They've had my already limited bandwidth in a chokehold since yesterday
NASA Astronomy Picture of the Day
Oct 10, 2023
Hidden Orion from Webb
The Great Nebula in Orion has hidden stars. To the unaided eye in visible light, it appears as a small fuzzy patch in the constellation of Orion. But this image was taken by the Webb Space Telescope in a representative-color composite of red and very near infrared light. It confirms with impressive detail that the Orion Nebula is a busy neighborhood of young stars, hot gas, and dark dust. The rollover image shows the same image in representative colors further into the near infrared. The power behind much of the Orion Nebula (M42) is the Trapezium - a cluster of bright stars near the nebula's center. The diffuse and filamentary glow surrounding the bright stars is mostly heated interstellar dust. Detailed inspection of these images shows an unexpectedly large number of Jupiter-Mass Binary Objects (JuMBOs), pairs of Jupiter-mass objects which might give a clue to how stars are forming. The whole Orion Nebula cloud complex, which includes the Horsehead Nebula, will slowly disperse over the next few million years.
https://apod.nasa.gov/apod/astropix.html?
Third space station leak in a year prompts doubts about Russia’s programme
Mon 9 Oct 2023 17.42 EDT
The Russian segment of the International Space Station (ISS) has sprung its third coolant leak in under a year, raising new questions about the reliability of the country’s space programme even as officials said crew members were not in danger.
Flakes of frozen coolant spraying into space were seen in an official live feed of the orbital lab provided by Nasa on Monday, and confirmed in radio chatter between US mission control and astronauts.
“The Nauka module of the Russian segment of the ISS has suffered a coolant leak from the external (backup) radiator circuit, which was delivered to the station in 2012,” Russian space agency Roscosmos said on Telegram, adding temperatures remained normal in the affected unit.
Nauka, which means “science” in Russian and is also known as the Multipurpose Laboratory Module-Upgrade (MLM), launched in 2021.
US mission control in Houston could be heard asking astronauts on the American side to investigate.
“Hi, we’re seeing flakes outside, we need a crew to go to the cupola, we think windows five or six, and confirm any visual flakes,” an official said to the astronauts.
“There’s a leak coming from the radiator on MLM,” Jasmin Moghbeli replied later.
This is the third coolant leak to hit the Russian side of the ISS in less than a year. On 15 December 2022, dramatic Nasa TV images showed white particles resembling snowflakes streaming out of the rear of a docked Soyuz MS-22 spacecraft for several hours.
Speculation about the cause centred on an unlucky strike by a tiny space rock, or micro-meteor.
That spaceship returned to Earth uncrewed, and then another uncrewed Soyuz was sent to replace it a few months later. Two Russians and an American crew member had to stay for a year-long mission as a result, returning home only last month.
A similar leak in mid-February also affected the Russian Progress MS-21 cargo ship, which had been docked to the ISS since October 2022.
The succession of leaks lowers the probability they were caused by meteorites.
Space analyst Jonathan McDowell told AFP: “You’ve got three coolant systems leaking – there’s a common thread there. One is whatever, two is a coincidence, three is something systemic,” he said, speculating that a subcontractor company may be at fault.
“It really just emphasises the degrading reliability of Russian space systems. When you add it to the context of their failed moon probe in August, they’re not looking great.”
The Russian space sector, which has historically been the pride of the country, has been facing difficulties for years, between lack of funding, failures and corruption scandals.
The ISS is one of the few areas of continuing cooperation between Moscow and Washington since the start of the Russian offensive in Ukraine and the international sanctions that followed.
https://www.theguardian.com/science/2023/oct/09/leak-from-international-space-station-poses-no-danger-to-crew-says-russia
Space insurers brace for more claims after propulsion trouble on four GEO satellites
October 9, 2023
Propulsion problems on four satellites using the same kind of power modules are expected to result in at least $50 million in claims for insurers already facing more than $800 million in losses this year following two major spacecraft failures.
