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Sigmetnow

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Re: Astronomical news
« Reply #350 on: August 18, 2020, 07:53:34 PM »
Northrop Grumman just launched its second satellite rescue mission
Loren Grush Aug 17, 2020
Quote
On Saturday, a Northrop Grumman spacecraft, designed to give a dying satellite a new lease on life, launched into space. Its objective is to latch onto an aging satellite that’s been in space for 16 years and prolong the old robot’s life in orbit by giving it a new set of engines and fuel.

The spacecraft is named MEV-2, for Mission Extension Vehicle 2. MEV-2’s predecessor was the groundbreaking MEV-1 satellite, which launched in October 2019. MEV-1 made history in February when it successfully grabbed hold of another satellite already in orbit, marking the first time that two commercial satellites had docked in space. MEV-1’s target was an out-of-commission communications satellite called Intelsat 901, which has been in space for nearly 20 years. After docking with Intelsat 901, MEV-1 nudged the satellite into a new orbit, allowing the spacecraft to start operating again and extending its life for at least five more years.

MEV-2 will try a few new things during its time in space
MEV-1 successfully demonstrated a concept known as satellite servicing — an emerging industry that is focused on sending handy satellites into space in order to fix, repair, or upgrade other satellites already in orbit. Now, with MEV-2, Northrop Grumman is going to try again. “It’s very similar,” Joe Anderson, vice president of operations and business development at Space Logistics, a wholly owned subsidiary of Northrop Grumman that oversees the MEV missions, tells The Verge. “MEV-2 is essentially a carbon copy of MEV-1 from a design standpoint.”

However, MEV-2 will try a few new things during its time in space. For one thing, it’s targeting a different type of satellite than the one MEV-1 wrangled. Intelsat 901 was no longer functioning and was located in an orbit above Earth often referred to as the “graveyard orbit.” Satellites orbiting many thousands of miles above the planet are moved to the graveyard orbit when they run out of fuel so that they don’t get in anyone’s way when they become inoperable. MEV-1 plucked Intelsat 901 out of the graveyard orbit and put it back in a coveted region known as geosynchronous orbit — a path above Earth where satellites match the rotation of the planet and seemingly hover over the same patch of sky at all times. The geosynchronous belt is a fairly critical orbit for satellites, home to many communications and Earth-observing probes.

““We will simply dock to them, and then take over the orbit and attitude control.”” …

Anderson says that these satellite servicing missions are a “business growth area” for Space Logistics and Northrop Grumman. Moving forward, the company is focusing on a new type of servicer called the Mission Robotic Vehicle, or MRV, which should take satellite tune-ups to a whole new level. Thanks to a partnership with DARPA, MRV will be able to do what the MEV satellites can do, but it will also be able to attach “pods” onto satellites that provide propulsion on their own, extending the life of a satellite by up to six years. Anderson notes the MRV will really be a multiservice satellite, capable of doing various types of repairs apart from providing extra propulsions. “That robotic vehicle can do other types of services such as detailed inspections, full repair missions,” he says. “So if someone has a stuck solar array, or antenna, for example, we may be able to use our robotic system to do those deployments. It can also grab onto the client vehicles and tug them and relocate them to other orbits as well.” …
https://www.theverge.com/2020/8/17/21366674/northrop-grumman-space-logistics-mev-2-satellite-servicing-life-extension
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Sigmetnow

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Re: Astronomical news
« Reply #351 on: August 19, 2020, 02:10:40 AM »
Oops.  :o

A car-size asteroid flew within 1,830 miles of Earth over the weekend — the closest pass ever — and we didn't see it coming
Quote
A car-size asteroid flew within about 1,830 miles (2,950 kilometers) of Earth on Sunday.

That's a remarkably close shave — the closest ever recorded, in fact, according to asteroid trackers and a catalog compiled by Sormano Astronomical Observatory in Italy.

Because of its size, the space rock most likely wouldn't have posed any danger to people on the ground had it struck our planet. But the close call is worrisome nonetheless, since astronomers had no idea the asteroid existed until after it passed by. ...
https://www.businessinsider.in/science/news/a-car-size-asteroid-flew-within-1830-miles-of-earth-over-the-weekend-the-closest-pass-ever-and-we-didnt-see-it-coming/articleshow/77603002.cms
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Sebastian Jones

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Re: Astronomical news
« Reply #352 on: August 19, 2020, 07:55:16 AM »
Oops.  :o

A car-size asteroid flew within 1,830 miles of Earth over the weekend — the closest pass ever — and we didn't see it coming
Quote
A car-size asteroid flew within about 1,830 miles (2,950 kilometers) of Earth on Sunday.

That's a remarkably close shave — the closest ever recorded, in fact, according to asteroid trackers and a catalog compiled by Sormano Astronomical Observatory in Italy.

Because of its size, the space rock most likely wouldn't have posed any danger to people on the ground had it struck our planet. But the close call is worrisome nonetheless, since astronomers had no idea the asteroid existed until after it passed by. ...
https://www.businessinsider.in/science/news/a-car-size-asteroid-flew-within-1830-miles-of-earth-over-the-weekend-the-closest-pass-ever-and-we-didnt-see-it-coming/articleshow/77603002.cms

To place how close this is into some context, Low Earth Orbit, where most man-made objects orbit, is anywhere below 1,200mi. So, had it's approach path and speed been different, it could have been captured by Earth's gravity and become a new moon!

Tom_Mazanec

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Re: Astronomical news
« Reply #353 on: August 19, 2020, 12:46:38 PM »
Quote
To place how close this is into some context, Low Earth Orbit, where most man-made objects orbit, is anywhere below 1,200mi. So, had it's approach path and speed been different, it could have been captured by Earth's gravity and become a new moon!
Umm, no. If it had been a bit closer, it could have hit one of those near-Earth satellites, but if not it would have just passed us by, as it actually did, even though it was a lot closer than actual geosynchronous satellites. To be captured you would need a third body to interact and slow it down. The best you could get would be a slowdown in the atmosphere to allow the Earth's gravity to capture it, but then it would go through the atmosphere again and crash.
SHARKS (CROSSED OUT) MONGEESE (SIC) WITH FRICKIN LASER BEAMS ATTACHED TO THEIR HEADS

crandles

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Re: Astronomical news
« Reply #354 on: August 19, 2020, 01:33:32 PM »
To place how close this is into some context, most close approaches are measured in lunar distances  of ~239000 miles. It isn't uncommon to have closest approach less than 1LD, there is one at .3LD due on 1 Sept.

This one is less than 0.01LD

At this distance it probably makes more sense to say close approach was 0.23 earth diameters. Close enough to say we will be hit every so often, but then we know that anyway.

It is shown as a disconcerting 0LD at https://www.spaceweather.com/ because they only show .1LD precision


Sigmetnow

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Re: Astronomical news
« Reply #355 on: August 21, 2020, 08:44:04 PM »
UAE Mars mission
Quote
Hope Mars Mission (@HopeMarsMission) 8/17/20, 7:02 AM
The #HopeProbe has successfully completed its first trajectory correction manoeuvre - a major milestone in its journey to #Mars. This marks the first firing of the probe’s six Delta-V thrusters, for course correction that will see the probe directly targeting Mars’ capture orbit.
https://twitter.com/hopemarsmission/status/1295314981198716928
Two images at the link.
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vox_mundi

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Re: Astronomical news
« Reply #356 on: August 21, 2020, 10:35:39 PM »
Exploding Stars May Have Caused Mass Extinction On Earth, Study Shows
https://phys.org/news/2020-08-stars-mass-extinction-earth.html

A team of researchers led by professor Brian Fields hypothesizes that a supernova about 65 light-years away may have contributed to the ozone depletion and subsequent mass extinction of the late Devonian Period, 359 million years ago.

A new study led by University of Illinois, Urbana-Champaign astronomy and physics professor Brian Fields explores the possibility that astronomical events were responsible for an extinction event 359 million years ago, at the boundary between the Devonian and Carboniferous periods.

The paper is published in the Proceedings of the National Academy of Sciences.

The team concentrated on the Devonian-Carboniferous boundary because those rocks contain hundreds of thousands of generations of plant spores that appear to be sunburnt by ultraviolet light—evidence of a long-lasting ozone-depletion event.

"To put this into perspective, one of the closest supernova threats today is from the star Betelgeuse, which is over 600 light-years away and well outside of the kill distance of 25 light-years," said graduate student and study co-author Adrienne Ertel.

... A supernova delivers a one-two punch, the researchers said. The explosion immediately bathes Earth with damaging UV, X-rays and gamma rays. Later, the blast of supernova debris slams into the solar system, subjecting the planet to long-lived irradiation from cosmic rays accelerated by the supernova. The damage to Earth and its ozone layer can last for up to 100,000 years.

However, fossil evidence indicates a 300,000-year decline in biodiversity leading up to the Devonian-Carboniferous mass extinction, suggesting the possibility of multiple catastrophes, maybe even multiple supernovae explosions. "This is entirely possible," Miller said. "Massive stars usually occur in clusters with other massive stars, and other supernovae are likely to occur soon after the first explosion."

