .

I decided to go to a cat show to find out. A show cat is different from a pet cat, but as Mark Hannon, former president of the Cat Fanciers’ Association, tells me, “A good pet cat doesn’t necessarily make a show cat, but a show cat should also be a good pet cat.” So, I figure it’s a start.

. . . .What makes a good cat, show-wise, is quite cut and dried, at least in theory. Cats are intended to adhere to what everyone refers to as “the standard,” meaning an ideal version of the breed, as rated by a judge. Cat shows are a way to proofread cats. Breed councils set the standards and can change them by vote, including whether to allow for different colors or change requirements from “medium to large” to “large to medium.” This seems astonishingly mundane; I’m told the debate can be very heated.

The current CFA standards are outlined in a booklet that spans 132 pages. To insiders, it’s the cat bible. To outsiders, it’s a goofy, arbitrary document. Both the Birman and the Cornish Rex get points for having a “Roman nose.” For RagaMuffins and Ragdolls, that’s penalized. The only cat where temperament is listed as a criterion is the Siberian: It’s supposed to be “unchallenging.” The Chartreux is supposed to have a smile.

This is a “good cat” in that it adheres to specified standards, but that’s not what we mean when we say a cat is “good,” for crying out loud!

To judge a cat is to love a cat. When judges evaluate a cat, they hold them, caress them, whisper to them, coo at them, even kiss them. Becoming a cat judge takes years, with all the studying, training, and testing, and it’s not for the cash. Show organizers generally cover judges’ flights, hotels, and meals. Otherwise, judges make a dollar and a quarter per cat.

“We do it because we enjoy handling these cats,” says Nancy Dodds, a cat judge who flew in from Arizona for the weekend. “They’re like artwork.”

Yes, but “judging a cat” in this way is, again, not what we mean by “a good cat”. After some other pilpul, the author finally narrows in on what a “good cat” is:

Jessica Austin, a PhD candidate in the Department of Sociology at the University of Colorado Boulder who studies the dynamic between people and cats, explains that cat owners like having a relationship with a being that is fairly independent and content to be on its own. “They see the cats as having their own interests, having their own needs, having their own desires, and that’s fine,” she says. “If you are a person who needs validation from your pet, maybe a cat is not the best pet for you.”

Cats provide a quiet kind of companionship. Austin quoted one of her research subjects — a cat dad — on their unique appeal: “It’s somebody who is content being alone together.”

. . .We’ve got a sense of what makes a good dog. It’s a loyal companion. It loves you unconditionally. Maybe it has a job, like hunting, herding, or being a cop. Even if it doesn’t, it probably knows a trick or two. With cats, it’s fuzzier.

Cats aren’t here to serve us; the relationship is more of a push and pull. They require boundaries. They are an exercise in consent.

To me, this may not be what makes a “good cat” but it is “why cats are good.” To me, d*gs are like servants: they are obsequious and obedient.  Yes, they love you unconditionally, but that’s not what humans do. Humans may love you in general, but not unconditionally, and sometimes they don’t want to fawn on you.  Yes, d*gs are like servants, but cats are like masters:

When a cat is dissatisfied, owners will know it, and its surroundings are often at fault. If you’ve got a “bad” cat, the bad is on you — your cat is scratching the couch because it doesn’t have anywhere else to scratch. Cats are not as eager to make people happy in the way dogs are, nor are they as motivated by food. People can only give them so many treats before they’re over it. “We are responsible for their emotional well-being, but they’re not responsible for ours,” Delgado says.

And that’s why cats are not pets. Rather, we are their staff.

***************

Finally, “Simon’s Cat” cartoons have been going for fifteen years, and here’s a 12-minute look back at its highlights. The caption for this is below.

We are celebrating 15 years of Simon’s Cat, featuring some of our all-time favourites in full colour!

Simon’s cat is NOT a “good cat”!

 

h/t: Barry, Christopher

Swindler's List: Deep Fake Robot Call; News Item: Oxygen Bottleneck, NASA Opens Osiris Rex Canister, Learning and Longevity, DNA Directed Assembly, Bleach Peddler Sentenced; Who's That Noisy; Your Questions and E-mails: Nuclear Batteries; Science or Fiction

Today we have plant as well as seed+fruit (i.e., acorn) photos from Rik Gern of Austin, Texas. Rik’s captions are indented, and you can enlarge his photos by clicking on them.

