Astronomical news

[vox_mundi]

After All This Time Searching for Aliens, Are We Stuck With the Zoo Hypothesis?
https://phys.org/news/2024-01-aliens-stuck-zoo-hypothesis.html

... Interest in Fermi's question has been piqued in recent years thanks to the sheer number of "potentially habitable" exoplanets discovered in distant star systems. Despite that, all attempts to find signs of technological activity ("technosignatures") have come up empty. In a recent study, a team of astrobiologists considered the possible resolutions and concluded that only two possibilities exist. Either extraterrestrial civilizations (ETCs) are incredibly rare (or non-existent), or they are deliberately avoiding contact with us (aka, the "zoo hypothesis").



The term was coined in 1973 by John A. Ball, a Harvard astrophysicist and scientist with MIT's Haystack Observatory. In a study of the same name, Ball addressed various proposed resolutions to the Fermi Paradox and some common assumptions made by SETI researchers. Among them is the belief that intelligent species exist in our galaxy, that they are older and more advanced than we are, and that they want to make contact with other intelligent species (including us). In contrast, Ball argued that advanced species are "deliberately avoiding interaction and that they have set aside the area in which we live as a zoo."

... Unlike the planetarium (simulation) hypothesis, the zoo hypothesis assumes that the intentions of the ETCs are benign, which could include wanting to avoid interfering with our technological or social development (i.e., the "Prime Directive" from Star Trek).

... "I think that the zoo hypothesis is more likely," Schulze-Makuch countered. "I believe so because (1) of the Copernican Principle. While I do think that humanity is something very special, being a technologically advanced life form, I can't fathom that we are truly unique or so rare in that capability that—for practical reasons—nothing is out there." The second reason, said Schulze-Makuch, has to do with the recent release of the so-called UFO Report, which demonstrated that unidentified aerial phenomena (UAP) are far more common than previously known:

"While we can't make a true scientific argument based on these, given their speculative nature, there are so many cases by now, quite a few with multiple lines of evidence, that we cannot simply ignore it. And if some of them can actually be attributed to ETI, it would mean that they don´t interfere with Earth matters or at least not to a large extent or clearly visible to us."

... Herein lies another difference between the Zoo and the planetarium hypothesis, which is that the former is more likely to be discoverable. As Schulze-Makuch summarized:

"If we are living in a simulation of some sort, we may never find out. But if the zoo hypothesis is correct, we would eventually. Our technology is getting more and more sophisticated, so we would catch up to ETI, and even if ETI could still hide their spacecraft, eventually, we would see their home worlds. But even hiding their spacecraft would get more and more difficult, and as sophisticated as they are, they would not be error-free, and accidents would happen. It is then tempting to attribute some of the UAP sightings as such… and this is still very speculative, but with more and more sensors coming online, we should be able to get a clearer picture soon."

Ian A. Crawford et al, Is the apparent absence of extraterrestrial technological civilizations down to the zoo hypothesis or nothing?, Nature Astronomy (2023)
https://www.nature.com/articles/s41550-023-02134-2

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[Sigmetnow]

Daily Telescope: A view of our star as Earth reaches perihelion
There is a bit of irony for those of us who live in the Northern Hemisphere.
Eric Berger - 1/4/2024, 8:00 AM

Welcome to the Daily Telescope. There is a little too much darkness in this world and not enough light, a little too much pseudoscience and not enough science. We'll let other publications offer you a daily horoscope. At Ars Technica, we're going to take a different route, finding inspiration from very real images of a universe that is filled with stars and wonder.

Good morning. It's January 4, and today's image is a photo of our star, Sol. The image was captured by NASA's Solar Dynamics Observatory, a spacecraft in geosynchronous orbit, on Wednesday.

So why a picture of the Sun? Because we've just passed perihelion, the point at which planet Earth reaches its closest point to the Sun. This year perihelion came at 00:38 UTC on Wednesday, January 3. We got to within about 91.4 million miles (147 million km) of the star. Due to its slightly elliptical orbit around the Sun, Earth will reach aphelion this year on July 5, at a distance of 94.5 million miles (152 million km).

There is a bit of irony for those of us who live in the Northern Hemisphere, of course. We approach nearest to the Sun at almost the coldest time of year, just a couple of weeks after the winter solstice. Our planet's seasons are determined by Earth's axial tilt, however, not its proximity to the Sun.

In any case, happy new year, a time when the world can seem full of possibility—shiny and bright like a star.

https://arstechnica.com/space/2024/01/daily-telescope-a-view-of-our-star-as-earth-reaches-perihelion/

⬇️ Sol, imaged by NASA's Solar Dynamics Observatory.
NASA

[Sebastian Jones]

I don't suppose it needs to be pointed out to many of the regulars on this forum that the dates of perihelion and aphelion vary as the years  pass and eventually N. Hemisphere summer will coincide with perihelion.
https://en.wikipedia.org/wiki/Milankovitch_cycles

[Bruce Steele]

“Synchronicity of the Earth's Rotation with the Moons Orbital Cycles and Solar Year
This document was prepared by Richard Heath as a letter for Nature magazine and submitted on 14th April 1994 but remained unpublished. It marks the discovery of a unit of time proposed and named the Chronon, as being 1/10000th of the Moon's orbit and also the difference between the sidereal and tropical day of the Earth. The paper also documents a discovery made, with Robin Heath, that one can divide up the solar year by its excess over the eclipse year to reveal an 18.618:19.618 ratio between these years, and many other interesting numerical facts not mentioned here. The puzzle is a connection between the rotation of the Earth, the solar year and the precession of the Moon's orbit which (a) may be explainable by science (b) appears to have puzzled Megalithic astronomers and (c) should puzzle us today. We find that the Earth's rotational day divides the year according to the 18.62 year cycle of the Lunar Nodes. The tropical solar year in days is factorised almost exactly by 18.618 times 19.618 and the Moon travels one ten thousandth of its orbit in the time difference between sidereal and tropical days. We have been considering a range of numerical coincidences present in arithmetical and geometrical analyses of astronomical cycles involving the Sun-Moon-Earth system. But here is an apparently lawful relationship concerning the Earth, Sun and Moon, one that is most unusual.”

I wish I could look at the stars and see a ratio. One ten thousandth of a lunar orbit is one Chronon !

[vox_mundi]

New Study Suggests Some Forms of Life Could Exist In Venus's Sulfuric Acid Clouds
https://phys.org/news/2024-01-life-venus-sulfuric-acid-clouds.html



A team of chemists and planetary scientists from Worcester Polytechnic Institute, Nanoplanet Consulting and MIT has found evidence that a form of life that uses sulfuric acid as a liquid medium could exist in some of the clouds covering Venus. The team has published their paper on the arXiv preprint server.

Prior research has suggested that if there is any kind of life form living on Venus, it would likely not be on the surface (it is far too hot) but in the clouds, where temperatures are closer to those found on Earth. But prior research has also shown that the clouds covering Venus are not made up of water; instead, they are constituted mostly of sulfuric acid.

Sulfuric acid is a mineral acid made up of sulfur, oxygen and hydrogen—on Earth, it is odorless, colorless and corrosive. But, the researchers note, there is no evidence that all life forms must have the same kind of liquid medium to function. In this new effort, they wondered if sulfuric acid could serve as a liquid medium for some form of life. To that end, they looked into the possibility of amino acids remaining stable when immersed in sulfuric acid at temperatures found in the clouds covering Venus.

