Space: The Final Frontier

[CaaC (John)+]

16 hours ago, nudge said:

Yes, keep on watching, the series cover that all in detail... It's crazy how the engineers who actually tried to intervene and get the launch delayed still felt guilty and blamed themselves for the rest of their lives, whereas NASA management who decided to launch despite knowing the risks and ignoring them said they did not feel guilty at all and would have made the same decision again, because they thought it was the right decision  Mental. 

Just watching E3 now A major malfunction.

My full respects go out to the other lady teacher member in Barbara Morgan who was a backup astronaut that never flew on the mission, she narrates calmy in the episodes knowing in the back of her mind she could have been aboard the fatal flight yet a year later was in the STS-118 flight in august 2007.

 

 

Edit: How the FUCK could you initiate and carry out an order to launch the shuttle when you wake up and see this 

Edited October 30, 2020 by CaaC (John)

[CaaC (John)+]

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What is it with all that dust?

Scientists solve another mystery about white dwarfs.

Scientists studying how comets and asteroids break up and vaporize if they get too close to their suns have resolved a conundrum about a class of stars known as white dwarfs.

Embers of dying suns, white dwarfs form when a star, having run out of its nuclear fuel, first expands to enormous size then collapses into a dense, Earth-sized remnant.

The initial, swollen size is called a red giant – and is large enough to consume planets as far out as Earth, and even Mars. It then implodes, leaving the white dwarf, which can initially be as hot as 50,000 degrees Celsius, until it gradually cools into obscurity.

So far, so good. But astronomers have found that about 4% of them appear to be accompanied by clouds of dust.

“This begs the question if white dwarfs should have cleared out all of this debris during the red giant phase, then why do some of them seem to have closely orbiting dusty debris discs,” Jordan Steckloff, of the Planetary Science Institute, US, told this week’s virtual meeting of the American Astronomical Society’s Division for Planetary Sciences.

Previously, he says, it was assumed that these discs were formed from planetesimals or asteroids that were far enough out to survive immolation in the red giant phase, but then fell inward, winding up so deep in the white dwarf’s gravity that they got ripped to shreds—something that occurs at a distance often referred to as the Roche limit.

These shreds would then be dispersed into a “nice tight dusty debris disc” by the pressure of the light emitted by the star.

But there was a big problem with that theory. One would expect younger white dwarfs to have less stable planetary systems, thanks to the gravitational mayhem that accompanied the effect of the red giant destroying all of the inner planets. In other words, they should have more worldlets falling toward the star to be ripped into dust.

Also, younger white dwarfs are hotter – and therefore brighter – and should be better at making dusty discs out of the debris of shredded planetesimals.

But that, Steckloff says, is not what astronomers have seen. Young super-hot white dwarfs do not have dust disks. “It’s only when white dwarfs cool to less than about 27,000 degrees Kelvin (27,000°C) that we actually see dusty debris discs start to appear.”

The answer, he says, is something fairly obvious (in hindsight) but previously overlooked: if a planetesimal falls too close to a super-hot star, not only will it get shredded into dust, that dust will then be vaporized by the heat – a process he refers to as sublimation. The result: no dusty disc.

“It needs to be outside the sublimation limit and inside the Roche limit,” he says.

The Roche limit is determined by the star’s mass, but the sublimation limit is determined by its brightness, which declines as it cools.

And, he says, it turns out that for young, super-hot white dwarfs, the Roche limit is inside the sublimation limit. I.e., anything that falls close enough to the star to be shredded will also be vaporized.

It is only when the white dwarf cools to somewhere between 25,000 and 32,000 Celsius, he says, that this reverses – with the exact temperature depending on what type of minerals the dust is composed of. In fact, the figure comes even closer to 27,000 degrees if it is assumed that the dust in these discs is similar to the materials in our own Solar System’s asteroids.

And that might be one of his most important findings.

“The 27,000-degree limit suggests that the material that we find orbiting around white dwarfs is likely analogous to [asteroids] in our own Solar System,” he says.

https://cosmosmagazine.com/space/astrophysics/what-is-it-with-all-that-dust/

 

[CaaC (John)+]

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Bits of big asteroid found on a small one

NASA’s Bennu sampling mission maybe a twofer.

Scientists poring over images from the asteroid 101955 Bennu, now being orbited by NASA’s OSIRIS-REx spacecraft, have found boulders that appear to be pieces blown off the asteroid Vesta billions of years ago.

Vesta is the second-largest asteroid in the Solar System and lies well out in the heart of the Asteroid Belt. It measures 525 kilometres across, and while it is largely intact, it is known to have taken a pummeling from ancient impacts.

