4554 - EARTH-SIZE EXOPLANET ?

 

-    4554 -   EARTH-SIZE  EXOPLANET ?      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?

-

--------------------------------------------  -    4554 -   EARTH-SIZE  EXOPLANET ?      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?

--------------------------------------------  4554  -  EARTH-SIZE  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 progenitor for those planet engulfment events. The tidal disruption of rocky planets allows us to probe their interior composition and compare with Earth.

-

-    The researchers analyzed TOI-6255 b, whose radius is ~1.08 and mass is ~1.44 of Earth’s and located just over 20.4 parsecs (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 cosmos, 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.

-

-    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 ( 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. As their name literally implies, these worlds are Jupiter-sized or larger gas planets and are also potentially far too hot for life as we know it to exist. But what is the significance of TOI-6255 b being an Earth-sized planet as opposed to a Jupiter-sized planet, or larger?

-

-    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.

-

-   Tidal disruption could be a potential fate of rocky planets. Therefore, what are the chances of tidal disruption occurring for rocky planets in our solar system, and why?  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.”

-

-

September 12, 2024                EARTH-SIZE  EXOPLANET ?               4554

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

--------  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, September 12, 2024  ---------------------------------

 

 

 

 

 

           

 

 

-

-   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 progenitor for those planet engulfment events. The tidal disruption of rocky planets allows us to probe their interior composition and compare with Earth.

-

-    The researchers analyzed TOI-6255 b, whose radius is ~1.08 and mass is ~1.44 of Earth’s and located just over 20.4 parsecs (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 cosmos, 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.

-

-    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 ( 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. As their name literally implies, these worlds are Jupiter-sized or larger gas planets and are also potentially far too hot for life as we know it to exist. But what is the significance of TOI-6255 b being an Earth-sized planet as opposed to a Jupiter-sized planet, or larger?

-

-    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.

-

-   Tidal disruption could be a potential fate of rocky planets. Therefore, what are the chances of tidal disruption occurring for rocky planets in our solar system, and why?  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.”

-

-

September 12, 2024                EARTH-SIZE  EXOPLANET ?               4554

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

--------  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, September 12, 2024  ---------------------------------

 

 

 

 

 

           

 

 

4553 - NEW TELESCOPES - CCD's to improve sensitivity?

 

-    4553 -  NEW  TELESCOPES  -  CCD's  to improve sensitivity?  -  Scientists have used sensitive CCDs on a telescope to study the night sky. Berkeley Lab designed and processed the ultra-low-noise detectors, which could improve future experiments to understand our universe.

----------------------------------  4553  -  NEW  TELESCOPES  -  CCD's  to improve sensitivity?

-

-    Using an instrument on the 4.1-meter Southern Astrophysical Research (SOAR) Telescope, researchers obtained the first astronomical spectrum using skipper charge-coupled devices (CCDs). “Skipper CCDs” can get down to very low noise levels, which helps astronomers see distant galaxies.

-

-   On March 31 and April 9, 2021, researchers used skipper CCDs to collect astronomical spectra from a galaxy cluster, two distant quasars, a galaxy with bright emission lines, and a star that is potentially associated with a dark-matter-dominated ultra-faint galaxy.

-

-    In a first for astrophysical CCD observations, they achieved sub-electron readout noise and counted individual photons at optical wavelengths.   CCDs were invented in the United States in 1969, and forty years later scientists were awarded the Nobel Prize in Physics for their achievement.

-

-    The devices are two-dimensional arrays of light-sensitive pixels that convert incoming photons into electrons. Conventional CCDs are the image sensors first used in digital cameras, and they remain the standard for many scientific imaging applications, such as astronomy, though their precision is limited by electronic noise.

-

-    Cosmologists seek to understand the mysterious natures of dark matter and dark energy by studying the distributions of stars and galaxies. To do this, they need advanced technology that can see fainter, more distant astronomical objects with as little noise as possible.

-

-    Existing CCD technology can make these measurements but take a long time or are less efficient. So, astrophysicists must either increase the signal, by investing more time on the world’s largest telescopes, or decrease the electronic noise.