They tested 20 biogenic amino acids by suspending small samples in jars of sulfuric acid for four weeks at temperatures observed in cloud layers on Venus situated 48 to 64 kilometers above the surface. They found that 19 of the amino acids remained either unreactive or were chemically modified in ways that would allow life to exist.

The researchers suggest that, should amino acids make their way to the clouds covering Venus (such as via a meteor), they could conceivably interact with other organic material also delivered by a meteor to start some form of living material, one with a sulfuric acid medium. Amino acids, they note, are the building blocks from which proteins are made, which is a requisite for life on Earth. They further suggest that their findings also broaden the range of possible life-sustaining planets in other parts of the universe.

Maxwell D. Seager et al, Stability of 20 Biogenic Amino Acids in Concentrated Sulfuric Acid: Implications for the Habitability of Venus' Clouds, arXiv (2024)
https://arxiv.org/abs/2401.01441

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New Research On Microbes Expands the Known Limits for Life on Earth and Beyond
https://phys.org/news/2024-01-microbes-limits-life-earth.html

New research led by Stanford University scientists predicts life can persist in extremely salty environments, beyond the limit previously thought possible.

The study, published Dec. 22 in Science Advances, is based on analysis of metabolic activity in thousands of individual cells found in brines from industrial ponds on the coast of Southern California, where water is evaporated from seawater to harvest salt. The results expand our understanding of the potential habitable space throughout our solar system, and of the possible consequences of some earthly aquatic habitats becoming saltier as a result of drought and water diversion.

The new research is part of a large collaboration called Oceans Across Space and Time led by Cornell University professor Britney Schmidt and funded by NASA's Astrobiology Program, which brings together microbiologists, geochemists, and planetary scientists. Their goal: to understand how ocean worlds and life co-evolve to produce detectable signs of life, past or present. Understanding the conditions that make an ocean world habitable, and developing better ways to detect signals of biological activity, are steps toward predicting where life could be found elsewhere in the solar system.

... "We're curious to find out at what point water activity becomes too low, salinity becomes too high, and where microbial life can no longer survive," said Paris. Seawater has a water activity level of about 0.98, compared to 1 for pure water. Most microbes stop dividing below water activity of 0.9, and the absolute lowest water activity level reported to sustain cell division in a laboratory setting is just over 0.63.

In the new study, the researchers predicted a new limit of life. They estimate life could be active at levels as low as 0.54.

... The research team made three key improvements to previous research. First, instead of using pure cultures, which are a scientist's standard best guess at which particular species or strain of microbe is going to be the most resilient, they went to an actual ecosystem. At the salt works, the environment naturally selected for a complex community of organisms best adapted to those particular conditions.

Second, the researchers used a more flexible definition of life. They considered not only cell division, but also cell building as a sign of life. "It's a little like observing a human eating a meal, or growing. It's a sign of active life, and a necessary precursor of replication, but much faster to observe," Dekas said.

In hundreds of brine samples—some of them so salty they were thick as syrup—they identified the water activity level and how much if any carbon and nitrogen was being incorporated into cells found in the brines. With this approach, they were able to detect when a cell increased its biomass by as little as half of 1%. By contrast, conventional methods focused on cell division can only detect biological activity after cells have roughly doubled their biomass. Then, based on how this process slowed as water activity decreased, the scientists predicted the cutoff for it would stop altogether.

Third, while other scientists have measured carbon and nitrogen incorporation in brines at a bulk level, the Stanford team conducted a cell-by-cell analysis with a rare instrument at Stanford called a nanoSIMS—one of only a handful in the country. This sensitive technique allowed them to observe activity in individual cells in the midst of other "pickled" cells whose presence would obscure the signal of activity in a bulk analysis, and achieve their low detection limit.

Emily R. Paris et al, Single-cell analysis in hypersaline brines predicts a water-activity limit of microbial anabolic activity, Science Advances (2023)
https://www.science.org/doi/10.1126/sciadv.adj3594

[vox_mundi]

NASA Selects Bold Proposal to 'Swarm' Proxima Centauri With Tiny Robot Probes
https://phys.org/news/2024-01-nasa-bold-swarm-proxima-centauri.html

... "We want to look for signs of biology and even technology, and so it would be good to get probes very close to the planet, to get good pictures and spectra of the surface and atmosphere. That will be tough for one probe, as we don't know very well where the planet will be 24-plus years in the future. By sending a bunch of probes in a spread, at least a few should get close to the planet, giving us the close-up view we want."

... While it could take many decades before an interstellar mission is ready to travel to Alpha Centauri, Eubanks, and his colleagues are honored and excited to be among NASA's selectees for the 2024 NIAC program. For them, the research took many years but is closer to realization than ever. "It's been a long time—almost a decade—and we feel honored to be selected," said Eubanks. "Now the real work begins."

https://www.nasa.gov/general/swarming-proxima-centauri/



Tiny gram-scale interstellar probes pushed by laser light are likely to be the only technology capable of reaching another star this century. We presuppose availability by mid-century of a laser beamer powerful enough (~100-GW) to boost a few grams to relativistic speed, lasersails robust enough to survive launch, and terrestrial light buckets (~1-sq.km) big enough to catch our optical signals. Then our proposed representative mission, around the third quarter of this century, is to fly by our nearest neighbor, the potentially habitable world Proxima b, with a large autonomous swarm of 1000s of tiny probes.

Given extreme constraints on launch mass (grams), onboard power (milliwatts), and coms aperture (centimeters to meters), our team determined in our work over the last 3 years that only a large swarm of many probes acting in unison can generate an optical signal strong enough to cross the immense distance back to Earth. The 8-year round-trip time lag eliminates any practical control by Earth, therefore the swarm must possess an extraordinary degree of autonomy, for example, in order to prioritize which data is returned to Earth. Thus, the reader will see that coordinating the swarming of individuals into an effective whole is the dominant challenge for our representative mission to Proxima Centauri b. Coordination in turn rests on establishing a mesh network via low-power optical links and synchronizing probes’ on-board clocks with Earth and with each other to support accurate position-navigation-timing (PNT).

Our representative mission begins with a long string of probes launched one at a time to ~0.2c. After launch, the drive laser is used for signaling and clock synchronization, providing a continual time signal like a metronome. Initial boost is modulated so the tail of the string catches up with the head (“time on target”). Exploiting drag imparted by the interstellar medium (“velocity on target”) over the 20-year cruise keeps the group together once assembled. An initial string 100s to 1000s of AU long dynamically coalesces itself over time into a lens-shaped mesh network #100,000 km across, sufficient to account for ephemeris errors at Proxima, ensuring at least some probes pass close to the target.

A swarm whose members are in known spatial positions relative to each other, having state-of-the-art microminiaturized clocks to keep synchrony, can utilize its entire population to communicate with Earth, periodically building up a single short but extremely bright contemporaneous laser pulse from all of them. Operational coherence means each probe sends the same data but adjusts its emission time according to its relative position, such that all pulses arrive simultaneously at the receiving arrays on Earth. This effectively multiplies the power from any one probe by the number N of probes in the swarm, providing orders of magnitude greater data return.

A swarm would tolerate significant attrition en route, mitigating the risk of “putting all your eggs in one basket,” and enabling close observation of Proxima b from multiple vantage points. Fortunately, we don’t have to wait until mid-century to make practical progress – we can explore and test swarming techniques now in a simulated environment, which is what we propose to do in this work. We anticipate our innovations would have a profound effect on space exploration, complementing existing techniques and enabling entirely new types of missions, for example picospacecraft swarms covering all of cislunar space, or instrumenting an entire planetary magnetosphere. Well before mid-century we foresee a number of such missions, starting in Earth or lunar orbit, but in time extending deep into the outer Solar system. For example, such a swarm could explore the rapidly receding interstellar object 1I/’Oumuamua or the solar gravitational lens. These would both be precursors to the ultimate interstellar mission, but also scientifically valuable in their own right.