Bennu is only 490 metres across and is on an orbit that comes close enough to Earth that there is a small chance that it might hit us sometime late next century.

Figuring out how pieces of the one asteroid got to the other, scientists say, is an important clue to unravelling the history of Bennu, as well as probing the behaviour and evolution of asteroids during the history of the Solar System.

The boulders first attracted attention because they are much brighter than other materials on Bennu’s surface, Daniella DellaGiustina of the University of Arizona will tell this week’s virtual meeting of the American Astronomical Society’s Division of Planetary Sciences (DPS).

Even on the spacecraft’s early images of the asteroid, she says, these boulders stood out as bright spots, 1.5 to four metres in diameter. “There were six of them,” she says. “The brightest is almost 30 sigma [standard deviations] brighter than the mean [for Bennu’s surface].”

Or, to put it less technically, these boulders were about three to six times brighter than the bulk of Bennu’s surface (which is about the colour of charcoal).

But that proved to be just the beginning. “We have now identified about 77 [such] boulders and analysed 44 of them,” says Humberto Campins, a planetary scientist from the University of Central Florida, who is also part of the study team.

The analysis, he adds, involves using spectroscopic techniques to see how these boulders reflect different wavelengths of sunlight.

The scientists have found that they contain the mineral pyroxene, a known component of Vesta – but the boulders probably didn’t come from chips of Vesta hitting Bennu itself. More likely, they are remnants of a larger piece that hit Bennu’s parent body – possibly even the one that smashed it into the bits – some of which later coalesced to form Bennu.

It’s an exciting find, he says, because until recently it had been believed that when an asteroid is hit hard enough to break it up, the impactor would be vaporised and leave no traces.

Now, that appears not to be the case, meaning that it may be possible to use this information to help figure out the process by which Bennu’s parent asteroid was destroyed.

Better yet, he says, it’s likely that Bennu is strewn with smaller chips of the same type of rocks. If so, it’s possible that when OSIRIS-REx briefly touched down on Bennu last week to snag a sample for return to Earth, it may have gotten a few of them.

If so, Campins says, the sample return mission might turn out to be an unexpected twofer: in effect, “a sample return mission to both Bennu and Vesta”.

Japan’s Hayabusa2 mission to asteroid 162173 Ryugu may have the same unexpected bonus. Ryugu also has bright boulders, Eri Tatsumi of the Instituto de Astrofísica de Canarias, Tenerife, Spain will tell the DPS meeting – though these appear to have come from a source other than Vesta.

For these twofers to occur, however, the samples have to get safely back to Earth. Japan’s is already en route, expected to parachute down in Woomera, South Australia, on 6 December.

NASA’s won’t arrive until 2023. But the agency says that it has collected so much material that a flap intended to seal its sample collection chamber after the sample was collected can’t close, causing it to expedite its process of stowing the sample away onboard, before too much precious material escapes into space

https://cosmosmagazine.com/space/astronomy/bits-of-big-asteroid-found-on-small-one/

 

 

[CaaC (John)+]

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Durham University Prof Carlos Frenk's prize a 'huge honour'

A cosmologist who helped shape the understanding of dark matter and the structure of galaxies has been awarded a top physics prize.

Prof Carlos Frenk has been awarded the 2020 Paul Dirac Medal and Prize for theoretical physics by the Institute of Physics (IoP).

The Durham University researcher was one of the originators of the Cold Dark Matter (CDM) theory.

It is the second year in a row a Durham professor has won the award.

A university spokesman said research carried out by Prof Frenk and his Durham colleagues had "created an internationally-renowned capability for predicting the observable properties of galaxies in a CDM universe".

Prof Frenk said: "Paul Dirac was one of the greatest physicists of the 20th Century and one of the founders of quantum physics. To receive a medal named after him is a huge honour.

"Medals like this are awarded to individuals, but science is an international collaborative effort.

"I share this honour with the many colleagues and students with whom I have had the privilege of working over the years at Durham and elsewhere."

The IoP also recognised Durham researchers Prof Martin Cann and Dr Karis Baker, who received the Rosalind Franklin Silver Medal and Prize alongside other members of the Physics of Life Network 2 steering group.

In 2019, Durham University's Prof Keith Ellis won the Paul Dirac medal for his work on quantum chromodynamics.

https://www.bbc.co.uk/news/uk-england-tyne-54781590

 

[nudge]

Voyager 2 is back online after 8 months of radio silence  it's technology of the 70s...never fails to amaze me. 