Supernova triggers for End-Devonian extinctions, Proceedings of the National Academy of Sciences (2020)
https://www.pnas.org/content/early/2020/08/17/2013774117
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vox_mundi

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Re: Astronomical news
« Reply #357 on: August 27, 2020, 08:29:13 PM »
Waterworld: Meteorite Study Suggests Earth May Have Been Wet Since It Formed
https://phys.org/news/2020-08-meteorite-earth.html

A new study finds that Earth's water may have come from materials that were present in the inner solar system at the time the planet formed—instead of far-reaching comets or asteroids delivering such water. The findings published Aug. 28 in Science suggest that Earth may have always been wet.

Researchers from the Centre de Recherches Petrographiques et Geochimiques (CRPG, CNRS/Universite de Lorraine) in Nancy, France, including one who is now a postdoctoral fellow at Washington University in St. Louis, determined that a type of meteorite called an enstatite chondrite contains sufficient hydrogen to deliver at least three times the amount of water contained in the Earth's oceans, and probably much more.

Enstatite chondrites are entirely composed of material from the inner solar system—essentially the same stuff that made up the Earth originally.

... Enstatite chondrites are rare, making up only about 2 percent of known meteorites in collections.

But their isotopic similarity to Earth make them particularly compelling. Enstatite chondrites have similar oxygen, titanium and calcium isotopes as Earth, and this study showed that their hydrogen and nitrogen isotopes are similar to Earth's, too. In the study of extraterrestrial materials, the abundances of an element's isotopes are used as a distinctive signature to identify where that element originated.

"If enstatite chondrites were effectively the building blocks of our planet—as strongly suggested by their similar isotopic compositions—this result implies that these types of chondrites supplied enough water to Earth to explain the origin of Earth's water, which is amazing!" Vacher said.

The paper also proposes that a large amount of the atmospheric nitrogen—the most abundant component of the Earth's atmosphere—could have come from the enstatite chondrites.

L. Piani el al., "Earth's water may have been inherited from material similar to enstatite chondrite meteorites," Science (2020).
https://science.sciencemag.org/content/369/6507/1110

Anne H. Peslier, "The origins of water", Science (2020).
https://science.sciencemag.org/content/369/6507/1058
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Sigmetnow

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Re: Astronomical news
« Reply #358 on: September 08, 2020, 07:34:13 PM »
Preventing muscle wasting in microgravity (and on earth)

Mutant "mighty mice" stay bulked up in space but untreated mice lose muscle and bone mass, scientists say
September 8, 2020
Quote
Bulked-up, mutant "mighty mice" held onto their muscle during a monthlong stay at the International Space Station, returning to Earth with ripped bodybuilder physiques, scientists reported Monday. The findings hold promise for preventing muscle and bone loss in astronauts on prolonged space trips like Mars missions, as well as people on Earth who are confined to bed or need wheelchairs.

A research team led by Dr. Se-Jin Lee of the Jackson Laboratory in Connecticut sent 40 young female black mice to the space station in December, launching aboard a SpaceX rocket.

In a paper published in the Proceedings of the National Academy of Sciences, Lee said the 24 regular untreated mice lost considerable muscle and bone mass in weightlessness as expected - up to 18%.

But the eight genetically engineered "mighty mice" launched with double the muscle maintained their bulk. Their muscles appeared to be comparable to similar "mighty mice" that stayed behind at NASA's Kennedy Space Center.

In addition, eight normal mice that received "mighty mouse" treatment in space returned to Earth with dramatically bigger muscles. The treatment involves blocking a pair of proteins that typically limit muscle mass.

A SpaceX capsule brought all 40 mice back in good condition, parachuting into the Pacific off the California coast in January. Some of the ordinary mice were injected with the "mighty mice" drug after returning and quickly built up more muscle than their untreated companions, Lee said. …
https://www.cbsnews.com/news/mighty-mice-keep-muscle-space-scientists/

Article has the (CBS version of the) 11-min webcast video of the [mousetronauts’] 5 December 2019 SpaceX CRS-19 launch, up to the moment of Dragon deploy:  https://www.cbsnews.com/video/spacex-launches-dragon-cargo-ship-to-space-station/
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vox_mundi

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Re: Astronomical news
« Reply #359 on: September 08, 2020, 10:35:41 PM »
Sensors of World's Largest Digital Telescope Camera Snap First 3,200-Megapixel Images at SLAC
https://www6.slac.stanford.edu/news/2020-09-08-sensors-world-largest-digital-camera-snap-first-3200-megapixel-images-slac.aspx

Crews at the Department of Energy's SLAC National Accelerator Laboratory have taken the first 3,200-megapixel digital photos—the largest ever taken in a single shot—with an extraordinary array of imaging sensors that will become the heart and soul of the future camera of the Large Synoptic Survey Telescope at the  Vera C. Rubin Observatory.



Its data will feed into the Rubin Observatory Legacy Survey of Space and Time (LSST) – a catalog of more galaxies than there are living people on Earth and of the motions of countless astrophysical objects. Using the LSST Camera, the observatory will create the largest astronomical movie of all time and shed light on some of the biggest mysteries of the universe, including dark matter and dark energy.





Legacy Survey of Space and Time (LSST)
https://www.lsst.org/

https://www.symmetrymagazine.org/article/the-worlds-largest-astronomical-movie
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vox_mundi

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Re: Astronomical news
« Reply #360 on: September 09, 2020, 11:01:08 PM »
NASA’s OSIRIS-REx Observes an Asteroid in Action
https://www.nasa.gov/feature/goddard/2020/osiris-rex-observes-an-asteroid-in-action

... Since arriving at the asteroid, the team has observed and tracked more than 300 particle ejection events on Bennu. According to the authors, some particles escape into space, others briefly orbit the asteroid, and most fall back onto its surface after being launched. Ejections most often occur during Bennu’s local two-hour afternoon and evening timeframe. 

During a number of observation campaigns between January and September 2019 dedicated to detecting and tracking mass ejected from the asteroid, a total of 668 particles were studied, with the vast majority measuring between 0.5 and 1 centimeters (0.2-0.4 inches), and moving at about 20 centimeters (8 inches) per second, about as fast – or slow – as a beetle scurrying across the ground. In one instance, a speedy outlier was clocked at about 3 meters (9.8 feet) per second.

"To give you an idea, all of those 200 particles we observed during the first event after arrival would fit on a 4-inch x 4-inch tile," he said. "The fact that we can even see them is a testament to the capabilities of our cameras."



Using data collected by NASA’s OSIRIS-REx mission, this animation shows the trajectories of particles after their emission from asteroid Bennu’s surface. The animation emphasizes the four largest particle ejection events detected at Bennu from December 2018 through September 2019. Additional particles, some with lifetimes of several days, that are not related to the ejections are also visible.

https://agupubs.onlinelibrary.wiley.com/doi/toc/10.1002/(ISSN)2169-9100.Explore1
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sidd

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Re: Astronomical news
« Reply #361 on: September 10, 2020, 07:50:59 AM »
Re: OSIRIS-REx

Charming. Thanks.

sidd

Sigmetnow

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Re: Astronomical news
« Reply #362 on: September 10, 2020, 10:08:56 PM »
Quote
Eric Berger (@SciGuySpace) 9/10/20, 10:02 AM
NASA says it will purchase between 50g and 500g of lunar soil from commercial providers. 80 percent of funds to be paid only on delivery. This is a big deal!
beta.sam.gov/opp/7772617761…
https://twitter.com/sciguyspace/status/1304057566318800896

They don’t even return it to earth!  “Delivery” via contract takes place there on the moon.
Contract(s) will be awarded to the Lowest Price Technically Acceptable offer
 
NASA wants to buy Moon rocks from private companies
Can you prove you’ve bagged lunar dirt? NASA will pay you
Loren Grush September 10, 2020 9:40 am
Quote
NASA is officially in the market for Moon rocks — and it’s willing to pay any company that’s capable of scooping them up.

Today, the space agency is putting out a call for proposals from companies, challenging them to snag small samples of rocks on the Moon’s surface. The companies will have to prove that they have collected lunar samples in some kind of small container by sending pictures and data to NASA. If satisfied, NASA pledges to purchase the samples for between $15,000 and $25,000. Eventually, NASA will retrieve the rock samples and bring them back to Earth.

NASA ultimately wants the exchange to happen before 2024 — the agency’s current deadline for sending people back to the Moon. For companies that can pull this off, NASA will pay a small portion of the money when awarding the contract and during launch. The rest of the funds will be received when the sample is bagged. NASA says it may also make multiple awards to separate companies that can grab Moon rocks. …
https://www.theverge.com/platform/amp/2020/9/10/21429850/nasa-moon-rocks-sampling-commercial-space-transaction-lunar-marketplace

Quote
Eric Berger (@SciGuySpace) 9/10/20, 12:24 PM
Quick and dirty legal analysis of today's NASA announcement, the Outer Space Treaty, and international law:
https://twitter.com/sciguyspace/status/1304093383581937665
Prof. Chris Newman (@ChrisNewman1972) 9/10/20, 12:20 PM

…. It’s the only way to get meaningful international law: let’s act in accordance with the Treaty (which this does) and let anyone who objects put up or shut up.
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Sigmetnow

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Re: Astronomical news
« Reply #363 on: September 13, 2020, 03:51:41 PM »
—-  Camera & sound from Space Shuttle Booster!
Quote
Julia (@julia_bergeron) 9/9/20, 11:44 AM
Way back Wednesday.
Riding the Booster with Shuttle with enhanced sound from Skywalker Sound. Truly an amazing experience.
https://twitter.com/julia_bergeron/status/1303720863867514881

"Riding the Booster" Never Sounded Better

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vox_mundi

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Re: Astronomical news
« Reply #364 on: September 14, 2020, 01:44:35 AM »
... we've got company ...

