Sunday, November 12, 2023

Incredible New Videos Show NASA Smashing Into Asteroid

Noor Al-Sibai
Sat, November 11, 2023 


Super Smash Bros

An amateur astronomer has compiled new footage from NASA's groundbreaking asteroid-smashing mission to show just how incredible the collision really was.

As ScienceAlert reports, Barcelona-based citizen scientist Jacint Roger Perez processed the videos, which he posted on Twitter in GIF form, from newly-released raw images from the Double Asteroid Redirection Test (DART) mission that successfully deflected an asteroid called Dimorphos last September.

Alongside the NASA spaceship used to ram into Dimorphos, the Italian Space Agency sent a tiny cubesat called LICIAcube — and it was new footage from LICIAcube's two cameras that Perez used to compile his stunning views of what happened just before, during, and after the DART craft slammed into the asteroid.

https://twitter.com/landru79/status/1720528631779266852

The DART impact, ScienceAlert explains, ended up having a way larger, more visible, and longer-lasting effect than scientists were expecting.

As NASA reported last December, more than two million pounds of material ejected from the itty bitty Dimorphos asteroid, which was only 525 feet across and orbited its larger brother Didymos every 11 hours and 55 minutes.

https://twitter.com/landru79/status/1720828117038534676

Dead on Impact


After the impact, a whopping 6,214-mile tail of debris trailed the asteroid for months on end — and although scientists were looking to only alter the orbit of the "moonlet" asteroid by about seven minutes, the impact of NASA's refrigeration-sized spacecraft was diminished by a whopping 33 minutes.

Interestingly enough, multiple teams of scientists hypothesized earlier this year that Dimorphos was displaced from its orbit so significantly not just because of the DART impact, but also because of the massive debris tail the collision caused.

As ScienceAlert reported back in March, the journal Nature published a series of articles about the Dimorphos debris, with three of them finding that the asteroid's long post-smashing tail seemed to increase its momentum more than anyone could have expected.

This mission's purpose wasn't just for the love of the game, but rather to see whether we could divert any killer asteroids screaming towards Earth to avert the kind of world-shattering disaster that made dinosaurs extinct.

Obviously, it was way more successful than scientists anticipated — and it made for some pretty stunning and badass imagery of a space-age wrecking rally, just as a bonus.

More on DART: Something Weird is Going on With the Asteroid NASA Smashed

NASA probe to observe near-Earth asteroid's 2029 close encounter

Steve Gorman
Fri, November 10, 2023 







The NASA spacecraft OSIRIS-APEX hovers over the surface of the near-Earth asteroid Apophis

By Steve Gorman

(Reuters) - About 5-1/2 years from now, astronomers predict, an asteroid about as wide as the Empire State Building is tall will streak through space within 20,000 miles (32,200 km) of Earth, the closest any celestial object of that size will have come to our planet in modern history.

When it does, a spacecraft launched by NASA in 2016 is expected to be in position to provide a detailed examination of this rare close encounter.

The mission, directed by University of Arizona scientists, is expected to yield insights into planetary formation and knowledge that could inform efforts to build a defense system against possible doomsday asteroid collisions with Earth.

At the time of its 2004 discovery, the asteroid Apophis, named for a demon serpent embodying evil and chaos in ancient Egyptian mythology, appeared to pose a dire impact threat to Earth, with scientists forecasting a potential collision in 2029. Refined observations have since ruled out any impact risk for at least another century.

Still, its next approach in 2029 will bring the asteroid within a cosmic cat's whisker of Earth - less than one-tenth the moon's distance from us and well within the orbits of some geosynchronous Earth satellites.

The spacecraft now headed for a rendezvous with Apophis is OSIRIS-REx, which made headlines plucking a soil sample from a different asteroid three years ago and sending it back to Earth in a capsule that made a parachute landing in Utah in September.

SPACECRAFT'S SECOND ACT

Rather than retire the spacecraft, NASA has rebranded it as OSIRIS-APEX - short for APophis EXplorer - and fired its thrusters to put it on course for its next target.

The Apophis expedition was detailed in a mission overview published in the Planetary Science Journal.

Apophis, oblong and somewhat peanut-shaped, is a stony asteroid believed to consist mostly of silicate materials along with iron and nickel. Measuring about 1,110 feet (340 meters) across, it is due to pass within about 19,800 miles (31,860 km) of Earth's surface on April 13, 2029, becoming visible to the naked eye for a few hours, said Michael Nolan, deputy principal investigator for the mission at the University of Arizona.

"It's not going to be this glorious show," Nolan said, but it will appear as a point of reflected sunlight in the night sky over Africa and Europe.

An asteroid that large passing so near to Earth is estimated to occur roughly once every 7,500 years. The Apophis flyby is the first such encounter predicted in advance.

The tidal pull of Earth's gravity likely will cause measurable disturbances to the asteroid's surface and motion, changing its orbital path and rotational spin. Tidal forces could trigger landslides on Apophis and dislodge rocks and dust particles to create a comet-like tail.

The spacecraft is set to observe the asteroid's Earth flyby as it nears and ultimately catches up with Apophis. These images and data would be combined with ground-based telescope measurements to detect and quantify how Apophis was altered as it passed by Earth.

OSIRIS-APEX is scheduled to remain near Apophis for 18 months - orbiting, maneuvering around it and even hovering just over its surface, using rocket thrusters to kick up loose material and reveal what lies beneath.

PLANETARY SCIENCE AND DEFENSE


Like other asteroids, Apophis is a relic of the early solar system. Its mineralogy and chemistry are largely unchanged in more than 4.5 billion years, offering clues to the origin and development of rocky planets like Earth.

Close examination of Apophis could give planetary defense experts valuable information about the structure and other properties of asteroids. The more scientists know about the composition, density and orbital behavior of such celestial "rubble piles," the greater the chances of devising effective asteroid-deflection strategies to mitigate impact threats.

NASA deliberately crashed a spacecraft into a small asteroid last year in a planetary-defense test that nudged the rocky object from its normal path, marking the first time humankind altered the natural motion of a celestial body.

Apophis is substantially larger than that asteroid but tiny compared with the one that struck Earth 66 million years ago, wiping out the dinosaurs.

While not big enough to pose an existential threat to life on Earth, an Apophis-sized asteroid striking the planet at hypersonic speed still could devastate a major city or region, Nolan said, with ocean impact unleashing tsunamis.

"It wouldn't be globally catastrophic in the sense of mass extinctions," but an impact "would definitely come under the category of bad," Nolan said.

"This thing is coming in at many miles per second if it hits. And at that speed, it kind of doesn't whether if it's made of gravel or ice or rocks or whatever. It's just a big, heavy thing moving fast," Nolan added.

(Reporting by Steve Gorman in Los Angeles; Editing by Will Dunham)

Could scientists stop a 'planet killer' asteroid from hitting Earth?