The following photos were taken in Eagle River, Wisconsin last September.  What the seven species represented here have in common is proximity; they were all located in a six- or eight-foot radius of one another.

I was driving and enjoying the fall colors as they played out among the trees when I noticed spots of tiny red dots by the roadside. Getting out to examine them I found several clusters of British Soldier Lichen (Cladonia cristatella), giving the landscape an otherworldly science fiction-like look.

Of course, the Soldier Lichen were commingled with many other types of ground plants including these Crown Tipped Coral Fungus (Artomyces pyxidatusy):

A very common ground plant in the area is a moss known as Urn Haircap (Pogonatum urnigerum). Here it is with a fresh load of fertilizer courtesy of either John Deer or Jane Doe. All part of the landscape, folks!

Mushrooms are easy to find, but harder to identify. Seek by iNaturalist had a little trouble with the species on this log, but I believe they are Shelf mushrooms:

At the other end of the log was a small batch of Oyster mushrooms (Pleurotus ostreatus):

A surprise resident of this small patch of land was a lone Canadian Goldenrod (Solidago canademsis) plant. This was surprising, as I usually see them growing in clusters.

Hanging a few feet above this cornucopia were acorns from  the Northern Red Oak (Quercus rubra). I love the look of these seeds; they look like antique ornaments that were once beautifully carved, polished and buffed, but have withstood some damage over the years, but in fact they all popped out of the tree less than a year prior to the time the pictures were taken.

As I mentioned earlier, all these species were found practically within arm’s reach of one another, and there were plenty more attractive species that I just didn’t get good pictures of. It never fails to amaze me what you can see if you keep your eyes open. Endless forms indeed!

UPDATE: The NSS says that the hamhanded tweet-changing was done without the society’s usual vetting, with a tweeter panicking and taking out the Jewish part.  They have corrected the tweet now to what’s below, which is what they should have posted in the first place:

We’re joining in solidarity with others across the nation this evening to remember the six million Jewish men, women, and children who were murdered during the Holocaust, alongside the many others killed under Nazi persecution. Be the light in the darkness.#LightTheDarkness pic.twitter.com/Ss28NcNgmi

— National Secular Society (@NatSecSoc) January 27, 2024

**************************

It’s not often that I devote a post to a single tweet, but this one deserves it. It was put up by the British National Secular Society to “commemorate” Holocaust Memorial Day—the day in 1945 when Auschwitz was liberated by the Red Army.

Here’s what you see now:

It's #HolocaustMemorialDay, when we remember all the atrocities of the Holocaust. #LightTheDarkness #FragilityOfFreedom pic.twitter.com/454aGavuYh

— National Secular Society (@NatSecSoc) January 27, 2024

But here’s the original, which I can’t find on the site. . . .

Clearly, the Holocaust, originally described as “the murder of 6 million Jewish children, women, and men” has been replaced simply by “the atrocities”, as noted by the reader below.

Now why on earth would they do that? I can think of only one explanation. Actually two, but the alternative explanation—it’s a “secular” society so it can’t name a religion—doesn’t make sense.

Working hypothesis: the word “Jewish” has become pejorative. Even to the National Secular Society!

 

Interesting edit there… pic.twitter.com/SfTRW0Vqwg

— Ben Cooper (@bencooper) January 27, 2024

 

h/t: Jez, Orli

Our planet sits in the Habitable Zone of our Sun, the special place where water can be liquid on the surface of a world. But that’s not the only thing special about us: we also sit in the Galactic Habitable Zone, the region within the Milky Way where the rate of star formation is just right.

The Earth was born with all the ingredients necessary for life – something that most other planets lack. Water as a solvent. Carbon, with its ability to form long chains and bind to many other atoms, a scaffold. Oxygen, easily radicalized and transformable from element to element, to provide the chain reactions necessary to store and harvest energy. And more: hydrogen, phosphorous, nitrogen. Some elements fused in the hearts of stars, other only created in more violent processes like the deaths of the most massive stars or the collisions of exotic white dwarfs.

And with that, a steady, long-lived Sun, free of the overwhelming solar flares that could drown the system in deadly radiation, providing over 10 billion years of life-giving warmth. Larger stars burn too bright and too fast, their enormous gravitational weight accelerating the fusion reactions in their cores to a frenetic pace, forcing the stars to burn themselves out in only a few million years. And on the other end of the spectrum sit the smaller red dwarf stars, some capable of living for 10 trillion years or more. But that longevity does not come without a cost. With their smaller sizes, their fusion cores are not very far from their surfaces, and any changes or fluctuations in energy result in massive flares that consume half their faces – and irradiate their systems.