According to multiple insurance sources, Yahsat’s Al Yah 3, Avanti Communications’ Hylas 4, and Northrop Grumman’s two Mission Extension Vehicles (MEV-1 and MEV-2) are operating with reduced power to their thrusters following a problem with onboard Power Processing Units (PPUs).
The PPUs from Aerojet Rocketdyne provide the electrical power their thrusters need for station-keeping in geostationary orbit (GEO). One of the sources said Al Yah 3, Hylas 4, and MEV-2 have each lost one of two onboard PPUs since the issue emerged in 2022. The youngest of these spacecraft, MEV-2, launched in 2020.
While reducing the voltage remaining PPUs supply thrusters appears to have stopped the power modules from failing altogether, insurers say the workaround will have some impact on their 15-year design life.
Mary Engola, a spokesperson for space propulsion and power systems at Aerojet Rocketdyne — recently sold to L3Harris — referred questions to Northrop Grumman, which built the satellites based on its Orbital ATK-heritage GEOStar-3 platform. Northrop Grumman spokesperson Jessica Kershaw declined to comment.
All four affected spacecraft were built at Northrop Grumman’s facility in Dulles, Virginia, and launched to geostationary orbit between 2018 and 2020. The PPU problem only affects satellites built using the hybrid chemical-and-electric version of the GEOStar-3 satellite bus.
UAE-based Yahsat did not respond to requests for comment about the health of Al Yah 3, the first satellite built on the GEOStar-3 platform. Al Yah 3 was launched short of its target orbit by an Ariane 5 rocket in January 2018, requiring the satellite to burn through fuel reserves to get back on track in an initial hit to its service life.
Avanti’s Hylas 4 launched in April 2018 on an Ariane 5. An Avanti spokesperson said all of the British operator’s satellites “are healthy and operating normally” but would not elaborate.
An insurance source said the expected reduction in service life for Hylas 4 is not enough to trigger an insurance claim.
Northrop Grumman’s MEV-1 and MEV-2 were launched in 2019 and 2020, respectively, and are currently extending the missions of two separate Intelsat satellites they are attached to in GEO.
Operating under Northrop Grumman’s SpaceLogistics in-orbit-servicing subsidiary, the MEVs are using their onboard propulsion so their fuel-drained clients can maintain station-keeping.
MEV-1 and MEV-2 docked with Intelsat 901 and Intelsat 10-02 in 2020 and 2021, respectively, and are under contract with these satellites for five years before undocking to serve other customers that SpaceLogistics has yet to announce.
“We don’t anticipate any changes to the MEV missions for Intelsat,” Intelsat spokesperson Melissa Longo said.
David Todd, head of space content at analysis firm Seradata, told SpaceNews the MEV issue is likely to result in a $50 million insurance claim. Yahsat made a claim of around $115 million for Al Yah-3’s earlier launch issue, he added, which would likely reduce a payout resulting from its PPU trouble.
Some insurers will add the PPU claims to the roughly $300 million in losses racked up last year for accounting reasons, which would still result in a profit for 2022.
This year is a different story. Insurers expect total loss claims totaling $770 million from just ViaSat-3 Americas and Inmarsat-6 F2 alone, in addition to $40 million from Arcturus, and around $25 million from Azersky/Spot-7.
One insurer said the Capella Space radar imaging satellite lost in a Rocket Lab Electron launch failure Sept. 19 will also likely result in a claim of around $5 million, and that a payload from remote sensing firm Changguang Satellite Technology on the Chinese Ceres-1 rocket that failed Sept. 21 was also insured.
Capella spokesperson Sarah Preston confirmed the company’s Acadia 2 satellite was insured but declined to comment on the amount.
Insurers had at one point expected $550 million in total premium income in 2023 — which could be reduced if launches are delayed, meaning the market is on track for a heavy loss for the year.
