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Space: The Final Frontier


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Frank Drake's original idea of building a radio telescope in a lunar crater on the dark side of the Moon has been resurrected. Not likely to happen any time soon, but it's quite an interesting read!

https://astronomy.com/news/2021/01/arecibo-is-dead-should-we-build-its-replacement-on-the-moon

Would be cool to see it happening...

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Icy asteroids?

A novel study of meteorites raises a swag of Earth-origin questions.

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The parent asteroids of carbonaceous chondrite meteorites are likely "frozen mud balls" – similar to the comets that Harvard astronomer Fred Whipple described, and demonstrated in class with a 200kg dirty snowball.

Stony meteorites known as carbonaceous chondrites show signs of liquid water no more than a million years ago, scientists say.

This is a startling discovery because carbonaceous chondrites are believed to be chips blown off the surfaces of ancient asteroids whose composition hasn’t altered since the dawn of the Solar System, 4.5 billion years ago.

And while planetary scientists have long suspected that these asteroids once contained water, they didn’t know whether that water still persists in the form of ice or was long ago lost to space, says Simon Turner, an isotope geochemist at Macquarie University in Australia. 

To test this, Turner and colleagues in Australia, the US and France ran a long-shot experiment. 

They obtained samples from nine carbonaceous chondrites that had been collected within a couple of days of falling to Earth—quickly enough that the Earth’s humid environment didn’t have time to overwhelm the subtle chemical signatures the researchers hoped to find. 

Then, in a study just published in Science, they measured the various isotopes of uranium and thorium within the samples. 

They focused on these elements, Turner says, because uranium is highly soluble in water, whereas thorium isn’t. “Any fluid flow [through the rock] should separate these two elements from each other,” he explains.

Most importantly, it would separate uranium-234 (half-life 246,000 years) from its decay product thorium-230 (half-life 75,400 years).

“That would set a clock ticking that would continue to tick for a couple hundred thousand or a million years,” Turner says. 

After that, the thorium will have decayed to a point where it can no longer be adequately measured.

Amazingly, all of the carbonaceous chondrites Turner’s team tested contained isotope ratios that indicated that they had seen liquid water flowing through them recently enough for the method to detect. That means the asteroids from which they originated are “frozen mudballs, rather than solid rocks”. 

When exactly that occurred is open to debate. It’s possible it happened when the meteorites hit Earth’s atmosphere and their surfaces were heated into the incandescent streaks we see as meteors. But according to Turner, it was more likely a consequence of the impact that blasted them off their parent asteroids and sent them hurtling into space, eventually to fall to Earth.

However it happened, it means these parent asteroids still contain ice. 

“That could be of interest for mining asteroids,” Turner says – and it also adds to the likelihood that asteroids were a major part of how the infant Earth received its water.

Humberto Campins, a planetary scientist from the University of Central Florida, US, who was not a member of the study team, calls it a significant discovery. 

Not that he’s surprised to find that asteroids still contain water. Recent asteroid space missions by Japan and the US, he says, have found spectroscopic signals of hydrated silicates on the surfaces of their respective asteroids. That’s not ice per se, but Campins says, “it’s still water, which could be mobilised during impacts”.

What makes the new finding really interesting, he says, is what it reveals about how impacts may affect the evolution of materials on asteroids. “The collisional history of asteroids is more complex than we thought,” he says.

https://cosmosmagazine.com/space/astronomy/icy-asteroids/

 

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Madam Starmaker

Henrietta Swan Leavitt transformed a powerful astronomical tradition.

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Henrietta Swan Leavitt working at her desk in the Harvard College Observatory. Credit: Wikimedia Commons

When it comes to prestige in US education, few names carry more weight than Harvard University.

Founded in 1636 in Cambridge, in the Massachusetts Bay Colony, as New College, Harvard is the US’s oldest institution of higher education.

People today might think of Harvard for its legal and business studies but from its early days, it was known as a centre of scientific research.