Brandon Specktor
Sat, November 11, 2023 

We see an enormous, fiery asteroid falling through Earth's atmosphere and very nearly hitting our blue planet.


It's a classic science fiction scenario: An enormous asteroid is discovered hurtling toward Earth that is sure to trigger a cataclysmic extinction upon impact. Intrepid scientists have only a year to launch a preemptive strike against the space rock — to knock it off course or blow it to bits — with the fate of humankind at stake. Can they stop it?

This doomsday scenario is, in all likelihood, one humans alive today will never have to face. Astronomers have mapped the trajectories of more than 33,000 asteroids that make occasional close approaches to Earth, and none pose any risk of impact for at least the next 100 years.

Still, scientists understand that disaster can descend with little warning; thousands of asteroids move hidden in the sun's glare, including many rocks large enough to obliterate entire cities, and the European Space Agency (ESA) warns that dozens of "planet killer" asteroids — those measuring wider than 0.6 mile (1 kilometer) and capable of triggering a global extinction event — still lurk undiscovered in our solar system.

For this reason, space agencies take the doomsday scenario "very seriously," Brent Barbee, an aerospace engineer at NASA's Goddard Spaceflight Center and a professor of aerospace engineering at the University of Maryland, told Live Science. And after years of research — including the world's first mission to deflect an actual asteroid in space — the international community's efforts have yielded two viable ways of changing a potentially deadly asteroid's course: hitting it with a high-speed impactor, or pummeling it with nuclear explosives.

Related: NASA's most wanted: The 5 most dangerous asteroids in the solar system
The kinetic impactor method


An animation visualizes DART's approach to its asteroid target.

Currently, the only proven way to deflect an asteroid is the kinetic impactor method — essentially, a very, very high-stakes game of cosmic pool.

"The kinetic impactor is a spacecraft that basically just rams into the asteroid at high speed and transfers its momentum to the asteroid, much like playing billiards," Barbee said. "But then the ejected material that comes off the asteroid from the impact point can provide additional momentum change for the asteroid and push it a little bit harder."

NASA tested the kinetic impactor method with the recent Double Asteroid Redirection Test (DART) — a $325 million mission that intentionally crashed a speeding spaceship into the 580-foot-wide (177 meters) asteroid Dimorphos in Sept. 2022.

Dimorphos posed no threat to Earth but made a prime target due to its size and orbit around a larger companion asteroid, Didymos. Following the successful impact on Sept. 26, Dimorphos' orbit around Didymos slowed by a whopping 33 minutes — a result of both the impact and the massive plume of dust ejected from the asteroid's surface. The mission — humanity's first and so far only attempt to alter the course of an asteroid — was a smashing success.

In September 2022, NASA’s DART probe smashed into the Dimorphos asteroid. The Hubble Space Telescope managed to capture an image of the giant dust plume that was generated.

However, the kinetic impactor method has its drawbacks, Barbee said. Particularly, the bigger the target asteroid is, the more kinetic impactors are required to deflect it.

For example, to deflect an asteroid measuring roughly 2,000 feet (610 m) wide — or about three times the size of Dimorphos — scientists would need to simultaneously launch between 39 and 85 Falcon Heavy rockets carrying kinetic impactors, Barbee said, citing the results of a mock asteroid deflection exercise conducted at the International Academy of Astronautics Planetary Defense Conference this year. To deflect an asteroid measuring 4,900 feet (1.5 km) wide — a true "planet killer" — we'd need to simultaneously launch anywhere from 565 to 1,266 kinetic impactors, depending on which part of Earth the asteroid was poised to strike. (A glancing blow takes less mass to deflect than a dead-center hit).

"Either way, those numbers are completely impractical," Barbee said.
The nuclear option

We see the top of a Titan II nuclear missile in its silo in Arizona

The current "best option" for deflecting a large asteroid is to launch a nuke at it, Barbee said.

"A single appropriately sized nuclear explosive device was, in our analysis, found to be capable of deflecting even the 1.5 kilometer size asteroid," he added.

Logistically, the process would begin like a routine interplanetary mission, with a nuclear weapon mounted securely atop a standard launch vehicle, then delivered to the asteroid on a small spacecraft. From there, the weapon could be detonated near the asteroid during a high-speed flyby — or, ideally, the nuke-carrying spacecraft could rendezvous with the target asteroid, orbiting it for months or even years to find the perfect angle of approach, much like NASA's OSIRIS-REx spacecraft did with asteroid Bennu from Dec. 2018 to Oct. 2020. The ideal spot for a nuclear detonation would be within a few hundred feet of the asteroid, Barbee said.

Then, the explosion — a blast that would look nothing like any nuclear bomb ever detonated on Earth.

"Space, of course, is a vacuum… so you don't get a big pressure wave, or any of the thermal effects of a terrestrial detonation," Barbee said. "You get a whole lot of radiation all at once."

This torrent of radiation would penetrate and vaporize a thin outer layer of the asteroid's surface. Then, like a kinetic impactor on steroids, the vaporized material would shoot off the asteroid, giving the rock a powerful shove away from the explosion. If positioned correctly, the explosion would knock the planet-killer off its collision course with Earth.

This method could be equally effective at disrupting smaller "city killer" asteroids, too — those measuring at least 165 feet (50 m) in diameter, which is generally considered the minimum size for an asteroid to reach Earth's surface, Barbee said. While a kinetic impact against such a rock runs the risk of fragmenting it, forming chunks of unknown sizes moving in unpredictable ways, a well-placed nuke could simply "blow the asteroid to smithereens," solving the problem at once, Barbee added.

However, for now the "nuke it" method exists only in simulations based on data from terrestrial explosions. Many factors, including the size and composition of the asteroid, and the timeframe and trajectory of its approach to Earth, would ultimately impact such a mission's success.

Timing is everything


Two NASA researchers watch a wall of screens showing the rocky surface of the asteroid Dimorphos, moments before the DART spacecraft smashes into it

The biggest challenge with both methods is timing. In their Planetary Defense Conference exercises, astronomers were given 15 years' warning before the hypothetical asteroid's impact with Earth. This gave them ample time to plan, launch and rendezvous a spacecraft with the asteroid.

If a real planet-killer was discovered just a year or two before impact, things would get dicey.

"The typical interplanetary mission development timeline is about five years," Barbee said. "The way things stand right now, getting something off the ground in a year would be very difficult. I don't want to say outright that it would be impossible, but it would certainly be a big challenge."

That's why the best planetary defense is detecting asteroids early — charting them, monitoring them, and developing a contingency plan of attack. Many ground-based observatories are already on the case, with several space-based missions — including NASA's NEO Surveyor and ESA's NEOMIR satellites — in the works to join them. Hopefully, together, these eyes on the skies will keep scientists well informed about any killers lurking in the cosmic fog.

"Asteroid impacts are one of the few natural disasters that we actually have the means to both foresee and prevent," Barbee said. "And so we're taking advantage of that fact and trying to become as prepared as possible."