While many claims are still being finalized, the space insurance market has not seen this level of potential annual losses for two decades, and sources say several underwriters are considering withdrawing from the sector in a move that would reduce capacity for covering sizable risks.
https://spacenews.com/space-insurers-brace-for-more-claims-after-propulsion-trouble-on-four-geo-satellites/
New Gaia release reveals rare lenses, cluster cores and unforeseen science
Oct 10, 2023
Today, ESA's Gaia mission releases a goldmine of knowledge about our galaxy and beyond. Among other findings, the star surveyor surpasses its planned potential to reveal half a million new and faint stars in a massive cluster, identify over 380 possible cosmic lenses, and pinpoint the positions of more than 150 000 asteroids within the Solar System.
Gaia is mapping our galaxy and beyond in extraordinary multi-dimensional detail, completing the most accurate stellar census ever. The mission is painting a detailed picture of our place in the Universe, enabling us to better understand the diverse objects within it.
The mission’s latest ‘focused product release’ builds further on this, providing many new and improved insights into the space around us. The release brings exciting and unexpected science: findings that go far beyond what Gaia was initially designed to discover and dig deep into our cosmic history.
So – what’s new from Gaia?
Half a million new stars: Gaia's observing mode extended to unlock cluster cores
Gaia’s third data release (DR3) contained data on over 1.8 billion stars, building a pretty complete view of the Milky Way and beyond. However, there remained gaps in our mapping. Gaia had not yet fully explored areas of sky that were especially densely packed with stars, leaving these comparatively unexplored – and overlooking stars shining less brightly than their many neighbours.
Globular clusters are a key example of this. These clusters are some of the oldest objects in the Universe, making them especially valuable to scientists looking at our cosmic past. Unfortunately, their bright cores, chock-full of stars, can overwhelm telescopes attempting to get a clear view. As such, they remain missing jigsaw pieces in our maps of the Universe.
To patch the gaps in our maps, Gaia selected Omega Centauri, the largest globular cluster that can be seen from Earth and a great example of a ‘typical’ cluster. Rather than just focusing on individual stars, as it typically would, Gaia enabled a special mode to truly map a wider patch of sky surrounding the cluster’s core every time the cluster came into view.
"In Omega Centauri, we discovered over half a million new stars Gaia hadn't seen before – from just one cluster!" says lead author Katja Weingrill of the Leibniz-Institute for Astrophysics Potsdam (AIP), Germany, and a member of the Gaia collaboration.
"It’s not just patching up holes in our mapping, although this is valuable in itself," adds co-author and Gaia Collaboration member Alexey Mints, also of the AIP. "Our data allowed us to detect stars that are too close together to be properly measured in Gaia's regular pipeline. With the new data we can study the cluster’s structure, how the constituent stars are distributed, how they’re moving, and more, creating a complete large-scale map of Omega Centauri. It’s using Gaia to its full potential – we’ve deployed this amazing cosmic tool at maximum power."
This finding not only meets but actually exceeds Gaia’s planned potential. The team used an observing mode designed to ensure that all of Gaia’s instruments are running smoothly. "We didn’t expect to ever use it for science, which makes this result even more exciting," adds Katja.
The new stars revealed in Omega Centauri mark one of the most crowded regions explored by Gaia so far.
Gaia is currently exploring eight more regions in this way, with the results to be included in Gaia Data Release 4. These data will help astronomers to truly understand what is happening within these cosmic building blocks, a crucial step for scientists aiming to confirm the age of our galaxy, locate its centre, figure out whether it has gone through any past collisions, verify how stars change through their lifetimes, constrain our models of galactic evolution, and ultimately infer the possible age of the Universe itself.
Looking for lenses: Gaia the accidental cosmologist
While Gaia was not designed for cosmology, its new findings peer deep into the distant Universe, hunting for elusive and exciting objects that hold clues to some of humanity’s biggest questions about the cosmos: gravitational lenses.