Signs of Life Found On Venus. Phosphine Gas On Venus Indicates That Microbes Exist There.
https://webcache.googleusercontent.com/search?q=cache:dUWrpm80WHsJ:https://earthsky.org/%3Fp%3D343883+&cd=1&hl=en&ct=clnk&gl=us

Image: https://preview.redd.it/wx4yza3qrum51.jpg?auto=webp&s=67a3b605fec12978a30acae05367e290682420b5

Earth & Sky accidentally broke a press embargo two days early.

Scientists have detected trace amounts of the gas phosphine in the clouds of Venus, a potential indicator of life on Earth's inhospitable neighbor because on our planet this molecule is produced by microbes that inhabit oxygen-free environments.

Co-author Janusz Petkowski noted:

This means either this is life, or it’s some sort of physical or chemical process that we do not expect to happen on rocky planets.

We really went through all possible pathways that could produce phosphine on a rocky planet. If this is not life, then our understanding of rocky planets is severely lacking.

PH3 gets destroyed by ultraviolet light-related chemistry, and so has a short lifetime in planetary atmospheres. This means if phosphine is detected, there must be an ongoing process generating or replenishing it.

William Bains at MIT, who led the work on trying to assess other natural ways to make phosphine on Venus. Some ideas included sunlight, minerals blown upwards from the surface, volcanoes, or lightning, but none of these could make anywhere near enough of it. These kinds of sources could only make, at most, one ten thousandth of the amount of phosphine that the telescopes saw. So something is producing a lot more of the gas. According to Paul Rimmer at Cambridge University, terrestrial organisms would only need to work at about 10% of their maximum productivity in order to produce the amount of phosphine found on Venus.



Pre-release: Nature Astronomy, embargoed: September 14, 2020
https://www.nature.com/articles/s41550-020-1174-4
https://ras.ac.uk/news-and-press/news/hints-life-venus

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

For 3 billion years, ending about 750 million years ago, Venus was likely hospitable, leaving the tantalizing possibility that we’ve detected the last vestiges of an ancient ecosystem.

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



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

Phosphine Could Signal Existence of Alien Anaerobic Extraterrestrial Life
https://phys.org/news/2019-12-smelly-poisonous-molecule-sure-fire-extraterrestrial.amp

Most life on Earth, specifically all aerobic, oxygen-breathing life, wants nothing to do with phosphine, neither producing it nor relying on it for survival.

Now MIT researchers have found that phosphine is produced by another, less abundant life form: anaerobic organisms, such as bacteria and microbes, that don't require oxygen to thrive. The team found that phosphine cannot be produced in any other way except by these extreme, oxygen-averse organisms, making phosphine a pure biosignature—a sign of life (at least of a certain kind).

In a paper recently published in the journal Astrobiology, the researchers report that if phosphine were produced in quantities similar to methane on Earth, the gas would generate a signature pattern of light in a planet's atmosphere. This pattern would be clear enough to detect from as far as 16 light years away by a telescope such as the planned James Webb Space Telescope. If phosphine is detected from a rocky planet, it would be an unmistakable sign of extraterrestrial life.

... "It's a really toxic molecule for anything that likes oxygen. But for life that doesn't like oxygen, it seems to be a very useful molecule."

Phosphine, they found, has no significant false positives, meaning any detection of phosphine is a sure sign of life. The researchers then explored whether the molecule could be detectable in an exoplanet's atmosphere. They simulated the atmospheres of idealized, oxygen-poor, terrestrial exoplanets of two types: hydrogen-rich and carbon dioxide-rich atmospheres. They fed into the simulation different rates of phosphine production and extrapolated what a given atmosphere's spectrum of light would look like given a certain rate of phosphine production. ...

Clara Sousa-Silva et al. Phosphine as a Biosignature Gas in Exoplanet Atmospheres, Astrobiology (2019)
https://arxiv.org/abs/1910.05224

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

Could There Be Life In the Cloudtops of Venus?
https://phys.org/news/2020-08-life-cloudtops-venus.amp

In a paper just published in the journal Astrobiology, Sara Seager from MIT and colleagues suggest a way that microbial life could permanently reside in the lower atmosphere of Venus. The idea that microbes might exist in the Venusian clouds, at an altitude of 50 to 65 kilometers above ground level, was proposed more than 50 years ago by the late Carl Sagan, and has since been advanced by many other authors.

Previous papers didn’t elaborate on what life in the clouds means, and how it might interact with the atmosphere. A 2004 paper pointed out that sulfur (specifically a compound called cyclooctasulfur) could be used by microbes as a UV sunscreen and a means for converting ultraviolet light to other wavelengths of light that could be used for photosynthesis. It was speculated that this could be the basis for an ecosystem at Venus, where certain chemotrophic organisms complete the nutrient cycling.

Seager and her colleagues have come up with a much more elegant solution. They suggest that the droplet habitat in which the microbes reside would inexorably grow, and would be forced by gravity to settle in the hotter, uninhabitable layer below the Venusian clouds. As the droplets evaporate during settling, the microbes would dry out, and the lower haze layer would become a depot for desiccated, dormant life. But upward drafts would regularly lift the dormant microbes back into the clouds, where they would be rehydrated and become active again.



Sara Seager et al. The Venusian Lower Atmosphere Haze as a Depot for Desiccated Microbial Life: A Proposed Life Cycle for Persistence of the Venusian Aerial Biosphere, Astrobiology (2020)
https://www.liebertpub.com/doi/10.1089/ast.2020.2244

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

Unidentified ‘Absorbers’ Soak Up Solar Energy in Upper Cloud Layer of Venus
http://www.sci-news.com/space/unidentified-absorbers-venus-07560.html

... Venusian clouds contain strange, dark patches, called “unknown absorbers” because they absorb large amounts of solar radiation.

No one has yet determined what these dark patches are, but scientists have speculated that they might be forms of sulfur, ferric chloride or even microscopic life.

Now, a team of scientists led by Yeon Joo Lee, a researcher in the Center for Astronomy and Astrophysics at the Technical University of Berlin, has shown that the unknown absorbers are affecting Venus’s weather

By studying more than a decade of data from Venus Express, Akatsuki, Messenger and the Hubble Space Telescope, the researchers found a relationship between Venus’ clouds and its winds. The clouds absorb solar radiation, which causes temperature changes that affect wind patterns. The unknown absorbers seem to play a role in this process by affecting the planet’s albedo, or how much energy is reflected back to space.

“It is hard to conceive of what would cause a change in the albedo without a change in the absorbers,” said Sanjay Limaye, a planetary scientist at the University of Wisconsin-Madison and paper co-author.

In part because it is difficult to explain the absorbers’ changes inorganically, Limaye has explored the possibility that they might be microorganisms. He’s in good company. The idea of life in the Venusian atmosphere dates back to a 1967 paper co-authored by Carl Sagan.

Limaye observed that the particles making up the dark patches in Venus’s clouds resemble microorganisms in Earth’s atmosphere. “Since there are few species which have physical, chemical and spectral properties that are consistent with the composition of the Venus clouds, they may have evolved independently on Venus.”

Yeon Joo Lee et al. . Long-term Variations of Venus’s 365 nm Albedo Observed by Venus Express, Akatsuki, MESSENGER, and the Hubble Space Telescope[/b], Astronomical Journal, 2019
https://iopscience.iop.org/article/10.3847/1538-3881/ab3120
« Last Edit: September 14, 2020, 03:51:54 PM by vox_mundi »
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vox_mundi

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Re: Astronomical news
« Reply #365 on: September 14, 2020, 03:49:41 PM »
^ ... we are not alone ...

Watch today’s major announcement from the Royal Astronomical Society
https://astronomynow.com/2020/09/14/watch-todays-major-announcement-from-the-royal-astronomical-society/

The Royal Astronomical Society is hosting a news conference today to announce a groundbreaking astronomy result. Tune in here at 4pm BST (1500 GMT) to watch the news conference. (11AM EST)

.

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

Sign of Life On Venus Discovered With Hawaii Telescope
http://astrobiology.com/2020/09/phosphine-detected-in-the-atmosphere-of-venus---an-indicator-of-possible-life.html

Phosphine Detected In The Atmosphere of Venus - An Indicator of Possible Life?

The presence of phosphine is seen by many astrobiologists as a "biosignature" i.e. an indicator of the possible presence of life. The detection was made by the Atacama (ALMA) array located in Chile and the James Clerk Maxwell telescope located in Hawaii. The research team includes members from the University of Manchester, the Massachusetts Institute of Technology, and Cardiff University. A paper will appear in the 14 September issue of Nature Astronomy.