Dark matter may have it's own 'invisible' periodic table of elements

Paul Sutter
Fri, November 10, 2023

A composite image showing the distribution of dark matter, galaxies, and hot gas in the core of the merging galaxy cluster Abell 52. The blue areas show regions with the most mass; dark matter makes up most of this mass.


The universe may have produced dark matter in the first few minutes of the Big Bang, according to new research. Those particles then got trapped into ultradense pockets. Some of those pockets splintered off to become black holes, which then dissolved into a shower of multiple dark matter particle "species," creating a "dark matter periodic table" of invisible elements, the study authors suggest.

Physicists still struggle to explain dark matter — the mysterious, invisible form of matter that makes up the vast majority of the universe's mass. While cosmologists and astronomers have identified circumstantial evidence for the existence of dark matter, from the rotation rates of stars within galaxies to the largest structures visible in the cosmos, they have not identified exactly what the dark matter is.

Previous work assumed that dark matter was simple: a single kind of extremely lightweight particle, flooding the universe, that hardly ever interacted with normal matter. But intense searches for new such particles have come up empty. That led cosmologists to wonder if the dark matter particles might be much rarer, but also much heavier. However, theoretical physicists have struggled to find models that would seed the early universe with the right number of such heavy particles.


In the new study, published in October in the preprint database arXiv, a team of cosmologists found a way to generate massive dark matter particles soon after the Big Bang. The trick was to sprinkle in black holes.

The paper noted that the early universe underwent severe phase transitions as the forces of nature split off from each other, going from a single unified force into the four fundamental forces of today. At each transition, the underlying physics changed. This isn't as wild as it sounds, as scientists can reproduce the last of these transitions in particle accelerators: At high enough energies, recreating the first few seconds of the Big Bang, we can observe the electromagnetic and weak nuclear forces merging into one.

The researchers found that ultraheavy dark matter could get trapped during one of these early-universe phase transitions. If the transition was messy, it would trigger the formation of bubbles, where some pockets of the universe had transitioned to the new physics while the rest had not yet made the change (like water boiling, with the gas phase of water trapped in bubbles surrounded by liquid).

In their model, the earliest dark matter was light but dark matter from later periods was heavy. In this scenario, dark matter gets trapped inside the bubbles, where the densities skyrocket to the point where all the dark matter collapses and forms black holes. Those black holes soon evaporate via Hawking radiation — in which radiation slowly "leaks" out of black holes in the form of thermal energy — well before the appearance of normal matter.

But as the black holes evaporate, dark matter makes a comeback, as the black holes spit out new dark matter particles before they die, the team's model showed. This clever mechanism limits the total amount of massive dark matter in the universe, because only so much can escape the black holes before they evaporate completely.

This evaporation process also generates a slew of dark matter particle species. While all of the dark matter particles share many characteristics (such as likely near-total invisibility), they would differ in their masses, speeds, and ways of interacting with normal matter. In this model, dark matter is a vast collection of different kinds of particles, much like normal matter is composed of the entire periodic table of the elements.

RELATED STORIES

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Experimental evidence for this idea is still a long ways away, as it is right now a deeply hypothetical concept. Direct detection of one or more dark matter particle species would certainly bolster the idea. And astronomers are currently developing ways to observe gravitational waves from the big bang, which would give us direct observational access to this critical epoch in the history of the universe.

There could be all sorts of new interactions among these dark matter species, leading to a complex web of physics acting invisibly throughout the universe.

Powerful new thrusters for NASA's moon-orbiting Gateway space station get a test (photo)
Andrew Jones
Thu, November 9, 2023 

A solar electric propulsion thruster emits the blue hue of Xenon gas during testing. Vibrant blue light emanates in a circular shape from the dark grey thruster, which is mounted inside a vacuum chamber. The blue light then narrows into a plume as it moves farther away from the thruster, illuminating the otherwise darkened chamber.

NASA and Aerojet Rocketdyne are taking a big step in testing a new ion propulsion engine that will help power lunar exploration.

The Advanced Electric Propulsion System (AEPS) has been undergoing qualification testing at NASA's Glenn Research Center in Cleveland, according to a statement from the agency.

AEPS is a Hall effect thruster, which accelerates ions to generate thrust. The AEPS uses electricity generated by solar arrays to create a steady stream of ionized xenon gas, producing low but highly efficient thrust.

Related: NASA's Gateway moon-orbiting space station explained in pictures

The 12-kilowatt Hall thruster is the most powerful electric propulsion thruster in production, according to NASA, being over two times more powerful than the current state-of-the-art in-space electric propulsion. The agency says the new thruster will be critical to future science and exploration missions at the moon and beyond.

"AEPS is truly a next-generation technology," Clayton Kachele, the AEPS project manager at NASA's Glenn Research Center in Cleveland, said in a statement in July, during an earlier testing run.

"Current electric propulsion systems use around four and a half kilowatts of power, whereas here we're significantly increasing power in a single thruster," Kachele added. "That capability opens a world of opportunity for future space exploration, and AEPS will get us there farther and faster."

The thrusters will be used on the Power and Propulsion Element (PPE) of Gateway; NASA's planned lunar space station that will support Artemis missions and more. Xenon gas for the engines will be among the supplies needed to be replenished by cargo missions to the Gateway to keep the small lunar station operating smoothly. A dedicated Xenon Transfer System (XTS) is being developed by OHB in Bremen, Germany for this purpose.

RELATED STORIES:

Artemis 4 astronauts will be 1st crew to use NASA's moon-orbiting Gateway in 2028

Watch NASA's next-generation lunar Gateway space station build up in concept video

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NASA will test a second thruster qualification article in 2024. That test will simulate conditions that AEPS will likely experience during Gateway's initial orbit raising and transition to lunar orbit. NASA plans to operate the thrusters for 23,000 hours in total during a nearly four-year test campaign inside NASA Glenn's vacuum chambers.

PPE is currently scheduled to launch on a SpaceX Falcon Heavy rocket in November 2025.


The oldest continents in the Milky Way may be 5 billion years older than Earth's

Briley Lewis
Thu, November 9, 2023 

This artist's rendition shows one possible appearance for the planet HD 219134b, the nearest confirmed rocky exoplanet found to date outside our solar system. The planet is 1.6 times the size of Earth, and whips around its star in just three days. Scientists predict that the scorching-hot planet -- known to be rocky through measurements of its mass and size -- would have a rocky, partially molten surface with geological activity, including possibly volcanoes.


The oldest continents in our galaxy may have arisen 5 billion years before Earth’s, new research suggests — and that means there may be multiple worlds in the Milky Way harboring alien life even more advanced than our own.