And on top of it all, our neighborhood in the galaxy, on a small branch of a great spiral arm situated about 25,000 light-years from the center, seems tuned for life: a Galactic Habitable Zone.

Too close to the center and any emerging life must contend with an onslaught of deadly radiation from countless stellar deaths and explosions, a byproduct of the cramped conditions of the core. Yes, stars come and go, quickly building up a lot of the heavy elements needed for life, but stars can be hundreds of times closer together in the core. The Earth has already suffered some extinction events likely triggered by nearby supernovae, and in that environment we simply wouldn’t stand a chance. Explosions would rip away our protective ozone layer, exposing surface life to deadly solar UV radiation, or just rip away our atmosphere altogether.

And beyond our position, at greater galactic radii, we find a deserted wasteland. Yes, stars appear and live their lives in those outskirts, but they are too far and too lonely to effectively spread their elemental ash to create a life-supporting mixture. There simply isn’t enough density of stars to support sufficient levels of mixing and recycling of elements, meaning that it’s difficult to even build a planet out there in the first place.

And so it seems that life would almost inevitably arise here, on this world, around this Sun, in this region of the Milky Way galaxy. There’s little else that we could conceivably call home.

The post The Galactic Habitable Zone appeared first on Universe Today.

It's the pump! But you knew that.

The post Skeptics in the Pub. Cholera. Chapter 8b first appeared on Science-Based Medicine.

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If you could rewind your life to the very beginning and then press play, would everything turn out the same? Or could making an accidental phone call or missing an exit off the highway change not just your life, but history itself? And would you remain blind to the radically different possible world you unknowingly left behind?

In Fluke, myth-shattering social scientist Brian Klaas dives deeply into the phenomenon of random chance and the chaos it can sow, taking aim at most people’s neat and tidy storybook version of reality. The book’s argument is that we willfully ignore a bewildering truth: but for a few small changes, our lives—and our societies—could be radically different.

Offering an entirely new lens, Fluke explores how our world really works, driven by strange interactions and apparently random events. How did one couple’s vacation cause 100,000 people to die? Does our decision to hit the snooze button in the morning radically alter the trajectory of our lives? And has the evolution of humans been inevitable or are we simply the product of a series of freak accidents?

Drawing on social science, chaos theory, history, evolutionary biology, and philosophy, Klaas provides a brilliantly fresh look at why things happen—all while providing mind-bending lessons on how we can live smarter, be happier, and lead more fulfilling lives.

Brian Klaas grew up in Minnesota, earned his DPhil at Oxford, and is now a professor of global politics at University College London. He is a regular contributor for The Washington Post and The Atlantic, host of the award-winning Power Corrupts podcast, and frequent guest on national television. Klaas has conducted field research across the globe, interviewing despots, CEOs, torture victims, dissidents, cult leaders, criminals, and everyday power abusers. He has also advised major politicians and organizations including NATO, the European Union, and Amnesty International. His previous book, for which he appears on this podcast, was Corruptible: Who Gets Power and How it Changes Us. His new book is Fluke: Chance, Chaos and Why Everything We Do Matters. You can find him at BrianPKlaas.com and on X @brianklaas.

Shermer and Klaas discuss:

• contingency and necessity/convergence
• chance and randomness
• complexity and chaos theory
• Jorge Luis Borges “The Garden of Forking Paths”
• self-organized criticality
• limits of probability in a complex, ever-changing world
• frequency- vs. belief-type probability
• ceteris paribus, or “all else being equal” but things are never equal
• economic forecasting
• free will, determinism, and compatibilism
• Holy Grail of Causality
• Easy Problem of Social Research and the Hard Problem of Social Research
• Was the original theory wrong, or did the world change?
• When Clinton lost, Silver pointed to his model as a defense: 71.4 percent isn’t 100 percent! There was nearly a 30 percent chance of Clinton losing in the model, so the model wasn’t wrong—it was just something that would happen nearly a third of the time!
• Special Order 191 and the turning point of the Civil War
• Implicit in the baby Hitler thought experiment is the idea that without Hitler the Nazis wouldn’t rise to power in Germany, World War II wouldn’t happen, and the Holocaust would be avoided. It therefore assumes that Hitler was the sole, or at least the crucial, cause of those events. Many historians would take issue with that viewpoint, arguing that those cataclysms were all but inevitable. Hitler might have affected some outcomes, they’d say, but not the overall trajectory of events. The Nazis, the war, and the genocide were due to larger factors than just one man.
• weak-link problem
• complex world defined by tipping points, feedback loops, increasing returns, lock-in, emergence, and self-organized criticality
• QWERTY and path dependency, Betamax vs. VHS, cassette v. CD v. streaming.