 

[CaaC (John)+]

2 hours ago, nudge said:

Voyager 2 is back online after 8 months of radio silence  it's technology of the 70s...never fails to amaze me. 

 

Brilliant that, to think Voyager 2 was launched in 1977, went to sleep and now NASA has woken it up again.

_______________________________________________________________________________________________________________________________

Voyager 2

https://solarsystem.nasa.gov/missions/voyager-2/in-depth/

 

Terminations and future of the probe

Voyager 2 is not headed toward any particular star, although in roughly 42,000 years it will pass 1.7 light-years from the star Ross 248. And if undisturbed for 296,000 years, Voyager 2 should pass by the star Sirius at a distance of 4.3 light-years. Voyager 2 is expected to keep transmitting weak radio messages until at least the mid-2020s, more than 48 years after it was launched.

As the power from the RTG slowly reduces, various items of equipment have been turned off on the spacecraft. The first science equipment turned off on Voyager 2 was the PPS in 1991, which saved 1.2 watts.

Year	End of specific capabilities as a result of the available electrical power limitations[72]
1998	Termination of scan platform and UVS observations
2007	Termination of Digital Tape Recorder (DTR) operations (It was no longer needed due to a failure on the High Waveform Receiver on the Plasma Wave Subsystem (PWS) on June 30, 2002.)
2008	Power off Planetary Radio Astronomy Experiment (PRA)
2016 approx	Termination of gyroscopic operations?
2019	CRS heater turned off
2020 approx	Initiate instrument power-sharing
2025 or slightly afterwards	Can no longer power any single instrument

Edited November 3, 2020 by CaaC (John)
Restore link

[CaaC (John)+]

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5 November 2020 /  Richard A Lovett

Tracing the origins of fast radio bursts

Two teams spot the first event in the Milky Way.

Radio astronomers monitoring the sky for unusual events have found a fast radio burst (FRB) in the constellation Vulpecula, 30,000 light-years from Earth in the Milky Way. It is the first time such an event has been observed in our galaxy.

Now called FRB 200428, it occurred on 28 April and is reported by two independent teams: one using an instrument in Canada and the other an array of detectors in the southwestern US.

FRBs are enormous blasts of radio energy that in a few milliseconds can broadcast as much energy in radio waves as the monthly output of the Sun in all forms, combined.

By intergalactic standards, FRB 200428 is a pipsqueak – a factor of 30 weaker than the weakest known extragalactic FRB, and 1000 times less powerful than the average one, says Christopher Bochenek from California Institute of Technology, who was a member of one of the teams.

But still, “this is the most luminous radio source ever detected in our own galaxy”, adds Daniele Michilli, an astrophysicist with Canada’s McGill Space Institute and a member of the other.

It is also close enough, Bochenek says, for astronomers to be able to link it to a gamma-ray source known as SGR 1935+2154. “This is the first FRB that has come from a known object”.

SGR 1935+2154 is a magnetar. “That’s a type of neutron star whose magnetic field is so strong they squish atoms into pencil-like shapes.”

Such stars are known to produce brief, intense flares that emit rapid bursts of gamma rays and X-rays. In fact, Bochenek’s team found, FRB 200428 was accompanied by just such an outburst of X-rays.

Magnetars have long been regarded as a top candidate for producing FRBs, says Bing Zhang, an astrophysicist at the University of Nevada, US. “People have been speculating this for many years.”

But, he adds, his team was working with a giant radio telescope in China and happened to be watching the magnetar from 16 April to 29 April but saw no signs of FRBs accompanying 29 other gamma-ray bursts emitted by it during that time interval. (His team was unable to observe FRB 200428 itself.)

“This is puzzling but very interesting,” Zhang says.

Further compounding the puzzle is that some of the gamma-ray bursts not accompanied by FRBs were brighter than the one associated with FRB 200428.

Perhaps, Zhang says, these other flares actually did produce FRBs but emitted them in narrow beams that didn’t happen to point our way. Or perhaps only “very special” types of gamma-ray-creating events produce FRBs. “We don’t have a very clear conclusion yet,” he says.

What we do know is that FRBs can indeed be created by magnetars. “Before, we had more than 15 different models.”

Meanwhile, astronomers are hoping to see more FRBs like FRB 200428 in our own galaxy. “We’ll see how special, or not special, it is,” Zhang says.

How long we have to wait for that, Bochenek adds, is unknown. “We don’t know how lucky we got,” he says. “This could a once-in-five-year event, or it could be every few months.”