Astrobiologists think a planet needs to have certain features to support life: oxygen in its atmosphere, something to shield organisms from dangerous radiation and liquid water, for a start. Although big land masses aren't strictly necessary for living things to emerge, Earth's history shows that they're important for life to thrive and exist for long periods of time. So, if an exoplanet had continents before Earth, it follows that there might be older, more advanced life on that world.

This line of thought led Jane Greaves, an astronomer at Cardiff University astronomer in the U.K., to answer the question: When did the first continents appear on a planet in our galaxy? Turns out, two exoplanets' continents — and perhaps life — may have arisen four to five billion years before Earth's.


If life on another planet had a five-billion-year head start, it "could potentially host life more evolved than us," Greaves wrote in a study, published in the September issue of the journal Research Notes of the American Astronomical Society.

Continents form due to plate tectonics, the movement of plates of rock that float atop the molten innards of a planet. Heat from a planet's core keeps that magma from hardening and halting continents' movement. That heat comes from radioactive elements — like uranium-238, thorium-232, and potassium-40 — in the planet's core, which give off energy as they decay.

Newly discovered Earth-size planet TOI 700 e orbits within the habitable zone of its star in this illustration. Its Earth-size sibling, TOI 700 d, can be seen in the distance.

Most of those radioactive elements came from catastrophic cosmic events, like supernova explosions and collisions between the dead husks of giant stars, known as neutron stars. Traces of those elements can be detected in the wavelengths of light that stars emit. In her new work, Greaves used levels of uranium-238 and potassium present in nearby stars, plus the ages of stars as measured by the Gaia satellite, to estimate when a hypothetical rocky planet around each of these stars became hot enough for plate tectonics to emerge.

She found that the first continents formed around nearby sun-like stars up to 2 billion years earlier than Earth's plate tectonics began. The oldest continents of a nearby star are around HD 4614, about 20 light-years from Earth. Earth's starting time, however, is average for our cosmic neighborhood.

Two stars stand out from the pack, though: The planets of two stars a bit smaller than our sun (HD 76932 and HD 201891), located 70 to 110 light-years away from us respectively in a region known as the "thick disk", could have formed continents up to 5 billion years earlier than us. Based on her sample of just 29 stars and astronomers' current best estimates for how likely a planet is to be habitable, Greaves wrote, "there could be two systems in this sample alone with biospheres more advanced than here on Earth."

Determining potentially interesting and habitable planets, like these identified by Greaves, is crucial preparation for NASA's future Habitable Worlds Observatory, which astronomers will use to observe Earth-like planets — and hopefully signs of life — in the 2040s. Greaves hopes future work will analyze more stars to determine if they could have planets with plate tectonics, which, she wrote, "could help to uncover more old systems where life on land could pre-date that on Earth."

These small galaxies were shredded by their larger siblings — but they survived

Sharmila Kuthunur
Fri, November 10, 2023

Artist’s impression of a dwarf galaxy undergoing tidal stripping.


While galaxies appear to be lonely wanderers in the vast universe, many in fact huddle closely in clusters, held together by their collective gravity. And sometimes, it would appear, they also munch on one another.

In other words, larger galaxies in these pockets merge with and gobble smaller ones to grow even bigger — our own Milky Way galaxy actually cannibalized a small neighbor galaxy and gained supremacy about 10 billion years ago.

As for what happens to the smaller galaxies getting shredded by their massive counterparts? Well, while few disappear without a trace,, new research shows that some tiny galaxies are dense enough to power through. Those mighty realms are able to hold onto their cores and become what astronomers call Ultra Compact Dwarfs, or UCDs.

Related: Dark energy camera reveals galaxies caught in a cosmic 'tug of war' (photo)

Using the Gemini North Telescope located near the Mauna Kea mountain in Hawaii, the team behind the research spotted galactic cannibalism in action near the Virgo Cluster, a large grouping of thousands of galaxies relatively nearby to Earth. And in a first, the researchers found small galaxy victims transitioning into UCDs. As many as 106 galaxies exhibited far-reaching envelopes of stars, suggesting their outer layers were being ripped apart by nearby large galaxies. Meanwhile, however, tight groupings of stars in their centers reveal their gravitational grip is strong enough to survive the merger, astronomers say.

After stars and gas in the galaxies' outer layers are pried out in full, astronomers expect the tiny galaxies will come to represent late-stage UCDs.

"It's exciting that we can finally see this transformation in action," Eric Peng, an astronomer at National Optical-Infrared Astronomy Research Laboratory, said in a statement. "It tells us that many of these UCDs are visible fossil remnants of ancient dwarf galaxies in galaxy clusters, and our results suggest that there are likely many more low-mass remnants to be found."

Peng and his colleagues first spotted these candidate UCD progenitors in images taken by the Canada–France–Hawaii Telescope, also located near the summit of Hawaii's Mauna Kea mountain. However, in those images, it was very difficult to clearly distinguish the target galaxies from other faraway galaxies beyond the Virgo Cluster, according to the new study.

So, the team used Gemini North to perform follow up observations to accurately measure galaxy distances, then removed all background galaxies such that only the candidate UCDs within the Virgo Cluster could be seen.

The results showed these UCDs resided "almost exclusively near the largest galaxies," Kaixiang Wang, the study's lead author and a scientist at Peking University in China, said in the statement. "We immediately knew that environmental transformation had to be important."

This research is described in a paper published Wednesday (Nov. 8) in the journal Nature.



Scientists Say There May Have Been a Second Big Bang

Victor Tangermann
Sat, November 11, 2023 


Instead of a single Big Bang that brought the universe into existence billions of years ago, cosmologists are starting to suspect there may have been a second transformative event that could explain the vast abundance of dark matter in the universe.

As New Scientist reports, our recent glimpses into early moments of the universe, just millions of years after the Big Bang, could allow us to gain new insights into this "dark" Big Bang, which could solve a conundrum that's been plaguing astronomers for almost half a century.

Dark matter is the hypothetical form of matter that doesn't interact with light or electromagnetic fields in any way, yet appears to make up roughly 27 percent of the known universe.

Astronomers have long attempted to explain why clusters of galaxies move in ways that our existing Standard Model of physics can't account for. To make the math work, the dominant explanation is that there's a bunch of stuff out there that we can't see.

Despite our best efforts, however, we're still unable to observe this matter directly.  Now, some researchers are wondering whether a second big bang might have brought the exotic substance into existence after the regular matter we're accustomed to dealing with.

"People always assume everything is created at the same time in a single big bang, but who really knows?" Katherine Freese, physics professor at the University of Texas at Austin, told New Scientist.

In a yet-to-be-peer-reviewed paper, Freese and her colleagues suggest that a "Dark Big Bang" may have "occurred when the universe was less than one month old."

They suggest the event could've formed several different kinds of dark matter, including "darkzillas" — yes, that's a "Godzilla" reference — which are monstrously sized particles 10 trillion times the mass of a single proton.

However, if the event was more gradual instead of forceful and abrupt, the Dark Big Bang would've produced lighter "dark cannibal" particles that would absorb each other with each collision.

