JimsAstronomy

Sunday, November 24, 2024

4617 - 2023 DISCOVERIES - in astronomy -

- 4617 - 2023 DISCOVERIES - in astronomy. - For the James Webb Space Telescope in outer space December 25 is a pretty special birthday. Fans will be celebrating the second anniversary of the launch of NASA's James Webb Space Telescope (JWST). Since coming online in mid-2022 it is the most powerful telescope ever built.

---------------------------------- 4617 - 2023 DISCOVERIES - in astronomy

- Not long after coming online, the JWST immediately discovered six enormous "universe breaker" galaxies, containing what seemed to be almost as many stars as the Milky Way, dating to just 500 million years after the Big Bang.

- The finding caused a stir in the astronomical world, with some scientists suggesting that it had put our current view of galaxy evolution, or even our understanding of the universe, into doubt. The strange discovery pointed to a deepening mystery around how large galaxies first bloomed in our universe.

- After running simulations, other astronomers suggested that the galaxies might not contain as many stars as first seemed, and could instead just be glowing unusually brightly. Whatever the answer, follow-up observations of the mysterious galaxies are needed before scientists can be certain.

- The universe is expanding, but depending on where cosmologists look, it's doing so at different rates. In the past, the two best experiments to measure the expansion rate were the European Space Agency's Planck satellite (which gave a most likely expansion rate of 67 kilometers per second per megaparsec) and the Hubble Space telescope, which studied pulsating stars called Cepheids and found a higher value of 73 km/s/Mpc. (kilometer/second/megaparsec)

- Cosmologists thought this tension might be down to uncertainty caused by Hubble not distinguishing between Cepheids and background stars, but the JWST had a result of 74 km/s/Mpc.

- The large ancient galaxies on the JWST's list of discoveries and black holes like CEERS 1019, which had a mass 10 million times that of our sun and was found by the JWST just 570 million years after the Big Bang, making it the oldest black hole spotted. Earlier this month, the telescope discovered an even older massive black hole 440 million years after the universe began.

- How these swelled to such staggering scales so early on is an ongoing mystery. The telescope's ultrapowerful eye has also revealed glimpses of completely new, unexplainable objects. After being trained on the Orion Nebula, the JWST found 42 pairs of Jupiter-mass binary objects, or "JuMBOs", Jupiter-sized planets drifting through space in pairs, some as far apart from each other as 390 times the distance between Earth and the sun.

- The JuMBOs are too small to be stars, but as they exist in pairs, they are unlikely to be rogue planets ejected from solar systems. Their discovery has alerted astronomers to a brand-new formation mechanism for planets or even for failed stars.

- Another feature of the JWST is its ability to measure a spectrum of the atmospheres of distant exoplanets, a toolkit which enabled it to spot the potential signs of life in on a Goldilocks water world 120 light-years away. The exoplanet it found, “K2-18 b”, is a sub-Neptune planet (weighing in somewhere between the mass of Earth and Neptune) orbiting the habitable zone of a red dwarf star.

- After taking an atmospheric spectrum, the JWST found it rich with hydrogen, methane and carbon dioxide which are all chemical markers of a hydrogen-rich world that is a prime contender for extraterrestrial life.

- More tantalizing still was the detection of dimethyl sulfide (DMS), a cabbage-smelling compound only known to be produced by microscopic algae in Earth's oceans.

- Stars and galaxies aren't evenly spread throughout our universe. Instead, they're connected by an enormous cosmic web which is a gigantic network of crisscrossing celestial super-highways paved with hydrogen gas and dark matter.

- Taking shape in the chaotic aftermath of the Big Bang, the web's tendrils formed as clumps from the roiling broth of the young universe; where multiple strands of the web intersected, galaxies eventually formed.

- Insights into the structure of this web not only give us a glimpse of the chaotic particle interactions that led to a universe existing in the first place. Astronomers using the JWST were stunned when they spotted the earliest strand of this web ever seen. It was a gassy tendril made of of 10 closely packed galaxies spanning more than 3 million light-years in length.

- The filament formed when the universe was just 830 million years old, and is partially wrapped around a bright black hole. Researchers hope to find answers as to how these very first galaxies formed.

- Another addition to the JWST's long list of cosmic distance records this year was its discovery of the most distant gravitationally lensed object ever seen — an "Einstein ring" produced by the warping of light from a distant galaxy. How distant? A mind-bending 21 billion light years away, which, given the universe's 13.8 billion years of age, means that the light from the galaxy traveled almost twice that distance due to the universe expansion.

- Dark matter is the unseen substance believed to make up 70% of the universe's matter.