From what we're told the researchers have concluded that abiotic mechanisms (i.e. ones that do not involve life) that might produce phosphine cannot account for the large amount that they have detected. The phosphine has been detected in the region within the atmosphere of Venus that is considered by some to be potentially habitable. As to what spin the researchers put on this, we'll have to wait for reporters who have the press release or are allowed to participate in the Zoom press conference thing tomorrow at 15:00 GMT to let us know

An international team of scientists using the James Clerk Maxwell Telescope on Hawaii island has discovered the potential for life on Venus.

« Last Edit: September 14, 2020, 04:10:55 PM by vox_mundi »
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vox_mundi

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Re: Astronomical news
« Reply #366 on: September 14, 2020, 05:47:16 PM »
Scientists Find Gas Linked to Life in Atmosphere of Venus
https://www.theguardian.com/science/2020/sep/14/scientists-find-gas-linked-to-life-in-atmosphere-of-venus

Phosphine, released by microbes in oxygen-starved environments, was present in quantities larger than expected

Astronomers detected phosphine 30 miles up in the planet’s atmosphere and have failed to identify a process other than life that could account for its presence.

The discovery raises the possibility that life gained a foothold on Earth’s inner neighbour and remnants clung on – or floated on, at least – as Venus suffered runaway global warming that made the planet hellish.

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

Phosphine gas in the cloud decks of Venus,
https://www.nature.com/articles/s41550-020-1174-4

Abstract
Measurements of trace gases in planetary atmospheres help us explore chemical conditions different to those on Earth. Our nearest neighbour, Venus, has cloud decks that are temperate but hyperacidic. Here we report the apparent presence of phosphine (PH3) gas in Venus’s atmosphere, where any phosphorus should be in oxidized forms. Single-line millimetre-waveband spectral detections (quality up to ~15σ) from the JCMT and ALMA telescopes have no other plausible identification. Atmospheric PH3 at ~20 ppb abundance is inferred. The presence of PH3 is unexplained after exhaustive study of steady-state chemistry and photochemical pathways, with no currently known abiotic production routes in Venus’s atmosphere, clouds, surface and subsurface, or from lightning, volcanic or meteoritic delivery. PH3 could originate from unknown photochemistry or geochemistry, or, by analogy with biological production of PH3 on Earth, from the presence of life. Other PH3 spectral features should be sought, while in situ cloud and surface sampling could examine sources of this gas.


PH3 1–0 spectrum of the whole planet, with 1σ errors (here channel to channel) of 0.11 × 10−4 per 1.1 km s−1 spectral bin.

... We conclude that the candidate detection of PH3 is robust, for four main reasons. First, the absorption has been seen, at comparable line depth, with two independent facilities; second, line measurements are consistent under varied and independent processing methods; third, overlap of spectra from the two facilities shows no other such consistent negative features; and fourth, there is no other known reasonable candidate transition for the absorption other than PH3.

... derived abundances range from ~20 ppb (using our theoretical estimate) up to ~30 ppb

The presence of even a few parts per billion of PH3 is completely unexpected for an oxidized atmosphere (where oxygen-containing compounds greatly dominate over hydrogen-containing ones).
« Last Edit: September 14, 2020, 06:41:50 PM by vox_mundi »
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kassy

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Re: Astronomical news
« Reply #367 on: September 14, 2020, 08:05:25 PM »
Cool find.
Þetta minnismerki er til vitnis um að við vitum hvað er að gerast og hvað þarf að gera. Aðeins þú veist hvort við gerðum eitthvað.

Sebastian Jones

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Re: Astronomical news
« Reply #368 on: September 15, 2020, 12:55:47 AM »
Scientists Find Gas Linked to Life in Atmosphere of Venus
https://www.theguardian.com/science/2020/sep/14/scientists-find-gas-linked-to-life-in-atmosphere-of-venus

Phosphine, released by microbes in oxygen-starved environments, was present in quantities larger than expected

Astronomers detected phosphine 30 miles up in the planet’s atmosphere and have failed to identify a process other than life that could account for its presence.
..........................................
The presence of even a few parts per billion of PH3 is completely unexpected for an oxidized atmosphere (where oxygen-containing compounds greatly dominate over hydrogen-containing ones).

Twitter, at least one corner of it, has been noting that penguin guano can emit phosphine, and that maybe penguins colonized Venus....
However, given the terribly hot conditions, it is more likely that Pernese dragons have been visiting, and leaving traces of Firestone.
https://pern.fandom.com/wiki/Firestone

Sigmetnow

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Re: Astronomical news
« Reply #369 on: September 15, 2020, 04:20:58 PM »
Quote
Twitter, at least one corner of it, has been noting that penguin guano can emit phosphine, and that maybe penguins colonized Venus....

Quote
Jonathan McDowell (@planet4589) 9/14/20, 5:21 PM
Don't get me wrong. I for one welcome our new Venusian floating penguin overlords.
https://twitter.com/planet4589/status/1305617803630739456
Jonathan McDowell: For those confused by the penguin ref: penguins are a major sources of phosphine on Earth. Therefore, Occam's razor implies that they are also the most likely source of phosphine of Venus. Right??
< Venus has a denser atmosphere suited for tiny little wings. Theory checks out.
<< Yes the venusian penguin is the only logical answer. Sulphuric rain would just roll off their sleek feathers
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Tor Bejnar

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Re: Astronomical news
« Reply #370 on: September 15, 2020, 04:34:54 PM »
I'm convinced ... Now how do I get this news to Q-what's-its-name?  :P
[Please don't believe me.]
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vox_mundi

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Re: Astronomical news
« Reply #371 on: September 15, 2020, 04:59:50 PM »
...more stellar science from the Univ. of Bremen [re: penguins and phosphine] ...



Calculating the True Pressure Required to Propel Penguin Feces
https://phys.org/news/2020-07-true-pressure-required-propel-penguin.amp

... and the answer is—a little more than 10 to 60 kilopascals.

Projectile Trajectory of Penguin's Faeces and Rectal Pressure Revisited
https://arxiv.org/abs/2007.00926v1

... don't stand behind them!
“There are three classes of people: those who see. Those who see when they are shown. Those who do not see.” ― Leonardo da Vinci

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vox_mundi

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Re: Astronomical news
« Reply #372 on: September 16, 2020, 01:50:39 AM »
“There are three classes of people: those who see. Those who see when they are shown. Those who do not see.” ― Leonardo da Vinci

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kassy

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Re: Astronomical news
« Reply #373 on: September 16, 2020, 01:18:49 PM »
And we shall call the cloud city Bespin.  ;)

I bet a drone space ship that flies there and samples some of the clouds will be cheaper...
Þetta minnismerki er til vitnis um að við vitum hvað er að gerast og hvað þarf að gera. Aðeins þú veist hvort við gerðum eitthvað.

interstitial

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Re: Astronomical news
« Reply #374 on: September 16, 2020, 01:54:54 PM »
And we shall call the cloud city Bespin.  ;)

I bet a drone space ship that flies there and samples some of the clouds will be cheaper...
I agree if you can't go outside a probe makes more sense.

Sigmetnow

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Re: Astronomical news
« Reply #375 on: September 16, 2020, 08:09:54 PM »
Hints of life renew interest in Venus, and a private mission could lead the way
Stephen Clark
Quote
The announcement Monday of the discovery of phosphine gas in the clouds of Venus — an indicator of possible life — has raised hopes among scientists for new robotic missions to renew exploration of Earth’s planetary neighbor.

If Rocket Lab founder Peter Beck gets his way, a privately-funded mission could get the next crack at probing Venus’s soupy atmosphere. NASA Administrator Jim Bridenstine also tweeted Monday: “It’s time to prioritize Venus.”

Putting together a private mission to Venus
The mission Beck is planning would send an entry probe in the atmosphere of Venus. It wouldn’t answer all the questions scientists have about Venus, but could open doors to new ways of exploring the solar system, Beck said.

With its light-class Electron rocket and Photon spacecraft platform, Rocket Lab could deliver nearly 60 pounds — about 27 kilograms — of useful payloads to Venus, according to Beck.

“It might not sound a lot, but 27 kilograms is a lot of radio. That’s a lot of science instrument,” Beck said. “It’s a lot of really good stuff. So we can do some pretty incredible things with that.”


NASA last year selected four proposals from scientists for the next mission in the agency’s Discovery program, a line of cost-capped robotic interplanetary probes.

The DAVINCI+ mission would send a descent probe into the atmosphere of Venus to precisely measure its composition down to the surface, according to NASA. The mission would help scientists understand how the atmosphere formed and evolved, and accumulate more information about the history of water at Venus.

A hardened “sphere” will carry the instruments to the surface of Venus, measuring atmospheric composition and conditions at various altitudes throughout a gradual hour-long descent. Cameras on the descent sphere and an orbiter component to the mission will map surface rock types, according to NASA.

The VERITAS mission would carry a synthetic aperture radar instrument on an orbiting spacecraft to survey nearly the entire surface of the Venus, according to NASA. The VERITAS orbiter would collect data on the types of rock that make up Venus’s crust, and like DAVINCI+, would pursue signs of ancient water on the planet.