These particles aren't unlike one of the leading dark matter candidates, called "weakly interacting massive particles" (WIMPs), which astronomers have posited for decades to explain the mysterious forces falling outside of the Standard Model of physics.

Freese is now hoping that studying gravitational waves emerging from the universe's gravitational wave background could shed more light on her Dark Big Bang theory.

Her work is part of a greater shift in the astronomy community. Instead of one big event that created the universe, cosmologists are now wondering whether the universe may have gone through several phase transitions, slowly bringing everything from matter to dark matter into being.

By measuring disturbances in signals sent out by highly magnetized neutron stars called pulsars, scientists have been trying to pinpoint the origin of these gravitational waves or ripples in space-time, with the hopes of gaining insights into the earliest days of the universe.

Perhaps then we can get one step closer to unraveling the mystery surrounding the existence of dark matter — or whether "darkzillas" or "dark cannibals" might account for a good portion of the stuff that surrounds us.

More on the Big Bang: Amazing Video Soars Through James Webb's Dazzling 3D View of Universe


Webb and Hubble Telescopes Team Up to Image ‘Mothra’ and a Massive ‘Christmas Tree’ Cluster

Isaac Schultz
Thu, November 9, 2023 

A swathe of the recently imaged galaxy clusters.

It’s not yet December, but NASA is already in a festive mood: the Webb and Hubble space telescopes recently imaged MACS0416, a pair of colliding galaxy clusters 4.3 billion light-years from Earth that is bedecked in sparkling lights.

The image combines visible and infrared light, the respective wheelhouses of Hubble and Webb, to create a sweeping view of the colliding clusters. The Webb observations were taken as part of the Prime Extragalactic Areas for Reionization and Lensing Science, or PEARLS, program, and the Hubble data was collected as part of the Frontier Fields program, which began in 2014.

Two papers detail aspects of the image. One, published in Astronomy and Astrophysics, describes the “extremely magnified monster star” nicknamed Mothra, after the fictional monster that features prominently in the Godzilla franchise. The other paper is accepted for publication in The Astrophysical Journal and is currently hosted on the preprint server arXiv; that work details 14 transient objects seen in the galaxy cluster. These transients are objects that vary in their observed brightness over time, causing the smattering of colors to twinkle in the eye of a telescope.

“We’re calling MACS0416 the Christmas Tree Galaxy Cluster, both because it’s so colorful and because of these flickering lights we find within it. We can see transients everywhere,” said Haojing Yan, an astrophysicist at the University of Missouri in Columbia and lead author of one of the papers, in the same release.

The full image of the galaxies, complete with smears of gravitational lensing.

Twelve of the transients spotted are too faint and red for Hubble to see, so the Webb data was critical in getting a more complete image of the field. The researchers believe the other two transients are supernovae—vast explosions that occur at the end of a star’s life.

The star nicknamed Mothra is located in a galaxy that existed about three billion years after the Big Bang. The research team believes that the monster star is probably in a binary system with another supergiant star, which the team has fittingly nicknamed Godzilla. Mothra is anywhere between 10,000 and one million times our Sun’s mass, and may hint at the nature of dark matter.

In their paper, the team stated that axionic dark matter models (which focus on axions, a theoretical particle named for a detergent) are consistent with their observations in certain mass ranges for the axion. Earlier this year, another case of extreme gravitational lensing boosted the case for axionic dark matter.

As Webb and Hubble continues their investigation of the cosmos, our understanding of dark matter, the universe’s evolution, and the myriad objects that compose the cosmos will come into sharper relief. Their data—as well as the observations of other telescopes, like the nascent Euclid Space Telescope—will help us understand the makeup of the cosmos.
Gizmodo

Cosmic ‘Christmas tree’ dazzles in new image captured by Hubble and Webb

Ashley Strickland, CNN
Thu, November 9, 2023 

A panorama of colliding galaxy clusters glimmers in a new image, captured by the combined forces of the two most powerful space observatories ever created.

The cosmic phenomenon, called MACS0416, is 4.3 billion light-years from Earth. Eventually, the merging pair of giant clusters will combine to form an even more massive collection of glittering galaxies.

New details of the celestial feature have emerged in the colorful image, which unites the observational powers of Hubble Space Telescope in visible light and the James Webb Space Telescope in infrared light, which is invisible to the human eye.

Together, the renowned observatories present a more comprehensive look at the universe. Hubble has long been used to search for faint, distant galaxies across different wavelengths of light. Webb’s infrared gaze enables that search to occur at even farther distances, detecting invisible light deeper into the early days of the universe.

A light-year, equivalent to 5.88 trillion miles, is how far a beam of light travels in a year. Given the distance between Earth and the objects from the early days of the universe, when telescopes such as Webb observe this light, it’s effectively like looking into the past.

“We are building on Hubble’s legacy by pushing to greater distances and fainter objects,” said Rogier Windhorst, regents professor in Arizona State University’s School of Earth and Space Exploration, in a statement.

Windhorst is the principal investigator of the PEARLS, or Prime Extragalactic Areas for Reionization and Lensing Science, program that conducted the Webb observations.
A ‘Christmas tree’ of galaxies

The colors in the new image, released Thursday, are used to indicate distance. Blue-hued galaxies are the closest, bursting with star formation and easily seen in visible light by Hubble. The red galaxies are more distant, best detected by Webb in infrared light.

“The whole picture doesn’t become clear until you combine Webb data with Hubble data,” Windhorst said.

The new Webb observations were used to search for objects that change in brightness over time, called transients.

Within the galactic clusters’ field of view, Webb helped astronomers identify 14 transients, all of which were visible due to gravitational lensing. This cosmic effect occurs when closer objects — such as the galactic clusters — act like a magnifying glass for distant objects. Gravity essentially warps and amplifies the light of distant galaxies in the background of whatever is doing the magnifying, enabling observations of otherwise invisible celestial features.

The transients include 12 stars or star systems and two supernovas in galaxies that were amplified using gravitational lensing.

“We’re calling MACS0416 the Christmas Tree Galaxy Cluster, both because it’s so colorful and because of these flickering lights we find within it. We can see transients everywhere,” said Haojing Yan, associate professor of physics and astronomy at the University of Missouri. Yan is lead author of one study describing the findings that has been accepted for publication in The Astrophysical Journal.
Spotting a stellar giant

One transient in particular captured the attention of astronomers, a star system they have nicknamed “Mothra,” the titular giant monster of a 1961 Japanese film. The stellar system, magnified by a factor of 4,000 due to gravitational lensing, was traced to a galaxy that existed 3 billion years after the big bang created the universe.

The Webb and Hubble composite image includes "Mothra," a star system magnified by the galactic cluster pair as well as another unseen object. - NASA/ESA/CSA/STScI

The team nicknamed the star system Mothra due to its extreme magnification and brightness.