November 24, 2024 2023 DISCOVERIES - in astronomy 4618

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

-------- Comments appreciated and Pass it on to whomever is interested. ---

--- Some reviews are at: -------------- http://jdetrick.blogspot.com -----

-- email feedback, corrections, request for copies or Index of all reviews

--- to: ------ jamesdetrick@comcast.net ------ “Jim Detrick” -----------

--------------------- --- Sunday, November 24, 2024 ---------------------------------

4618 - LIGHT - is it a particle or a wave?

- 4618 - LIGHT - is it a particle or a wave? From the most distant stars in the sky to the screen in front of your face, light is everywhere. But the exact nature of light, and how it travels, has long puzzled scientists. One question in particular has vexed thinkers from Issac Newton to Albert Einstein: Is light a particle or a wave?

------------------------------------- 4618 - LIGHT - is it a particle or a wave?

- As a species, we seem driven to understand the fundamental nature of the world around us, and this particular puzzle kept 19th-century scientists busy. Today, there's no doubt about the answer: Light is both a particle and a wave. But how did scientists reach this mind-bending conclusion?

- The starting point was to scientifically distinguish between waves and particles. You would describe an object as a particle if you can identify it as a point in space. A wave is an object that you don't define as a point in space and you need to give a frequency of oscillation and distance between maximum and minimum for the wave/

- The first conclusive evidence of the wave nature of light came in 1801, when Thomas Young performed his now-famous double-slit experiment. He placed a screen with two holes in front of a light source and observed the behavior of the light after it had passed through the slits. The light hitting the wall showed a complicated pattern of bright and dark bands, known as interference fringes.

- As the light waves passed through each hole, they generated partial waves that radiated spherically, intercepting each other and adding or subtracting to the final intensity. If the light was a particle, you would have ended up with two bunches on the other side of the screen. But we have interference, and we see light everywhere after the screen, not just at the position of the holes. That's proof that light is indeed a wave.

- Eighty-six years later, Heinrich Hertz became the first to demonstrate the particle nature of light. He noticed that when ultraviolet light shone on a metal surface, it generated a charge, a phenomenon called the “photoelectric effect”. However, the significance of his observation wasn't fully understood until many years later.

- Atoms contain electrons in fixed energy levels. Shining light on them is therefore expected to give the electrons energy and enable them to escape from the atom, with brighter light liberating electrons faster. But in experiments following Hertz's work, several unusual observations seemed to completely contradict this classical understanding of physics.

- It was Einstein who finally solved this puzzle, for which he was awarded a Nobel prize in 1921. Rather than absorbing light continuously from a wave, atoms actually receive energy in packets of light called “photons”, explaining odd observations such as the existence of a cutoff frequency.

- But what determines whether light behaves as a wave or as a particle? Light is not sometimes a particle and sometimes a wave. It is always both a wave and a particle. It's just that we highlight one of the properties depending on which experiment we do.

- In day-to-day life, we mostly experience light as a wave, and it's this form that physicists find most useful to manipulate. There's a full field called metamaterials, by shaping a material with the same features as light, we can enhance the interaction of light with the material and control the waves. For example, we can make solar absorbers that can absorb light more efficiently for energy generation or metamaterial MRI probes which are much more effective.

- However, light's double nature, known as wave “particle duality”, is absolutely fundamental to the existence of the world as we know it. This strange twinned behavior also extends to other quantum particles, like electrons.

- You could not have an atom be stable if you didn't have quantum mechanics with the electrons in specific states. If you remove the fact that it is a particle, you remove the fact that it has a specific energy and life could not exist.

November 23, 2024 LIGHT - is it a particle or a wave? 4618

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

-------- Comments appreciated and Pass it on to whomever is interested. ---

--- Some reviews are at: -------------- http://jdetrick.blogspot.com -----

-- email feedback, corrections, request for copies or Index of all reviews

--- to: ------ jamesdetrick@comcast.net ------ “Jim Detrick” -----------

--------------------- --- Sunday, November 24, 2024 ---------------------------------

Saturday, November 23, 2024

4616 - EXOPLANETS - in other solar systems?

- 4616 - EXOPLANETS - in other solar systems? - How many additional “Exoplanets” are in known systems? One thing we’ve learned in recent decades is that exoplanets are surprisingly common. So far, we’ve confirmed nearly 6,000 planets, and we have evidence for thousands more.

----------------------------------------- 4616 - EXOPLANETS - in other solar systems?

- Most of these exoplanets were discovered using the transit method. though we there are other methods as well. Many stars are known to have multiple planets, such as the TRAPPIST-1 system with seven Earth-sized worlds.