-

-    Skipper CCDs were introduced in 1990 to reduce electronic noise to levels that allow the measurement of individual photons. They do this by taking multiple measurements of interesting pixels and skipping the rest. This strategy enables skipper CCDs to increase the precision of measurements in interesting regions of the image while reducing total readout time.

-

-   In 2017, scientists pioneered the use of skipper CCDs for dark matter experiments such as SENSEI and OSCURA, but today’s presentation showed the first time the technology was used to observe the night sky and collect astronomical data.

-

-   What’s incredible is that these photons traveled to our detectors from objects billions of light-years away, and we could measure each one individually.

-

-    With the first successful demonstration of skipper-CCD technology for astrophysics, scientists are already working to improve it. The next generation of skipper CCDs, developed by Berkeley Lab and Fermilab, is 16 times faster than current devices.

-

-

September 11, 2024     NEW  TELESCOPES  -  CCD's  to improve sensitivity?            4553

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

--------  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, September 12, 2024  ---------------------------------

 

 

 

 

 

           

 

 

4552 - MARS - possible life found?

 

-    4552 -  MARS  -  possible life found?  -    Perseverance Mars rover finds possible signs of ancient Red Planet life.  On Earth, these types of features in rocks are often associated with the fossilized record of microbes living in the subsurface.

----------------------------------------  4552  -  MARS  -  possible life found?

-    NASA's Perseverance rover has discovered a rock on Mars that may have once hosted microbial life. The rock, nicknamed 'Cheyava Falls”, has chemical compositions and structures that could have been formed by ancient life, although non-biological processes cannot yet be ruled out.

-

-   The rover came across an intriguing, arrowhead-shaped rock that hosts chemical signatures and structures that could have been formed by microbial life billions of years ago, when Mars was significantly wetter than it is today. Inside the rock Perseverance's instruments detected organic compounds, which are precursors to the chemistry of life as we know it. Wisping through the length of the rock are veins of calcium sulfate, which are mineral deposits that suggest water, also essential for life, once ran through the rock.

-

-   The rover also found dozens of millimeter-sized splotches, each surrounded by a black ring and mimicking the appearance of leopard spots. These rings contain iron and phosphate, which are also seen on Earth as a result of microbe-led chemical reactions.

-

-    On Earth, these types of features in rocks are often associated with the fossilized record of microbes living in the subsurface.   Cheyava Falls sits at the edge of an ancient,  437-yard-wide river valley named “Neretva Vallis”. Scientists suspect this ancient channel was carved out long ago due to water gushing into Jezero Crater; Neretva Vallis runs along the inner wall of this region.

-

-     In one possible scenario, mud that already possessed organic compounds got dumped into the valley and later cemented into the Cheyava Falls rock, which Perseverance sampled on July 21, 2024, A second episode of water oozing into the formed rock would have created the object's calcium sulfate veins and black-ringed spots the team sees today.

-

-   To be clear, the rock's visible features aren’t irrefutable evidence of ancient microbial life on Mars. It is possible that the observed calcium sulfate entered the rock at uninhabitably high temperatures, perhaps during a nearby volcanic event. However, whether such non-biological chemical reactions could have resulted in the observed black-ringed spots is an open question.

-

-     We have zapped that rock with lasers and X-rays and imaged it literally day and night from just about every angle imaginable.   Scientifically, Perseverance has nothing more to give.  To fully grasp what really unfolded in the ancient river valley billions of years ago, scientists are keen to get the Cheyava Falls sample to Earth, where it can be scrutinized with powerful instruments that Perseverance’s limited suite doesn't have.

-

-    The complex Mars Sample Return effort, however, has run into many snags in recent months after its costs spiked to $11 billion. In its current form, the program requires multiple launches to Mars to place a vehicle on the Red Planet, after which either Perseverance will travel to the vehicle and drop off its collected samples, or pop those samples over to a retrieval helicopter that can complete the handoff. Then, an ascender would launch the samples into orbit, where a spacecraft would collect them and return them to Earth.

-

-

September 9, 2024              MARS  -  possible life found?               4552

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

--------  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”  -----------

--------------------- ---  Monday, September 9, 2024  ---------------------------------

 

 

 

 

 

           

 

 

4551 - CARBON - abundant in early galaxy?