Surprisingly, Mothra has appeared before, detected in Hubble observations nine years ago. Astronomers are stumped as to how this happened, because there must be a specific alignment between the galactic cluster and the more distant star to cause the magnification at a point in time. So how did Mothra also appear magnified in the new Webb observations?

“The most likely explanation is a globular star cluster that’s too faint for Webb to see directly,” said José Diego, researcher at the Institute of Physics of Cantabria in Spain and lead author of another paper describing the finding, published in the journal Astronomy & Astrophysics. “But we don’t know the true nature of this additional lens yet.”

James Webb Space Telescope gets ready for the holidays with a cosmic Christmas Tree 

Robert Lea
Thu, November 9, 2023 

A smattering of galaxies seen as countless dots of light.


The James Webb Space Telescope (JWST) left astronomers feeling festive recently as it allowed them to image a distant, colorful cluster of galaxies they have dubbed the "Christmas Tree Galaxy Cluster."

In this cluster, the James Webb Space Telescope discovered flickering "Christmas lights" in the form of 14 new transient objects — celestial objects that brighten dramatically before dating . The winter wonderland is officially called MACS041, and is located about 4.3 billion light-years from Earth.

"We're calling MACS0416 the Christmas Tree Galaxy Cluster, both because it's so colorful and because of the flickering lights we find within it," Haojing Yan, an associate professor in the University of Missouri Department of Physics and Astronomy, said in a statement. "Transients are objects in space, like individual stars, that appear to suddenly brighten by orders of magnitudes and then fade away. These transient objects appear bright for only a short period of time and then are gone; it’s like we’re peering through a shifting magnifying glass."

Related: James Webb Space Telescope reveals most distant Milky Way galaxy doppelganger


a smattering of galaxies seen as countless dots of light

Spotting so many transients in this galaxy was achieved by teaming the JWST up with the Hubble Space Telescope; the sheer number of transients spotted in one go, thanks to the duo, implies there are a lot more yet to be found within the Christmas Tree Galaxy Cluster. It's almost like the Christmas gift for astronomers that'll keep on giving.
Putting up the Christmas tree with Einstein

The light from the Christmas Tree Galaxy Cluster began its journey across the cosmos when the solar system, now 4.6 billion years old, was newly formed and just around 300 million years old. This would ordinarily make it too faint for even the JWST to see in detail, but a little trick first acknowledged by Albert Einstein made observing this cosmic Christmas a little easier.

In his 1915 theory of general relativity, which concerns the nature of gravity, Einstein said objects of great mass must warp the very fabric of space and time, united as a single entity called space-time, giving rise to a curvature we experience as gravity. And when anything — including light — passes these curved regions of space, those things' paths get curved. The closer to the body of mass a thing is, the more extreme the curvature it experiences.

As a result, when an object passes between Earth and a distant light source, the light from that background object takes a varied amount of time to reach us, as its path isn't following a straight line due to the curvature created by the passing object. This can ultimately cause that background object to appear amplified from our vantage point. The concept is called "gravitational lensing" as the intervening object acts as a natural, cosmic magnifying glass.

The JWST has been tapping into this phenomenon, with great success, to see some of the universe's earliest galaxies — and its view of the Christmas Tree Galaxy Cluster is its latest example.

"We can see so many transients in certain regions of this area because of a phenomenon known as gravitational lensing, which is magnifying galaxies behind this cluster," Yan said. "Right now, we have this rare chance that nature has given us to get a detailed view of individual stars that are located very far away. While we are currently only able to see the brightest ones, if we do this long enough — and frequently enough — we will be able to determine how many bright stars there are and how massive they are."
A monster in the Christmas tree?

The transients were found by Yan and the team as they were looking at four sets of images captured by the JWST over around four months, as part of the JWST’s PEARLS GTO 1176 program. The team has identified two objects in the images as supernova explosions that happen as stars reach the end of their lifespans. Yan is thrilled by this result, as he and his team can now use those supernovas to study the galaxies in which they are happening.

"The two supernovas and the other twelve extremely magnified stars are of different nature, but they are all important," Yan explained. "We have traced the change in brightness over time through their light curves, and by examining in detail how the light changes over time, we’ll eventually be able to know what kind of stars they are."

The astronomers also found something else extraordinary in the Christmas Tree Galaxy Cluster: A monster star in a galaxy, seen as it was when the universe was just 3 billion years old. They have named the star "Mothra" after the monstrous moth, Kaiju, from Japanese cinema.

The galaxy in which Mothra lurks was lensed to around 4,000 times its original brightness. The object lensing this galaxy is currently unknown, but Yan and the team estimate it has a mass of between 10,000 and 1 million times that of the sun. "The most likely explanation is a globular star cluster that’s too faint for the JWST to see directly," Jose Diego, research lead author and a scientist at the Instituto de Física de Cantabria scientist, said in a separate statement. "But we don’t know the true nature of this additional lens yet."

What is extra interesting about Mothra's galaxy is the fact it was also visible and lensed in Hubble Space Telescope images taken nine years ago. Normally, a lensing object and a background galaxy would move out of alignment over such a period, but Mothra's home galaxy and the object lensing it seem to have stuck together. In the future, Yan and the team hope to both figure out the nature of this lensing object and uncover some of its characteristics.

"We'll be able to understand the detailed structure of the magnifying glass and how it relates to dark matter distribution," Yan concluded. "This is a completely new view of the universe that’s been opened by JWST."

One of two papers detailing the observation of the Christmas Tree Galaxy Cluster was published in November in the journal Astronomy and Astrophysics, while the other has been accepted for publication in the Astrophysical Journal with a preprint available on the research repository arXiv.


The Hubble Space Telescope has found evidence of a "wandering" black hole about 5000 light years away in the Milky Way galaxy. Astronomers estimate that there could be 100 million black holes wandering around our galaxy. Credit: NASA Goddard Space Flight 


NASA's James Webb telescope spotted the most distant galaxy in the universe that looks like ours

Marianne Guenot
Fri, November 10, 2023 

The James Webb Space Telescope spotted a twin of the Milky Way in the depths of the universe.


The galaxy formed shortly after the Big Bang, which was thought to be impossible.


This could mean there's a missing ingredient in our models of how the univer
se formed.

The James Webb Space Telescope (JWST) has spotted the most distant example of a galaxy in the universe that looks similar to the Milky Way.

The galaxy, named ceers-2112, is more than 11.7 billion years old and is the earliest example of a barred spiral galaxy ever seen.

Astronomers were surprised to see it because cosmic models suggest barred spiral galaxies only started emerging around 6.9 billion years after the Big Bang.

The latest discovery, published in the journal Nature, could upheave our models of the universe and how dark matter influenced galaxy formation in its early days, study authors said.
A barred spiral galaxy exists in the universe's infancy

With its advanced imaging capabilities, JWST has allowed us to peer into the early universe with more precision than ever before.