If you enjoy the podcast, please show your support by making a $5 or $10 monthly donation.

In the beginning, the Universe was so hot and so dense that light could not travel far. Photons were emitted, scattered, and absorbed as quickly as the photons in the heart of the brightest stars. But in time the cosmos expanded and cooled to the point that it became transparent, and the birthglow of the Big Bang could traverse space and time for billions of years. We still see it as the microwave cosmic background. As the Universe expanded it grew dark, filled only with warm clouds of hydrogen and helium. In time those clouds collapsed to form the first stars, and light again filled the heavens.

None of the stars we see today were among those first stars. Modern stars are rich with elements such as carbon and iron. Heavier elements only formed in stellar cores and other astrophysical processes. The first stars we made only of hydrogen and helium. They must have been massive beasts, with fleeting lives that ended in brilliant supernova explosions. Only their remnants remain. There have been several deep sky searches for these first stars, but we have so far not seen them. There is some indirect evidence of them in the distant Universe, but we have not yet seen their light. Now a new study argues that the Nancy Grace Roman Space Telescope might capture their dying radiance.

How a TDE of a first-generation star might be observed. Credit: Chowdhury, et al

Formally known as the Wide-Field Infrared Survey Telescope (WFIRST), The Roman Space Telescope is scheduled to launch in late 2026. Like the JWST, it will observe the cosmos in infrared, but Roman will have a wider field of view. This will better enable it to find the highly redshifted light of the first stars. However, the authors note that given the short lifespan of these first stars, Roman will not likely observe them directly. They instead propose looking for evidence of these stars as they are consumed by a black hole.

Specifically, the team proposes looking for what are known as Tidal Disruption Events (TDEs). When a star passes near a black hole, the gravitational tidal forces of the black hole can rip the star apart. As a result, the remnants of the star can be strewn across a large arc. This process takes time and creates a stream of heated gas. The authors modeled the emission spectra of this gas for a first-generation star and found they have a unique signature that lasts for a considerable amount of time. Much of the light from such a TDE would be emitted in the strong ultraviolet, but since they would occur at a cosmic redshift of about z = 10, the light we see would be shifted to the infrared, making it observable by JWST and the Roman Space Telescope.

The authors note that the rate at which TDEs occur for first-generation stars depends on several factors, but given reasonable estimates Roman could expect to see tens of these TDEs per year. So in a few years, we might finally be able to capture the last dying light of the first stars.

Reference: Chowdhury, Rudrani Kar, et al. “Detecting Population III Stars through Tidal Disruption Events in the Era of JWST and Roman.” arxiv preprint arXiv:2401.12752 (2024).

The post Nancy Grace Roman Could Find the First Stars in the Universe appeared first on Universe Today.

We live in an age of renewed space exploration, colloquially known as Space Age 2.0. Unlike the previous one, this new space age is characterized by inter-agency cooperation and collaboration between space agencies and the commercial space industry (aka. NewSpace). In addition to sending crews back to the Moon and onto Mars, a major objective of the current space age is the commercialization of Low Earth Orbit (LEO). That means large constellations of satellites, debris mitigation, and plenty of commercial space stations.

To accommodate this commercial presence in LEO, Sierra Space has developed the Large Integrated Flexible Environment (LIFE) habitat, an inflatable module that can be integrated into future space stations. As part of the Commercial Low Earth Orbit Development Program, NASA, Sierra Space, and ILC Dover (the Delaware-based engineering manufacturing company) recently conducted a full-scale burst pressure test of their LIFE habitat. The test occurred at NASA’s Marshall Space Flight Center in Huntsville, Alabama, and was caught on video (see below).