Less known is the role that women played at Harvard in developing astronomy as a science. Prominent among these starry women was Henrietta Swan Leavitt, born on 4 July 1868 in Lancaster, Massachusetts.

In 1888 Leavitt entered the Society for the Collegiate Instruction of Women, which later became Radcliffe College, an offshoot of male-only Harvard. Her studies ranged from classical Greek, fine arts and philosophy, to analytical geometry and differential calculus.

Let’s backtrack a little to set the scene.

In 1839, William Cranch Bond was persuaded to bring his own equipment to Harvard to establish a de facto observatory and to serve as the college’s first (unpaid) “Astronomical Observer”.

“A visit from a brilliant comet a few years [in 1843] later helped stimulate the purchase of a 15-inch [38 cm] Great Refractor telescope from Munich, which remained the largest instrument in America for the next two decades,” Harvard’s official history says.

In 1877, Harvard graduate Edward Charles Pickering left the Massachusetts Institute of Technology (MIT), where he was a professor of physics, to become a professor of astronomy and director of the Harvard College Observatory.

Smithsonian Magazine’s 2013 article “The women who mapped the Universe and still couldn’t get any respect”, called Pickering a “progressive thinker – at least when it came to opening up educational opportunities”.

It says that while at MIT Pickering “revolutionised” scientific education “by encouraging students to participate in experiments”. He was also noteworthy for inviting female students to attend his lectures. 

One of Pickering’s most important innovations at Harvard Observatory was to take advantage of recent developments in astrophotography taken by attaching cameras to telescopes. He introduced the use of the meridian photometer to measure the magnitude of stars and established a catalogue of photographs.

So enthusiastic was Pickering for this new field of discovery that the number of images produced overwhelmed his staff’s ability to analyse them.

“So began an era in Harvard Observatory history were women – more than 80 during Pickering’s tenure, from 1877 to his death in 1919 – worked for the director, computing and cataloguing data,” Smithsonian says.

Viewed one way, this could be seen as an advancement for women in science, or at the very least in the workforce.

Referred to as “computers”, women working at the observatory studied and curated glass-plate photographs that became known as the HCO Astronomical Photographic Plate Collection, which the university says is “the world’s largest archive of stellar glass plate negatives, amassing over 500,000 celestial moments captured in time, some dating back to the mid-1800s”.

“Some of these women would produce significant work on their own; some would even earn a certain level of fame among followers of female scientists,” Smithsonian says. “But the majority are remembered not individually but collectively, by the moniker Pickering’s Harem.”

Even after Pickering’s death, women performed largely clerical tasks such as reducing photographs to render images as clear as possible; classifying stars by comparing photographs to known catalogues; and cataloguing the photographs themselves, making careful notes of each image’s date of exposure and the region of the sky. Notes were then copied into tables, which included the star’s location in the sky and its magnitude.

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In 1912, “computer” Henrietta Swan Leavitt made a discovery that the American Association of Variable Star Observers (AAVSO) says “was to become one of the cornerstones of modern astronomical science”.

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Leavitt’s work had involved examining images of Cepheid variables, which the CSIRO describes as “types of pulsating variable stars [that] exhibit a definite relationship between their period and their intrinsic luminosity. Such period-luminosity relationships are invaluable to astronomers as they are a vital method in calculating distances within and beyond our galaxy.”

But the real discovery was yet to come. “While recording and cataloguing the data on her variable stars, Leavitt found she could accurately and consistently relate the period of a given star’s brightness cycle to its absolute magnitude,” says the AAVSO. “The discovery of this simple and hitherto-unknown relationship made it possible, for the first time, to calculate their distance from Earth.”

In 1908 Leavitt published a paper called “1777 variables in the Magellanic Clouds” in the Annals of the Astronomical Observatory of Harvard College. In it, she noted that the brighter variables had a longer period.

In 1912, in the Harvard College Observatory Circular, she published “Periods of 25 variable stars in the Small Magellanic Cloud”.