------------------------------------------------------------





... Proxima Centaurians return the favor with their battle fleet



... Ack, Ack!.... Ack, Ack, Ack!

[Sigmetnow]

NASA Selects Bold Proposal to 'Swarm' Proxima Centauri With Tiny Robot Probes

Thoughts:
 
- Cool!  (Although Proxima Centaurians and future Earth ships might not think so.)
 
- A refueled Starship could take thousands of them, accelerate them more than an expendable rocket could, and release them beyond the asteroid belt or etc.  A pre-positioned fuel depot beyond earth, or a tag-along Starship tanker, could add even more ∆v boost, to get them on their way.
 
- After releasing the probes, a huge extended antenna array and solar panels could allow one or more Starships to act from behind the swarm as a communications relay station, providing an alternative to the “(~1-sq.km) terrestrial light buckets.”
 
- But: more debris in cislunar space, even pico-size, is not a good thing.

[Sigmetnow]

An incoming micro-asteroid was detected a few hours before atmospheric entry.  Its trajectory was well established, and so videographers were able to catch it as it burned up over Berlin.
 

A small asteroid hit Earth on January 21, 2024
 
The space rock struck on schedule above an area west of Berlin, Germany. The asteroid was only about 1 meter (3 feet) in diameter. It posed no danger to people on the ground

1/21/24, 9:13 AM  https://x.com/rainmaker1973/status/1749072797739979116
 
➡️ pic.twitter.com/W5GaE0oD8l   13 sec, streak through the night sky.

[morganism]

NASA and Sierra Space Burst a Space Station on Purpose
January 22, 2024 by Brian Wang

NASA and Sierra Space intentionally burst an inflatable space station in ground testing. It surpassed the 63 PSI goal and is stronger than normal steel space stations. The test article reached over 77 PSI before failing.

The inflatable station has nine layers of material for the walls.

There is an inflatable module on the space station built by a different company. However, the technology is proven in space.

The layers of material are better at managing the harsh environment of space while giving more volume for the same or less weight.

(pics)

https://www.nextbigfuture.com/2024/01/nasa-and-sierra-space-burst-a-space-station-on-purpose.html#more-191986

[morganism]

(fascinating article on MWay evo. The GAIA info has been incorporated into the model with awesome results)


The New Story of the Milky Way’s Surprisingly Turbulent Past

The latest star maps are rewriting the story of our Milky Way, revealing a much more tumultuous history than astronomers suspected
(...)
By 2021 astronomers had found 60 streams in the halo; 23 of them had likely birthplaces in dwarf galaxies or in the Milky Way's globular clusters (mysterious bound balls of up to a million stars that orbit our galaxy). Altogether, Bonaca says, there were “10 times more streams than before Gaia.” The stars are generally around 10 billion years old. The ages of the streams themselves are harder to estimate, but they are probably a few billion years old. Bonaca expects that astronomers will eventually find around 100 streams.

The streams running through the halo were some of the first signs of the galaxy's departure from stability. Then scientists began uncovering other groupings of stars that didn't follow expected patterns. In 2017 Bonaca and her team found a batch of Milky Way stars in the wrong place: they were in the old, metal-poor halo and had the orbits of old halo stars, but they had the metal-rich chemistry of younger stars from the Milky Way's disk. Bonaca wondered whether they were disk stars that had somehow wandered up into the halo.

The next year a team led by Vasily Belokurov of the University of Cambridge found an entirely different batch of stars in the halo that were going unusually fast and in the opposite direction from the rest of the halo. They named the wrong-way batch, which was bean-shaped, Sausage. A different team, led by Helmi, found that the bean's stars were also old and metal-poor; they called the bean Gaia-Enceladus, for the earth goddess Gaia's son, Enceladus. And in 2023 Bonaca and her colleagues found a stream of stars with the same old, metal-poor chemistry and wrong-way motion as the bean and thought this stream was probably tracing the bean's fall into the Milky Way. The astronomical community pragmatically settled on a compromise name for the bean, the Gaia-Enceladus Sausage (GES); the generic noun for a GES-type entity is “blob.”

Meanwhile the Belokurov team had “rediscovered” Bonaca's team's misplaced disk stars, by now known to be part of the GES. In other words, in the midst of a foreign blob of metal-poor stars was a group of metal-rich stars native to the Milky Way. He and his colleagues suggested that when the GES collided with our galaxy, it splashed the native stars out of their normal orbits in the disk and up into the halo. They called the star group Splash.

Putting their blobs, streams and splashes together, astronomers concluded that between eight billion and 10 billion years ago, Enceladus—about a quarter of the size of the Milky Way—struck our galaxy head-on and merged into it as a blob. “Head-on, you smash in, fall apart fast and die,” Belokurov says. GES stars now make up most of the Milky Way's halo, and the merger thickened its disk. Bonaca calls it “the most transformative event in Milky Way history.”

Older, less violent transformations had happened not in the halo but in the body of the galaxy itself. In 2022 three different teams found signs of a protogalaxy apparently turning into a galaxy. Again, verification was complicated and hinged on knowing which stars were native to the Milky Way.

Harvard's Conroy was part of a team that measured the in situ stars' chemistry and found two populations: one group was ancient, metal-poor, moving chaotically and forming stars slowly; the other was younger, metal-rich, moving coherently and forming stars 10 times faster. The astronomers thought the populations represented different stages of galactic history and called these stages “simmering” and “boiling,” respectively. Meanwhile Belokurov and a team measured in situ stars' orbits and also found two epochs, he says: an early one with metal-poor stars' orbits going “all over the place” and a later one with stars richer in metals that were orbiting more coherently—“a transition,” he says, “from hot mess to relatively cold spinning disk.” They called the hot mess Aurora, after the ancient Greek goddess of dawn. Hans-Walter Rix of the Max Planck Institute for Astronomy in Heidelberg, Germany, and his team looked at the chemistry of two million in situ stars across the sky and found a gravitationally bound group of ancient, metal-poor stars in the center of the galaxy. They called it “the poor old heart” of the Milky Way.

Names aside, all three teams agree that they're probably studying the same transformation: a chaotic protogalaxy full of old, metal-poor stars going in no particular direction that then spun up into a disk and began to form new stars like fireworks. Bonaca, who was on Conroy's team, isn't sure the observations have converged into one consistent story, “but it does look like we're seeing some of the same things,” she says. “It's a little like the elephant.”
(more, and dust)

https://www.scientificamerican.com/article/the-new-story-of-the-milky-ways-surprisingly-turbulent-past/

[morganism]

Skyscraper-sized asteroid to pass within 1.7m miles of Earth on Friday

Nasa says it will be a harmless flyby by the giant rock, one of several near-Earth objects slated to swing by the planet this week

An asteroid as big as a skyscraper will pass within 1.7m miles (2.7mkm) of Earth on Friday.

Don’t worry: there’s no chance of it hitting us since it will miss our planet by seven times the distance from the Earth to the moon.

Nasa’s Center for Near Earth Object Studies estimates the space rock is between 690 and 1,575 feet (210 and 480 meters) across. That means the asteroid could be similar in size to New York City’s Empire State Building or Chicago’s Willis Tower.