The European Space Agency is also weighing a selection of its next medium-class, cost-capped science mission. One of the European finalists, named EnVision, is a proposed orbiter that would launch to Venus in 2032 with similar objectives as VERITAS — to map the planet in unprecedented detail with radar.

Russia’s Venera-D mission is in the early stages of development. Venera-D would consist of an orbiter and a lander, with a launch no earlier than the late 2020s. …
https://spaceflightnow.com/2020/09/14/hints-of-life-raises-interest-in-venus-missions-and-a-privately-funded-probe-could-lead-the-way/

Images below: 
- Artist’s illustration of Rocket Lab’s Photon satellite bus.
- Artist’s concept of an entry probe like the one being designed for NASA’s proposed DAVINCI+ mission.
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vox_mundi

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Re: Astronomical news
« Reply #376 on: September 17, 2020, 10:14:00 PM »
“There are three classes of people: those who see. Those who see when they are shown. Those who do not see.” ― Leonardo da Vinci

Insensible before the wave so soon released by callous fate. Affected most, they understand the least, and understanding, when it comes, invariably arrives too late

vox_mundi

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Re: Astronomical news
« Reply #377 on: September 21, 2020, 01:03:59 AM »
Russian Nuclear Space Tug
https://german-kmw.livejournal.com/112316.html



Russia is starting to build a full-size 200kW nuclear-powered space tug prototype/mockup with, what looks like, a Hall ion thruster.

Interplanetary? Probably aspirational.
“There are three classes of people: those who see. Those who see when they are shown. Those who do not see.” ― Leonardo da Vinci

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vox_mundi

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Re: Astronomical news
« Reply #378 on: September 21, 2020, 01:06:57 AM »
Infrared Eyes On Enceladus: Hints of Fresh Ice In Northern (and Southern) Hemisphere
https://www.jpl.nasa.gov/news/news.php?feature=7748
https://phys.org/news/2020-09-infrared-eyes-enceladus-hints-fresh.html



New composite images made from NASA's Cassini spacecraft are the most detailed global infrared views ever produced of Saturn's moon Enceladus. And data used to build those images provides strong evidence that the northern hemisphere of the moon has been resurfaced with ice from its interior.

Cassini's Visible and Infrared Mapping Spectrometer (VIMS) collected light reflected off Saturn, its rings and its ten major icy moons—light that is visible to humans as well as infrared light. VIMS then separated the light into its various wavelengths, information that tells scientists more about the makeup of the material reflecting it.

The VIMS data, combined with detailed images captured by Cassini's Imaging Science Subsystem, were used to make the new global spectral map of Enceladus.

The new spectral map shows that infrared signals clearly correlate with that geologic activity, which is easily seen at the south pole. That's where the so-called "tiger stripe" gashes blast ice and vapor from the interior ocean.

But some of the same infrared features also appear in the northern hemisphere. That tells scientists not only that the northern area is covered with fresh ice but that the same kind of geologic activity—a resurfacing of the landscape—has occurred in both hemispheres. The resurfacing in the north may be due either to icy jets or to a more gradual movement of ice through fractures in the crust, from the subsurface ocean to the surface.

Infrared images of Enceladus were used to make this interactive 3D globe at the link.

https://www.jpl.nasa.gov/news/news.php?feature=7748
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vox_mundi

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Re: Astronomical news
« Reply #379 on: September 23, 2020, 11:40:47 PM »
New Analysis of Black Hole Reveals a Wobbling Shadow
https://phys.org/news/2020-09-analysis-black-hole-reveals-shadow.html



In 2019, the Event Horizon Telescope Collaboration delivered the first image of a black hole, revealing M87*—the supermassive object in the center of the M87 galaxy. The team has now used the lessons learned last year to analyze the archival data sets from 2009-2013, some of them not published before.

The analysis reveals the behavior of the black hole image across multiple years, indicating persistence of the crescent-like shadow feature, but also variation of its orientation—the crescent appears to be wobbling. The full results appeared today in The Astrophysical Journal.

Expanding the analysis to the 2009-2017 observations, scientists have shown that M87* adheres to theoretical expectations. The black hole's shadow diameter has remained consistent with the prediction of Einstein's theory of general relativity for a black hole of 6.5 billion solar masses.

But while the crescent diameter remained consistent, the EHT team found that the data were hiding a surprise: The ring is wobbling, and that means big news for scientists. For the first time they can get a glimpse of the dynamical structure of the accretion flow so close to the black hole's event horizon, in extreme gravity conditions. Studying this region holds the key to understanding phenomena such as relativistic jet launching, and will allow scientists to formulate new tests of the theory of general relativity.

Maciek Wielgus et al. Monitoring the Morphology of M87* in 2009–2017 with the Event Horizon Telescope, The Astrophysical Journal (2020).
https://iopscience.iop.org/article/10.3847/1538-4357/abac0d
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Sigmetnow

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Re: Astronomical news
« Reply #380 on: September 24, 2020, 04:29:37 PM »
—- ISS Maneuvers to avoid space debris from a 2019 Japanese rocket breakup
Quote
Thomas Burghardt (@TGMetsFan98) 9/22/20, 4:34 PM
The 3 crew members on the ISS have boarded the Soyuz MS-16 spacecraft due to a predicted close approach to a piece of space debris at 22:21 UTC. An avoidance maneuver is being conducted at 21:19 UTC using the Progress MS-14 spacecraft’s engines.
https://twitter.com/tgmetsfan98/status/1308504974721245187
Intl. Space Station (@Space_Station) 9/22/20, 4:25 PM

The station is preparing to avoid a piece of unknown space debris being tracked by @NASA_Johnson flight controllers and @US_SpaceCom. The Exp 63 crew has relocated to its Soyuz crew ship. The time of closest approach is 6:21 pm ET. More... go.nasa.gov/2G546FF
https://twitter.com/space_station/status/1308502770530435072

Quote
Jonathan McDowell (@planet4589) 9/22/20, 7:53 PM
The debris object that ISS avoided is now available on SpaceTrack as 2018-084CQ, 46477, from the breakup of Japan's H-2A F40 rocket stage. At 2221:07 UTC it passed within a few km of ISS at a relative velocity of 14 6 km/s, 422 km over the Pitcairn Is in the S Pacific
~ Correction: it passed within a few km of the position ISS would have been at if it hadn't manuevered
~ H2A F40 launched GOSAT-2 in Oct 2018. The stage appears to have made a depletion burn to lower orbit from 597 x 618 km to 598 x 520 km. Nevertheless it underwent a major breakup on 2019 Feb 6.
~ 77 debris objects have been cataloged from the breakup; 5 have reentered so far. This plot shows the locations at conjunction time of the remaining 72 (almost all in one plane) and the pre-maneuver track of ISS for +/- 10 min
⬇️Image below.
Jonathan McDowell (@planet4589) 9/22/20, 8:50 PM

Most of the debris objects are still at somewhat higher altitudes, but they will eventually decay through the ISS height range pic.twitter.com/qMYNcXFrIr
https://twitter.com/planet4589/status/1308555063690919936

Quote
Jim Bridenstine (@JimBridenstine) 9/22/20, 5:25 PM
Maneuver Burn complete. The astronauts are coming out of safe haven
Jim Bridenstine:  The @Space_Station has maneuvered 3 times in 2020 to avoid debris. In the last 2 weeks, there have been 3 high concern potential conjunctions. Debris is getting worse! Time for Congress to provide @CommerceGov with the $15 mil requested by @POTUS for the Office of Space Commerce.
https://twitter.com/jimbridenstine/status/1308540671725318144
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Sigmetnow

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Re: Astronomical news
« Reply #381 on: September 24, 2020, 05:08:57 PM »
Quote
—- ISS Maneuvers to avoid space debris from a 2019 Japanese rocket breakup

In recent years, international space organizations have agreed to de-orbit rocket upper stages, build satellites so they burn up completely on re-entry, and retire aging satellites to “graveyard orbits” away from popular space locations.
Still…

• “Potential conjunctions” are becoming more frequent
• Frequent enough for governments to be concerned
   • Concerned enough to budget money to address the problem

• Access to space is getting commercialized, more reliable, and cheaper
• Space tech has, within the past few years, progressed to the point that solutions are in the development stages:
    • “Space tugs” that can attach to aging satellites and keep them oriented correctly and extend their lives, or move them to a graveyard orbit, or deorbit them.
   • SpaceX’s reusable Starship is planned to have a compartment like the Space Shuttle that will open to allow retrieval of space objects, for repair, repositioning or return to earth.
   • Smaller spacecraft are being built that can grasp or snag debris in nets for disposal.

• Expect that governments and major space companies will, in their own interest, fund a continual flow of “cleanup missions” in the years ahead.
• Eventually such cleanup will be autonomous, robotic, and constant — like city street sweepers, but at a whole new level! ;)
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Tom_Mazanec

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Re: Astronomical news
« Reply #382 on: September 24, 2020, 05:18:05 PM »
It better be soon.
If not w e could have a Kessler cascade where satellite collisions spread debris to cause more collisions like the chain reaction of an atomic bomb.
SHARKS (CROSSED OUT) MONGEESE (SIC) WITH FRICKIN LASER BEAMS ATTACHED TO THEIR HEADS

vox_mundi

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Re: Astronomical news
« Reply #383 on: September 24, 2020, 08:50:55 PM »
Faint Orbital Debris That Threatens Satellites Not Being Monitored Closely Enough, Warn Astronomers
https://phys.org/news/2020-09-faint-orbital-debris-threatens-satellites.html

University of Warwick astronomers are warning that orbital debris posing a threat to operational satellites is not being monitored closely enough, as they publish a new survey finding that over 75% of the orbital debris they detected could not be matched to known objects in public satellite catalogs.