The CSIRO notes that Leavitt received scant recognition for her work but later astronomers such as Edwin Hubble and Ejnar Hertzsprung used her discoveries as foundations on which to build their own research.

In 1924, Hubble was able to use the Cepheid variables to calculate the nebula Andromeda’s distance from Earth, which was the first measurement for a galaxy outside the Milky Way.

The AAVSO says that in 1925, Swedish mathematician Gosta Mittag-Leffler wrote a letter to Leavitt in which he signalled his intention to nominate her for the Nobel Prize in Physics.

He was told that Leavitt had died, of stomach cancer, on 12 December 1921.

https://cosmosmagazine.com/space/madam-starmaker/

 

 

Edited by CaaC (John)
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Milliseconds measure galactic gravity

Data from pulsars widens the knowledge of dark matter and gravitational waves.

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The ripples in the Milky Way disk are shown, along with the tidal debris from the Sagittarius dwarf galaxy. The pulsars analysed by Sukanya Chakrabarti and collaborators to calculate galactic accelerations are shown in the inset. Credit: IAS; Dana Berry.

Scientists measuring tiny changes in the arrival times of signals from millisecond pulsars have found a new way to measure both gravitational waves and the galaxy’s distribution of dark matter.

Pulsars are rapidly rotating neutron stars that, like cosmic lighthouses, beam out radio signals that sweep the heavens – beams that can be detected by radio telescopes each time they point in our direction. Millisecond pulsars are ones that do this every few thousandths of a second.

They produce an incredibly steady metronomic beat. “Their temporal stability rivals atomic clocks,” says Sukanya Chakrabarti, of Rochester Institute of Technology, in New York, US.

When changes do occur, they provide important clues to astrophysical processes that have nothing to do with the pulsars themselves.

Yesterday, at a virtual meeting of the American Astronomical Society (AAS), Joseph Simon of the University of Colorado examined more than a dozen years of data from two of the world’s most powerful radio telescopes – Green Bank in West Virginia, US, and Arecibo in Puerto Rico, and found small changes that appear to be due to gravitational waves passing through the Earth. 

These waves, says Simon, toss the entire Earth slightly toward one group of pulsars and away from others, causing their signals to arrive slightly sooner or later than expected. “The only thing we know that causes this pattern is a passing gravitational wave,” he says.

Not that the Earth is shifting enough for anyone but an astrophysicist to care about. The pulsar signals’ expected arrival times changed by only a few hundred nanoseconds – the equivalent of the Earth being pushed a dozen metres or so over the course of years.

Still, it’s indicative of the incredible precision with which pulsar signals can be measured. And it might also be a fitting obituary to Arecibo, which recently collapsed when crucial cables frayed and broke. “The science legacy of Arecibo is really, great, and we are incredibly saddened by its loss,” Simon says.

Chakrabarti’s finding is, if anything, even more impressive.

She reported at the AAS meeting that, rather than using ordinary pulsars, she used binary pulsars – ones that orbit each other in pairs, much like binary stars. 

These orbits mean that the arrival times of each pulsar’s signals shifts as the first one and then the other is closer to Earth. Tiny changes to this rhythm reveal how the pulsars are responding to the galaxy’s gravitational field.

“That allows us to use them as galactic accelerometers,” Chakrabarti says, “much like the accelerometers in your iPhone.” 

It’s not a big effect. In a study of 14 binary pulsars, Chakrabarti found that they were changing velocity by only a few centimetres per second. “That’s roughly the speed of a crawling baby,” she says. “And not a very fast baby, at that.”

But given the extraordinary precision with which pulsar signals can be measured, it was enough for her team to measure the gravitational field of the galaxy over a sphere about 3200 light-years in a radius around the Earth. 

From that, she says, it was possible to map out the average density of matter in and around our part of the galaxy, and determine how much of that matter was invisible: dark matter, in other words.

It’s a finding that may help astrophysicists better understand the role dark matter plays in the galaxy as a whole, but it can also help physicists figure out how to detect it on Earth, by showing how much is in our vicinity. 