- But even within known planetary systems there could be planets we’ve overlooked. Perhaps their orbit doesn’t pass in front of the star from our vantage point, or the evidence of their presence is buried in data noise.

- Rather than combing through the observational data trying to extract more planets from the noise, the authors suggest that we look at the orbital dynamics of known systems to see if planets might be possible between the planets we know.

- Established systems are millions or billions of years old, so their planetary orbits must be stable on those timescales. If the planets of a system are “closely packed,” then adding new planets to the mix would cause the system to go all akilter. If the system is “loosely packed,” then we could add hypothetical planets between the others, and the system would still be dynamically stable.

- To show how this would work, the authors consider seven planetary systems discovered by the Transiting Exoplanet Survey Satellite (TESS) known to have two planets. Since it isn’t likely that a system has only two planets, there is a good chance they have others. The team then ran thousands of simulations of these systems with hypothetical planets, calculating if they could remain stable over millions of years.

- They found that for two of the systems, extra planets (other than planets much more distant than the known ones) could be ruled out on dynamical grounds. Extra planets would almost certainly destabilize the systems. But five of the systems could remain stable with more planets. That doesn’t mean those systems have more planets, only that they could.

- One of the things this work shows is that most of the currently known exoplanetary systems likely have yet-undiscovered worlds. This approach could also help us sort systems to determine which ones might deserve a further look. We are still in the early stages of discovery, and we are gathering data with incredible speed. We need tools like this so we aren’t overwhelmed by piles of new data.

- It is a good thing we found this Earth-Sized Planet now. It’s about to be destroyed. Astronomers have confirmed the existence of exoplanets with extremely small orbits around their stars. But what about exoplanets that get close enough to be devoured by their star, and what if it’s an Earth-sized exoplanet?

- Researchers investigated an Earth-sized exoplanet with an orbital period of only 5.7 hours, known as “ultra-short-period” (USP) exoplanets, that could eventually experience what’s known as “tidal disruption”, resulting in its devourment by its star.

- Tidal disruption could be a potential fate of rocky planets. It seems like about 10 percent of sun-like stars might have engulfed their rocky planets. This system “TOI-6255” is the best-known for those planet engulfment events. The tidal disruption of rocky planets allows us to probe their interior composition and compare with Earth.

- “TOI-6255 b” radius is 1.08 and mass is 1.44 of Earth’s and located just over 65.2 light-years from Earth. However, while being Earth-sized holds promise for life, TOI-6255 b’s 5.7-hour orbit not only make this exoplanet far too hot for life as we know it to exist, but this also means its orbit takes it dangerously close to what’s known as “Roche limit”.

- The “Roche limit” is the distance a smaller object can orbit a larger object until the larger object’s gravity tears the smaller object to pieces, along with TOI-6255 b also experiencing the tidal disruption, which is a common occurrence throughout the universe including black holes.

- This planet is doomed for tidal disruption in 400Myr which is short on cosmic scale (13Gyr). The planet is also tidally distorted to be football like in shape (10 percent deviation from sphere), in comparison Earth’s tidal distortion due to the moon is only 1e-7 [0.0000001] level.

- The “orbital phase curve” study of this planet could confirm that it is indeed tidally distorted. We know what the phase curve should look like for a spherical planet, tidally distorted planet has a strong deviation from that. We can also see if the surface of the planet is covered by lava pool as would be expected on a planet this hot.

- USPs are exoplanets whose orbits are less than one day and whose masses are less than 2x the Earth. Only about 100 USPs have been discovered with a 2014 study estimating approximately 0.5 percent exist around Sun-like stars and a 2019 study discussing their bulk composition (i.e., mass of its iron core and mantle).

- Given their extremely short orbit, these worlds are likely too hot for life as we know it to exist, and along with USPs are the familiar “hot Jupiters” who orbit their stars in only a few days and astronomers estimate their population is in the hundreds.

- These worlds are Jupiter-sized or larger gas planets and are also potentially far too hot for life as we know it to exist. Planets similar to Earth in size are most likely rocky i.e. mostly made of iron core and silicate mantle. They show us what terrestrial planets in other planetary systems are made of. Jupiter-sized planets are most certainly covered by thick hydrogen and helium atmospheres. Jupiter-sized planets are unlikely to harbor life.

- While TOI-6255 b isn’t due for disassembly for another 400 million years, watching any exoplanet get ripped to shreds by its host star could provide important insights regarding the planet’s exterior and interior compositions, thus helping us better understand the similarities between exoplanets and planets within our own solar system.

- These unique worlds and their extremely tight orbits have challenged our understanding of solar system architecture throughout our Milky Way Galaxy, as Mercury is the closest planet to our Sun, and it still takes 88 days to complete one orbit.