The research forms part of DebrisWatch, an ongoing collaboration between the University of Warwick and the Defense Science and Technology Laboratory (UK) aiming to provide a fresh take on surveys of the geosynchronous region that have been conducted in the past. The results are reported in the journal Advances in Space Research

... Many of the faint, uncatalogued debris appear to be tumbling, showing significant brightness variation across the observation window.

... The astronomers focused their survey on the geosynchronous region, located roughly 36,000 kilometers above the Equator, where satellites orbit with a period that matches the Earth's rotation. Far above the outermost layer of the Earth's atmosphere, there are no natural mechanisms (like atmospheric drag) to induce orbital decay, so debris generated in the vicinity of the geosynchronous region will remain there for a very long time indeed.

James A. Blake et al. DebrisWatch I: A survey of faint geosynchronous debris, Advances in Space Research (2020)
https://www.sciencedirect.com/science/article/abs/pii/S0273117720305664
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vox_mundi

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Re: Astronomical news
« Reply #384 on: September 25, 2020, 09:13:24 PM »


On Oct. 20, the OSIRIS-REx mission will perform the first attempt of its Touch-And-Go (TAG) sample collection event. Not only will the spacecraft navigate to the surface using innovative navigation techniques, but it could also collect the largest sample since the Apollo missions.

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

New Measurements Show Moon Has Hazardous Radiation Levels
https://phys.org/news/2020-09-moon.html

When the next astronaut to reach the moon walks on the lunar surface in 2024, she'll face radiation levels 200 to 1000 times higher than on Earth.

While Apollo mission astronauts carried dosimeters to the moon to measure radiation, the data was never reported.

The first systematically documented measurements of radiation on the moon were undertaken in January 2019 when China's Chang'e 4 robotic spacecraft mission landed on the far side of the Moon, according to a new study in the journal Science Advances.

Astronauts on moon missions would experience an average daily radiation dose equivalent to 1,369 microsieverts per day -- about 2.6 times higher than the International Space Station crew's daily dose, the study said.

"The radiation levels we measured on the Moon are about 200 to 1000 times higher than on the surface of the Earth and 5 to 10 times higher than on a flight from New York to Frankfurt," said Robert Wimmer-Schweingruber, a professor of physics at the University of Kiel in Germany and the corresponding author of the study that published Friday, in a statement.

"Because astronauts would be exposed to these radiation levels longer than passengers or pilots on transatlantic flights, this is a considerable exposure."

"Basically, the less you see of the sky, the better. That's the primary source of the radiation,"

S. Zhang el al., First measurements of the radiation dose on the lunar surface, Science Advances (2020)
https://advances.sciencemag.org/lookup/doi/10.1126/sciadv.aaz1334
« Last Edit: September 25, 2020, 09:54:53 PM by vox_mundi »
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vox_mundi

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Re: Astronomical news
« Reply #385 on: September 29, 2020, 01:00:12 AM »
Salty Lake, Ponds May Be Gurgling Beneath Mars' South Pole
https://phys.org/news/2020-09-salty-lake-ponds-gurgling-beneath.html

More liquid water may exist beneath the Martian surface than we realized, according to new research published today in Nature Astronomy. The new paper describes several newly detected subglacial water bodies beneath the Martian south pole, in addition to the described water body found two years ago.


Blue regions show high reflective permittivity—a potential sign of liquid water. Image: S. E. Lauro et al., 2020/Nature Astronomy

In the latest study appearing in the journal Nature Astronomy, the scientists provide further evidence of this salty underground lake, estimated to be 12 miles to 18 miles (20 kilometers to 30 kilometers) across and buried 1 mile (1.5 kilometers) beneath the icy surface.

Even more tantalizing, they've also identified three smaller bodies of water surrounding the lake. These ponds appear to be of various sizes and are separate from the main lake.

The research team led by Roma Tre University's Sebastian Emanuel Lauro used a method similar to what's been used on Earth to detect buried lakes in the Antarctic and Canadian Arctic. They based their findings on more than 100 radar observations by Mars Express from 2010 to 2019; the spacecraft was launched in 2003.

All this potential water raises the possibility of microbial life on—or inside—Mars. High concentrations of salt are likely keeping the water from freezing at this frigid location, the scientists noted. The surface temperature at the South Pole is an estimated minus 172 degrees Fahrenheit (minus 113 degrees Celsius), and gets gradually warmer with depth.

Multiple subglacial water bodies below the south pole of Mars unveiled by new MARSIS data, Nature Astronomy (2020)
https://www.nature.com/articles/s41550-020-1200-6
« Last Edit: September 29, 2020, 02:46:15 AM by vox_mundi »
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vox_mundi

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Re: Astronomical news
« Reply #386 on: September 29, 2020, 05:15:54 PM »
Second Alignment Plane of Solar System Discovered
https://phys.org/news/2020-09-alignment-plane-solar.html


Artist’s impression of the distribution of long-period comets. The converging lines represent the paths of the comets. The ecliptic plane is shown in yellow and the empty ecliptic is shown in blue. The background grid represents the plane of the galactic disk.

A study of comet motions indicates that the solar system has a second alignment plane. Analytical investigation of the orbits of long-period comets shows that the aphelia of the comets, the point where they are farthest from the Sun, tend to fall close to either the well-known ecliptic plane where the planets reside or a newly discovered "empty ecliptic." This has important implications for models of how comets originally formed in the solar system.

Models of solar system formation suggest that even long-period comets originally formed near the ecliptic and were later scattered into the orbits observed today through gravitational interactions, most notably with the gas giant planets. But even with planetary scattering, the comet's aphelion, the point where it is farthest from the Sun, should remain near the ecliptic. Other external forces are needed to explain the observed distribution.

The solar system does not exist in isolation; the gravitational field of the Milky Way galaxy in which the solar system resides also exerts a small but non-negligible influence. Arika Higuchi, an assistant professor at the University of Occupational and Environmental Health in Japan and previously a member of the NAOJ RISE Project, studied the effects of the galactic gravity on long-period comets through analytical investigation of the equations governing orbital motion.

She showed that when the galactic gravity is taken into account, the aphelia of long-period comets tend to collect around two planes. First the well-known ecliptic, but also a second "empty ecliptic." The ecliptic is inclined with respect to the disk of the Milky Way by about 60 degrees. The empty ecliptic is also inclined by 60 degrees, but in the opposite direction. Higuchi calls this the "empty ecliptic" based on mathematical nomenclature and because initially it contains no objects, only later being populated with scattered comets. ...

Arika Higuchi. Anisotropy of Long-period Comets Explained by Their Formation Process, The Astronomical Journal (2020)
https://iopscience.iop.org/article/10.3847/1538-3881/aba94d
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Re: Astronomical news
« Reply #387 on: September 30, 2020, 06:31:09 AM »
Planet Collision Simulations Give Clues to Atmospheric Loss from Moon's Origin
https://phys.org/news/2020-09-planet-collision-simulations-clues-atmospheric.html

Earth could have lost anywhere between ten and 60 percent of its atmosphere in the collision that is thought to have formed the Moon.

New research led by Durham University, UK, shows how the extent of atmospheric loss depends upon the type of giant impact with the Earth

Researchers ran more than 300 supercomputer simulations to study the consequences that different huge collisions have on rocky planets with thin atmospheres.

They found that grazing impacts – like the one thought to have formed our Moon 4.5 billion years ago – led to much less atmospheric loss than a direct hit.

They also found that slow giant impacts between young planets and massive objects could add significant atmosphere to a planet if the impactor also has a lot of atmosphere.

The simulations revealed the different outcomes when one or more of these variables are changed, leading to atmospheric loss or gain, or sometimes the complete obliteration of the impacted planet.


https://www.dur.ac.uk/research/news/item/?itemno=42216

Kegerreis J, et al, Atmospheric Erosion by Giant Impacts onto Terrestrial Planets: A Scaling Law for any Speed, Angle, Mass, and Density, The Astrophysical Journal Letters 2020
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Re: Astronomical news
« Reply #388 on: September 30, 2020, 07:39:35 PM »
Stellar Explosion in Earth's Proximity
https://phys.org/news/2020-09-stellar-explosion-earth-proximity.html

Physicists from the Technical University of Munich (TUM) have found evidence of a supernova that exploded near the Earth around 2.5 million years ago.

In layers of a manganese crust that are around two and a half million years old a research team led by physicists from the Technical University of Munich has now confirmed the existence of both iron-60 and manganese-53.

"The increased concentrations of manganese-53 can be taken as the "smoking gun"—the ultimate proof that this supernova really did take place," says first author Dr. Gunther Korschinek.