The latest study is no exception. To a layperson, the picture below may look like little more than a colorful blob — and when looking at information coming from the early days of the universe, that's the kind of image that we're usually working with.


Three near-infrared pictures of ceers-2112 provided by JWST imaging are shown here. This image was cropped from the original.Costantin, L., Pérez-González, P.G., Guo, Y. et al. A Milky Way-like barred spiral galaxy at a redshift of 3. Nature (2023). https://doi.org/10.1038/s41586-023-06636-x. CC-BY 4.0

But with JWST's precise measurement instruments, scientists were able to squeeze out crucial information about ceers-2112's characteristics. For them, there is little doubt: this picture suggests this is a barred spiral galaxy.

But this galaxy is in redshift 3, a technical term suggesting it appeared about 2 billion years after the birth of the universe

That's a conundrum, as a barred spiral galaxy is a very tall order for such a young universe.

Previous models had suggested such complex galaxies would take at least a few billion years to evolve. Scientists had thought you couldn't find a barred spiral galaxy before the universe was about 6.9 billion years old.

"The discovery of ceers-2112 shows that it can happen in only a fraction of that time, in about one billion years or less," Alexander de la Vega, a physicist and cosmologist at the University of California, Riverside, said in a press release accompanying the findings.

"It is the first publication that finds in the childhood of the universe these spiral galaxies that have a disk with a central bar," Yetli Rosas Guevara, an astrophysicist of the Spanish Donostia International Physics Center who was not involved in the study, told El País.
The findings could shed light on the early days of dark matter

The new finding suggests something is wrong with models predicting what was happening in the early days of the universe.

"In the past, when the universe was very young, galaxies were unstable and chaotic. It was thought that bars could not form or last long in galaxies in the early universe," de la Vega said.

Simulations "really struggle to reproduce such systems at those epochs," Luca Costantin, study lead author and astrophysicist at the Centro de Astrobiología in Madrid, told Space.com.

"We now need to understand which key physical ingredient is missing in our models — if something is missing," Costantin told Space.com.

One factor that doesn't quite align is the role of dark matter in the early days of galaxy formation.

As a reminder, the stuff that makes up everyone on Earth, our planet, our galaxy, and everything we can observe, is ordinary matter, or baryon. But physicists think baryon makes up only 5% of our universe. The other 95% — about 27% of dark matter and 68% of dark energy — remain huge mysteries in physics.

Some models suggest there was an "over-abundance" of dark matter in the early days of the universe, study co-author Jairo Abreu, a researcher at the University of La Laguna, told Space.com.

But that doesn't quite make sense with the latest findings: barred spiral galaxies are more likely to be made up of baryon, said Abreu.

This suggests that "these models may need to adjust how much dark matter makes up galaxies in the early universe, as dark matter is believed to affect the rate at which bars form," said de la Vega.
Venus’s Skies Are Covered in Oxygen, Actually
Isaac Schultz
Fri, November 10, 2023 

Venus' cloudy skies.

While air is a gaseous delight unique to Earth, a team of astrophysicists have made a satisfying discovery: the direct observation of atomic oxygen on Venus’ dayside, confirming that the element crucial for our existence exists on both sides of the hellish planet.

About 96% of the atmosphere on the second planet from the Sun is made up of carbon dioxide, a smidge of other gasses including nitrogen, and practically no oxygen. But there is some oxygen, and some of the element was found previously on Venus’ dark side. Now, the same can be said of the world’s scalding sunny side.

Venus wasn’t always so uncomfortable, with an average temperature of 850° Fahrenheit and a toxic atmosphere rich with clouds of sulfuric acid. The planet is sometimes referred to as Earth’s fraternal twin, due to the similarities and obvious differences between the two worlds. Venus may have had oceans once, which evaporated when the planet got stuck in a runaway greenhouse effect (though later research indicated what may have been water oceans were actually lakes of lava).

“Venus is not hospitable, at least for organisms we know from Earth,” Heinz-Wilhelm Hübers, a physicist at the German Aerospace Center and lead author of the study, told Reuters. “We are still at the beginning of understanding the evolution of Venus and why it is so different from Earth.”

In quick succession in Spring 2021, NASA and ESA announced three missions focused on Venus; the United States’ space agency had greenlit VERITAS and DAVINCI+, while the Europeans announced the Venus orbiter EnVision. The VERITAS mission has since been delayed due to funding issues, but space agencies remain committed to better understanding the yellowish world, which could offer insights into Earth’s own evolution over its 4.6-odd billion years of existence.

In other words, we’re setting ourselves up for a whole new portrait of the second planet from the Sun, which will come into focus around 2030.

More: Why Venus Is Soon to Be the Most Exciting Place in the Solar System

Oxygen detected in Venus' hellish atmosphere

Joanna Thompson
Fri, November 10, 2023 

Hemispheric view of Venus.


Venus' atmosphere is notoriously hellish. Its air is corrosive and hot enough to melt lead. Its billowing clouds are poisonous to humans. Sometimes, it rains acid. But researchers just discovered that, sandwiched between layers of toxic gas, this inhospitable atmosphere contains a thin layer of molecular oxygen.

Historically, Venus has received far less scientific attention than Earth's other neighbor, Mars. Recent reports that the organic compound phosphine may (or may not) exist in the Venusian clouds, however, have sparked new interest in studying the planet.

The new measurements come courtesy of NASA's Stratospheric Observatory for Infrared Astronomy (SOFIA), a Boeing 747 that the agency retrofitted with a 2.7-meter (8.9 feet) infrared telescope. A team of German astrophysicists pored through data from SOFIA, focusing on 17 positions in Venus' atmosphere, on both the planet's dayside and nightside. They detected molecular oxygen — a gas composed of nonbonded oxygen atoms — in all of them. The results were published Nov. 7 in the journal Nature Communications.

But that doesn't mean astronauts would be able to breathe oxygen on Venus just as they would on Earth. Molecular oxygen is distinct from the oxygen that we breathe on our planet: Whereas breathable oxygen consists of two bonded oxygen atoms, creating the molecule O2, molecular oxygen is a soup of single, free-floating oxygen atoms. If we tried to breathe it, it would react too easily with the tissues in our lungs and wouldn't make it to our bloodstream.

Oxygen had been previously observed on the nightside of Venus, but this marks the first time researchers have detected it in the day-lit regions as well. The researchers suspect that the molecular oxygen builds up as the sun's heat breaks down carbon dioxide and carbon monoxide molecules. Winds high in the atmosphere then whisk it over to the planet's nightside, where the free oxygen atoms gradually react with other elements.


Surface warmth on a Venus volcano.

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The molecular oxygen layer also probably has a slight cooling effect on the upper layers of Venus' atmosphere. This modest cooling isn't enough to offset the planet's runaway greenhouse effect, but it does hint at Venus' milder, more pleasant past.