- One similarity between our solar system and exoplanetary systems is the Roche limit. Tidal disruption could be a potential fate of rocky planets. Tidal disruption of planets is minimal in our solar system. However, the rings of Saturn are thought to originate from tidal disruption of satellites around Saturn. Tidal forces are strongly dependent on orbital separation, only objects with the shortest orbital period experience significant tides.

November , 2024 EXOPLANETS - in other solar systems? 4616

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

-------- Comments appreciated and Pass it on to whomever is interested. ---

--- Some reviews are at: -------------- http://jdetrick.blogspot.com -----

-- email feedback, corrections, request for copies or Index of all reviews

--- to: ------ jamesdetrick@comcast.net ------ “Jim Detrick” -----------

--------------------- --- Saturday, November 23, 2024 ---------------------------------

Thursday, November 21, 2024

4615 - COSMIC EXPANSION – zigzags in space time?

- 4615 - COSMIC EXPANSION – zigzags in space time?- A new James Webb space telescope study has revealed the true origins of a luminous quasar that has been duplicated six times as its light "zig-zags" through space-time via a phenomenon first predicted by Albert Einstein. The unusual light show could help tackle one of cosmology's biggest problem.

----------------------------------- 4615 - COSMIC EXPANSION – zigzags in space time?

- Researchers discovered the "Einstein zig-zag" phenomenon while analyzing six mirror images of a single gravitationally lensed quasar in the distant cosmos. Image data from the James Webb Space Telescope (JWST) to uncover an example of a previously hypothetical phenomenon known as an "Einstein zig-zag" where light from an object in the distant cosmos passes through two different regions of warped space-time.

- The newly confirmed effect, which was discovered among six identical copies of a luminous quasar, could shed light on an issue that is beginning to plague cosmology. In 2018, astronomers discovered a quartet of identical bright points billions of light-years from Earth, later named J1721+8842.

- Initially, the scientists assumed that the four lights were mirror images of a single quasar, a luminous galactic core powered by a feeding black hole, that had been duplicated through a phenomenon known as "gravitational lensing."

- Gravitational lensing happens when light from a distant object appears to get bent as it passes through warped space-time that has been pulled out of shape by the immense gravity of a lensing object, usually a massive galaxy or cluster of galaxies, located between the distant object and the observer.

- This warping effect can either duplicate the initial light source, as the light takes different routes around the lensing object, or stretch out the light into luminous halos, known as Einstein rings after Albert Einstein, who first predicted gravitational lensing with his theory of general relativity in 1915.

- In the 2022 study, researchers discovered that J1721+8842 had two additional points of light alongside the original quartet, as well as a faint red Einstein ring. The newly discovered points were slightly fainter than the other four points, which led researchers to suspect that the light show showed a pair of adjacent quasars, known as a binary quasar, that had been duplicated three times rather than a single quasar that had been copied six times.

- Light from Einstein rings and other gravitationally lensed objects appears to bend around their lensing objects. But in reality, the light is travelling in a straight line through warped space-time.

- Researchers reanalyzed J1721+8842 using new data from JWST and found that all six points of light are actually from a single quasar after all. The team also found that newly unveiled bright spots have been lensed around a second massive object farther away from the first, which is also responsible for the faint Einstein ring seen in more recent images.

- After observing the light curves of each bright spot over two years, researchers showed that there is a slight delay in the time it takes the two faintest duplicate images to reach us, which suggests that the light in these copies has to travel farther than the other four bright spots. This is likely because the light in these images passes around the opposite sides of each lensing object (i.e. around the left side of the first lens and right side of the second lens).

- The study team has named this "extremely rare lensing configuration" an Einstein zig-zag because light from some of the double-lensed bright spots has swerved back and forth as it passed around both lensing galaxies.

- Gravitationally lensed objects, such as Einstein rings, are treasured by astronomers and cosmologists because the warped light can help reveal the mass of the galaxies that lensed them. This, in turn, can help reveal secrets of the universe such as the secret identity of dark matter and how dark energy drives cosmic expansion.

- JWST has been exceptionally good at finding these objects in parts of the universe where we have never been able to see them before. But unfortunately, the state-of-the-art telescope has also highlighted discrepancies we cannot currently explain.

- For example, measurements from the telescope have confirmed that different parts of the universe are expanding at different rates, which threatens to "break" our understanding of cosmology. Researchers refer to this problem as the “Hubble tension”.

- However, researchers believe that the newly confirmed Einstein zig-zag could help to smooth out this tension because its unique configuration will allow astronomers to precisely measure both the Hubble constant — the rate at which cosmic expansion is accelerating — and the amount of dark energy — the invisible force driving the universe's expansion — in this region of space.