 

-    4551 -  CARBON  -  abundant in early galaxy?  -   Carbon is surprisingly abundant in an early galaxy.  The James Webb Space Telescope (JWST) has once again found evidence that the early universe was a far more complex place than we thought.

-----------------------------------  4551  -  CARBON  -  abundant in early galaxy?

-

-   This time we have detected the signature of carbon atoms present in a galaxy that formed just 350 million years after the Big Bang.  This is one of the earliest galaxies ever observed.

-

-   Earlier research suggested that carbon started to form in large quantities relatively late, about one billion years after the Big Bang.  But,  we’ve found that carbon formed much earlier.   It might even be the oldest metal of all.

-

-   ‘Metal’ is the name astronomers give to any element heavier than hydrogen or helium, and seeing metals like carbon so early is a surprise. Carbon is one of the building blocks of life on Earth, but it also plays a role in galaxy and solar system formation. It is one of the materials that can accumulate in the protoplanetary disks around stars, snowballing to become planets, moons, and asteroids.

-

-   Astronomers weren’t expecting to see that process happening so early.  When the first stars (called population-III stars) were born, in an era of the universe known as “Cosmic Dawn”, the only plentiful elements around were hydrogen and helium. All heavier elements didn’t yet exist. They were only able to form later, inside the cores of stars, therefore wouldn’t be detectable until well after the deaths of the first stars.

-

-    Dying population-III stars that explode as supernovas throw their heavier elements out into the universe, allowing future populations of stars to develop rocky planets with more interesting chemistry.

-

-    The galaxy in question, named “GS-z12”, is thought to contain largely second generation stars, built from the remains of those first supernovas. Astronomers didn’t expect the building blocks of the galaxy to be carbon-rich.

-

-    The earliest stars produced much more oxygen than carbon.   We had thought that carbon was enriched much later, through entirely different processes, but the fact that it appears so early tells us that the very first stars may have operated very differently than expected.

-

-   JWST’s “Near Infrared Spectrograph” allowed astronomers to break down the light coming from the distant galaxy into its constituent parts, revealing all the different wavelengths present. Every element and chemical compound has its own signature when viewed via spectroscopy, and the signal for carbon was very strong. There was also a fainter signal for neon and oxygen, though those remain tentative detections for the moment.

-

-    How carbon emerged before oxygen is an open question, but one hypothesis proposes that scientists now need to revisit their models of population-III star supernovas. If these supernovas occurred with less energy than previously thought, then they would scatter carbon from the stars’ outer shells, while most of the oxygen present would be captured within the event horizon as the stars collapsed into black holes.

-

-   Regardless of how it happened, there is now a strong case for heavy elements early in the universe.  JWST is revealing unexpected details about the first galaxies that will ultimately make scientists’ predictions about the evolution of the universe.

-

-    These observations tell us that carbon can be enriched quickly in the early universe.  And, because carbon is fundamental to life as we know it, it’s not necessarily true that life must have evolved much later in the universe. Perhaps life emerged much earlier.   Although if there’s life elsewhere in the universe, it might have evolved very differently than it did here on Earth.

-

-

September 9, 2024          CARBON  -  abundant in early galaxy?                   4551

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

--------  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”  -----------

--------------------- ---  Monday, September 9, 2024  ---------------------------------

 

 

 

 

 

           

 

 

4550 - ATOM INTERFEROMETER - new discoveries in space?

 

-    4550 -  ATOM  INTERFEROMETER  -  new discoveries in space?  -    Space-based atom interferometry will lead to exciting new discoveries and fantastic quantum technologies impacting everyday life, and will transport us into a quantum future.

-

---------------  4550  -  ATOM  INTERFEROMETER  -  new discoveries in space?

  Scientists at NASA's Cold Atom Lab (CAL) onboard the International Space Station (ISS) have announced that, for the first time, they have successfully made high-precision measurements using a quantum sensor based on ultra-cold atoms of the element Rubidium.