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"Gaia is a real lens-seeker," says co-author Christine Ducourant of Laboratoire d’Astrophysique de Bordeaux, France, and a member of the Gaia collaboration. "Thanks to Gaia, we’ve found that some of the objects we see aren’t simply stars, even though they look like them. They’re actually really distant lensed quasars – extremely bright, energetic galactic cores powered by black holes. We now present 381 solid candidates for lensed quasars, including 50 that we deem highly likely: a goldmine for cosmologists, and the largest set of candidates ever released at once."
The team identified the candidates from an extensive list of possible quasars (including those from Gaia DR3). Five of the possible lenses are potential Einstein crosses, rare lensed systems with four different image components shaped like a cross. (See 12 such configurations discovered by Gaia in 2021.)
Finding lensed quasars is challenging. A lensed system’s constituent images can clump together on the sky in misleading ways, and most are very far away, making them faint and tricky to spot.
"The great thing about Gaia is that it looks everywhere, so we can find lenses without needing to know where to look,” adds co-author Laurent Galluccio of Université Côte d’Azur, France, and member of the Gaia collaboration. “With this data release, Gaia is the first mission to achieve an all-sky survey of gravitational lenses at high resolution."
Extending Gaia’s value into cosmology brings synergy with ESA’s Euclid mission, recently launched on its quest to explore the dark Universe. While both focus on different parts of the cosmos – Euclid on mapping billions of galaxies, Gaia on mapping billions of stars – the lensed quasars discovered by Gaia can be used to guide future exploration with Euclid.
Asteroids, stacked starlight and pulsating stars
Other papers published today offer further insight into the space around us, and the diverse and sometimes mysterious objects within it.
One reveals more about 156 823 of the asteroids identified as part of Gaia DR3. The new dataset pinpoints the positions of these rocky bodies over nearly double the previous timespan, making most of their orbits – based on Gaia observations alone – 20 times more precise. In the future, Gaia DR4 will complete the set and include comets, planetary satellites and double the number of asteroids, improving our knowledge of the small bodies in nearby space.
Another paper maps the disc of the Milky Way by tracing weak signals seen in starlight, faint imprints of the gas and dust that floats between the stars. The Gaia team stacked six million spectra to study these signals, forming an incredibly large dataset of weak features that have never before been measured in such a large sample. The dataset will hopefully allow scientists to finally narrow down the source of these signals, which the team suspects to be a complex organic molecule. Knowing more about where this signal comes from helps us to study the complex and intertwined physical and chemical processes active throughout our galaxy, and to understand more about the material lying between stars.
Last but by no means least, a paper characterises the dynamics of 10 000 pulsating and binary red giant stars in by far the largest such database available to date. These stars were part of a catalogue of two million variable star candidates released in Gaia DR3, and are key when calculating cosmic distances, confirming stellar characteristics, and clarifying how stars evolve throughout the cosmos. The new release provides a better understanding of how these fascinating stars change over time.
"This data release further demonstrates Gaia’s broad and fundamental value – even on topics it wasn’t initially designed to address," says Timo Prusti, Project Scientist for Gaia at ESA.
"Although its key focus is as a star surveyor, Gaia is exploring everything from the rocky bodies of the Solar System to multiply imaged quasars lying billions of light-years away, far beyond the edges of the Milky Way. The mission is providing a truly unique insight into the Universe and the objects within it, and we’re really making the most of its broad, all-sky perspective on the skies around us."
The next steps
Gaia’s previous Data Release, Gaia DR3, came on 13 June 2022. It was the most detailed survey of the Milky Way to date, and a treasure trove of data on strange ‘starquakes’, asymmetrically moving stars, stellar DNA and more. Gaia DR3 contained new and improved details for almost two billion stars in the Milky Way, and included the largest catalogues of binary stars, thousands of Solar System objects, and – more distantly and outside of our galaxy – millions of galaxies and quasars.
https://www.esa.int/Science_Exploration/Space_Science/Gaia/New_Gaia_release_reveals_rare_lenses_cluster_cores_and_unforeseen_science
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