Commercial space has become one of the fastest-growing businesses on Earth. In the past decade, the space economy has expanded by over 60% and is currently valued at around $400 billion. This is expected to grow considerably in the coming years as launch services increase, small satellites (CubeSats) become more affordable, and orbital stations are built. As the International Space Station (ISS) nears retirement, these commercial stations will provide opportunities for research and development, orbital manufacturing, and space tourism.

Sierra Space, the developer of the Dream Chaser reusable spaceplane, has demonstrated its commitment to the commercialization of LEO and the NewSpace economy. The first iteration of their inflatable habitat, LIFE 1.0, measures 6 meters (~20 feet) long and 9 meters (~30 feet) in diameter and can be launched using conventional rockets and inflates once in orbit. With a volume of 285 cubic meters (over 10,000 ft3), it can accommodate four astronauts, with additional room for science experiments, exercise equipment, and Sierra Space’s Astro Garden® plant-growing system.

The purpose of a burst pressure test is to gauge the structural tolerances of a component, be it a fuel tank or an inflatable module. The data gained from this test will assist engineers in simulating how the module will fare in the vacuum of space. Once development and testing are complete, the module will be used on commercial space stations like Orbital Reef, a collaborative effort between Blue Origin and Sierra Space. Future versions, like Life 2.0 and 3.0, will offer additional volume and be able to accommodate larger crews and more science operations.

According to their National Strategic Plan (released in 2022), one of NASA’s strategic goals is to develop a human spaceflight economy in collaboration with the NewSpace industry. In 2021, as part of a Commercial LEO Destinations (CLDs) project, NASA Space Act Agreements with three companies to design commercial space stations. This includes the Orbital Reef proposed by Blue Origin and Sierra Space, the Starlab space station by Nanoracks LLC, Voyager Space, Lockheed Martin, and Northrop Grumman’s free flyer commercial space station.

Starlab, from Nanoracks, Voyager Space, and Lockheed Martin – a continuously crewed, free-flying commercial space station in low-Earth Orbit. Credits: NanoRacks/Lockheed Martin/Voyager Space

As per NASA’s plan, creating a human spaceflight economy will ensure continued research and development in space while “allowing NASA to focus Government resources on the challenges of deep space exploration through Artemis.” Another goal is to maintain the legacy of the ISS long past its retirement:

“Since its inception, industry, academia, and our international partners have used the International Space Station (ISS) as a testbed for research and the development and maturation of state-of-the-art systems that increase access to space. NASA is supporting new space stations from which we and other customers can purchase services and stimulate the growth of commercial human spaceflight activities. As commercial LEO destinations become available, we intend to implement an orderly transition from current ISS operations to these new commercial destinations.”

Further Reading: Sierra Space

The post Watch a House-Sized Space Habitat (Intentionally) Burst appeared first on Universe Today.

Although our Moon formed 4.5 billion years ago, it’s still evolving. The interior continues to cool and its orbit is slowly changing. As a result, the Moon has lost 150 feet of its circumference. That shrinkage contributes to near-constant moonquakes, and those trigger landslides and other surface changes. The Moon is currently uninhabited, but all that activity threatens future Artemis landing sites and missions at the South Pole.

In a recent paper, planetary scientists point out that the potential of strong seismic events from active thrust faults should be a top consideration when NASA and other agencies are planning permanent outposts on the Moon. This is particularly true as the Artemis mission planners plot exploration of the South Pole. “Our modeling suggests that shallow moonquakes capable of producing strong ground shaking in the south polar region are possible from slip events on existing faults or the formation of new thrust faults,” said the study’s lead author Thomas R. Watters, a senior scientist emeritus in the National Air and Space Museum’s Center for Earth and Planetary Studies. “The global distribution of young thrust faults, their potential to be active, and the potential to form new thrust faults from ongoing global contraction should be considered when planning the location and stability of permanent outposts on the Moon.”

The Moon is particularly vulnerable to the large-scale effects of moonquakes. That’s because its surface is very brittle and easily broken up during a quake. One of the strongest quakes in lunar history occurred in the 1970s and lasted for hours. Such a lengthy event does quite a bit of damage to the lunar surface. So, even a light moonquake could cause significant damage via landslides.

Our Shaky, Shrinking Moon

Moonquakes generally happen within a hundred miles or so of the lunar surface. On Earth, that might result in a fairly mild quake. But, since the Moon’s surface is so brittle, the effects of those “shakes” are much more noticeable. According to Nicholas Schmerr, a co-author of the paper and an associate professor of geology at the University of Maryland, this means that shallow moonquakes can devastate hypothetical human settlements on the Moon.