Bochenek’s, Michilli’s, and Zhang’s teams’ studies all appear in today’s issue of Nature.

https://cosmosmagazine.com/space/astronomy/tracing-the-origins-of-fast-radio-bursts/

 

[CaaC (John)+]

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6 November 2020 

Playing detective on a galactic scale

A Huge new dataset will solve Milky Way mysteries.

An Australian-led team of “galactic archaeologists” has just released the largest set of stellar chemical data ever compiled, containing information from 600,000 stars.

This new dataset will help astronomers solve many questions about the structure and evolution of the Milky Way, unravelling mysteries about star formation, chemical enrichment, migrations and galaxy mergers. 

The 500GB of data is the result of 342 nights of observing over the last seven years by HERMES, a spectrograph attached to the Anglo Australian Telescope (AAT) in rural New South Wales. HERMES can collect light from more than 300 stars at once and separate out their light into spectra, from which astronomers discern the unique “fingerprints” of the chemical elements within the star.

“It’s a bit like a galactic version of the game Cluedo,” says Sven Buder, an astrophysicist from the Australian National University and a member of the Galactic Archaeology with HERMES (GALAH) collaboration.

“The chemical information we’ve gathered is rather like stellar DNA – we can use it to tell where each star has come from. We can also determine their ages and movements and furnish a deeper understanding of how the Milky Way evolved.”

Sarah Martell, another member of the collaboration from UNSW Sydney, explains that the chemical abundance patterns of stars can also “tell us what has been happening in the galaxy before they formed – were there supernova explosions? What elements have previous generations of stars been able to eject into the environment? Has fresh gas fallen in from outside the Milky Way?”

The dataset is the third to be released by the GALAH project. The previous observations, released in 2018, fuelled research into areas ranging from the evolution of the Milky Way to the existence of exoplanets. The project anticipates observing another 250,000 stars before the end of 2022, shooting for one million in total.

Most of the stars observed were within 10,000 light-years of the Sun – a conscious choice by the team in order to delve into the nitty-gritty details of our own stellar neighbourhood.

“There are good reasons to think that our side of the galaxy is very similar to the far side in terms of stellar ages, orbits, and chemical compositions,” Martell says, “so a thorough dataset in the solar neighbourhood lets us make a lot of inferences about the rest of the galaxy.”

Interestingly, the team found that more than 20,000 of these nearby stars don’t share the same age or composition as our Sun and many of its neighbours – because they’re interlopers from another galaxy.

“We know that roughly eight billion years ago the shape of the Milky Way changed drastically when it collided with another, smaller galaxy, which contained millions of stars,” Buder explains.

“We’ve now used the stellar DNA to identify some of the prime suspects for the assault. These stowaways are so different they can only have come from somewhere else.”

This new collection of stellar information may also answer a puzzle that has plagued astronomers for years: the cosmological lithium problem.

Lithium was forged in the hot, dense conditions of the early Universe, but according to standard models of the Big Bang, we should observe a lot more of this element than we actually do.

“Basically, a lot of the oldest stars have burned much of the Big Bang lithium, so our measurements for this element come out lower than the amount that was initially synthesised in the early Universe,” says Sanjib Sharma, another collaborator from ASTRO 3D and the University of Sydney.

“We have found that one type of star, known as evolved giants, should have burned through pretty much all of their lithium by now, but a lot of them have much more of it than we expected. The GALAH data will help us discover why.”

The massive dataset is now freely available for astronomers around the world to use in their own research, and it will be particularly useful in conjunction with other complementary datasets.

“GALAH is just one of several surveys going on at the moment that are collecting chemical abundance data on the scale of hundreds of thousands to a million stars, and there are great synergies between those projects,” Martell explains.

GALAH thoroughly samples the Milky Way, while the APOGEE survey, for example, uses infrared to peer into the dusty plane of the galaxy, and the LAMOST survey can observe much more distant stars.

“We are working on clever ways to combine the datasets from the different surveys to build a comprehensive catalogue for the Milky Way,” says Martell.

https://cosmosmagazine.com/space/astronomy/playing-detective-on-a-galactic-scale/

 

[Stan]

How cool does that look

 

[nudge]

Rocket launches are always amazing... Love watching it live, and spaceflight photography is also breathtaking. Certainly a fascinating job to have...

Really excited about and looking forward to the first 15km test flight of the Starship SN8 prototype next week. A huge difference compared to the previous 150m hops. This is the first Starship prototype that will test the launch, return, and landing capability ahead of the push to orbit next year. Such an aesthetically pleasing design. Hope the test flight is a success.

https://twitter.com/cnunezimages/status/1324509498678087680?s=20

[CaaC (John)+]

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Lady Stardust was a star of astrophysics

Margaret Burbidge found her calling early.