November 21, 2024 COSMIC EXPANSION – zigzags in space time? 4615

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

-------- Comments appreciated and Pass it on to whomever is interested. ---

--- Some reviews are at: -------------- http://jdetrick.blogspot.com -----

-- email feedback, corrections, request for copies or Index of all reviews

--- to: ------ jamesdetrick@comcast.net ------ “Jim Detrick” -----------

--------------------- --- Thursday, November 21, 2024 ---------------------------------

Wednesday, November 20, 2024

4614 - The SUN'S SOLAR CYCLES?

- 4614 - The SUN'S SOLAR CYCLES? We now know that the Sun is governed by its powerful magnetic fields, and as these fields cycle through their changes, the Sun becomes more active. Right now the Sun is at its solar maximum, a time of increased activity.

--------------------------------------------- 4614 - The SUN'S SOLAR CYCLES?

- October 18, 2024, the Sun has reached its Solar Maximum and it could last for one year. For most of human history, the Sun appeared stable going about its business fusing hydrogen into helium beyond our awareness and helping Earth remain habitable. But in our modern technological age, that facade fell away.

- Solar Maximum is a phase of the cycle, our star is now exhibiting maximum activity. The Sun’s intense magnetic fields produce more sunspots and solar flares than at any other time in its 11-year cycle.

- The Solar Maximum is all based on the Sun’s magnetic fields. These fields are measured in Gauss units, which describe magnetic flux density. The Sun’s poles measure about 1 to 2 gauss, but sunspots are much higher at about 3,000 gauss. (Earth is only 0.25 to 0.65 gauss at its surface.) Since the magnetic field is so much stronger where sunspots appear, they inhibit convective heating from deeper inside the Sun. As a result, sunspots appear as dark patches.

- Sunspots are visual indicators of the Sun’s 11-year cycle. During solar maximum, the number of sunspots, and therefore, the amount of solar activity, increases. This increase in activity provides an opportunity to learn about our closest star, but, also causes real effects at Earth and throughout our solar system.

- In May 2024, the Sun launched multiple CMEs. As the magnetic fields and charged particles reached Earth, they triggered the strongest geomagnetic storm in 200 decades. These created colorful aurorae that were visible much further from the poles than usual. These aurorae were likely among the strongest displays in the last 500 years.

- Scientists know the Sun is at its solar maximum. But it lasts for an entire year. They won’t know when its activity peaks until after they’ve watched it for months and its activity has declined.

- Each cycle is different, making it difficult to label peak solar activity. Different peaks have different durations and have higher or lower peaks than others. Understanding the Sun’s cycle is important because it creates space weather.

- During solar maximum, the increased sunspots and flares also mean more coronal mass ejections (CMEs.) CMEs can strike Earth, and when they do, they can trigger aurorae and cause geomagnetic storms. CMEs, which are blobs of hot plasma, can also affect satellites, communications, and even electrical grids.

- During the solar maximum, the Sun produces an average of three CMEs every day, while it drops to one CME every five days during the solar minimum. The CMEs’ effect on satellites causes the most concern. In 2003, satellites experienced 70 different types of failures. The failures ranged from erroneous signals in a satellite’s electronics to the destruction of electrical components. The solar storm that occurred in 2003 was deemed responsible for 46 of those 70 failures.

- CMEs are also a hazard for astronauts orbiting Earth. The increased radiation poses a health risk, and during storms, astronauts seek safety in the most shielded part of the ISS, Russia’s Service Module.

- Galileo and other astronomers noticed sunspots hundreds of years ago but didn’t know exactly what they were. In a 1612 pamphlet titled “Letters on Sunspots,” Galileo wrote ‘The sun, turning on its axis, carries them around without necessarily showing us the same spots, or in the same order, or having the same shape.’ This contrasted with others’ views on the spots, some of which suggested they were natural satellites of the Sun.

- We’ve known about the Sun’s magnetic fields for 200 hundred years, though at first, scientists didn’t know the magnetism was coming from the Sun. In 1724, an English geophysicist noticed that his compass was behaving strangely and was deflected from magnetic north throughout the day. In 1882, other scientists correlated these magnetic effects with increased sunspots.

- In recent decades, we’ve learned much more about our stellar companion thanks to spacecraft dedicated to studying it. NASA and the ESA launched the Solar and Heliospheric Observatory (SOHO) in 1995, and NASA launched the Solar Dynamics Observatory (SDO) in 2010. In 2011, we got our first 360-degree view of the Sun thanks to NASA’s two Solar TErrestrial RElations Observatory (STEREO) spacecraft. In 2019, NASA launched the Parker Solar Probe, which also happens to be humanity’s fastest spacecraft.

