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NASA Astronomy Picture of the Day
November 26, 2024
The Sombrero Galaxy from Webb and Hubble
This floating ring is the size of a galaxy. In fact, it is a galaxy – or at least part of one: the photogenic Sombrero Galaxy is one of the largest galaxies in the nearby Virgo Cluster of Galaxies. The dark band of dust that obscures the mid-section of the Sombrero Galaxy in visible light (bottom panel) actually glows brightly in infrared light (top panel). The featured image shows the infrared glow in false blue, recorded recently by the space-based James Webb Space Telescope (JWST) and released yesterday, pictured above an archival image taken by NASA's Hubble Space Telescope in visible light. The Sombrero Galaxy, also known as M104, spans about 50,000 light years and lies 28 million light years away. M104 can be seen with a small telescope in the direction of the constellation Virgo.
https://apod.nasa.gov/apod/astropix.html
https://www.theregister.com/2024/11/25/camp_century_nasa_images/
Abandoned US Army 'city under the ice' imaged in serendipitous NASA find
Mon 25 Nov 2024 23:30
Deep within the ice sheet of Greenland lies a US military secret that hasn't been seen since the 1960s, but a NASA flyover earlier this year has provided an unprecedented look at the buried Cold War relic.
Camp Century, constructed in 1959 by the US Army Corps of Engineers, was built directly into the ice sheet of Greenland, giving it an interior reminiscent of Echo Base on the frozen world of Hoth in The Empire Strikes Back.
At the heart of the facility was the PM-2A portable nuclear reactor, which provided power for the sprawling "city under the ice" that included housing for 200 soldiers, a theater, gym, post exchange, library, and even a chapel.
The camp was ostensibly built as a scientific outpost, and work at the facility did contribute to modern climate models thanks to ice core drilling – but its true purpose was Project Iceworm, the US Army's plan to deploy hundreds of cold-hardened Minuteman nuclear missiles capable of striking the Soviet Union across Greenland's frozen tundra.
That never came to fruition, leading to Camp Century's abandonment in 1967, after which the installation was buried under accumulating ice and snow. Camp Century is now believed to be at least 30 meters, or 100 feet, below the surface.
The only real look at Camp Century over the decades has been via ground-penetrating radar that provided, at best, a two-dimensional confirmation that some of the thousands of feet of tunnels, and whatever contents were left behind, are still down there.
That all changed in April, NASA reported this week, when the space agency's Earth Observatory unexpectedly picked up an anomaly while doing an ice sheet survey using an aircraft equipped with NASA's Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR).
UAVSAR, which in this case was being operated by scientists onboard a Gulfstream III aircraft, has the advantage of shooting radar signals directly downward and at an angle, meaning it's able to produce maps with more dimensionality than typical ground-penetrating radar that only aims straight down.
"We were looking for the bed of the ice and out pops Camp Century," said NASA JPL cryospheric scientist and project co-lead Alex Gardner. "We didn't know what it was at first."
JPL glaciologist and remote sensing specialist Chad Greene noted that the serendipitous image captured by UAVSAR shows individual structures of Camp Century that, when compared to existing layout plans, gives an unprecedented view into the state of the facility after nearly 60 years under the ice.
"Our goal was to calibrate, validate, and understand the capabilities and limitations of UAVSAR for mapping the ice sheet's internal layers and the ice-bed interface," Greene noted.
That said, while UAVSAR has granted new insights into the state of Camp Century, the images aren't perfect. NASA noted that, because of the angular nature of part of the capture, a band on the image makes it look like Century is below the ice bed, which is in reality miles below the ice sheet – far deeper than the ruins of the abandoned facility.
The error is due to the angled radar picking up the ice bed further in the distance, NASA explained.
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Why Camp Century still matters
Because of the imperfections in the UAVSAR image of Camp Century, the image is "a novel curiosity" rather than a useful bit of scientific data, NASA said.
Understanding more about Camp Century's status, its depth under the ice, and the status of the frozen water above it is critical, however, because it contains a lot of nuclear, biological, and chemical waste that the Army wasn't too worried about in the pre-climate change era.