While a very close supernova could inflict massive harm to life on Earth, this one was far enough away. It only caused a boost in cosmic rays over several thousand years. "However, this can lead to increased cloud formation," says co-author Dr. Thomas Faestermann. "Perhaps there is a link to the Pleistocene epoch, the period of the Ice Ages, which began 2.6 million years ago."

... accelerator mass spectrometry is so sensitive that it even allows us to calculate from our measurements that the star that exploded must have had around 11 to 25 times the size of the sun."

G. Korschinek et al, Supernova-Produced Mn53 on Earth, Physical Review Letters (2020)
https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.125.031101
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Tom_Mazanec

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Re: Astronomical news
« Reply #389 on: October 01, 2020, 12:00:42 AM »
vox_mundi, that supernova may not have been close enough to cause a mass extinction 2.5 million years ago, but it looks like a gamma ray burst was close enough to us 440 million years ago to cause a mass extinction:
https://arxiv.org/pdf/2009.13539.pdf
Quote
The best place and time to live in the Milky Way
R. Spinelli ‹1
, G. Ghirlanda2
, F. Haardt1, 2, 3 G. Ghisellini2
, G. Scuderi4
1 Dipartimento di Scienza e Alta Tecnologia, Università dell’Insubria, Via Valleggio 11, 22100 Como, Italy
2
INAF – Osservatorio Astronomico di Brera, Via E. Bianchi 46, 23807 Merate (LC), Italy
3
INFN – Sezione Milano–Bicocca, Piazza della Scienza 3, 20126 Milano, Italy
4 Dipartimento di Fisica G. Occhialini, Università Milano–Bicocca, Piazza della Scienza 3, 20126 Milano, Italy
Received September 18, 2020; accepted
ABSTRACT
Context. Among the most powerful cosmic events, supernovae (SNe) and γ´ray bursts (GRBs) can be highly disruptive for life:
their radiation can be harmful for biota or induce extinction by removing most of the protective atmospheric ozone layer on terrestrial
planets. Nearby high-energy transient astrophysical events have been proposed as possible triggers of mass extinctions on Earth.
Aims. We aim at assessing the habitability of the Milky Way (MW) along its cosmic history against potentially disruptive astrophysical
transients with the scope of identifying the safest places and epochs within our Galaxy. We also test the hypothesis that long GRBs
had a leading role in the late Ordovician mass extinction event („ 440 Myrs ago).
Methods. We characterise the habitability of the MW along its cosmic history as a function of galactocentric distance of terrestrial
planets. We estimate the dangerous effects of transient astrophysical events (long/short GRBs and SNe) with a model which binds
their rate to the specific star formation and metallicity evolution within the Galaxy along its cosmic history. Our model also accounts
for the probability of forming terrestrial planets around FGK and M stars.
Results. Until „6 billion years ago the outskirts of the Galaxy were the safest places to live, despite the relatively low density of
terrestrial planets. In the last „4 billion years, regions between 2 and 8 kpc from the center, featuring a higher density of terrestrial
planets, became the best places for a relatively safer biotic life growth. We confirm the hypothesis that one long GRB had a leading
role in the late Ordovician mass extinction event. In the last 500 Myrs, the safest galactic region is comprised between 2 and 8 kpc
from the center of the MW, whereas the outskirts of the Galaxy have been sterilized by 2–5 long GRBs.
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vox_mundi

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Re: Astronomical news
« Reply #390 on: October 01, 2020, 03:37:50 AM »
Did NASA Detect a Hint of Life On Venus In 1978 and Not Realize It?
https://www.livescience.com/amp/life-on-venus-pioneer-13.html



... digging through archival NASA data, Rakesh Mogul, a biochemist at Cal Poly Pomona in California, and colleagues have found a hint of phosphine picked up by Pioneer 13 — a probe that reached Venus in December 1978.

"When the [Nature Astronomy paper] came out, I immediately thought of the legacy mass spectra," Mogul told Live Science.

Mogul and his coauthors were broadly familiar with the data from the missions, he said. "So, for us, it was a natural next step to give the data another look.  As such, after consulting with my co-authors, we identified the original scientific articles, and promptly started looking for phosphorous compounds."

The discovery, published to the arXiv database Sept. 22 and not yet peer reviewed, doesn't tell researchers much beyond what was reported in Nature Astronomy — though it does make the presence of phosphine (made up of a phosphorus atom and three hydrogens) even more certain, they said. The 1978 data comes from the Large Probe Neutral Mass Spectrometer (LNMS), one of several instruments that descended into Venus' atmosphere as part of the Pioneer 13 mission.

Pioneer 13 dropped a large probe (the LNMS) into Venus' clouds; suspended from a parachute, the probe collected data and beamed it back to Earth as it plummeted toward its robotic death. (Three smaller probes also dropped from Pioneer 13 without parachutes.) The LNMS sampled the atmosphere and ran those samples through mass spectrometry, a standard lab technique used to identify unknown chemicals. When scientists first described the LNMS results in the 1970s, they didn't discuss phosphorus-based compounds like phosphine, focusing instead on other chemicals.

LNMS wasn't built to hunt phosphine-like compounds, and would have had a hard time distinguishing the gas from other molecules that have similar masses. But Pioneer 13's sample did have evidence of some molecule present in the gas that had the same mass as phosphine — in amounts that match the levels described in the Nature Astronomy paper.

... Mogul and his colleagues also found hints of other chemicals that shouldn't arise naturally in Venus' clouds — substances like chlorine, oxygen and hydrogen peroxide.

"We believe this to be an indication of chemistries not yet discovered," they wrote, "and/or chemistries potentially favorable for life."

Rakesh Mogul, et.al, Is Phosphine in the Mass Spectra from Venus’ Clouds?
https://arxiv.org/ftp/arxiv/papers/2009/2009.12758.pdf

https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1978-078D

https://nssdc.gsfc.nasa.gov/nmc/experiment/display.action?id=1978-078D-06
« Last Edit: October 01, 2020, 04:18:35 AM by vox_mundi »
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Re: Astronomical news
« Reply #391 on: October 02, 2020, 04:22:11 PM »
Rogue Earth-Mass Planet Discovered Freely Floating In the Milky Way Without a Star
https://phys.org/news/2020-10-rogue-earth-mass-planet-freely-milky.html



... Finding something in deep space that emits no light of its own is extremely challenging. But two organizations are doing just that. They're the Optical Gravitational Lensing Experiment (OGLE) collaboration and the Korean Microlensing Telescope Network (KMTN) collaboration.

Now, a team of scientists from both groups has announced the discovery of a low-mass rogue planet. There are no stars near it, and its distance from Earth is unconfirmed. The team says it proves that the microlensing technique is effective at finding Earth-mass planets that are free-floating in space.

The newly discovered planet, which has been named "OGLE-2016-BLG-1928," was discovered in a microlensing event that lasted only 41.5 minutes. That's not much time for detailed data to be gathered.

... A relatively tiny object like a low-mass planet doesn't bend much light, and not for too long, either. In their paper, the authors say, "Microlensing events due to terrestrial-mass rogue planets are expected to have extremely small angular Einstein radii (.1 µas) and extremely short timescales (0.1 day)." According to the authors, this is the "most extreme short-timescale microlens discovered to date."

Theoretical work shows that there could be billions, or even trillions, of free-floating planets in the Milky Way. In their work, the authors lists the ways these planets can end up orphaned: Planet-planet scattering; dynamical interactions between giant planets that lead to orbital disruption of smaller, inner planets; interactions between the stars in binary or trinary systems and star clusters; stellar fly-bys; and the evolution of the host star past the main sequence.



Mroz et al., A terrestrial-mass rogue planet candidate detected in the shortest-timescale microlensing event. arXiv:2009.12377
https://arxiv.org/abs/2009.12377
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Re: Astronomical news
« Reply #392 on: October 12, 2020, 05:55:41 PM »
Death by Spaghettification: Scientists Record Last Moments of Star Devoured by Black Hole
https://phys.org/news/2020-10-death-spaghettification-scientists-moments-star.html



A rare blast of light, emitted by a star as it is sucked in by a supermassive black hole, has been spotted by scientists using telescopes from around the world.

The phenomenon, known as a tidal disruption event, is the closest flare of its kind yet recorded, occurring just 215 million light-years from Earth. It is caused when a star passes too close to a black hole and the extreme gravitational pull from the black hole shreds the star into thin streams of material—a process called 'spaghettification'. During this process some of the material falls into the black hole, releasing a bright flare of energy which astronomers can detect.

... Using the European Southern Observatory's Very Large Telescope and New Technology Telescope, the Las Cumbres Observatory global telescope network, and the Neil Gehrel's Swift Satellite, the team was able to monitor the flare, named AT2019qiz, over a six-month period as it grew brighter and then faded away.

"The observations showed that the star had roughly the same mass as our own Sun, and that it lost about half of that to the black hole, which is over a million times more massive," said Nicholl, who is also a visiting researcher at the University of Edinburgh.

"Because we caught it early, we could actually see the curtain of dust and debris being drawn up as the black hole launched a powerful outflow of material with velocities up to 10 000 km/s," said Kate Alexander, NASA Einstein Fellow at Northwestern University in the US. "This unique 'peek behind the curtain' provided the first opportunity to pinpoint the origin of the obscuring material and follow in real time how it engulfs the black hole."