Discovered in 2008, the asteroid is designated as 2008 OS7. It won’t be back our way again until 2032, but that will be a much more distant encounter, staying 45m miles away.

The harmless flyby is one of several encounters this week. Three much smaller asteroids also will harmlessly buzz the Earth on Friday, no more than tens of yards across, with another two on Saturday. On Sunday, an asteroid roughly half the size of 2008 0S7 will swing by, staying 4.5m miles away.

https://www.theguardian.com/science/2024/feb/01/asteroid-near-earth-nasa

( there was some cool sci going on here, had some cool cross sections, and even found a moonlet)

https://echo.jpl.nasa.gov/


https://www.asterank.com/

[Sigmetnow]

Jason Perry @volcanopele
 
.@NASAJuno is now about 84 minutes or so from C/A with Io. Current altitude is 171,500 km. Imaging starts in 1 hour and 15 minutes. 
pic.twitter.com/9sx4zoixIr 
 —
During the previous encounter, JunoCam got great views of Io's north polar region, the first time this area had been seen up close! The images revealed an area of mostly red-brown plains dotted by numerous non-volcanic mountains, mesas, and plateaus.
➡️ pic.twitter.com/zIuh3NcA1h 
2/3/24, 11:13 AM  https://x.com/volcanopele/status/1753813990944518395
Thread with info and pics!

[Sigmetnow]

Jupiter’s moon Io

Björn Jónsson @bjorn_jons
 
Image PJ58_26 from @NASAJuno on Feb 3, 2024. The small, bright features are specular reflections from features that normally appear dark (volcanic glass?). A plume is visible at lower right, it's been brightened rel to other parts of the image & is heavily processed. North is up.  pic.twitter.com/S7KTglwR6o 

2/4/24, 10:24 PM  https://x.com/bjorn_jons/status/1754345210895606183
 
< The great obsidian flats of Io. That has a nice ring to it!

 
Io, or Jupiter I, is the innermost and third-largest of the four Galilean moons of the planet Jupiter. Slightly larger than Earth's moon, Io is the fourth-largest moon in the Solar System, has the highest density of any moon, the strongest surface gravity of any moon, and the lowest amount of water of any known astronomical object in the Solar System.

[Sigmetnow]

The Andromeda galaxy is 6 times bigger in the sky than the full Moon: it's just too dim to clearly see it with the naked eye.
 
This composite image shows what it would look like at night if it was just brighter.
 
[📸 Tom Buckley-Houston] pic.twitter.com/IzfnT1k0JA 

[morganism]

and Andromeda is coming closer, right?

wonder if its brighter in UV?

[Sigmetnow]

NASA
In the spirit of #MardiGras, we’re letting the good times roll with this view of the Cartwheel Galaxy. This composite was created using Galaxy Evolution Explorer (GALEX), @NASAHubble (green); Spitzer Space Telescope (red); and @chandraxray (purple).
 
More: ➡️ go.nasa.gov/48efzuc 
 
2/13/24,  https://x.com/nasa/status/1757490580391702783

[vox_mundi]

Saturn's Largest Moon Most Likely Uninhabitable
https://phys.org/news/2024-02-saturn-largest-moon-uninhabitable.html



A study led by Western astrobiologist Catherine Neish shows the subsurface ocean of Titan—the largest moon of Saturn—is most likely a non-habitable environment, meaning any hope of finding life in the icy world is dead in the water.

In the study, published in the journal Astrobiology, Neish and her collaborators attempted to quantify the amount of organic molecules that could be transferred from Titan's organic-rich surface to its subsurface ocean, using data from impact cratering.

Comets impacting Titan throughout its history have melted the surface of the icy moon, creating pools of liquid water that have mixed with the surface organics. The resulting melt is denser than its icy crust, so the heavier water sinks through the ice, possibly all the way to Titan's subsurface ocean.

Using the assumed rates of impacts on Titan's surface, Neish and her collaborators determined how many comets of different sizes would strike Titan each year over its history. This allowed the researchers to predict the flow rate of water carrying organics that travel from Titan's surface to its interior.

Neish and the team found the weight of organics transferred in this way is quite small, no more than 7,500 kg/year of glycine—the simplest amino acid, which makes up proteins in life. This is approximately the same mass as a male African elephant. (All biomolecules, like glycine, use carbon—an element—as the backbone of their molecular structure.)

"One elephant per year of glycine into an ocean 12 times the volume of Earth's oceans is not sufficient to sustain life," said Neish. "In the past, people often assumed that water equals life, but they neglected the fact that life needs other elements, in particular carbon."

Other icy worlds (like Jupiter's moons Europa and Ganymede and Saturn's moon Enceladus) have almost no carbon on their surfaces, and it is unclear how much could be sourced from their interiors. Titan is the most organic-rich icy moon in the solar system, so if its subsurface ocean is not habitable, it does not bode well for the habitability of other known icy worlds.

"This work shows that it is very hard to transfer the carbon on Titan's surface to its subsurface ocean—basically, it's hard to have both the water and carbon needed for life in the same place," said Neish.



Catherine Neish et al, Organic Input to Titan's Subsurface Ocean Through Impact Cratering, Astrobiology (2024)
https://www.liebertpub.com/doi/10.1089/ast.2023.0055

[SteveMDFP]

Saturn's Largest Moon Most Likely Uninhabitable
https://phys.org/news/2024-02-saturn-largest-moon-uninhabitable.html

"One elephant per year of glycine into an ocean 12 times the volume of Earth's oceans is not sufficient to sustain life," said Neish. "In the past, people often assumed that water equals life, but they neglected the fact that life needs other elements, in particular carbon."

Catherine Neish et al, Organic Input to Titan's Subsurface Ocean Through Impact Cratering, Astrobiology (2024)
https://www.liebertpub.com/doi/10.1089/ast.2023.0055

I don't see the logic here.  It's not clear to me that there's any mechanism for that organic carbon to exit that ocean.  With no oxygen, it won't turn into CO2, for example.  It's not a lot of carbon going in, but it may have been accumulating for a billion years.  And, there may be carbon entering that ocean from the moon's interior.  And there may have been abundant carbon from the time of formation.  That ocean could be saturated with carbon-containing organic molecules.  Anaerobic life could be flourishing.

[vox_mundi]

That is definitely the weak logic of their hypothesis. Carbonaceous chondrites could have seeded the ocean billions of years ago. And amino acid formation is not limited to interstellar space. Since it's raining methane/ethane on that moon (which needs to be constantly renewed) I think they have plenty of carbon. Maybe we'll find out with Dragonfly

[morganism]

Titan; isn't one whole hemisphere of Tethys covered with carbon from orbital debris?

and

Osiris Rex haul less than i was expecting.

After designing, producing, and testing new tools, the ARES curation engineers successfully removed the fasteners in January and completed disassembly of the TAGSAM head. The remaining Bennu sample was revealed and carefully poured into wedge-shaped containers. 1.81 ounces (51.2 grams) were collected from this pour. Combined with the previously measured 2.48 ounces (70.3 grams) and additional particles collected outside of the pour, the bulk Bennu sample mass totals 4.29 ounces (121.6 grams). NASA will preserve at least 70% of the sample at Johnson for further research by scientists worldwide, including future generations.

https://blogs.nasa.gov/osiris-rex/2024/02/15/nasa-announces-osiris-rex-bulk-sample-mass/

[Sigmetnow]

… the bulk Bennu sample mass totals 4.29 ounces (121.6 grams). NASA will preserve at least 70% of the sample at Johnson for further research by scientists worldwide, including future generations.