-

-    Working versions of these sensors would offer new opportunities for scientific discoveries through the study of quantum phenomena, testing the limits of fundamental physics and maybe even pushing beyond theories such as general relativity and the Standard Model of particle physics.

-

-    CAL researchers were able to measure the subtle vibrations of the ISS itself, using an instrument called an atom interferometer,  It's one of the most advanced technologies for making high-precision measurements. The technique is based on the same principles as optical interferometry, where light is split into two beams that travel along different optical paths before getting combined to produce interference. Any differences between the beams' paths allows for extremely precise detection of changes in the environment.

-

-   Instead of light, however, atom interferometry uses atoms cooled to near absolute zero (-459 degrees Fahrenheit or -273 degrees Celsius), and relies on their ability to exist in multiple positions and motions at the same time due to quantum effects that become apparent at this ultra-cold temperature.

-

-   When atoms move through an interferometer, they create patterns called fringes, which contain information about forces like gravity or other environmental influences. And, because atoms move much slower than light, they are affected by these forces for a longer time, allowing for very precise measurements that are much more sensitive than their optical counterparts.

-

-    On Earth, atom interferometers have allowed scientists to achieve incredible feats, such as building absolute gravimeters and investigating changes in fundamental constants of nature with baffling accuracy. But physicists have been eager to apply atom interferometry in space, where microgravity helps eliminate interference and allows scientists to take even longer measurements that would actually, in turn, improve the instrument's sensitivity altogether.

-

-   The CAL scientists were able to run their measurements remotely from Earth.  It will become possible to make even more precise measurements of gravity that would allow us to investigate and understand our cosmos in greater detail than ever.  They could reveal the composition of planets and moons in our solar system, because different materials have different densities that create subtle variations in gravity.

-

-   This enhanced sensitivity could also enable scientists to finally detect dark matter, an elusive substance that has remained a cosmic mystery due to its weak interactions with particles and gravitational fields.

-

-    Atom interferometry could also be used to test Einstein's theory of general relativity in new ways.  This is the basic theory explaining the large-scale structure of our universe, and we know that there are aspects of the theory that we don’t understand correctly. This technology may help us fill in those gaps and give us a more complete picture of the reality.

-

-    Space-based atom interferometry will lead to exciting new discoveries and fantastic quantum technologies impacting everyday life, and will transport us into a quantum future.

-

-

September 9, 2024    ATOM  INTERFEROMETER  -  new discoveries in space?      4550

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

--------  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, September 8, 2024  ---------------------------------

 

 

 

 

 

           

 

 

4549 - LASERS - how small in our future?

 

-    4549 -  LASERS  -  how small in our future?  -   High-powered titanium sapphire lasers have been shrunk down with scientists planning to cram hundreds or thousands onto a four-inch wafer in a new chip.   Researchers have built a titanium-sapphire (Ti:Sa) lasers that are 10,000 times smaller than any previous similar device and fit them onto a chip.

-------------------------------------------  4549  -  LASERS  -  how small in our future?

-

-   Until now, such lasers have cost upwards of $100,000. But with a new approach scientists believe the cost could drop to $100 per laser.  They also claimed that thousands of lasers could be built onto one four-inch wafer in the future and the cost per laser could become minimal. These small-scale lasers could be used in future quantum computers, in neuroscience and even in micro-level surgeries.

-

-   The experimental laser relies on two crucial processes. First, they ground a sapphire crystal down to a layer just a few hundred nanometers thick. They then fashioned a swirling vortex of tiny ridges, into which they shone a green laser pointer. With each rotation within that vortex, the laser’s intensity increased.

-

-    Sapphire is a very tough material. And when you grind it down, oftentimes, it doesn’t like it, it cracks, or it damages what you’re using to try to grind out.   Once this problem was solved,  the process as "smooth sailing."

-

-   One reason the team is so optimistic is that its lasers can be tuned to different wavelengths; specifically, from 700 to 1,000 nanometers, or red to infrared.  The laser’s intensity is increased via a series of vortexes within the crystal’s surface.