An outflow powers the optical rise of the nearby, fast-evolving tidal disruption event AT2019qiz, Monthly Notices of the Royal Astronomical Society (2020)
https://academic.oup.com/mnras/article/499/1/482/5920142

« Last Edit: October 12, 2020, 09:41:52 PM by vox_mundi »
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Re: Astronomical news
« Reply #393 on: October 13, 2020, 08:51:45 PM »
The Puzzle of the Strange Galaxy Made of 99.9% Dark Matter is Solved
https://phys.org/news/2020-10-puzzle-strange-galaxy-dark.html



Astronomers have measured how much dark matter there is around galaxies, and have found that it varies between 10 and 300 times the quantity of visible matter. However, a few years ago, the discovery of a very diffuse object, named Dragonfly 44, changed this view. It was found that this galaxy has 10,000 times more dark matter than the stars. Taken back by this finding, astronomers have made efforts to see whether this object is really anomalous, or whether something went wrong in the analysis of the observations. Now we have the answer.

An international team led by the Kapteyn Institute of the University of Groningen (the Netherlands), with participation by the Instituto de Astrofísica de Canarias (IAC) and the University of La Laguna (ULL), has found that the total number of globular clusters around Dragonfly 44 and, therefore, the dark matter content, is much less than earlier findings had suggested, which shows that this galaxy is neither unique nor anomalous. The result was recently published in Monthly Notices of the Royal Astronomical Society (MNRAS).

... By an exhaustive analysis of the system of globular cluster around Dragonfly 44, the researchers have detected that the total number of globular clusters is only 20, and that the total quantity of dark matter is around 300 times that of the luminous matter, which means that it is not way outside the normal value for this type of galaxies.

"The fact that in our work we found only 20 globular clusters, compared with the 80 previously claimed, reduces drastically the amount of dark matter which the galaxy is believed to contain," explains Ignacio Trujillo, an IAC researcher and a co-author of the article. "Moreover, with the number of globular clusters we found, the amount of dark matter in Dragonfly 44 is in agreement with what is expected for this type of galaxies. The ratio of visible to dark matter is no longer 1 in 10,000 but one in 300," adds Trujillo.

Teymoor Saifollahi et al, The number of globular clusters around the iconic UDG DF44 is as expected for dwarf galaxies, Monthly Notices of the Royal Astronomical Society (2020)
https://academic.oup.com/mnras/advance-article-abstract/doi/10.1093/mnras/staa3016/5919454?redirectedFrom=fulltext
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Sigmetnow

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Re: Astronomical news
« Reply #394 on: October 14, 2020, 04:43:18 AM »
One satellite, one rocket stage.  Probability of collision is 1-20%.
Oct 16  00:56UTC. 
< One (Cosmos 2004) is an old Russian communication/navigation satellite from the 1980s, and the other (CZ-4C R/B) is the upper stage of a Chinese Long March rocket that launched in 2009. Both of them are inactive and have been for a long time. 


LeoLabs, Inc. (@LeoLabs_Space) 10/13/20, 6:42 PM
We are monitoring a very high risk conjunction between two large defunct objects in LEO. Multiple data points show miss distance <25m and Pc between 1% and 20%. Combined mass of both objects is ~2,800kg.
Object 1: 19826
Object 2: 36123
TCA: Oct 16 00:56UTC
Event altitude: 991km

https://twitter.com/leolabs_space/status/1316147305125490694
⬇️ Image below.
~ This is a potentially serious event. It is between 2 large objects and at high altitude, 991km. If there is a collision there will be lots of debris which will remain in orbit for a long time.

< What does “Pc between 1% and 20%” mean?
<< Probability of collision. Those percentages are very high, for context.

< What do the red lines mean?
Matt Shouppe (@MattShouppe) 10/13/20, 7:29 PM
That is the field of view of our New Zealand radar that tracks these objects in space

    < What do the red scribbles over New Zealand mean? Should I move away from the window?
    Tim Ackroyd (@tim_a) 10/13/20, 9:53 PM
    It's all good New Zealand! Just a "radar fence". Nothing to worry about. Enjoy what is left of your day.

< If all space debris is tracked and orbital mechanics are predictable (bar satellites that change their orbits) why was this not known about more than a few days before?
<< orbits are only stable and predictable for a few hundred cycles - then small minor effects like the moon, not-quite-round shape of earth etc add up to a few meters here and there.

< is there any way in situations like this to shove one of them into a graveyard orbit with a third device?
Regan Pestl (@rpestl) 10/13/20, 9:09 PM
Yes, with a few years of planning, likely possible. This event occurs in 2 days...so we are left with the “cross your fingers” option. Possibly the “close your eyes and put your fingers in your ears” approach also might work.

< Yes, inertia has kept these sats at their current altitude. Some debris may drop to lower orbit, some may raise, but bulk will stay at that altitude
< When's the next tracking opportunity?
Matt Shouppe (@MattShouppe) 10/13/20, 9:11 PM
We'll have several more passes over the next 48 hours; we will share more updates as we get new data!
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Tom_Mazanec

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Re: Astronomical news
« Reply #395 on: October 14, 2020, 01:12:02 PM »
Planets form faster than we thought:

Four annular structures in a protostellar disk less than 500,000 years old
https://www.nature.com/articles/s41586-020-2779-6
Quote
Annular structures (rings and gaps) in disks around pre-main-sequence stars have been detected in abundance towards class II protostellar objects that are approximately 1,000,000 years old1. These structures are often interpreted as evidence of planet formation1,2,3, with planetary-mass bodies carving rings and gaps in the disk4. This implies that planet formation may already be underway in even younger disks in the class I phase, when the protostar is still embedded in a larger-scale dense envelope of gas and dust5. Only within the past decade have detailed properties of disks in the earliest star-forming phases been observed6,7. Here we report 1.3-millimetre dust emission observations with a resolution of five astronomical units that show four annular substructures in the disk of the young (less than 500,000 years old)8 protostar IRS 63. IRS 63 is a single class I source located in the nearby Ophiuchus molecular cloud at a distance of 144 parsecs9, and is one of the brightest class I protostars at millimetre wavelengths. IRS 63 also has a relatively large disk compared to other young disks (greater than 50 astronomical units)10. Multiple annular substructures observed towards disks at young ages can act as an early foothold for dust-grain growth, which is a prerequisite of planet formation. Whether or not planets already exist in the disk of IRS 63, it is clear that the planet-formation process begins in the initial protostellar phases, earlier than predicted by current planet-formation theories11.

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Sigmetnow

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Re: Astronomical news
« Reply #396 on: October 15, 2020, 02:51:52 AM »
Quote
< Unfortunately, LeoLabs’ updated numbers on tomorrow’s conjunction between two defunct spacecraft over Antarctica doesn’t spell good things to come.  A miss distance of 12 meters, give or take, with a collision probability of over 10 percent.  :o

LeoLabs, Inc. (@LeoLabs_Space) 10/14/20, 12:09 PM
1/ This event continues to be very high risk and will likely stay this way through the time of closest approach. Our system generates new conjunction reports 6-8x per day on this event with new observation data each time.
https://twitter.com/leolabs_space/status/1316410780552699909
[gif of orbital conjunction at the link.]

LeoLabs, Inc.:
2/ Current risk metrics from our most recent CDMs:
Miss distance: 12 meters (+18/-12 meters)
Probability of Collision: >10%, scaled to account for large object sizes
Relative velocity: 14.7 km/s

[⬇️ Graph below]
LeoLabs, Inc.:

3/ Shortly after TCA, we will have a direct pass of CZ-4C R/B over our Kiwi Space Radar in New Zealand. We have scheduled a search mode scan during this time to ensure we only see two objects as expected and hopefully confirm that no new debris is detected.
[⬇️ Graphic below]
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Sigmetnow

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Re: Astronomical news
« Reply #397 on: October 15, 2020, 03:53:22 AM »
Upper stages top list of most dangerous space debris
October 13, 2020
Overall, 78% of the objects on the list are rocket bodies, and 80% of the objects were launched before 2000, when countries started adopting orbital debris mitigation guidelines. “These are really lingering problems from early in the Space Age.”
https://spacenews.com/upper-stages-top-list-of-most-dangerous-space-debris/
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Re: Astronomical news
« Reply #398 on: October 16, 2020, 03:58:49 AM »
Quote
LeoLabs, Inc. (@LeoLabs_Space) 10/15/20, 9:51 PM
No indication of collision.

CZ-4C R/B passed over LeoLabs Kiwi Space Radar 10 minutes after TCA. Our data shows only a single object as we'd hoped, with no signs of debris.

We will follow up in the coming days on Medium with a full in-depth risk assessment of this event!
https://twitter.com/leolabs_space/status/1316919600160903168
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Re: Astronomical news
« Reply #399 on: October 16, 2020, 04:03:23 AM »
Quote
Andrew McCarthy (@AJamesMcCarthy) 10/15/20, 11:19 AM
Yesterday morning I captured an incredibly brief and rare event, the ISS transiting the 4% illuminated moon during the daytime. #astrophotography #space #opteam
https://twitter.com/ajamesmccarthy/status/1316760737059008514
Details in the thread explain how the image was captured and created.
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