And it turns out that there isn’t a lot: only about 7 x 10-25 grams per cubic centimetre. “If I look at the amount of dark matter within the Earth, it’s less than a kilogram,” Chakrabarti says.

https://cosmosmagazine.com/space/astrophysics/galactic-precision-measurement/

 

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Cosmic collision spells the beginning of the end

Astronomers witness a possible new mechanism for galaxies to die.

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An artist’s impression of ID2299 shows the galaxy, the product of a galactic collision, and some of its gas being ejected by a “tidal tail” as a result of the merger. Credit: ESO/M. Kornmesser

Astronomers may have just witnessed a new way for galaxies to “die”, using the super-sensitive Atacama Large Millimeter/submillimeter Array (ALMA) in Chile.

The array of 66 radio telescopes, sprawled across the Atacama Desert about 1400 km north of Chile’s capital Santiago, watched as a galaxy nine billion light-years away ejected nearly half of its star-forming gas into space.


Key research points

  • A radio telescope array has observed a galaxy losing 46% of its total star-forming gas
  • Without this gas, the galaxy will stop creating stars within a few tens of millions of years and “die”
  • The ejection of gas was likely caused by a galaxy merger – suggesting a new mechanism by which galaxies end their lives

The astronomers suspect this cataclysmic event was triggered by two galaxies colliding and merging to form a new one – inspiringly called ID2299. This massive disruption event provides fresh insight into the mechanisms that can halt star formation, adding another piece to the complex puzzle of how galaxies evolve and die.

The research appears in Nature Astronomy.

“This is the first time we have observed a typical massive star-forming galaxy in the distant universe about to ‘die’ because of a massive cold gas ejection,” says lead researcher Annagrazia Puglisi, from Durham University, UK, and the Saclay Nuclear Research Centre (CEA-Saclay) in France.

Previous evidence has indicated that such ejections of star-forming gas can be caused by high-speed galactic winds blasted out from newly formed massive stars, or the powerful activity of black holes spinning at the hearts of massive galaxies.

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“Our study suggests that gas ejections can be produced by mergers,” says co-author Emanuele Daddi, of CEA-Saclay.

The clue that led to this conclusion came from a “tidal tail” – an elongated stream of stars and gas extending out into interstellar space. Usually, these features are faint, but the team managed to capture ID2299’s when it was just launching into space and so still relatively bright.

Daddi points out that winds and tidal tails can appear very similar. Previous research that observed winds driving galactic gas out into space could have actually seen tidal tails instead.

“This might lead us to revise our understanding of how galaxies die,” Daddi says.

The observed ejection makes up an astonishing 46% of the ID2299’s gas, and it’s spewing out at a remarkable rate – equivalent to 10,000 Suns worth of gas per year. This means the galaxy is rapidly losing the material it needs to create new stars.

The gas left in ID2299 won’t last long either: the galaxy is also busy forming stars hundreds of times quicker than our own Milky Way, consuming the leftover material.

The team estimates that ID2299 will shut down in just a few tens of millions of years – and when its stars eventually wink out, it will go dark forever.


Spotlight: galaxy deaths

  • Galaxies start to “die” when they lose or consume all their star-forming gas, so new stars can’t be born
  • Existing stars will eventually burn through their fuel and go dark, bringing the galaxy to its true end
  • Stars like our Sun can only last for around 10 billion years, but smaller, cooler red dwarf stars can last for trillions of years

https://cosmosmagazine.com/space/astronomy/cosmic-collision-spells-beginning-of-the-end/

 

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(all times Eastern U.S. time)

Jan. 16, Saturday
4:20 p.m. -- LIve coverage of the hot-first test of the Space Launch System rocket engines. (Test window opens at 5 p.m.)
TBD -- Press conference following the hot-first test of the Space Launch System rocket engines. (Approximately two hours after the test.)