-

-   The miniature lasers could be used in quantum computers helping to make them much smaller in the process. They could also revolutionize the field of optogenetics where scientists control neurons with light guided inside the brain; currently, they use chunky optical fiber technology.   Miniature Ti:Sa lasers can be used in laser surgery.

-

-    Hundreds, or even thousands, of lasers can fit on one four-inch wafer.  The first "tunable laser" for academic users could go on sale within two years. The potential applications of these miniaturized lasers are vast.

-

-

September 8, 2024            LASERS  -  how small in our future?                4549

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

--------  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, September 8, 2024  ---------------------------------

 

 

 

 

 

           

 

 

4548 - VOYAGER SPACECRAFT - they just keep going?

 

-    4548 -   VOYAGER  SPACECRAFT  -  they just keep going?  -   The Voyager 1 spacecraft is sending back a steady stream of scientific data from uncharted territory for the first time since a computer glitch sidelined the historic NASA mission seven months ago.

------------------------------  4548  -  VOYAGER  SPACECRAFT  -  they just keep going?

-

-   Currently the farthest spacecraft from Earth, Voyager 1 stopped communicating coherently with mission control in November 2023. The probe seemed caught up in a “Groundhog Day” scenario, with its flight data system’s telemetry modulation unit sending back an indecipherable repeating pattern of code from billions of miles away.

-

-   A creative fix by the Voyager mission team restored communication with the spacecraft, and engineering data began streaming back to mission control in April, 2024, informing the team of the spacecraft’s health and operational status.

-

-   However, data from Voyager 1’s four science instruments, which study plasma waves, magnetic fields and particles, was missing. This information is important to show scientists how particles and magnetic fields change as the probe flies farther away.

-

-  On May 19, 2024, the Voyager team sent a command to the spacecraft to start returning science data. Two of the instruments responded, but getting data back from the other two took time, and the instruments required recalibration. Now, all four instruments are beaming back usable science data, according to an update shared by NASA on June 13.

-

-   Voyager 1’s flight data system is responsible for collecting information from the spacecraft’s science instruments and bundling it with engineering data that reflects the probe’s health status. Mission control on Earth, located at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, receives that data in binary code, or a series of ones and zeroes.

-

-   It took time and some out-of-the-box thinking for Voyager mission specialists to decode the spacecraft’s garbled code. But once they did, they determined the cause of the issue: 3% of the flight data system’s memory was corrupted.

-

-     A single chip responsible for storing part of the system’s memory, including some of the computer’s software code, isn’t working properly and the loss of the code on the chip caused Voyager 1’s science and engineering data to be unusable.

-

-   Since there is no way to repair the chip, the team stored the affected code from the chip elsewhere in the system’s memory. They couldn’t pinpoint a location large enough to hold all the code, so they divided it into sections and stored it in different spots within the flight data system.  There are still minor fixes needed to manage the effects of the initial issue.

-

-   Among other tasks, engineers will resynchronize timekeeping software in the spacecraft’s three onboard computers so they can execute commands at the right time.  The team will also perform maintenance on the digital tape recorder, which records some data for the plasma wave instrument that is sent to Earth twice per year.

-

-     The spacecraft is currently about 15 billion miles away from Earth, while its sister vehicle, Voyager 2, has traveled more than 12 billion miles from Earth. The twin probes lifted off weeks apart in 1977, and after initially flying by Jupiter, Saturn, Uranus and Neptune, their missions have been extended to 46 years and counting.

-

-    Both are in interstellar space and the only spacecraft to operate beyond the heliosphere, the sun’s bubble of magnetic fields and particles that extends well beyond Pluto’s orbit.  As the sole extensions of humanity outside the heliosphere’s protective bubble, the two probes are alone on their cosmic treks as they travel in different directions.

-

-    Think of the planets of Earth’s solar system as existing in one plane. Voyager 1’s trajectory took it up and out of the plane after passing Saturn, while Voyager 2 passed over the top of Neptune and moved down and out of the plane.

-

-    The information collected by these long-lived probes, the only two spacecraft to directly sample interstellar space with their instruments, is helping scientists learn about the cometlike shape of the heliosphere and how it protects Earth from energized particles and radiation in interstellar space.