“You can think of the Moon’s surface as being dry, grounded gravel and dust,” he said. “Over billions of years, the surface has been hit by asteroids and comets, with the resulting angular fragments constantly getting ejected from the impacts,” Schmerr explained. “As a result, the reworked surface material can be micron-sized to boulder-sized, but all very loosely consolidated. Loose sediments make it very possible for shaking and landslides to occur.”

An LROC NAC mosaic of the Wiechert cluster of lobate scarps in Moon’s south pole region, left pointing arrows). A scarp crosscuts a small (?1 km) degraded crater (right-pointing arrow).

Quakes affect every part of the lunar surface. Global compressional stresses deform the surface, forcing splits and cracks to occur. These scarps—steep slopes and cliffs—exist everywhere there. In their paper, the team suggests that many are close to the epicenters of geologically recent quakes. And the regions where they occurred could still be active today. That includes the lunar South Pole.

Risks to Artemis

The team led by Watters examined data and images of the lunar South Pole and linked faults there to a major moonquake in the 1970s. The region is filled with scarps, which are prime evidence for moonquakes. Although they conclude that some regions in the area are probably safe enough for the Artemis missions, others are not. The team’s computer models show that the most dangerous areas are vulnerable to landslides triggered by seismic shaking. They continue to map the Moon and track its quakes to identify the riskiest areas for Artemis astronauts to land.

A mosaic of Shackleton Crater at the Moon’s south pole region. It shows a portion of an interior wall and floor, with arrows pointing to boulder falls likely created during seismic shaking during a moonquake. Image courtesy: NASA/KARI/ASU

That mission could take place by the end of the decade, when NASA hopes to establish long-term habitations for research and exploration. Schmerr points out that the risks to safety from even the slightest quakes can’t be overestimated. “As we get closer to the crewed Artemis mission’s launch date, it’s important to keep our astronauts, our equipment, and infrastructure as safe as possible,” Schmerr said. “This work is helping us prepare for what awaits us on the moon—whether that’s engineering structures that can better withstand lunar seismic activity or protecting people from really dangerous zones.”

The Artemis missions essentially mark NASA’s return to human exploration of the Moon. The idea is to collaborate with both commercial partners and international agencies to make this happen. Teams of lunar astronauts will establish an Artemis Base camp, and depend on a lunar gateway to connect the mission to Earth. Eventually, what they learn there will inform the first human missions to Mars.

For More Information

The Moon is Shrinking, Causing Landslides and Instability in Lunar South Pole
Tectonics and Seismicity of the Lunar South Polar Region
Artemis

The post The Moon is Still Shrinking, Explaining Why it Still Has Landslides appeared first on Universe Today.

As April’s ‘Great North American Eclipse’ nears, here’s a look at eclipses in time and space.

It comes around every total solar eclipse, and I fully expect to hear it trotted out once again this year, leading up to the Great North American eclipse on April 8th, 2024.

It’s often repeated (usually around the time leading up to a total solar eclipse) that the syzygy of the Earth, Moon and Sun is special, allowing totality to occur. To be sure, eclipses are extraordinary and spectacular events, and standing in the shadow of the Moon during totality is a spectacle that shouldn’t be missed.

But just how rare are the circumstances we witness on Earth during totality across time and space?

The path of totality across North America on April 8th, 2024. Credit: Michael Zeiler/The Great American Eclipse How Rare are Eclipses?

The Moon’s orbit intersects the ecliptic at two points, known as its ascending and descending nodes. We see lunar and solar eclipses on Earth when these nodes line up with the Sun (during a solar eclipse) or the Earth’s shadow (during a lunar eclipse). The Moon’s path is tilted just over 5 degrees versus the ecliptic plane. This means that most of the time, the Moon misses the Sun, and the Earth’s shadow. If it wasn’t tilted, an even more unique situation would occur. In this case, we’d see two eclipses (one lunar and one solar) occurring every synodic period or roughly just under once a month. As it is, eclipses worldwide happen in seasons or about twice a year as the nodes line up, with a solar and lunar eclipse about two weeks apart.