NASA - LIVE

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2 hours ago, CaaC (John) said:

(all times Eastern U.S. time)

Jan. 16, Saturday
4:20 p.m. -- LIve coverage of the hot-first test of the Space Launch System rocket engines. (Test window opens at 5 p.m.)
TBD -- Press conference following the hot-first test of the Space Launch System rocket engines. (Approximately two hours after the test.)

NASA - LIVE

338672527_download(4).thumb.png.b58c2cb228f763cfcc50893592084265.png

Fun fact: they are using pretty the same engines on SLS that were used on the Space Shuttle, just with upgraded computers and some other modifications :) It was truly well ahead its time.

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12 minutes ago, nudge said:

Fun fact: they are using pretty the same engines on SLS that were used on the Space Shuttle, just with upgraded computers and some other modifications :) It was truly well ahead its time.

Hopefully, I can be around a lot longer to see all the space adventures until I end up above in the heavens and looking around me 'Space, the Final Frontier' for me when it happens :x  :hh:

Edited by CaaC (John)
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Branson's Virgin rocket takes satellites to orbit

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Sir Richard Branson's rocket company Virgin Orbit has succeeded in putting its first satellites in space.

Ten payloads in total were lofted on the same rocket, which was launched from under the wing of one of the entrepreneur's old 747 jumbos.

Sir Richard is hoping to tap into what is a growing market for small, lower-cost satellites.

By using a jet plane as the launch platform, he can theoretically send up spacecraft from anywhere in the world. 

In reality, of course, his Virgin Orbit system has to be licensed in the locality where it is used, which at the moment is solely California. But there are well-advanced plans to bring the 747 and its rockets to Cornwall in south-west England, for example.

 

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AAS #237: five things we learned

Here are the key take-outs from the 237th meeting of the American Astronomical Society.

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The Hubble Space Telescope captured this image of the "butterfly wing"- shaped nebula, NGC 2346. The nebula is about 2,000 light-years away from Earth in the direction of the constellation Monoceros. Credit: NASA/STScI

Each January, the American Astronomical Society (AAS) conducts a meeting widely hailed as the “Superbowl of astronomy”, in which astronomers gather from around the world to share their latest results.

Last year it was in Honolulu. But this year, thanks to COVID-19, it was online—something that AAS had already practised for smaller meetings as far back as June 2020. Not surprisingly, given the rehearsal, they did a smash-bang job of it. But they also had a remarkable amount to present… plus a lot of fun. 

Part of the fun is simply that astronomy is the realm of gorgeous pictures. Who can help but be enchanted by things with names like the Butterfly Nebula or the Jewel Bug?

But gorgeous images weren’t the only thing to come out of the meeting. Here are five other highlights.

1. Astronomers love acronyms

Gone are the days when things were generally named for people or places: Mt Palomar, Lowell Observatory, Kitt Peak, Arecibo. Now, they’re cuter… and virtually everything is an acronym.

Some are simply designed to be short, pronounceable, and reasonably related to their purpose. ALMA is the Atacama Large Millimeter submillimeter Array (ie, a radio telescope) in Chile’s Atacama Desert. Pan-STARRS (Panoramic Survey Telescope and Rapid Response System) is a telescope that spans the heavens for anything that moves or quickly changes.

But there’s also a trend toward increasingly cool names, like CHIME (Canadian Hydrogen Intensity Mapping Experiment), and DECaLS (Dark Energy Camera Legacy Survey).

How cool is COOL? Or, more precisely, COOL-LAMPS: Chicago Optically-Selected Lenses at the Margins of Public Surveys (don’t ask; it’s about using human eyes to scan enormous amounts of data for gravitationally lensed galaxies that escape AI algorithms, which is a bit too much of a mouthful to explain in detail.)

But wildest by far? The Burst Alert Telescope (for gamma-ray bursts), and a companion project called Gamma-Ray Urgent Achiever for Novel Opportunities. The acronyms: BAT and BAT-GUANO.