If current climate change trends continue apace, NASA researchers determined in 2011, all the harmful stuff stored under the ice at Camp Century could leach into the surrounding ice well before surface melting begins to show changes.
And there's good reason to worry. There's lots of waste down there. By NASA's estimate, there are around 53,000 gallons of diesel fuel, 6.3 million gallons of waste water, including sewage from the camp's years in service, as well as an unknown quantity of radioactive waste and PCBs.
The Atomic Heritage Foundation estimates the PM-2A reactor may have created more than 47,000 gallons of low-level radioactive waste over its lifetime, and that or more is likely buried beneath the ice too.
Previous 2D radar images of Century show the presence of buried waste material, so scientists know it's there, but without better imaging they can't know if anything has shifted or could begin to leak.
NASA estimates that, by 2090, climate change could cause Greenland's ice sheet to destabilize above Camp Century, but that doesn't account for leaching into the ice before surface changes begin.
Camp Century was closed in 1967 after Project Iceworm, which sought to build thousands of miles of tunnels to deploy 600 missiles, failed due to a determination that Greenland's ice sheet was too unstable to support long-term subterranean facilities.
All that remains to note the presence of the facility today is a project led by the governments of Greenland and Denmark to keep watch on the site from a small outpost above the camp, which is located 150 miles inland from the US Space Force's Pituffik Space Base, formerly known as Thule Air Base, where construction of Camp Century was managed.
"Without detailed knowledge of ice thickness, it is impossible to know how the ice sheets will respond to rapidly warming oceans and atmosphere, greatly limiting our ability to project rates of sea level rise," Gardner said.
Environmental damage from Camp Century may be inevitable as the climate continues to change, likely unabated, unless the world's governments take action.
NASA noted that the flight that captured the new images of Camp Century would "enable the next generation of mapping campaigns in Greenland, Antarctica and beyond," though whether additional passes over Camp Century are planned to better map the facility is unknown.
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SpaceX to launch NASA’s Dragonfly drone mission to Titan
November 25, 2024 3:17 PM
Over the last few years, the Ingenuity helicopter on Mars made history by proving it was possible to fly a rotorcraft on another planet.
And soon NASA will take that concept one step further by launching a drone mission to explore an even more distant world: Saturn’s icy moon of Titan.
The Dragonfly mission is set to explore Titan from the air, its eight rotors keeping it aloft as it moves through the thick atmosphere and passes over the rough, challenging terrain below.
The aim is to look for potential habitability, studying the moon to work out if water-based or hydrocarbon-based life could ever have existed there.
Now, NASA has announced it has chosen a launch provider for this important mission, and it will be SpaceX.
With a $256.6 million contract, SpaceX will launch the rotorcraft using a Falcon Heavy rocket from Launch Complex 39A at NASA’s Kennedy Space Center in Florida, with the launch window open between July 5, 2028, and July 25, 2028.
The Falcon Heavy is SpaceX’s current super heavy launch vehicle, larger than the regularly used Falcon 9 but smaller than the Starship that is currently undergoing testing.
The Falcon Heavy has been used for launching previous NASA missions such as Psyche (an uncrewed mission to visit a metal asteroid) that require more mass than a Falcon 9 supports, but not as much as human spaceflight missions like the Artemis moon missions (which the Starship is intended for).
Though the Dragonfly rotorcraft will be small, it will need a heavy-lift launch vehicle to help it on its long mission to Titan.
As this is such a long distance, the use of a more powerful rocket can shorten the cruise phase in which the spacecraft travels through the solar system, meaning it will arrive at Titan earlier — in this case, the plan is for it to arrive in 2034.
Once Dragonfly arrives at Titan, it will be able to move between different sites on the moon, which is known for its diverse surface features, including rough and smooth areas as well as lakes and seas made of ethane and methane, plains, dunes, and impact craters.
The rotorcraft will use scientific instruments to measure chemistry on the moon to see whether it could have hosted the conditions for life.
“Dragonfly is a spectacular science mission with broad community interest, and we are excited to take the next steps on this mission,” said Nicky Fox, associate administrator of NASA’s Science Mission Directorate earlier this year when the mission was confirmed.