Margaret Burbidge, named by the American Association for the Advancement of Science (AAAS) as “one of the most influential astrophysicists of her time”, died on 5 April this year. She was 100 years old.

Among the many stories told about her remarkable life, one of the best is also one of the earliest. In a 1978 interview with the American Institute of Physics, she recounts how her “fascination” with the stars began at age four when she became seasick while on a night crossing of the English Channel with her family, on the way to France for a holiday.

“To take my mind off that, I was lifted up to look out of the porthole on the upper bunk to see the stars,” she says.

For a child growing up in foggy London, the sight of the stars at sea was amazing. “You know how they are at sea, on a clear night,” she says. “These twinkling lights then became another fascination to me, tracking down any kind of twinkling light and enjoying twinkling lights.”

This fascination with stars, and her groundbreaking work in astronomy and spectroscopy – the analysis of starlight by wavelength – led to her being nicknamed Lady Stardust.

Eleanor Margaret Peachey was born on 12 August 1919 in Stockport, Greater Manchester. The family moved to London when she was two and she went on to study astronomy, physics and mathematics at University College London, graduating with first-class honours in 1939.

She earned a PhD from UCL in 1943, in the thick of World War II, while also working as a caretaker at the university’s Mill Hill Park observatory.

As the war was ending, Burbidge applied for a postdoctoral fellowship to work and study in the US, at the renowned Mount Wilson Observatory in southern California; the outcome was unexpected.

As she wrote in a 1994 article titled “Watcher of the Skies” in the Annual Review of Astronomy and Astrophysics, “The letter of denial opened my eyes to a new and somewhat frightening situation: new, because I had never before experienced gender-based discrimination.”

The letter Burbidge received pointed out that Carnegie Fellowships were available only for men, and that women were not allowed to use the Mount Wilson telescopes. The experience caused her to become a champion for women’s rights for the remainder of a long and productive life.

Temporarily frustrated, she returned to UCL to do graduate studies. She also gave classes on practical astronomy, and one of her students, says a recent article in Sky & Telescope magazine, was an enthusiastic undergraduate named Arthur C Clarke.

AT UCL she also met a well-regarded young physicist, Geoffrey Burbidge, and they married in 1948. They continued their studies, and a series of grants allowed them to work at observatories in Europe, Canada and, in 1951, the US.

In 1955 Margaret again applied to join the staff at the Mount Wilson observatory, and again was turned down because of her sex.

As she says in “Watcher of the Skies”: “Standard reasons for not allowing women on the telescope included the fact that there were only male-oriented bathroom facilities on the mountain, and that the telescope technicians would object to operating under directions from a woman.”

Not to be deterred, Geoffrey applied for the Mount Wilson position and was hired. However, as The Guardian notes in its obituary for Margaret, when he went observing “she went along as his assistant. In reality, however, she operated the telescope and ran the observing program.”

In 1957 Margaret wrote the paper for which she is best known, “Synthesis of the Elements in Stars”, which was published in the journal Reviews of Modern Physics. The New York Times calls it “one of the most influential scientific papers of its era”.

She produced the work with Geoffrey, the renowned American physicist William Fowler and English astronomer Fred Hoyle; so great was its impact that the group became known in astronomical circles simply as B2FH.

In it, the authors argue that nearly all of the chemical elements, from aluminium to zinc, are forged in the bodies of stars, a process now called stellar nucleosynthesis, The Times says. “The heavier elements are synthesised from the lighter ones by thermonuclear reactions within stars. Loosed into space, these elements can also recombine to form new stars, beginning the cycle once more.”

Fowler believed the work “laid the foundations for all of modern nuclear astrophysics, and particle astrophysics as well,” The Times says.

In 1972 Burbidge become the first woman to direct Britain’s Royal Observatory. In 1977 she became a US citizen and was the first woman to serve as president of the American Astronomical Society, a position she held from 1976 to 1978.

“She simply wanted to be very good at her work as an observational astronomer, and I would say she was probably the best of her generation,” Burbidge’s daughter, Sarah, told Sky & Telescope magazine.

https://cosmosmagazine.com/space/astronomy/lady-stardust-was-a-star-of-astrophysics/

 

[CaaC (John)+]

 

 

Edited November 9, 2020 by CaaC (John)

[CaaC (John)+]

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Jupiter’s moon Europa may glow in the dark

An exciting destination just got more intriguing.