So, ahem: WAHOO (What in All Hell are these Organisations Originating?

2. Astronomers are persistent

If they encounter a mystery or a difficult problem, astronomers may set it aside for years, but eventually, they’ll come back to it. 

Such was the case for a star called KOI-5, which hosted the second possible exoplanet identified by NASA’s Kepler space telescope only 10 days into its mission.

The problem, says David Ciardi, of California Institute of Technology, was that KOI-5 turned out to be in a triple star system – ie, Tatooine, plus one. When Kepler first spotted it, Ciardi says, “it was promising”, but astronomers quickly gave up on trying to confirm that it had a planet, “mostly because it got complicated”.

Now, he says, thanks to additional observations by the Kepler’s successor, TESS (Transiting Exoplanet Survey Satellite), it’s become possible to unscramble the orbits of the three stars and determine that there really is a fourth body in the system: a planet about 60% the size of Saturn, orbiting one of them every five days. Persistence finally paid off.

3. The Milky Way is a Pringle doing “the wave” 

Most of us know that the Milky Way is a spiral galaxy. But that produces a rather simplistic mental image. “Our usual picture is as a flat disk, thinner than a pancake, peacefully rotating around its centre,” says Xinlun Cheng of the University of Virginia. “The reality is more complicated.”

Astronomers have long known that other spiral galaxies are actually slightly warped, like a potato chip or an old-fashioned vinyl record left out in the sun. Now, Cheng says, we know that the same also applies to ours.

By studying high-precision images of billions of stars collected by APOGEE and the European Space Agency’s Gaia space telescope, Cheng’s team was able to not only detect our galaxy’s own warp but describe it in detail.

What’s happening, he says, is that a long-ago perturbation, probably from another galaxy, pulled some of the Milky Way’s stars up, out of the plane of the disk. These then pulled neighbouring stars out of the plane, before themselves being drawn back into it, producing a warp that circles the galaxy about once every 440 million years.

Cheng compares it to football fans doing the wave. “All you do is stand up and sit down, but the effect is that the wave goes all the way around the stadium.”

4. There’s such a thing as a magnitude 27.8 starquake

The strongest earthquake ever known to have hit Earth was a magnitude 9.5 temblor that struck offshore from Chile in 1960. But now, astronomers have found evidence for one that was 1,000,000,000,000,000,000,000,000,000 times more powerful, which cracked the crust of an object known as a magnetar and produced a giant flare that astronomers spotted as a burst of gamma rays. 

The burst was so intense that, for a fraction of a second, it carried more gamma-ray energy than the entire rest of the universe, combined.

Magnetars are neutron stars with magnetic fields 100 trillion times stronger than the Earth’s, says Kevin Hurley, a space scientist at the University of California, Berkeley. 

The cause of the burst, he says, appears to have been a sudden shift in the star’s magnetic field, which ripped open its surface in a magnitude 27.8 starquake. 

That, says Hurley’s co-investigator Oliver Roberts, of Universities Space Research Institute, Alabama, US, allowed a jet of hot plasma to escape from the magnetar’s interior, “much like a photon torpedo from Star Trek”. And thus we boldly learn. 

5. The Milky Way has a “defensive halo”

Galaxies like our own remain young and vibrant by capturing gas clouds from intergalactic space. These clouds contain the materials that can produce the next generation of stars and planets… and, maybe, creatures like us.

But they also have halos of million-degree ionised gas that act as barricades to keep these clouds at bay – shredding and dispersing them before they reach us. 

“Our galaxy is in a gas crisis,” says Kat Barger, of Texas Christian University, US. “[Eventually] it will run out of gas.”

To study how this works, she used radio-telescope data to examine an incoming gas cloud called Complex A, mapping its density and motion at 123,000 locations. Based on this, she calculated that the cloud, which contains the mass of 2 million Suns and is currently 21,000 light-years away, is getting severely “beaten up” as it moves through the halo. 