“Exploring Titan will push the boundaries of what we can do with rotorcraft outside of Earth.”
https://www.digitaltrends.com/space/spacex-nasa-dragonfly-launch/
NASA, JAXA XRISM Mission Looks Deeply Into ‘Hidden’ Stellar System
Nov 25, 2024
The Japan-led XRISM (X-ray Imaging and Spectroscopy Mission) observatory has captured the most detailed portrait yet of gases flowing within Cygnus X-3, one of the most studied sources in the X-ray sky.
Cygnus X-3 is a binary that pairs a rare type of high-mass star with a compact companion — likely a black hole.
“The nature of the massive star is one factor that makes Cygnus X-3 so intriguing,” said Ralf Ballhausen, a postdoctoral associate at the University of Maryland, College Park, and NASA's Goddard Space Flight Center in Greenbelt, Maryland.
“It’s a Wolf-Rayet star, a type that has evolved to the point where strong outflows called stellar winds strip gas from the star’s surface and drive it outward. The compact object sweeps up and heats some of this gas, causing it to emit X-rays.”
A paper describing the findings, led by Ballhausen, will appear in a future edition of The Astrophysical Journal.
“For XRISM, Cygnus X-3 is a Goldilocks target — its brightness is ‘just right’ in the energy range where XRISM is especially sensitive,” said co-author Timothy Kallman, an astrophysicist at NASA Goddard.
“This unusual source has been studied by every X-ray satellite ever flown, so observing it is a kind of rite of passage for new X-ray missions.”
XRISM (pronounced “crism”) is led by JAXA (Japan Aerospace Exploration Agency) in collaboration with NASA, along with contributions from ESA (European Space Agency).
NASA and JAXA developed the mission’s microcalorimeter spectrometer instrument, named Resolve.
Observing Cygnus X-3 for 18 hours in late March, Resolve acquired a high-resolution spectrum that allows astronomers to better understand the complex gas dynamics operating there.
These include outflowing gas produced by a hot, massive star, its interaction with the compact companion, and a turbulent region that may represent a wake produced by the companion as it orbits through the outrushing gas.
In Cygnus X-3, the star and compact object are so close they complete an orbit in just 4.8 hours. The binary is thought to lie about 32,000 light-years away in the direction of the northern constellation Cygnus.
While thick dust clouds in our galaxy’s central plane obscure any visible light from Cygnus X-3, the binary has been studied in radio, infrared, and gamma-ray light, as well as in X-rays.
The system is immersed in the star’s streaming gas, which is illuminated and ionized by X-rays from the compact companion.
The gas both emits and absorbs X-rays, and many of the spectrum’s prominent peaks and valleys incorporate both aspects.
Yet a simple attempt at understanding the spectrum comes up short because some of the features appear to be in the wrong place.
That’s because the rapid motion of the gas displaces these features from their normal laboratory energies due to the Doppler effect.
Absorption valleys typically shift up to higher energies, indicating gas moving toward us at speeds of up to 930,000 mph (1.5 million kph).
Emission peaks shift down to lower energies, indicating gas moving away from us at slower speeds.
Some spectral features displayed much stronger absorption valleys than emission peaks.
The reason for this imbalance, the team concludes, is that the dynamics of the stellar wind allow the moving gas to absorb a broader range of X-ray energies emitted by the companion.
The detail of the XRISM spectrum, particularly at higher energies rich in features produced by ionized iron atoms, allowed the scientists to disentangle these effects.
“A key to acquiring this detail was XRISM’s ability to monitor the system over the course of several orbits,” said Brian Williams, NASA’s project scientist for the mission at Goddard.
“There’s much more to explore in this spectrum, and ultimately we hope it will help us determine if Cygnus X-3’s compact object is indeed a black hole.”
https://science.nasa.gov/missions/xrism/nasa-jaxa-xrism-mission-looks-deeply-into-hidden-stellar-system/
NASA Invites Media to Firefly Blue Ghost Mission 1 Launch to Moon
Nov 25, 2024
Media accreditation is open for the next delivery to the Moon through NASA’s CLPS (Commercial Lunar Payload Services) initiative and Artemis campaign for the benefit of humanity.