NASA’s Europa Clipper mission will conduct detailed reconnaissance of Jupiter’s moon Europa. Credit: NASA

In news that is sure to delight every kid with stickers of stars and planets on their ceiling, planetary scientists have discovered that the night-side of Jupiter’s moon Europa may glow in the dark.

The illuminating lab simulations, performed by NASA’s Jet Propulsion Laboratory (JPL), could help future spacecraft peer deep into the moon’s sub-surface oceans.

Europa is one of the most exciting places in the Solar System because of its potential to harbour extraterrestrial life. Though only the size of our own Moon, it’s thought to have a vast subsurface sea with twice as much water as all of Earth’s oceans combined, covered by a thick frozen crust.

Jupiter’s massive gravitational influence stretches and squeezes this icy world as it orbits, generating heat in the interior through friction – so even though it’s more than 700 million kilometres from the Sun, Europa could be habitable for life.

The outer surface of the moon is bombarded by high levels of radiation, channelled by Jupiter’s powerful magnetic field. According to the new study published in Nature Astronomy, this radiation might prove the key to studying the moon’s composition.

Led by JPL scientist Murthy Gudipati, the research team simulated the interactions between high-energy charged particles and the surface of Europa by irradiating salted ice with energetic electrons. This, they discovered, causes the ice to emit a visible greenish glow – a phenomenon called electron-stimulated luminescence.

“Owing to the unique radiation environment and rich geological and compositional diversity on its surface, the night-time ice glow occurring on Europa may be very unique and unlike any other phenomenon in our Solar System,” the authors write in their paper.

“In some ways, you could almost think of this as an ice aurora,” comments Jonti Horner, an astronomer at the University of Southern Queensland in Australia, who was not involved in the study. “The ice and material in it are being bombarded by high energy electrons, and that makes it glow – with different chemical species giving off different colours.”

The intensity of the glow depends on the composition of the ice: the presence of sodium chloride and carbonate produced a fainter light, while epsomite produced a brighter light.

The authors suggest that “these emission characteristics could be used to determine the chemical composition of Europa’s surface during night-time low-altitude fly-bys of spacecraft such as the Europa Clipper.”

NASA’s Europa Clipper mission is slated for launch in the mid-2020s and aims to conduct a detailed survey of Europa, from the thin atmosphere to the subsurface ocean to the deep interior. Alongside taking measurements and images, it will sample molecules in the atmosphere and scout out potential spots for a future lander.

The mission could also take advantage of the “ice aurora” predicted by this study in order to work out what minerals are common on the surface of Europa’s ice. By observing the intensities of radiation-induced light emitted by the surface, Europa Clipper could build a composition map of the moon.

“It sounds like a really clever way to take advantage of a natural phenomenon to do science – something astronomers and planetary scientists are great at,” says Horner.

Earth-bound telescopes have observed Europa in the visible spectrum before, including the Keck Observatory and the Hubble Space Telescope, but no significant emissions were detected. However, the large distances between the Earth and Europa may be partially to blame. From low altitude – just 50 kilometres above the surface – the Europa Clipper mission has a better chance.

These measurements could give us a better understanding of the sub-surface ocean, placing constraints on properties such as salinity. Looking further forward, they could also help identify the most interesting places on Europa to visit.

Horner explains: “It’s going to be really hard for us to ever land on Europa, much harder than Mars, but people are really keen to try it one day – and these kinds of observations might really help focus the decisions on where such a lander should go.”

This research may also be relevant to other celestial bodies exposed to high doses of ionising radiation, such as two of Jupiter’s other moons, Io and Ganymede.

https://cosmosmagazine.com/space/astronomy/jupiters-moon-europa-may-glow-in-the-dark/

 

[CaaC (John)+]

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Mining with microbes in space

Can bacteria extract useful materials from rocks?

Astronaut Luca Parmitano places biomining reactors into a centrifuge on board the International Space Station. Credit: European Space Agency

The first mining experiments in space have revealed that microbes can efficiently extract elements from rocks in zero gravity.

The tests, performed by astronauts on the International Space Station (ISS), open up possibilities for the human exploration and settlement of the Solar System.

“On Earth, microorganisms play prominent roles in natural processes such as the weathering of rocks into soils and the cycling of elements in the biosphere,” the researchers explain in a paper in the journal Nature Communications. 

“Microorganisms are also used in diverse industrial and manufacturing processes, for example in the process called biomining.”