- Our understanding of the Sun and its cycles is far more complete now. The current cycle, Cycle 25, is the 25th one since 1755. Scientists use sunspots to track solar cycle progress; the dark spots are associated with solar activity, often as the origins for giant explosions—such as solar flares or coronal mass ejections—that can spew light, energy, and solar material out into space.

- Solar Cycle 25 sunspot activity has slightly exceeded expectations. The most powerful flare so far in Cycle 25 was on October 3rd, when the Sun emitted an X9 class flare. But scientists anticipate more flares and activity to come. There can be significantly powerful storms even in the cycle’s declining phase, though they’re not as common.

- On October 3, 2024, the Sun emitted a strong solar flare. This solar flare is the largest of Solar Cycle 25 and is classified as an X9.0 flare. X-class denotes the most intense flares, while the number provides more information about its strength.

- The Sun’s 11-year cycle is just one of its cycles, nested in larger cycles. The “Gleissberg cycle” lasts between 80 to 90 years and modulates the 11-year cycle. The “de Vries cycle” or “Suess cycle” lasts between 200 and 210 years, and the “Hallstatt cycle” lasts about 2,300 years. Both of these cycles contribute to long-term solar variation.

- However, even with all we know about the Sun, there are big gaps in our knowledge. The Sun’s magnetic poles switch during the 11-year cycle, and scientists aren’t sure why. There’s a lot more to learn about the Sun, but we won’t run out of time to study it any time soon. It’s in the middle of its 10-billion-year lifetime and will be a main-sequence star for another five billion years.

November 20, 2024 The SUN'S SOLAR CYCLES? 4614

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

-------- Comments appreciated and Pass it on to whomever is interested. ---

--- Some reviews are at: -------------- http://jdetrick.blogspot.com -----

-- email feedback, corrections, request for copies or Index of all reviews

--- to: ------ jamesdetrick@comcast.net ------ “Jim Detrick” -----------

--------------------- --- Wednesday, November 20, 2024 ---------------------------------

Tuesday, November 19, 2024

4611 - ASTRONOMERS WHITNESS BLACK HOLE?

- 4611 - ASTRONOMERS WHITNESS BLACK HOLE? - For the first time, astronomers see the creation of atoms. They can measure the temperature of the matter and see the microphysics in this remote explosion. They witnessed the titanic collision between two neutron stars that resulted in the birth of the smallest black hole ever seen and forged precious metals like gold, silver, and uranium.

--------------------------------- 4611 - ASTRONOMERS WHITNESS BLACK HOLE?

- The astronomers snapshot of this violent and powerful collision, which occurred 130 million light-years away from us in the galaxy NGC 4993, was created with a range of instruments, including the Hubble Space Telescope.

- It will hopefully paint a picture of the "past, present, and future" of the mergers of these dense dead stars. This could reveal the origins of elements heavier than iron, which can't be forged in even the most massive stars.

- The collision and merger of the neutron stars results in a powerful blast of light called a "kilonova." As the wreckage of this event expands at nearly the speed of light, the kilonova illuminates its surroundings with light as bright as hundreds of millions of suns.

- This remarkable' explosions from colliding, dead stars could reveal the true expansion rate of the universe. We can now see the moment where atomic nuclei and electrons are uniting in the afterglow. We see the creation of atoms, we can measure the temperature of the matter, and we can see the microphysics in this remote explosion.

- We see before, during, and after the moment of birth of the atoms. The gold in your jewelry came from the universe's most violents events. Neutron stars are born when stars at least 8 times as massive as the sun exhaust their fuel for nuclear fusion and can no longer support themselves against their own gravity.

Get the Space.com Newsletter

Breaking space news, the latest updates on rocket launches, skywatching events and more!

Your Email Address

Contact me with news and offers from other Future brands

Receive email from us on behalf of our trusted partners or sponsors

By submitting your information you agree to the Terms & Conditions and Privacy Policy and are aged 16 or over.

The outer layers of these stars are blasted away in supernova explosions, leaving a stellar remnant with a mass equal to between 1 and 2 suns crushed into a diameter of around 12 miles (20 kilometers).

The collapse of the core forces electrons and protons together, creating a sea of particles called neutrons. This material is so dense that a mere sugar cube's worth of neutron star matter would weigh 1 billion tons if brought to Earth. That's about the same as cramming 150,000,000 elephants into the same space that a sugar cube occupies.

It is probably no surprise that this extreme and exotic matter plays a key role in creating elements heavier than iron.