A six-day launch window opens no earlier than mid-January 2025 for the first Firefly Aerospace launch to the lunar surface.
The Blue Ghost flight, carrying 10 NASA science and technology instruments, will launch on a SpaceX Falcon 9 rocket from Launch Complex 39A at the agency’s Kennedy Space Center in Florida.
Media prelaunch and launch activities will take place at NASA Kennedy.
Attendance for this launch is open to U.S. citizens and international media. International media must apply by Monday, Dec. 9, and U.S. media must apply by Thursday, Jan. 2.
Media interested in participating in launch activities must apply for credentials at:
https://media.ksc.nasa.gov
The company named the mission Ghost Riders in the Sky. It will land near a volcanic feature called Mons Latreille within Mare Crisium, a more than 300-mile-wide basin located in the northeast quadrant of the lunar near side.
The mission will carry NASA investigations and first-of-their-kind technology demonstrations to further our understanding of the Moon’s environment and help prepare for future human missions to the lunar surface, as part of the agency’s Moon to Mars exploration approach.
This includes payloads testing lunar subsurface drilling, regolith sample collection, global navigation satellite system abilities, radiation tolerant computing, and lunar dust mitigation.
The data captured also benefits humanity by providing insights into how space weather and other cosmic forces impact Earth.
Under the CLPS model, NASA is investing in commercial delivery services to the Moon to enable industry growth and support long-term lunar exploration.
As a primary customer for CLPS deliveries, NASA aims to be one of many customers on future flights.
https://www.nasa.gov/news-release/nasa-invites-media-to-firefly-blue-ghost-mission-1-launch-to-moon/
Spacetech startup TakeMe2Space to launch AI lab in space in December
Nov 26, 2024, 07:39:00 PM IST
A Hyderabad-based startup is set to launch an artificial intelligence lab in space on board ISRO's PSLV rocket next month, the company said here on Tuesday.
TakeMe2Space, a space technology firm based in Hyderabad, said its 'Orbital Infrastructure - Technology Demonstrator'(MOI-TD), billed as India's first AI lab in space, will demonstrate real-time data processing in orbit, making space research more affordable and accessible.
The MOI-TD launch is scheduled for mid-December aboard ISRO's PSLV C60 mission.
Satellites capture petabytes of data daily, of which up to 40 per cent is potentially unusable due to cloud cover or other factors, which has to be transmitted to Earth for processing.
By processing data directly in space, MOI-TD delivers the relevant insights to users, drastically lowering both the cost of data transmission and latency, said Ronak Kumar Samantray, founder and CEO of TakeMe2Space.
Users can access the satellite platform through OrbitLab, a web-based console to upload AI models for applications such as environmental monitoring, deforestation tracking, maritime activity observation, greenhouse gas emission detection and custom earth observation use cases.
The satellite-as-a-service platform has already secured its inaugural research partners, including a leading Malaysian university and an enterprising group of 9th and 10th graders from an Indian school, demonstrating the potential for democratising space research.
The mission represents a significant step towards building data centres in space, the company said.
While the current mission focuses on Earth observation applications, the technology paves the way for future space-based computing capabilities that could support a wide range of applications, similar to current cloud computing services.
All testing and evaluation of the MOI-TD platform was facilitated by the IN-SPACe Technical Center. IN-SPACe, the single window government agency for all space sector activities of private entities, played a key role in accelerating the development of the platform.
MOI-TD includes control software and hardware components, including reaction wheels, magnetorquers, an advanced onboard computer, and an AI accelerator.
The satellite also features flexible solar cells that could power future satellites, a company statement said.
https://economictimes.indiatimes.com/tech/startups/spacetech-startup-takeme2space-to-launch-ai-lab-in-space-in-december/articleshow/115701888.cms
Sidus Space Announces LizzieSat™-2 Ready for Launch
November 26, 2024 at 5:30 AM PST
Sidus Space (NASDAQ: SIDU) (the "Company" or "Sidus"), an innovative, agile space mission enabler, announced the successful completion of the launch processing of LizzieSat™-2 at the Astrotech Space Operations facility at Vandenberg Space Force Base in California.