“At some point Starship will demonstrate an automated Lunar landing and return with a few tonnes of Moon rocks….”
 
https://caseyhandmer.wordpress.com/2021/10/28/starship-is-still-not-understood/

[morganism]

There’s One Last Place Planet 9 Could Be Hiding

 A recently submitted study to The Astronomical Journal continues to search for the elusive Planet Nine (also called Planet X), which is a hypothetical planet that potentially orbits in the outer reaches of the solar system and well beyond the orbit of the dwarf planet, Pluto. The goal of this study was to narrow down the possible locations of Planet Nine and holds the potential to help researchers better understand the makeup of our solar system, along with its formation and evolutionary processes. So, what was the motivation behind this study regarding narrowing down the location of a potential Planet Nine?

Dr. Mike Brown, who is a Richard and Barbara Rosenberg Professor of Astronomy at Caltech and lead author of the study, tells Universe Today, “We are continuing to try to systematically cover all of the regions of the sky where we predict Planet Nine to be. Using data from Pan-STARRS allowed us to cover the largest region to date.”

Pan-STARRS, which stands for Panoramic Survey Telescope and Rapid Response System, is a collaborative astronomical observation system located at Haleakala Observatory and operated by the University of Hawai’I Institute of Astronomy with telescope construction being funded by the U.S. Air Force. For the study, the researchers used data from Data Release 2 (DR2) with the goal of narrowing down the possible location of Planet Nine based on findings from past studies.

the end, the team narrowed down possible locations of Planet Nine by eliminating approximately 78 percent of possible locations that were calculated from previous studies. Additiotally, the researchers also provided new estimates for the approximate semimajor axis (measured in astronomical units (AU)) and Earth-mass size of Planet Nine at 500 and 6.6, respectively. So, what are the most significant results from this study, and what follow-up studies are currently being conducted or planned?

“While I would love to say that the most significant result was finding Planet Nine, we didn’t,” Dr. Brown tells Universe Today. “So instead, it means that we have significantly narrowed the search area. We’ve now surveyed approximately 80% of the regions where we think Planet Nine might be.”

https://www.universetoday.com/165774/theres-one-last-place-planet-9-could-be-hiding/


A Pan-STARRS1 Search for Planet Nine

    We present a search for Planet Nine using the second data release of the Pan-STARRS1survey. We rule out the existence of a Planet Nine with the characteristics of that predicted in Brown & Batygin (2021) to a 50% completion depth of V=21.5. This survey, along with previous analyses of the Zwicky Transient Facility (ZTF) and Dark EnergySurvey (DES) data, rules out 78% of the Brown \& Batygin parameter space. Much of the remaining parameter space is at V>21 in regions near and in the area where the northern galactic plane crosses the ecliptic.

https://arxiv.org/abs/2401.17977

[morganism]

 We are pleased to announce that registration and abstract submission is now open for "The Uranus Flagship: investigating new paradigms for outer planet exploration" Workshop to be held in Greenbelt, MD from 21 to 23 May 2024.  Join us as we discuss practical aspects of the next planetary flagship and how we can employ new paradigms to better enable robust outer planet exploration.

 

We also seek abstracts on the following topics:

1. Near term technologies.  Infusions of near-term (TRL 4-6) technologies may help enhance the science return of power and data rate constrained missions.  We especially seek contributions on technologies that can help save mass or power or can improve science data volume return.

 

2. Mission science drivers.  We seek broad summary discussions that can highlight the breadth of measurements that contribute to answering Decadal thematic questions, how they drive the mission architecture, and which measurements/methods offer the highest science return.  Each abstract should focus on a single UOP science objective (from the Decadal study) when discussing the above topics.

 

3. Interdisciplinary and cross-divisional science.  Flagship missions often contribute to science beyond the STM.  Topics can include best examples of how this has worked on other missions, innovative investigations that could contribute UOP interdivisional science without changing the mission design, and how UOP exploration will benefit other Division's decadal survey goals, etc.

 

Please visit our website to register and submit abstracts:

 https://science.gsfc.nasa.gov/690/uranus-flagship

[Sigmetnow]

Solar flare and multiple network outages this morning. Related?

How's your network this morning? DownDetector has multiple networks suffering through nationwide outages. Hard to say, though, if it's actually widespread.
2/22/24, 6:37 AM  https://x.com/lanceulanoff/status/1760629771527176383
⬇️ Image below from: pic.twitter.com/uigDlPa4c5 

Apparently a solar flare, not the Russians 😂, is responsible for the nationwide cell outage. …
2/22/24, 8:54 AM  https://x.com/rightglockmom/status/1760664415274234121
➡️ pic.twitter.com/q3eMxSlJXR  2 minute TV news (weather) piece.

⬇️ Infographic below from: https://www.spaceweather.gov/homepage 

—-
EDIT

Some people are attributing cell network outages (AT&T, Verizon) in the U.S to last night’s X-class #SolarFlare. However, flares only cause radio degradation on the *dayside* of the Earth. As you can see below, the U.S was not affected by the event. So it’s just a coincidence!

2/22/24, 10:39 AM  https://x.com/ryanjfrench/status/1760690840656286048
➡️ pic.twitter.com/A5kImCmStC 
More discussion at the link. The time and location of the outage doesn’t seem to match the timing of the flare; but there was another flare hours earlier; flares can cause problems on Earth’s nightside, or globally; but this one ‘wasn’t strong enough’….

Coincidence? Maybe.  IMO we can’t say for sure whether the outage was an effect of a solar flare without knowing more about AT&T’s hardware and global interconnections, and how they might have been affected.

[morganism]

There's an invisible monster on the loose, barreling through intergalactic space so fast that if it were in our solar system, it could travel from Earth to the Moon in 14 minutes. This supermassive black hole, weighing as much as 20 million Suns, has left behind a never-before-seen 200,000-light-year-long "contrail" of newborn stars, twice the diameter of our Milky Way galaxy. It's likely the result of a rare, bizarre game of galactic billiards among three massive black holes.

"We think we're seeing a wake behind the black hole where the gas cools and is able to form stars. So, we're looking at star formation trailing the black hole," said Pieter van Dokkum of Yale University in New Haven, Connecticut. "What we're seeing is the aftermath. Like the wake behind a ship we're seeing the wake behind the black hole." The trail must have lots of new stars, given that it is almost half as bright as the host galaxy it is linked to.

The black hole lies at one end of the column, which stretches back to its parent galaxy. There is a remarkably bright knot of ionized oxygen at the outermost tip of the column. Researchers believe gas is probably being shocked and heated from the motion of the black hole hitting the gas, or it could be radiation from an accretion disk around the black hole. "Gas in front of it gets shocked because of this supersonic, very high-velocity impact of the black hole moving through the gas. How it works exactly is not really known," said van Dokkum.

"This is pure serendipity that we stumbled across it," van Dokkum added. He was looking for globular star clusters in a nearby dwarf galaxy. "I was just scanning through the Hubble image and then I noticed that we have a little streak. I immediately thought, 'oh, a cosmic ray hitting the camera detector and causing a linear imaging artifact.' When we eliminated cosmic rays we realized it was still there. It didn't look like anything we've seen before."

Because it was so weird, van Dokkum and his team did follow-up spectroscopy with the W. M. Keck Observatories

in Hawaii. He describes the star trail as "quite astonishing, very, very bright and very unusual." This led to the conclusion that he was looking at the aftermath of a black hole flying through a halo of gas surrounding the host galaxy.