A irregularly shaped near spherical blue cloud with nodules extending from it

An illustration shows a cloud of material erupting from a collision of neutron stars (Image credit: NASA Goddard/CI Lab)

Neutron stars don't always live in isolation. Some of these dead stars occupy binary systems along with a companion living star. In rare instances, this companion star is also massive enough to create a neutron star, and it isn't "kicked away" by the supernova explosion that creates the first neutron star.

The result is a system with two neutron stars orbiting each other. These objects are so dense that as they swirl around each other, they generate ripples in spacetime (the four-dimensional unification of space and time) called gravitational waves that ripple through space, carrying away angular momentum.

As the system loses angular momentum, the orbit of the neutron stars tightens, meaning that the neutron stars move closer to each other. This results in gravitational waves rippling away faster and faster, carrying away more and more angular momentum.

This situation ends when neutron stars are close enough for their immense gravity to take over and drag these extremely dense dead stars together to collide and merge.

This collision sprays out neutron-rich matter with temperatures of many billions of degrees, thousands of times hotter than the sun. These temperatures are so hot that they are similar to those of the rapidly inflating universe just one second after the Big Bang.

An artist's depiction of colliding black holes causing ripples in the fabric of space-time.

An artist's depiction of colliding neutron stars sending out ripples in spacetime called gravitational waves. (Image credit: R. Hurt/Caltech-JPL)

Ejected particles like electrons and neutrons dance around the body, birthed by the colliding neutron stars, which rapidly collapse to form a black hole in a fog of plasma that cools over the next few days.

Atoms in this cooling cloud of plasma quickly grab free neutrons via what is called the rapid neutron capture process (r-process) and also ensnare free electrons. This creates very heavy but unstable particles that rapidly decay. This decay releases the light that astronomers see as kilonovas, but it also creates lighter elements that are still heavier than iron, like gold, silver and uranium.

This team saw the afterglow of particles being snatched to forge heavy elements like Strontium and Yttrium, reasoning that other heavy elements were undoubtedly created in the aftermath of this neutron star collision.

"The matter expands so fast and gains in size so rapidly, to the extent where it takes hours for the light to travel across the explosion," team member Kasper Heintz, a researcher at the Niels Bohr Institute, said. "This is why, just by observing the remote end of the fireball, we can see further back in the history of the explosion. Closer to us, the electrons have hooked to atomic nuclei, but on the other side, on the far side of the newborn black hole, the 'present' is still just the future."

4613 - ASTEROID HITS EARTH ?

- 4613 - ASTEROID HITS EARTH ? - An asteroid hit the Earth just hours after being detected. It was the 3rd 'imminent impactor' of 2024. A small asteroid burned up in Earth's atmosphere off the coast of California just hours after being discovered and before impact monitoring systems had registered its trajectory.

------------------------------------------------ 4613 - ASTEROID HITS EARTH ?

- October 2024, an asteroid impacted Earth's atmosphere just hours after being detected. Somehow, it managed to circumvent impact monitoring systems during its approach to our planet. However, on the bright side, the object measured just 3 feet in diameter and posed very little threat to anything on Earth's surface.

- This asteroid, “2024 UQ”, was first discovered on October 22 by the Asteroid Terrestrial-impact Last Alert System (ATLAS) survey in Hawaii. This is a network of four telescopes that scan the sky for moving objects that might be space rocks on a collision course with Earth. Two hours later, the asteroid burned up over the Pacific Ocean near California, making it an "imminent impactor."

- The small amount of time between detection and impact means impact monitoring systems, operated by the European Space Agency's Near-Earth Object Coordination Center, didn't receive tracking data about the incoming asteroid until after it struck Earth.

- ATLAS survey obtained images that included detections of a small object in a high-probability collision course. However, due to the location of the object near the edge of two adjacent fields, the candidate was recognized as a moving object only a few hours later.

- By the time the astrometry reached the impact monitoring systems, the impact had already happened. The asteroid was the third imminent impactor detected this year. As for the two other asteroids that were been detected within hours of impacting Earth in 2024, the first is known as “2024 BX1”. It measured around 3.3 feet wide and burned up harmlessly over Berlin, Germany in January. The other, “2024 RW1”, exploded over the Philippines on September 4.

- Planetary defense efforts that aim to catalog the myriad of space rocks in our neck of the cosmic woods have become a major priority for space agencies worldwide. Aside from the ATLAS survey, Catalina Sky Survey, ESA's NEOCC and other projects like them, NASA is developing a new infrared telescope known as NEO Surveyor to hunt for potentially threatening near-Earth objects.