LizzieSat™-2 has been turned over to SpaceX and is ready for launch on the Bandwagon-2 rideshare mission, which is targeted for no earlier than December of 2024.
LizzieSat™-2 was designed and manufactured at Sidus Space’s state-of-the-art facility on Florida’s Space Coast.
The satellite is equipped with an advanced sensor suite that includes AIS, multi-spectral methane detection, and high-resolution visual spectrum sensors, as well as the HEO Holmes Imager, provided by HEO (USA), a subsidiary of Australian-based HEO.
The Holmes Imager is a cutting-edge technology that powers HEO Inspect, an in-orbit satellite inspection platform designed for non-Earth imaging (NEI) and the precise characterization of space objects.
LizzieSat™-2 will provide data through a monthly subscription contract for HEO, further demonstrating Sidus Space’s role as a leading provider of multi-mission space-based data solutions.
Leveraging Sidus’ proprietary FeatherEdge™ AI processor, LizzieSat™-2 will enable on-orbit data processing for actionable insights, supporting applications such as Space Situational Awareness (SSA), non-Earth Imaging, maritime monitoring, environmental assessments and disaster response.
"LizzieSat™-2 represents the next evolution of our modular satellite platform, showcasing its adaptability to host both Sidus-developed sensors and customer payloads, such as the HEO Holmes Imager," said Carol Craig, CEO of Sidus Space.
"This milestone highlights our commitment to delivering innovative, flexible and cost-effective solutions that address the diverse and evolving needs of our customers.
We are excited to expand our on-orbit presence and delivery of critical, near real-time data services."
The launch of LizzieSat™-2 marks a significant step in Sidus Space’s mission to expand its on-orbit presence, enabling the company to better serve its customers with scalable, real-time space-based data solutions.
By integrating advanced sensor technology, leveraging on-orbit processing and offering data-as-a-service capabilities, LizzieSat™-2 is designed to provide actionable insights that support applications across government, defense, intelligence and commercial sectors worldwide.
https://finance.yahoo.com/news/sidus-space-announces-lizziesat-2-133000456.html
Physicists Just Found a Quirk in Einstein's Predictions of Space-Time
26 November 2024
The fabric of space and time is not exempt from the effects of gravity. Plop in a mass and space-time curves around it, not dissimilar to what happens when you put a bowling ball on a trampoline.
This dimple in space-time is the result of what we call a gravity well, and it was first described over 100 years ago by Albert Einstein's field equations in his theory of general relativity.
To this day, those equations have held up. We'd love to know what Einstein was putting in his soup. Whatever it was, general relativity has remained pretty solid.
One of the ways we know this is because when light travels along that curved space-time, it curves along with it.
This results in light that reaches us all warped and stretched and replicated and magnified, a phenomenon known as gravitational lensing.
This quirk of space-time is not only observable and measurable, it's an excellent tool for understanding the Universe.
But a team of researchers has just found that the predicted curvature of space-time calculated using relativity does not always quite match up to what we observe, using data from the Dark Energy Survey that is currently mapping hundreds of millions of galaxies across the cosmos.
That doesn't mean there's something broken – but it does suggest that there may be something out there that we haven't accounted for.
"Until now, Dark Energy Survey data have been used to measure the distribution of matter in the Universe," explains physicist Camille Bonvin of the University of Geneva in Switzerland.
"In our study, we used this data to directly measure the distortion of time and space, enabling us to compare our findings with Einstein's predictions."
The Dark Energy Survey is an international collaboration that employs a powerful optical instrument mounted on the 4-meter Victor M. Blanco Telescope at the Cerro Tololo Inter-American Observatory in Chile.
Its main mission, as the name suggests, is to study dark energy, the mysterious force that drives the accelerating expansion of the Universe.
To do this, the instrument has been surveying the Universe as deeply as it possibly can. This means that it sees light across a range of epochs, peering deep into the history of the Universe to galaxies whose light has traveled for billions of years to reach us.
Led by astronomer Isaac Tutusaus of the University of Toulouse in France, a team of researchers realized they could use this wealth of data to test the predictive power of Einstein's physical description of the Universe.