This intergalactic skyrocket is likely the result of multiple collisions of supermassive black holes. Astronomers suspect the first two galaxies merged perhaps 50 million years ago. That brought together two supermassive black holes at their centers. They whirled around each other as a binary black hole.

Then another galaxy came along with its own supermassive black hole. This follows the old idiom: "two's company and three's a crowd." The three black holes mixing it up led to a chaotic and unstable configuration. One of the black holes robbed momentum from the other two black holes and got thrown out of the host galaxy. The original binary may have remained intact, or the new interloper black hole may have replaced one of the two that were in the original binary, and kicked out the previous companion.

When the single black hole took off in one direction, the binary black holes shot off in the opposite direction. There is a feature seen on the opposite side of the host galaxy that might be the runaway binary black hole. Circumstantial evidence for this is that there is no sign of an active black hole remaining at the galaxy’s core. The next step is to do follow-up observations with NASA's James Webb Space Telescope and the Chandra X-ray Observatory to confirm the black hole explanation.

https://science.nasa.gov/missions/hubble/hubble-sees-possible-runaway-black-hole-creating-a-trail-of-stars/

A Candidate Runaway Supermassive Black Hole Identified by Shocks and Star Formation in its Wake

https://iopscience.iop.org/article/10.3847/2041-8213/acba86

[johnm33]

These sound very similar to the dual production of quasars on opposite sides of a galaxy that Peratt noticed, he was told to shut up wouldn't and lost all his telescope time. Where images show the connection of quasars to galactic arms they're mostly clipped but some get through. Here's a simplified introduction to the work.


++Got that wrong it was Halton Arp

[vox_mundi]

'Zero chance' infamous Apophis collides with another asteroid, redirects to Earth ... we hope 🤞
https://phys.org/news/2024-03-chance-infamous-apophis-collides-asteroid.html

A new study led by Western astronomer Paul Wiegert posits what would happen if Apophis' orbit changed after a collision with another asteroid.

[morganism]

(for those interested in orbital eccentricities and climate mods. Also SETI folk should take a look.)

Close Stellar Encounters and Earth’s Orbit
(...)
Study the changes that have occurred in Earth’s climate over the millennia and it appears that fluctuations in the eccentricity of Earth’s orbit are involved. Kaib points to a specific episode that is illuminated by the analysis in this paper:

    “One example of such an episode is the Paleocene-Eocene Thermal Maximum 56 million years ago, where the Earth’s temperature rose 5-8 degrees centigrade. It has already been proposed that Earth’s orbital eccentricity was notably high during this event, but our results show that passing stars make detailed predictions of Earth’s past orbital evolution at this time highly uncertain, and a broader spectrum of orbital behavior is possible than previously thought.”

So we’re digging into the history of our planet’s orbit, along with that of the other planets. The authors’ research shows that stellar encounters are not uncommon. A star passes within 50,000 AU on average every million years, and within 10,000 AU every 20 million years. To study the matter, Kaib and Raymond use a hybrid integrator – a set of specialized numerical methods – called MERCURY to simulate these encounters, under conditions described in the paper. The computer runs show that orbital changes to Earth do indeed result, or are at least accelerated, by perturbations from other stars.

Complicating these calculations is the fact that orbital evolution is chaotic, so that beyond timescales on the order of 100 million years, it is impossible to do more than characterize it statistically. The authors point out that even the long-term stability of the Solar System is not guaranteed, as over the Sun’s lifetime there is a 1 percent chance that Mercury will be lost by collision with either the Sun or Venus.

The paper turns to a specific encounter, that with the star HD 7977, which is a G-class star in Cassiopeia now some 250 light years away. 2.8 million years ago, this star moved past the Solar System at about 27 kilometers per second, its trajectory taking it somewhere in the neighborhood of 13,200 AU from the Sun, although the authors point out the wide cone of uncertainty about the distance, which may have been as little as 3900 AU. The ‘impulse gradient’ that shows the level of perturbation to the planets was over an order of magnitude higher than the norm during this time.

Working this into their models, the authors find that the median value of 13,200 AU would have had little effect on the Solar System’s long term chaotic evolution, but a passage at 3900 AU would have affected the eccentricity of Earth’s orbit. This is in addition, of course, to whatever effect such a close passage would have on Oort Cloud objects. A passage at 3900 AU would be one of the ten most powerful encounters experienced in the history of our system given the star’s above average mass and an encounter velocity that is below the average.
(more)

https://www.centauri-dreams.org/2024/02/28/close-stellar-encounters-and-earths-orbit/


Passing Stars as an Important Driver of Paleoclimate and the Solar System's Orbital Evolution

https://iopscience.iop.org/article/10.3847/2041-8213/ad24fb

[vox_mundi]

A New Spin on Betelgeuse's Boiling Surface
https://phys.org/news/2024-03-betelgeuse-surface.html

Betelgeuse is a well-known red supergiant star in the constellation Orion. Recently it has gained a lot of attention, not only because variations in its brightness led to speculations that an explosion might be imminent, but also because observations indicated that it's rotating much faster than expected.

This latter interpretation is now put into question by an international team led by astronomers at Max Planck Institute for Astrophysics, who propose that Betelgeuse's boiling surface can be mistaken for rotation even in the most advanced telescopes. Other astronomers are actively analyzing new observational data to test such hypotheses.



Jing-Ze 竟泽 Ma 马 et al, Is Betelgeuse Really Rotating? Synthetic ALMA Observations of Large-scale Convection in 3D Simulations of Red Supergiants, The Astrophysical Journal Letters (2024)
https://iopscience.iop.org/article/10.3847/2041-8213/ad24fd

[Sigmetnow]

When the camera is in sync with the universe.
 
➡️ pic.twitter.com/voAqI5HMLc  1 min. Time lapses.  Sky view is motionless;  the horizon moves!

[Sigmetnow]

JPL’s Voyager team ‘extremely hopeful’ after ailing, faraway craft shows signs of former self
March 10, 2024

… Now, well into its twilight years, Voyager 1 is very sick. But amid weeks of concern at JPL – where a mission team, dwindling in number, talks with the crafts – a hopeful sign has finally emerged.

The elderly spacecraft has been speaking in gibberish since November 2023, and the Voyager engineering team has yet to fix the problem. As though a stroke left Voyager 1 with aphasia, it can hear the messages being sent from Earth but can’t respond coherently, providing no information on its health or status.

The issue likely lies in the flight data system (FDS), which compiles information about the spacecraft’s health, operational status and scientific observations into a string of 1’s and 0’s that are sent to Earth. Until recently, Voyager 1 had been transmitting a repetitive string of nonsense, indicating that the FDS may be “stuck”.

Without restoring communication, the Voyager team cannot tell what the probe needs to stay alive; consigning Voyager 1 to a lonely, unknowable demise.

“The likely cause of the issue is some type of corrupted bit structure in the FDS computer. We don’t know where that corruption is,” explained Dr. Suzanne Dodd, project manager for the Voyager Interstellar Mission, who describes this issue as the most serious she’s seen since joining the team in 2010.

In the past couple of weeks, Voyager 1 has shown promising signs of improvement. The probe is finally transmitting patterns of 1’s and 0’s that look familiar to the engineers.

“They’re not exactly what we would expect,” Dodd said. “But they do look like something that can show us that the FDS is at least partially working.”

When a crisis emerges at JPL, a “tiger team” is assembled to help attack the problem, temporarily aiding the mission team. Voyager’s longevity poses a unique challenge for the team. Almost every engineer and programmer who helped build the Voyagers have either retired or died.