The finding also highlights how much scientists still have to learn about Earth's hostile "twin." With two upcoming NASA missions, as well as one helmed by the European Space Agency, Venus is about to receive a lot more attention, which may mean more discoveries in the near future.

Between Venus' atmospheric currents, a layer of reactive oxygen

Conor Feehly
Thu, November 9, 2023 

This image of the Venus southern hemisphere illustrates the terminator – the transitional region between the dayside (left) and nightside of the planet (right).

Today, our sister planet Venus resembles an environment as close to hell as one can imagine. Surface temperatures on the amber world soar to 450 degrees Celsius (842 degrees Fahrenheit), while about 96% of the planet's crushing atmosphere is made up of carbon dioxide. Once upon a time, however, Venus may have resembled something much closer to our balmy home — Earth.

That was until runaway greenhouse gas processes, likely triggered by volcanic activity, sent Venus on a trajectory that resulted in the noxious neighbor we see today. However, in new research that furthers our understanding of the planet's atmospheric evolution, astronomers announced they've directly detected the presence of atomic oxygen in both the day and night side of the Venusian atmosphere.

Atomic oxygen is the highly reactive chemical cousin of molecular oxygen (the stuff we breathe and simply refer to as oxygen.) Unlike molecular oxygen, or O2, made of oxygen atom pairs, atomic oxygen is composed of individual oxygen atoms.

Related: The deadly atmosphere on Venus could help us find habitable worlds. Here's how

At risk of simplification, those individual oxygen atoms are therefore always ready to pair with another atom or molecule. That's what makes atomic oxygen so reactive — pairing up would make a single oxygen atom more stable, so these oxygen singlets want to react. This is also why molecular oxygen isn't as reactive. Its oxygen atoms are all buddied up.

Detecting atomic oxygen

The team of astronomers led by Heinz-Wilhelm Hübers, director of the German Aerospace Center, used the Stratospheric Observatory for Infrared Astronomy (SOFIA) — an airborne observatory, to collect data on Venus' atmosphere.

"We were able to plan a flight route which allowed us to observe Venus (which is at low elevation) shortly before sunset for three days, each day for about 20 minutes," Hübers told Space.com.

Onboard SOFIA was the upGREAT Terahertz heterodyne spectrometer, which was used for the observations. Hübers explained that this particular spectrometer is especially sensitive to the frequency and wavelength of atomic oxygen, which are 4.74 terahertz and 63.2 microns, respectively.

The atmosphere on Venus houses two strong currents. The lower of the two sits below 70 kilometers (43.5 miles) in altitude, where the equivalent of hurricane-force winds on Earth blow against the direction of Venus' rotation. The higher current sits above 120 kilometers (74.6 miles) in altitude with winds that flow in the direction of the planet's rotation.

"A layer of atomic oxygen exists between these two opposing atmospheric currents," Hübers says.

This layer of atomic oxygen, the scientists believe, is produced by ultraviolet radiation coming from the sun, which breaks down carbon dioxide and carbon monoxide in Venus' atmosphere into atomic oxygen and other molecules. In this process, known as photolysis, high-energy photons collide with carbon molecules to force the molecules to essentially rip apart.

Because the atomic oxygen is predominantly concentrated around 100 kilometers (62 miles) in altitude between the two circulation patterns, it's possible these currents play a role in distributing the substance around the planet. However, Hübers says the team couldn't quite quantify this yet with their current measurements.

Although, he does mention they observed a local enhancement of atomic oxygen on the planet's nightside, close to the line which separates day and night, known as the "terminator." Possibly, this enhancement could be caused by the terminator's winds.
Should future missions to Venus be worried?

While atomic oxygen was detected in Venus' atmosphere, it's worth noting that the concentration was much lower than what we find in Earth's atmosphere. Earth's atmosphere has roughly 10 times more atomic oxygen than Venus' does. In fact, the relatively high concentration of atomic oxygen in the atmosphere around our planet is considered a threat — these particles are responsible for some corrosion of satellites in Low Earth Orbit (LEO), including the International Space Station.

The presence of the highly reactive oxygen on Venus, therefore, shouldn't pose too much of a corrosive threat to any future satellites that get sent there.

"Besides that, it is very interesting to measure the altitude distribution of the atomic oxygen in the Venusian atmosphere in order to understand the chemistry and physics of the atmosphere better and to compare it with Earth," says Hübers.
Atomic oxygen, day and night

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It was important for researchers to collect data from both the day and night side of Venus, largely because the planet rotates at an excruciatingly slow pace — one day on Venus lasts 243 Earth days, or 5,832 hours.

According to Hübers, the most likely explanation for this slow rotation is that the gravity of the sun induced tides on Venus during an early stage of the planet's lifecycle, when it was more or less a liquid, molten body. The rotational energy of Venus possibly worked against the formation of tides on the world due to that molten structure, and eventually, scientists think it slowed to its current-day rotational speed.

Ultimately, the results from the study paint a picture of the Venusian atmosphere as starkly different to our own, and highlight how small differences in our past can accumulate over time to result in dramatically different futures.

The study was published Tuesday (Nov. 7) in the journal Nature Communications.


SEE 


Saturday, November 11, 2023

Komfo Anokye kola tree: Man denies chopping down 300-year-old tree in Ghana

Thomas Naadi - BBC News
Fri, November 10, 2023 




A man has appeared in court after a famous 300-year-old kola tree in southern Ghana was chopped down.

Pictures of the felled tree, located in the town of Feyiase, caused outrage among Ghanaians online.

The ancient tree dated back to the Ashanti Kingdom, part of modern-day Ghana. It was thought to have healing powers and became a tourist attraction for Ghanaians and foreigners alike.

The man pleaded not guilty to causing unlawful damage, and was granted bail.

He has not been named.

According to local lore, the tree grew in the spot where renowned priest Komfo Anokye spat a kola nut on the ground in the early 1700s.

Many in the community believed the black and white seeds of the kola tree could cure ailments and curses.

The tree was in the middle of a major road linking Ghana's commercial hub, Kumasi, to Lake Bosomtwe, a national tourist destination.

It was spared during the construction of the highway because of its popularity.

It is not clear why it was cut down now.

The director of research at Manhyia Palace, seat of the Ashanti royal family, Osei-Bonsu Safo Kantanka, told the BBC on Thursday that the site of the tree was significant in the history of the Ashanti Kingdom.

The Battle of Feyiase saw the Ashanti people battling for their independence against the powerful kingdom of Denkyira.

Mr Kantanka said the location of the tree "was the same spot the people of Denkyira were defeated by the Asantes".

Komfo Anokye, the man said to be responsible for the tree, was a powerful fetish priest - a person believed to act as a mediator between the spirit and living.

Oral tradition says he buried a sword in the ground, which remains firmly in place and can never be removed, on the premises of a hospital in Kumasi that bears his name.

The presence of the tree was a constant reminder of his exploits.