Only a fraction of it will eventually make its way through, she says – somewhere between half and 25%. “It’s getting elongated and fractured,” she says. “It’s dissolving.” 

Meanwhile, other astronomers are finding other unexpected structures in the galaxy. One of these, says Jeffrey Andrews, of Northwestern University, Illinois, US, is a streamer of 468 stars called Theia 456.

Prior generations of astronomers, he says, thought the Milky Way had only two types of star clusters: tight balls of hundreds of thousands to millions of stars, known as globular clusters; and smaller, less-dense groups known as “open clusters”, of which the Pleiades is the most famous.

But now, he says, the latest generation of star surveys are showing that the Milky Way has large numbers of previously unknown structures. “This is just the beginning,” Andrews says. “Theia 456 is just the tip of the iceberg.”

AAS #238 is scheduled for June this year: set your atomic clock.

https://cosmosmagazine.com/space/astronomy/aas-237-five-things-we-learned/
 
 
 

 

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To orbit… and beyond?

South Australia to be the first Australian state to send a satellite into space.

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Artist impression of SASAT1. Credit: Alex Preist / Inovor Technologies

South Australian Premier Steven Marshall today announced a $6.5 million partnership with the growing South Australian space industry to send a locally made small satellite into low Earth orbit in 2022.

Marshall says SA is the first Australian state government to embark on such an undertaking.

Dubbed the SASAT1 Space Services Mission, the satellite will gather information designed to assist and improve such things as emergency services, environment and water-quality monitoring, and mining and bushfire mitigation.

The mission will be led by the SmartSat Cooperative Research Centre (CRC) at the University of South Australia, with private SA space companies adding expertise. Adelaide-based Inovor Technologies will design, build and test the 6-unit Apogee satellite bus and deliver it to the launch contractor. Myriota will handle the Internet of Things (IoT) space services.

“The SASAT1 Space Services Mission will deliver significant value to our state and to our local space industry as well as paving the way for growth in spacecraft export, IoT sensor exports, Department of Defence and Australian Government space and defence-related projects and the South Australian supply chain,” Marshall said.

“The satellite will also allow South Australian school students to view firsthand the vital information we gain from satellites right here in their own backyard. This is just one step in getting our next generation excited about what a career in space could mean for them.”

SmartSat CRC CEO Andy Koronios said the mission is evidence of South Australia’s commitment to space and to transforming SA into a hi-tech economy.

“This mission will provide opportunities for small start-up companies to use the ongoing data captured by the satellite to develop analytics applications for government and commercial use,” said Koronios. He said SmartSat is “incredibly excited” to be leading SASAT1 and that they are “committed to providing expertise and R&D capability to make the mission a great success”.

Inovor Technologies CEO Matthew Tetlow said he hoped that “the whole state will rally behind” the SASAT1 program. He said it would be “helping to build a space ecosystem that will support the creation of more high-tech careers into the future for young South Australians… [It] will create new jobs, boost supply chain investment and, hopefully, inspire the people of South Australia.”

Royal Institution of Australia lead scientist Alan Duffy, an astrophysicist and Australian space industry enthusiast, who isn’t involved in the mission, says that it will see Australia taking steps towards being a leading player in the new space race.

The new space race, he says, “uses smaller, cheaper, but more advanced satellites to leapfrog the older, larger, and more expensive satellite technology seen in the more established space-faring nations. 

“Success with this mission will see South Australia, and indeed the nation as a whole, be much more attractive to international investment in a rapidly growing global space economy. That in turn will see jobs as well as new products and services created that benefit us all.”

https://cosmosmagazine.com/uncategorized/to-orbit-and-beyond/

 

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“Puffed-up” planet unlike any other

Gas giants may form more easily than suspected, say astronomers.

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New observations of the exoplanet WASP107b suggest that existing models of how gas giant planets form may not be quite right.

A team of astronomers, led by Caroline Piaulet from the Université de Montréal (UdeM) in Canada, used the Keck Observatory in Hawai’i to probe the giant planet’s internal structure. They discovered that its core mass is much lower than expected – which has big implications, according to co-author Björn Benneke, also from UdeM.