“So a lot of what the tiger team has had to do is go back and look through old documentation,” Dodd said. “Try to recreate how the code was done and why the code was done that way.” …

https://www.pasadenastarnews.com/2024/03/09/jpls-voyager-team-extremely-hopeful-after-ailing-faraway-craft-shows-signs-of-former-self/

[morganism]

Has anyone checked to make sure The Martian isn't aboard and sending in Hexadecimal?

I am waiting for Betelguse to kick out a new binary star, to really F with stellar astrophysicists and the Hertsprung/Russell diagram

[Sigmetnow]

Has anyone checked to make sure The Martian isn't aboard and sending in Hexadecimal?

I am waiting for Betelguse to kick out a new binary star, to really F with stellar astrophysicists and the Hertsprung/Russell diagram

What if it’s aliens, who found Voyager and are trying to communicate with us — from a safe distance….

[morganism]

Voyager 1 starts making sense again after months of babble

(getting a read out of that FDS soft/firmware. )

Veteran spacecraft shows signs of sanity with poke from engineers

Engineers are hopeful that the veteran spacecraft Voyager 1 might have turned a corner after spending the last three months spouting gibberish at controllers.

On March 1, the Voyager team sent a command, dubbed a "poke," to get the probe's Flight Data System (FDS) to try some other sequences in its software in the hope of circumventing whatever had become corrupted.

While Voyager 1's lifespan is not infinite, it has endured far longer than anticipated and might be about to dodge yet another bullet. On March 3, the mission team saw something different in the stream of data returned from the spacecraft, which had been unreadable since December.

An engineer with the Deep Space Network (DSN) was able to decode it, and by March 10, the team determined that it contained a complete memory dump from the FDS.

The FDS memory read-out contains its code, variables, and science and engineering data for downlink.

Prior to NASA's announcement, Dr Suzanne Dodd, project manager for the Voyager Interstellar Mission, said in a Pasadena Star-News report that the data being transmitted from the probe was "not exactly what we would expect, but they do look like something that can show us that the FDS is at least partially working."

https://www.theregister.com/2024/03/14/voyager_1_not_dead/

[Sigmetnow]

Did you know?
NASA only uses 15 digits of π for calculating interplanetary travel.
 
At 40 digits, you could calculate the circumference of a circle the size of the visible universe with an accuracy that'd fall off by less than the diameter of a hydrogen atom.
#piDay2024
3/14/24, https://x.com/rainmaker1973/status/1768180261580386718
 
pic.twitter.com/RBw75hHDVE  Textpic:  Pi digits

- Engineers: Fifteen (15) decimals of Pi is sufficient to calculate the Solar system circumference to a precision of a molecular width. 
- Astro-Physicists: Thirty-seven (37) decimals of Pi is sufficient to calculate the Universe's circumference to a precision of the width of a Hydrogen atom. 
- Particle-Physicists: Sixty-five (65) decimals of Pi is sufficient to calculate the Universe's circumference to a precision of a Planck length. 
- Mathematician: We calculate decimals of Pi to a hundred trillion digits for the sheer insanity of it.
3/14/24, https://x.com/johnsan46851615/status/1768358818855973182

Below Planck-length (smallest measurable distance), there is no practical purpose for digits of pi and it can be thought of as a ~66 digit integer that describes the number of voxels in this reality/simulation
3/15/24, https://x.com/elonmusk/status/1768538524242833525
 
 
=====
 
Northwestern U.S.
 
Oregon Outback becomes the largest International Dark Sky Sanctuary
March 11, 2024

The Oregon Outback Dark Sky Network (ODSN) has completed the first phase of a multi-phased project to establish a landscape-level International Dark Sky Sanctuary within the largest, contiguous dark sky zone in the lower 48 United States. Phase 1 (Lake County) of the proposed Oregon Outback International Dark Sky Sanctuary (OOIDSS) was certified as an International Dark Sky Sanctuary by DarkSky International, making it the largest International Dark Sky Sanctuary to date.

Phase 1 comprises 2.5 million acres in Lake County, southeastern Oregon. The certified area is about one-half the size of New Jersey in a region frequently referred to as the “Oregon Outback.” This novel nomination involved numerous federal, state, and local officials negotiating project boundaries and developing and endorsing a joint Lighting Management Plan (LMP). This effort required broad stakeholder engagement and is a model of collaboration and cooperation. When complete, the full OOIDSS will encompass over 11.4 million acres of protected night skies.

According to DarkSky Delegate Dawn Nilson, the environmental consultant who managed and authored the application, “As the population of Oregon and the trend of light pollution continue to rise, the unparalleled scale and quality of the Outback’s dark skies will long serve as a starry refuge for people and wildlife alike. Adherence to the LMP will allow this large expanse of land to serve as a demonstration site of sustainable lighting principles not only within southeastern Oregon but possibly the Pacific Northwest Region.”
…
According to the Light Pollution Science and Technology Institute  (2016), the Outback is located within the largest, contiguous, pristine dark sky zone in the lower 48 United States, and this certification helps to protect a large portion of that zone.
…
The intentions behind pursuing a large-scale sanctuary are to protect much of the unique, pristine, dark sky zone, to keep any additional dark sky recreation dispersed (as it is now), to allow a number of incorporated gateway communities to economically benefit from the same project, and to more effectively and efficiently manage a certification within a remote area. …

https://darksky.org/news/outback-dark-international-dark-sky-sanctuary/

[vox_mundi]

Astrophysicist Explains Science Behind Once-In-a-Lifetime Nova Outburst That Will Light Up the Sky This Year
https://phys.org/news/2024-03-astrophysicist-science-lifetime-nova-outburst.html

The total solar eclipse isn't the only reason to keep your eyes to the sky this year. For the first time in 80 years, a star system 3,000 light years away will be visible to the naked eye thanks to a once-in-a-lifetime nova outburst

NASA announced that the nova, which will create a "new" star in the night sky, will light up the night sky some time between now and September and be as bright as the North Star. One of only five recurring novae in our galaxy, it will be visible for a week before it fades back down.

https://blogs.nasa.gov/Watch_the_Skies/2024/02/27/view-nova-explosion-new-star-in-northern-crown/

The star system in question is T Coronae Borealis, or T CrB, and it contains a white dwarf and red giant, two stars that create the perfect conditions for a nova outburst.



What happens when these two stars co-orbit one another is that the white dwarf steadily strips away the atmosphere of the expanding red giant.

"The white dwarf is much smaller and much more compact, so you build up a little disk of mostly hydrogen and maybe some helium as well sitting on the white dwarf," Blazek says. "Eventually enough of it builds up and basically ignites. It's not literally burning in the sense of fire; it's thermonuclear burn and you have hydrogen undergoing a fusion reaction."

As it undergoes that runaway thermonuclear reaction, the white dwarf gets hotter, bigger and brighter, making it easier for us to see it back on Earth. This entire process is part of the natural lifecycle of these stars and why they happen every 80 years. After a white dwarf like this goes nova, it goes back to stripping gas away from the red giant, building up gas at the same rate before eventually another outburst occurs.

When a star like T CrB's white dwarf hits a certain mass after repeated novae and it can't support its own mass, it starts to collapse and erupts into a massive, bright explosion, known as a supernova. Novae occur every 80 years, but supernovae are one-time events because they are so powerful that they end up destroying a star. Type 1a supernovae are even more notable because they seem to always have the same brightness, which means they likely always happen to stars of the same mass, Blazek says.