- But it's not all just about detection and tracking. Space agencies are testing methods of redirecting incoming asteroids should the need ever arise. In 2022, NASA's DART mission crashed an impactor into a double asteroid system in an attempt to change its trajectory (the endeavor was a success). China is also developing its own mission to deflect an asteroid by 2030.

- The Taurid Meteoroid Stream, which is possibly responsible for the famous Tunguska and Chelyabinsk impacts, probably doesn't hide a civilization-killing asteroid. A swarm of interplanetary dust, rocks, comets and asteroids thought to be responsible for two famous impacts here on Earth has been found to be not quite as menacing as astronomers had feared.

- The risk of being hit by a large asteroid in the Taurid swarm is much lower than we believed, which is great news for planetary defense.

- The swarm in question is the “Taurid Meteoroid Complex”, which is a huge trail of debris that cuts across the path of Earth's orbit around the sun. It's responsible for several meteor showers, most notably the Southern Taurids that peak every year on November 5, and the Northern Taurids on November 12.

- Meteor showers are produced when swarms of tiny particles of dust, most just microns or millionths of a meter in size, burn up in the Earth's atmosphere. However, lurking among all the dust are larger chunks, from boulder-size rocks to full-blown asteroids. They all seem to come from a parent body, the short-period “Comet 2P/Encke”.

- Comet 2P/Encke was the second periodic comet to be discovered. And the first was Halley's Comet. A short-period comet is one that regularly orbits the sun more often than once every 200 years. (Comets that take longer than 200 years to complete an orbit are called long-period comets, and originate from deep within the distant Oort Cloud.) In 2P/Encke's case, it orbits every 3.3 years, the shortest orbit of any known periodic comet.

- “Encke” is pretty big for a short-period comet, spanning about 3 miles in diameter. It's also joined on its orbit by dozens of other minor bodies. The theory is that 2P/Encke and all its companions originated from a much larger body that fragmented as it came in from the outer solar system and got close to the heat of the sun.

- Estimates of when this occurred vary, from about 20,000 years ago to just 5,000 to 6,000 years ago, but the worry was that there may be kilometer-sized objects lurking in the Taurid Complex that we haven't discovered yet. Objects of this size could cause widespread damage were they to collide with our planet.

- However, having surveyed a wide swathe of sky around the Taurid Complex looking for any undiscovered objects there are fewer kilometer-sized objects in the Taurid Complex than had been thought.

- Fortunately, we found that it's likely there may only be a handful of asteroids, perhaps only nine to 14 of them, that fit this large size class in the swarm The parent object that originally created the swarm was probably closer to 10 kilometers in diameter rather than a massive 62 miles object.

- Some uncertainty does remain over the origin of the Taurid Complex, however. In 2014, astronomers using NASA's Infrared Telescope Facility on Mauna Kea, Hawaii, studied the spectra of many of the objects in the Taurid Complex and found a wide range of types, from stony S-type asteroids to carbon-rich C-types.

- This diversity called into question the idea that they'd all originated from a common parent body. However, a year later, a subsequent study that analyzed the spectra of 33 fireballs hailing from the Taurid Complex concluded that, despite the compositional variation, the fireballs all had spectral and physical characteristics consistent with having come from a comet that has broken apart.

- Regardless of their origin, and despite being linked to the last two destructive impacts on Earth, the 1908 Tunguska event and the 2013 Chelyabinsk airburst, it seems that the Taurid Complex does not harbor any hidden dangers. The objects that are present within the stream are on well-known orbits and do not currently pose a threat to Earth.

- We shouldn't get too comfortable. We still need to be vigilant about asteroid impacts. But, we can probably sleep better knowing these results.

November 18, 2024 ASTEROID HITS EARTH ? 4613

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

-------- Comments appreciated and Pass it on to whomever is interested. ---

--- Some reviews are at: -------------- http://jdetrick.blogspot.com -----

-- email feedback, corrections, request for copies or Index of all reviews

--- to: ------ jamesdetrick@comcast.net ------ “Jim Detrick” -----------

--------------------- --- Tuesday, November 19, 2024 ---------------------------------

JimsAstronomy

Sunday, November 24, 2024

4617 - 2023 DISCOVERIES - in astronomy -

4618 - LIGHT - is it a particle or a wave?

Saturday, November 23, 2024

4616 - EXOPLANETS - in other solar systems?

Thursday, November 21, 2024

4615 - COSMIC EXPANSION – zigzags in space time?

Wednesday, November 20, 2024

4614 - The SUN'S SOLAR CYCLES?

Tuesday, November 19, 2024

4611 - ASTRONOMERS WHITNESS BLACK HOLE?

4613 - ASTEROID HITS EARTH ?

About Me

Blog Archive