How a totality occurs. Credit: NASA

The precision-looking fit of the Moon over the Sun seen during totality is due to geometry. The Sun is about 400 times farther away from the Earth than the Moon, and 400 times as large in terms of physical diameter. But this is only approximate, and only true for our current epoch.

Geometry for lunar and solar eclipses, with the true scale of the Moon’s umbra during totality (bottom). From The Universe Today’s Ultimate Guide to Viewing the Cosmos. A Receding Moon

In fact, we know from the retro-reflectors placed on the Moon by Apollo astronauts that the Moon is moving away from us at 3.8 centimeters per year. About 600 million years from now, the last total solar eclipse will occur as seen from the Earth. Likewise, about a billion years in the past, the first brief annular solar eclipse must have occurred.

The apparent size of the Sun and Moon also vary slightly from one eclipse the the next. This ranges around half a degree (30 arcminutes) by few arcminutes (‘). This occurs as the Earth travels from perihelion to aphelion, and the Moon travels from perigee to apogee. When the Moon is too small to cover the Sun, a ‘ring of fire’ annular solar eclipse occurs.

The value difference for the apparent size of the Sun ranges from 31.6′ to 32.6′, and the Moon is 29.3′ to 34.1′. During the April 8th total solar eclipse, the Sun will be an apparent 31′ 57″ across. The Moon will be slightly larger, at 33′ 37″ across. This will yield a generous maximum totality of 4 minutes and 28 seconds in duration, as seen from near Nazas, Mexico .

A Fortunate Epoch

Even now in our current 5,000-year epoch, annulars are already more common, at 33.2% to 26.7% versus totals. The remainder are partials and rare hybrid annular-total eclipses.

“I found that whenever I use the phrase ‘cosmic coincidence’ to describe our current good fortune in the distance/diameter ratios favorable for a tight occultation of the Moon and Sun, almost predictably some of the responses will be ‘there are no coincidences,’ or ‘divine provenance,'” Eclipse chaser and cartographer Michael Zeiler told Universe Today. “I respond that often coincidences are true! We are simply lucky to live within the evolution of our solar system to witness total solar eclipses.”

Looking Out Across the Solar System

To be sure, solar eclipses do occur throughout the solar system. It’s all a matter of perspective, and literally knowing where and when to stand. New Horizons saw the Sun pass behind Pluto in 2015 (a sight no human eye has ever witnessed). Rovers on Mars have caught strange potato-shaped annular eclipses (or more properly, transits) courtesy of Deimos and Phobos.

Deimos transits the Sun, as seen by NASA’s Perseverance Rover of Sol 1037 (January 20th, 2024). Credit: NASA/JPL Image processing: Simeon Schmaub

These robotic observations of the Martian moons aren’t just pretty pictures. They also also researchers to refine and pin down the exact orbits of both Phobos and Deimos. This is handy, as Japans Martian Moons Explorer is headed to the pair in 2026.

What’s more, Phobos is doomed to crash into Mars millions of years from now… at some far off date, it will briefly be close enough to totally eclipse the Sun as seen from the Martian surface. If humans are on Mars on November 10th, 2084, they can witness an uber-rare, transit featuring Phobos, the Earth and the Moon.

Eclipses and the Curious Case of the Jovian Moons

Of course, none of these are are precise fits in terms of the eclipsing body versus the Sun. There is, however, another place in the solar system you could stand on a solid surface and witness totality similar to what’s seen on Earth. (Be sure to pack your space suit). Jupiter’s major moons produce eclipses very analogous to those seen on Earth as they pass one in front of the other. This happens in cycles that occur during what’s known as mutual eclipse-transit season. This happens when the major Galilean moons of Io, Europa, Ganymede and Callisto mingle as seen from our perspective.

Europa as seen from the surface of Callisto is a particularly good baseline ‘fit’. Europa is about 1/450th the size of the Sun, which is also 450 times farther away at certain points along its orbital path… not all that different than eclipse circumstances here on Earth. These events are faster, lasting only a few dozen seconds at most. Mutual transit-eclipse season occurs twice every Jovian orbit, or every six years. The next cycle resumes in 2026.

Io casts its shadow on Ganymede in 2009. Image credit: Christopher Go. A Twice a Decade Transit Season

We noticed this similarities of Jovian versus terrestrial eclipses while writing an article on mutual eclipse season in 2015. To be sure, eclipse seasons on the Earth tend to be biannual, while seasons in the Jovian system occur less frequently, about twice a decade. More distant moons may see similar celestial sights, but for now, my future plans for building an eclipse viewing hotel and resort are pegged for the surface of Callisto.