Biomining bacteria can catalyse the extraction of valuable elements like copper and gold from rocks. Here on Earth, they are routinely used to mine rare earth elements (REEs) such as lanthanides, scandium and yttrium. 

The useful physical properties of REEs, like ferromagnetism and luminescence, make them critical components of phones and computer screens, as well as useful in catalysis, metal alloy and magnet production.

But not only are REEs expensive to mine, but they are also rapidly running out. If humans want to explore further into the solar system and build settlements on other moons and planets, we need to figure out a way to mine these elements in situ.

Sphingomonas desiccabilis, the bacterium that was shown to biomine rare earth elements, growing on basalt rock. Microbes are stained to fluoresce green. Credit Rosa Santomartino

This new study aimed to investigate whether microbes could extract REEs under differing gravitational conditions. 

The researchers, led by Charles Cockell at the University of Edinburgh, UK, spent a decade developing miniaturised biomining reactors that could be sent up to the ISS. These matchbox-sized mining devices were loaded with small pieces of basalt – a common rock on the Moon and Mars – and submerged in different bacterial solutions before being launched in 2019.

Over three weeks, astronauts assessed the biomining potential of three different species of bacteria under varying gravitational conditions, from microgravity to simulated Mars gravity. 

The results show that the bacterium Sphingomonas desiccabilis leached REEs from basalt under all three levels of gravity, while the other two species of bacteria tested either showed reduced efficiency at low gravity or an inability to extract REEs at all.

The success of S. desiccabilis could help us source materials essential for surviving in space.

“Our experiments lend support to the scientific and technical feasibility of biologically enhanced elemental mining across the Solar System,” says lead author Charles Cockell, from the University of Edinburgh. 

“While it is not economically viable to mine these elements in space and bring them to Earth, space biomining could potentially support a self-sustaining human presence in space. 

“For example, our results suggest that the construction of robotic and human-tended mines in the Oceanus Procellarum region of the Moon, which has rocks with enriched concentrations of rare earth elements, could be one fruitful direction of human scientific and economic development beyond Earth.”

The researchers further note that bacteria could also one day be used to break down rock into the soil for growing food or extract minerals to use in life support systems that produce air and water.

This study may also be useful down here on Earth, helping scientists understand how gravity influences the growth and metabolic processes of microbial communities on the surface.

https://cosmosmagazine.com/space/astrobiology/mining-with-microbes-in-space/

 

[nudge]

 

[CaaC (John)+]

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An important discovery of a cold brown dwarf

Astronomers achieve a first using radio observations.

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Artist's impression of the cold brown dwarf BDR J1750+3809. Blue loops depict the magnetic field lines. Charged particles moving along these lines emit radio waves. Credit: ASTRON/Danielle Futselaar

Astronomers have reported the first direct discovery of a cold brown dwarf from its radio wavelength emission. 

It’s a significant breakthrough, as it demonstrates that it is possible to detect objects that are too cold and faint to be found in existing infrared and optical surveys. And that may include large, free-floating exoplanets.

BDR J1750+3809, as it has been designated, was found thanks to a collaboration between Europe’s LOFAR (LOw-Frequency Array) telescope and the Gemini North telescope and NASA InfraRed Telescope Facility (IRTF) in Hawaii.

Brown dwarfs are substellar objects straddling the boundary between the largest planets and the smallest stars. The first unambiguous observation did not occur until 1995. 

Sometimes dubbed failed stars, they lack the mass to trigger hydrogen fusion in their cores, instead of glowing at infrared wavelengths with leftover heat from their formation. While they lack the fusion reactions that keep the Sun shining, they can emit light at radio wavelengths. 

The underlying process powering this radio emission is familiar, as it occurs in Jupiter. The planet’s powerful magnetic field accelerates charged particles such as electrons, which in turn produces radiation.

Radio emissions have previously been detected from only a handful of cold brown dwarfs, and these had already been catalogued by infrared surveys. 

In the new work, the team first used a sensitive radio telescope to discover cold, faint sources, then made follow-up infrared observations with a large telescope to categorise them.

“In this discovery, Gemini was particularly important because it identified the object as a brown dwarf and also gave us an indication of the temperature of the object,” says Harish Vedantham from the Netherlands Institute for Radio Astronomy, lead author of a paper in The Astrophysical Journal Letters.

“The Gemini observations told us that the object was cold enough for methane to form in its atmosphere, showing us that the object is a close cousin of Solar System planets like Jupiter.” 

The ultimate goal, Vedantham says, is to understand magnetism in exoplanets and how it impacts their ability to host life.