[LRC1962]

If you're in the sweet spot on a sunny day. Total eclipse on its way Apr.8.
https://m.espacepourlavie.ca/sites/espacepourlavie.ca/files/styles/gal-photo-large/public/20240408_total_eclipse_north_america_web_en.png?itok=-O9dWyQV
Another view.

[John_the_Younger]

Conspiracy Theory alert: notice how the total eclipse path closely follows much of the eastern US-Canadian border?  Somebody must be up to something nefarious!
 

[vox_mundi]

“Take Off, You Hoser!”

*https://en.wiktionary.org/wiki/hoser

[Sigmetnow]

De-icing the Euclid spacecraft

ESA
A few layers of water ice – the width of a strand of DNA – are starting to impact @ESA_Euclid's vision.
 
This is a common issue for spacecraft in the freezing cold of space, but it's a potential problem for this highly sensitive mission that requires precision to investigate the nature of the dark Universe...
⬇️ Image below from: pic.twitter.com/CIxVCHs94J 
 
.@ESA_Euclid teams across Europe are now testing a newly designed procedure to de-ice the mission's optics.
If successful, the operations will validate their plan to keep Euclid’s optical system as ice-free as possible for the rest of its life in orbit.
 
Read more here 👇
https://www.esa.int/Science_Exploration/Space_Science/Euclid/Operations_begin_to_de-ice_Euclid_s_vision
 

3/19/24, 8:23 AM. https://x.com/esa/status/1770063542202315122
 
    ——

ESA
✅ Update 20 March: first results just announced confirm successful operations, @ESA_Euclid's sharp vision is restored. The initial analysis of #Euclid’s data validates the de-icing approach devised by the team.

3/20/24, 6:35 PM  https://x.com/esa/status/1770580011910676711

[morganism]

Oh no, its an invasion of darkness from Mexico! And they are headed right for Texas !

[Sigmetnow]

NASA Slashes Budget for Chandra, Its Greatest X-ray Observatory | Scientific American

In NASA’s latest budget request to Congress earlier this month, Chandra comes up short. The telescope—and its science—are degraded, NASA officials say; given the current climate of stopgap budget deals and correspondingly tighter purse strings, the agency has chosen to hasten the telescope’s end, freeing up the most of the $68 million per year currently spent on it over the course of the next five years. With Chandra gone, only Hubble would remain as the first—and last—of the Great Observatories. …

https://www.scientificamerican.com/article/nasa-slashes-budget-for-chandra-its-greatest-x-ray-observatory/


EDIT  — more:
 
Astronomers criticize proposed space telescope budget cuts
Jeff Foust March 21, 2024
https://spacenews.com/astronomers-criticize-proposed-space-telescope-budget-cuts/

[Sigmetnow]

Jasmine 🌌🔭 @astro_jaz
this is a BEAUTIFUL timelapse video made of europa and io passing over jupiter’s great red spot using hundreds of images from cassini!!
   —
credit: NASA JPL-Caltech/@kevinmgill
   —
the amount of people calling this fake is hilarious

3/30/24, https://x.com/astro_jaz/status/1774124560050241691

➡️ pic.twitter.com/I5k0ubKFlm  24 sec.

[morganism]

(Parker Solar Probe filmed a Hemholtz instability vortex in the corona, and your'e worried about sandworms ?)

https://mashable.com/article/nasa-sun-footage-parker-solar-probe

First Direct Imaging of a Kelvin–Helmholtz Instability by PSP/WISPR

https://iopscience.iop.org/article/10.3847/1538-4357/ad2208

[morganism]

(Europa Clipper still on track for Oct launch)

(...)
The Clipper spacecraft is due to blast off in October bound for Europa, one of dozens of moons orbiting the Solar System's biggest planet, and the nearest spot in our celestial neighborhood that could offer a perch for life.

"One of the fundamental questions that NASA wants to understand is, are we alone in the cosmos?" Bob Pappalardo, the mission's project scientist told AFP.

"If we were to find the conditions for life, and then someday actually find life in a place like Europa, then that would say in our own solar system there are two examples of life: Earth and Europa.

"That would be huge for understanding how common life might be throughout the universe."

The $5 billion probe is currently at NASA's Jet Propulsion Laboratory in California, sitting in a "clean room" -- a sealed area only accessible to people wearing head-to-toe covering.

The precautions are to ensure the probe remains free of contaminants to avoid transporting Earthly microbes to Europa.

After transport to Kennedy Space Center in Florida, Clipper is set to launch aboard a Space X Falcon Heavy rocket and begin an over-five-year journey that involves a pass by Mars to pick up speed.

In 2031, it should be in orbit around Jupiter and Europa, where it will begin a detailed study of the moon scientists believe is covered in frozen water.

"We have instruments like cameras, and spectrometers, a magnetometer and a radar that can... penetrate right through ice, bounce off liquid water and back to the surface to tell us how thick is the ice and where is liquid water located," Pappalardo said.

Mission managers do not expect to find little green men swimming in the water -- in fact, they're not even looking for life itself, only for the conditions that could support it.
(more)

https://www.rawstory.com/nasa-unveils-probe-bound-for-jupiter-s-possibly-life-sustaining-moon/

[vox_mundi]

[morganism]

Mystery of Where Gold and Platinum Come From Deepens After Gargantuan Cosmic Explosion

The brightest gamma-ray burst of all time came from a supernova but mysteriously didn't show signs of heavy elements.

In October 2022, an extremely bright flash caught the attention of the Gemini South telescope in Chile. It was quickly determined to be the brightest ever seen, hence its nickname: the Brightest Of All Time (the BOAT).

Now, a group of researchers has examined the event with the Webb Space Telescope and concluded that the BOAT’s cause was a supernova: an explosive and brilliant death of a star. The researchers also looked for heavy elements like gold and platinum but saw no signs of them, leaving the question of their origins just as open as before. The team’s research is published today in Nature Astronomy.

Heavy elements are produced by neutron-star mergers—at least, some of them are. The heavy stuff in the universe is too abundant for such stellar mergers to account for all of them. Even after two stars in a binary system explode, leaving the dense shells that are neutron stars, “it can take billions and billions of years for the two neutron stars to slowly get closer and closer and finally merge,” according to Peter Blanchard, an astronomer at Northwestern University and the study’s lead author, in university release.

“But observations of very old stars indicate that parts of the universe were enriched with heavy metals before most binary neutron stars would have had time to merge,” Blanchard added. “That’s pointing us to an alternative channel.”

Gamma-ray bursts come in two flavors: long- and short-duration. Short bursts are associated with stars merging and black holes forming, according to NASA, while the longer bursts are associated with stellar deaths. The BOAT is staunchly in the latter camp.
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https://gizmodo.com/gold-platinum-brightest-of-all-time-gamma-ray-burst-1851406426


JWST detection of a supernova associated with GRB 221009A without an r-process signature

https://www.nature.com/articles/s41550-024-02237-4

https://www.nature.com/articles/s41550-024-02237-4.pdf

[Sigmetnow]

Chris Hadfield @Cmdr_Hadfield

If you look closely at the 8 o’clock position from the Sun, halfway out this amazing image, you can see a comet in its death throes, just before it got vaporized.

Image: Petr Horálek (Institute of Physics in Opava)

Details: https://www.esa.int/ESA_Multimedia/Images/2024/04/Rare_sighting_of_doomed_SOHO_comet_during_solar_eclipse
 
4/19/24, https://x.com/cmdr_hadfield/status/1781473338189115457