Bill Kramer also did a fascinating look at eclipses throughout the solar system from a few years back, posted on his Eclipse-Chasers website.

The Hunt for ‘Exo-Eclipses’

So, what does this all say for eclipses beyond our solar system? Well, as of writing this, there are 5,506 exoplanets known… but claims of any ‘exomoons’ orbiting them remain controversial. Even the best known cases—such as the contentious recent Kepler-1513 b exomoon claim—still have very wide distance and diameter perimeters to say if good-fit eclipses are possible. Still, as the menagerie of extra-solar worlds grow and good exomoon candidates are found, we might yet be able to say with some authority just how common ‘exo-eclipses’ are very soon.

Perhaps, human astronauts will one day witness these far-flung eclipses. Imagine standing on the Earthward face of the Moon during a total lunar eclipse, and witnessing ‘a thousand sunsets’ as the Earth eclipses the Sun. For now, I’d wager that ideal tight-fit eclipses aren’t all that uncommon when you take into account the vast expanse of time and space… but totality over an expanse where life has evolved to enjoy it might be rare indeed.

The post How Rare Are Total Solar Eclipses… Really? appeared first on Universe Today.

All modern life shares a robust, hardy, efficient system of intertwined chemicals that propagate themselves. This system must have emerged from a simpler, less efficient, more delicate one. But what was that system, and why did it appear on, of all places, planet Earth?

This is the central question of abiogenesis, the generation of life from not-life. We do not yet have an answer to that question, but we do have a collection of curious clues and brilliant hypotheses that might lead us in the right direction.

First, the chemistry. All proteins on Earth are made from just 22 amino acids. Those amino acids require abundant amounts of organic molecules – the most basic building blocks of life. Astronomers have detected organic molecules, and even some amino acids, scattered throughout space, from the depths of interstellar gas clouds to the fragile meteoroids that wander the solar system. So it’s natural to assume that our planet, as it coalesced from the maelstrom that surrounded our infant Sun, was born with the right ingredients…but surely they couldn’t survive the initial formation of our planet, when it was still molten from the countless collisions that lead to its development.

Instead, these organic compounds must have been delivered to us well after the planet cooled and solidified. Astronomers believe that the first few million years in the solar system was a quite unfriendly time. Even after the protoplanetary disk around the Sun evaporated and the eight major planets of the system emerged victorious over their rivals, fragments and debris still littered the orbital lanes. Impact after impact struck each of the planets, with new rounds triggered by gravitational rearrangements of the giant outer worlds as they settled into stable, permanent configurations.

We still see the scars of that youthful violence today, visible on the sterile vacuum surfaces of the Moon and Mercury.

But in that violence came a chance for life. Fresh water, delivered by countless cometary impacts, replenished what the Earth lost during its molten state. And with that water, organic compounds rained onto the surface. Here too we see yet another delicate balancing act. If the Earth had been struck too few times, we might not have been wealthy enough in molecular resources to begin the ascent to life. If too many had come, however, the persistent heat of the impacts would have boiled our oceans and sent any nascent life scattering into interplanetary space.

We were lucky. Somewhere life gained a foothold. The earliest undisputed fossil evidence for life sets the clock as early as 3.5 billion years ago. More speculative evidence – again, this work becomes exceedingly difficult the farther back into the past we peer, because the earliest life was not much different than the non-living chemical reactions that preceded it, so it’s difficult to tell if some molecular imprint in a rock is the fossil of a living creature or merely some manifestation of exotic chemistry, and if there’s even a difference between them – suggests that life started as early as 4.5 billion years ago. That alone is surprising, given the hellish conditions our planet was experiencing at the time, with some scientists arguing that our world wasn’t even habitable until some 500 million years later.

But somewhere, in some quiet place, the magic happened. A chance group of molecules and chemical reactions began storing information, began self-replicating, and began catalyzing reactions. Some biologists suspect that it was deep-sea hydrothermal vents, which spew organic-rich molecules into their surroundings. Or perhaps it was in tidal pools, which provided a natural rhythm that would turn into the cycles of life. Or maybe hot springs, or even underground.

It may have happened more than once and in more than one way, but it appears from all available evidence that as soon as life could arise, it did arise.

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