They specifically measured the distortions of space-time due to gravity wells, at four distinct epochs: approximately 3.5 billion years ago, 5 billion years ago, 6 billion years ago, and 7 billion years ago.
Then, they compared these measurements to what Einstein's equations predict they should be. Interestingly, some of the measurements aligned neatly with the predictions – but not all of them.
"We discovered that in the distant past – 6 and 7 billion years ago – the depth of the wells aligns well with Einstein's predictions," Tutusaus explains.
"However, closer to today, 3.5 and 5 billion years ago, they are slightly shallower than predicted by Einstein."
The discrepancy is slight, but it could be important. It could mean, for example, that gravity wells have a slower growth rate more recently in the Universe.
In addition, measurements of the expansion of space-time suggest that the growth of the Universe is speeding up, and has accelerated more in the recent past.
The discrepancy could, therefore, suggest a link between the acceleration of the Universe driven by dark energy and the slow growth of gravity wells during the same epoch. More observations will need to be conducted to confirm, and add to, the team's findings.
"Our results show that Einstein's predictions have an incompatibility of 3 sigma with measurements. In the language of physics, such an incompatibility threshold arouses our interest and calls for further investigations," says physicist Natassia Grimm of the University of Geneva.
"But this incompatibility is not large enough, at this stage, to invalidate Einstein's theory. For that to happen, we would need to reach a threshold of 5 sigma.
It is therefore essential to have more precise measurements to confirm or refute these initial results, and to find out whether this theory remains valid in our Universe, at very large distances."
https://www.sciencealert.com/physicists-just-found-a-quirk-in-einsteins-predictions-of-space-time
https://www.nature.com/articles/s41467-024-53363-6
Solar maximum just knocked 3 satellites out of orbit. Here's why more may be on the way.
November 25, 2024
In early November, three tiny Australian satellites from Curtin University's Binar Space Program burned up in Earth's atmosphere.
That was always going to happen. In fact, Binar means "fireball" in the Noongar language of the First Nations people of Perth.
When a satellite is in low Earth orbit (2,000km or less), it experiences orbital decay as it drags closer and closer to the surface, eventually burning up.
But these cube satellites (CubeSats), known as Binar-2, 3 and 4, entered the atmosphere much sooner than originally planned. They only lasted for two months — a third of what was expected.
This significantly reduced valuable time for science and testing new systems.
The reason for their untimely demise? Our Sun has kicked into high gear, and the Binar satellites are far from the only casualty.
Recent high solar activity has been causing an unexpected headache for satellite operators in the last few years, and it's only increasing.
Solar activity includes phenomena such as sunspots, solar flares and solar wind — the stream of charged particles that flows toward Earth.
This activity is a product of the Sun's ever-changing magnetic field, and approximately every 11 years, it completely flips. At the midpoint of this cycle, solar activity is at its highest.
While this cycle is known, specific solar activity is challenging to predict — the dynamics are complex and solar forecasting is in its infancy.
In the last few months, indicators of solar activity were more than one and a half times higher than predictions for this point in the current cycle, labelled solar cycle 25.
What happened to Binar?
The Binar Space Program is a satellite research program operating out of Curtin University. It aims to advance our understanding of the Solar System and lower the barrier for operating in space.
The program began operations with its first satellite, Binar-1, in September 2021. This was less than a year into solar cycle 25 when solar activity was relatively low.
In these conditions, the ten-centimetre cube satellite started at an altitude of 420km and survived a full 364 days in orbit.
The program's follow-up mission — Binar-2, 3, and 4 — were three equally sized CubeSats. However, they were expected to last approximately six months owing to the extra surface area from new deployable solar arrays and a forecast increase in solar activity.
Instead, they only made it to two months before burning up. While cube satellite missions are relatively cheap, the premature ending of a mission will always be costly.
This is even more true for commercial satellites, highlighting the need for more accurate space weather forecasting.
The good news is the Sun will calm down again. Despite the current unexpectedly high solar activity, it will likely slow down by 2026, and is expected to return to a solar minimum in 2030.
While this was not an explicit goal of the mission, the Binar Space Program has now poignantly demonstrated the dramatic effects of solar activity on space operations.