-

-   Over time, both spacecraft have encountered unexpected issues and dropouts, including a seven-month period in 2020 when Voyager 2 couldn’t communicate with Earth. In August 2023, the mission team used a long-shot “shout” technique to restore communications with Voyager 2 after a command inadvertently oriented the spacecraft’s antenna in the wrong direction.

-

-   We never know for sure what’s going to happen with the Voyagers, but it is constantly amazes  when they just keep going. 

-

-

September 4, 2024          VOYAGER  SPACECRAFT  -  they just keep going?           4548

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

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--------------------- ---  Thursday, September 5, 2024  ---------------------------------

 

 

 

 

 

           

 

 

4547 - ROGUE PLANETS - roaming free of a star's gravity?

 

-    4547 -  ROGUE  PLANETS  -   roaming free of a star's gravity?  -   JamesWebb telescope discovers six new 'rogue worlds' that provide clues to star formation. Rogue planets, or free-floating planetary-mass objects , are planet-sized objects that either formed in interstellar space or were part of a planetary system before gravitational perturbations kicked them out.

---------------------------  4547  -  ROGUE  PLANETS  -   roaming free of a star's gravity?

-   Since these rogue planets were first observed in 2000, astronomers have detected hundreds of candidates that are untethered to any particular star and float through the interstellar medium (ISM) of our galaxy. In fact, some scientists estimate that there could be as many as 2 trillion rogue planets (or more) wandering through the Milky Way alone.

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-   Astronomers discovered six rogue planet candidates in an unlikely spot. The planets, which include the lightest rogue planet ever identified (with a debris disk around it), were spotted during Webb's deepest survey of the young nebula NGC 1333, a star-forming cluster about a thousand light-years away in the Perseus constellation. These planets could teach astronomers a great deal about the formation process of stars and planets.

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-   Most of the rogue planets detected to date were discovered using “gravitational microlensing”, while others were detected via “Direct Imaging”. The former method relies on "lensing events," where the gravitational force of massive objects alters the curvature of spacetime around them and amplifies light from more distant objects. The latter consists of spotting brown dwarfs (objects that straddle the line between planets and stars) and massive planets directly by detecting the infrared radiation produced within their atmospheres.

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-  Using data from Webb's Near-Infrared Imager and Slitless Spectrograph (NIRISS), astronomers  measured the spectrum of every object in the observed portion of the star cluster. This allowed them to reanalyze spectra from 19 previously observed brown dwarfs and led to the discovery of a new brown dwarf with a planetary-mass companion.

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-   This latter observation was a rare find that already challenges theories of how binary systems form. But the real kicker was the detection of six planets with five to 10 times the mass of Jupiter.  This means these six candidates are among the lowest-mass rogue planets ever found that formed through the same process as brown dwarfs and stars.

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-   The fact that Webb's observations revealed no objects lower than five Jupiter masses (which it is sensitive enough to detect) is a strong indication that stellar objects lighter than are more likely to form the way planets do.

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-     The most intriguing of the rogue planets was also the lightest: an estimated five Jupiter masses (about 1,600 Earths). Since dust and gas generally fall into a disk during the early stages of star formation, the presence of this debris ring around the one planet strongly suggests that it formed in the same way stars do.

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-   However, planetary systems also form from debris disks (circumsolar disks), which suggests that these objects may be able to form their own satellites. This suggests that these massive planets could be a nursery for a miniature planet system like our solar system, but on a much smaller scale.

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-    These observations confirm that nature produces planetary mass objects in at least two different ways, from the contraction of a cloud of gas and dust, the way stars form, and in disks of gas and dust around young stars, as Jupiter in our own solar system did.

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-    The new Webb observations indicate that such bodies account for about 10% of celestial bodies in the targeted cluster.  Current estimates place the number of stars in our galaxy between 100 and 400 billion stars and the number of planets between 800 billion and 3.2 trillion. At 10%, that would suggest that there are anywhere from 90 to 360 billion rogue worlds floating out there.

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September 2, 2024      ROGUE  PLANETS  -   roaming free of a star's gravity?        4547

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

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--------------------- ---  Tuesday, September 3, 2024  ---------------------------------