“Because magnetic phenomena of cold brown dwarfs are so similar to what is seen in Solar System planets, we expect our work to provide vital data to test theoretical models that predict the magnetic fields of exoplanets.”

https://cosmosmagazine.com/space/astronomy/important-discovery-of-a-cold-brown-dwarf/

 

[nudge]

Starship SN8 experienced some problems during the 3rd static fire test last night. Hopefully that won't delay the test flight for too long.

 

 

 

In the meantime, NASA Crew-1 is 70% GO at the moment based on the weather forecast, and the launch is scheduled for 00:49 GMT early Sunday morning.

[CaaC (John)+]

3 minutes ago, nudge said:

In the meantime, NASA Crew-1 is 70% GO at the moment based on the weather forecast, and the launch is scheduled for 00:49 GMT early Sunday morning

Will have to set my alarm for that launch.

[nudge]

4 minutes ago, CaaC (John) said:

Will have to set my alarm for that launch.

And hope it doesn't get delayed  

[nudge]

Ha, I knew it... Crew-1 launch delayed for 24 hours, now scheduled for early Monday morning GMT. @CaaC (John) you can turn off that alarm for now...

 

[CaaC (John)+]

Inner Solar System

Outer Solar System

[CaaC (John)+]

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Space isn’t the place to run out of fuel

A clever new gauge may help keep track of things.

Some satellites are decommissioned with fuel still in the tank. Credit: NASA Jet Propulsion Laboratory

Keeping an eye on your fuel levels in space can be tricky – and that can be costly.

Let a satellite’s tank run dry and you leave it stranded in its original orbit with no fuel to avoid smashing into things. Hold back more than you need, and you risk wasting quite a bit of money by retiring a satellite with fuel still on board.

The problem, of course, is that microgravity inside a spacecraft allows liquid to freely slosh about.

A common way to keep track of it is to estimate how much fuel is being burned with each thrust and subtract that amount from the volume of fuel in the tank.

However, engineers at the National Institute of Standards and Technology (NIST) in the US say that while this is quite accurate when a tank is close to full, estimates become more like rough guesses and eventually can miss the mark by as much as 10%. The error of each estimate carries on to the next.

The answer could lie in their new idea for fuel gauge, described in a paper in the Journal of Spacecraft and Rockets, which can digitally recreate a fluid’s 3D shape based on its electrical properties.

The concept, originally devised by NASA’s Manohar Deshpande, makes use of a low-cost imaging technique known as electrical capacitance volume tomography (ECVT).

Like a CT scanner, ECVT can approximate an object’s shape by taking measurements at different angles. But instead of shooting X-rays, electrodes emit electric fields and measure the object’s ability to store electric charge, or capacitance.

Deshpande then worked with Nick Dagalakis and colleagues in the NanoFab clean room at NIST’s Centre for Nanoscale Science and Technology to develop a prototype.

They first produced sensor electrodes using a process called soft lithography, in which they printed patterns of ink over copper sheets with a flexible plastic backing. Then, a corrosive chemical carved out the exposed copper, leaving behind the desired strips of metal.

Next, they lined the interior of an egg-shaped container, modelled after one of NASA’s fuel tanks, with the flexible sensors. Throughout the inside of the tank, electric fields emitted by each sensor could be received by the others, but how much of these fields ended up being transmitted depended on the capacitance of whatever material was inside the tank.

“If you have no fuel, you have the highest transmission, and if you have fuel, you’re going to have a lower reading, because the fuel absorbs the electromagnetic wave,” Dagalakis says.

“We measure the difference in transmission for every possible sensor pair, and by combining all these measurements, you can know where there is and isn’t fuel and create a 3D image.”

It’s still early, Dagalakis says, but it’s “a good starting point” – and the ECVT system could help overcome other challenges in space.

“The technology could be used to continuously monitor fluid flow in the many pipes aboard the International Space Station and to study how the small forces of sloshing fluids can alter the trajectory of spacecraft and satellites,” Deshpande adds.

https://cosmosmagazine.com/news/space-isnt-the-place-to-run-out-of-fuel/

 

[CaaC (John)+]

 

 

Edited November 15, 2020 by CaaC (John)

[CaaC (John)+]

@nudge, is the launch still a goer for later on? I put a tweet in but deleted it because I remembered you posted saying it was Monday morning now for the launch.

[nudge]

9 minutes ago, CaaC (John) said:

@nudge, is the launch still a goer for later on? I put a tweet in but deleted it because I remembered you posted saying it was Monday morning now for the launch.

It's 50% go based on weather conditions for 00:27 GMT tonight!