While the untimely loss of Binar-2, 3 and 4 was unfortunate, work has already begun on future missions. They are expected to launch into far more forgiving space weather.
https://www.livescience.com/space/the-sun/solar-maximum-just-knocked-3-satellites-out-of-orbit-heres-why-more-may-be-on-the-way
Scientists detect the most powerful cosmic rays ever — and their unknown source could be close to Earth
November 25, 2024
Scientists have detected the most energetic cosmic rays ever discovered, and they're being produced by mysterious sources relatively close to Earth.
The rays — which consist of electrons and their antimatter counterparts, positrons — were observed at energies all the way up to 40 teraelectronvolts (TeV), or 40,000 times the energy of visible light.
Spotted by the High Energy Stereoscopic System (HESS) observatory in Namibia, the rays lose energy as they travel through space due to their interactions with light and magnetic fields.
This means that for rays of this energy to be detected, their sources must be relatively nearby. Yet what, exactly, is producing them remains unknown. The researchers published their findings Nov. 25 in the journal Physical Review Letters.
"This is an important result, as we can conclude that the measured CRe [cosmic ray electrons] most likely originate from very few sources in the vicinity of our own solar system, up to a maximum of a few 1000 light years away, a very small distance compared to the size of our Galaxy," corresponding author Kathrin Egberts, head of experimental astroparticle physics at the University of Potsdam in Germany, said in a statement. (For comparison, the Milky Way is about 100,000 light-years across.)
Cosmic rays are high-energy particles produced by the sun; stellar explosions called supernovas; rapidly spinning neutron stars called pulsars; and other, unknown sources.
When the rays smash into Earth's upper atmosphere, they break into showers of particles that are detectable on Earth's surface. But reconstructing the rays that produced these particle showers is a painstaking and uncertain task.
To find the cosmic ray electrons, the researchers used the HESS observatory, an array of five 40-foot (12 meters) telescopes in the Khomas Highland of Namibia.
Over a decade, the telescopes scanned the upper atmosphere for faint signs of Cherenkov radiation left in the wake of the fast-moving rays.
Just as a plane traveling faster than the speed of sound creates a sonic boom, a particle moving through a light-slowing medium faster than light creates a faint blue glow around it.
By looking for this glow and using sophisticated algorithms to sift out noise, the scientists created an energy spectrum for the rays hitting Earth in unprecedented detail.
The quantities of these rays decreased drastically at higher energy scales — meaning it will be difficult for smaller space-based detectors to find them in sufficient numbers.
Yet the presence of particularly energetic particles gave the scientists a clear indication that at least some of the rays' sources are close to our planet.
"The very low fluxes at larger TeV limit the possibilities of space-based missions to compete with this measurement," corresponding author Mathieu de Naurois, a researcher at the French National Centre for Scientific Research in Paris, said in the statement.
"Thereby, our measurement does not only provide data in a crucial and previously unexplored energy range, impacting our understanding of the local neighbourhood, but it is also likely to remain a benchmark for the coming years."
https://www.livescience.com/space/scientists-detect-the-most-powerful-cosmic-rays-ever-and-their-unknown-source-could-be-close-to-earth
https://www.eurekalert.org/news-releases/1064916
SpaceX Starlink Mission
November 26, 2024
SpaceX is targeting Tuesday, November 26 for a Falcon 9 launch of 24 Starlink satellites, to low-Earth orbit from Launch Complex 39A (LC-39A) at NASA’s Kennedy Space Center in Florida.
The 3-hour launch window opens at 10:05 p.m. ET. If needed, a backup opportunity is available on Wednesday, November 27 starting at 9:39 p.m. ET.
A live webcast of this mission will begin about five minutes prior to liftoff, which you can watch here and on X @SpaceX.
You can also watch the webcast on the new X TV app.
This is the 15 flight for the first stage booster supporting this mission, which previously launched mPOWER-B, BlueBird-1, USSF-124, Crew-6, and 10 Starlink missions.
Following stage separation, the first stage will land on the A Shortfall of Gravitas droneship, which will be stationed in the Atlantic Ocean.
https://www.spacex.com/launches/mission/?missionId=sl-6-76