“This work addresses the very foundations of how giant planets can form and grow,” he explains. “It provides concrete proof that massive accretion of a gas envelope can be triggered for cores that are much less massive than previously thought.”

The research appears in the Astronomical Journal.

First detected in 2017, WASP-107b is about 200 light-years away in the constellation of Virgo and orbits very close to its host star – eight times nearer than Mercury is to the Sun. The planet is the size of Jupiter but much lighter, making it one of the least dense exoplanets known. Astronomers classify these as “super-puff” or “cotton-candy” planets.

“We had a lot of questions about WASP-107b,” says Piaulet. “How could a planet of such low-density form? And how did it keep its huge layer of gas from escaping, especially given the planet’s close proximity to its star?”

To answer these questions, Piaulet and team used the Keck Observatory to more accurately measure WASP-107b’s mass. They did so via the radial velocity method, observing how much the planet’s host star “wobbled” due to the planet’s gravitational influence.

Turns out WASP-107b is about 10 times lighter than Jupiter (or about 30 times more massive than the Earth).

Further calculations resulted in a surprising conclusion: the planet must have a solid core only around four times the mass of the Earth, meaning its thick, gaseous atmosphere makes up more than 85% of its total mass.

This is starkly different to the gas giants of our own solar system. Neptune, for example, has a similar mass to WASP-107b but its gas layer makes up only 5–15% of its total mass.

This finding may pose a challenge to our current models of how gas giants form, which are based on the planets in our own Solar System such as Jupiter and Saturn.

“Standard ideas of the ‘core accretion’ model for planet formation suggest you need about 10 times Earth’s mass before you can start really gathering lots of hydrogen and helium gas,” explains astronomer Jonti Horner, from the University of Southern Queensland, who was not involved in the study.

Despite being smaller, the core of WASP-107b has still attracted and retained an immense envelope of gas.

“That means that, if their estimated core mass is right, something unusual is going on,” Horner says. “Either our understanding of the formation of planets through core accretion is incomplete – which is certainly possible – or this planet formed in a totally different manner.”

Study co-author and super-puff planet expert Eve Lee, from McGill University in Canada, offers an explanation.

“The most plausible scenario is that the planet formed far away from the star, where the gas in the disc is cold enough that gas accretion can occur very quickly,” she says. “The planet was later able to migrate to its current position, either through interactions with the disc or with other planets in the system.”

Horner also suggests an alternative origin for the planet’s “puffiness”.

“It could be the result of tidal interactions with the star, as a result of the planet having a slightly non-circular orbit,” he says – an explanation that “doesn’t require our understanding of core accretion itself to be flawed, but one that requires more work to be done”.

The new Keck observations led to an additional exciting discovery – that this exosolar system is also home to a second, smaller planet. Dubbed WASP-107c, it’s about one-third as massive as Jupiter and has a much longer orbit than its planetary sibling: three years compared to WASP-107b’s 5.7 days.

Next, Piaulet and team hope to study this interesting exosolar system with the James Webb Space Telescope, slated to launch this year.

“Exoplanets like WASP-107b that have no analogue in our Solar System allow us to better understand the mechanisms of planet formation in general and the resulting variety of exoplanets,” Piaulet says.

Horner agrees: “It’s all well and good finding more and more planets that fit with our current models and ideas – but the best science comes when you find something that doesn’t fit.”

https://cosmosmagazine.com/space/astronomy/puffed-up-planet-unlike-any-other/

 

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NASA Celebrates Establishment of Center in Cleveland 80 Years Ago

On January 23, 1941, local authorities, military representatives, and agency officials assembled in Cleveland to initiate construction of the National Advisory Committee for Aeronautics (NACA) new research laboratory. NACA Director of Research George Lewis stated, “I feel confident today in saying that this new aircraft engine research laboratory will be the mecca for all the world's aircraft engine engineers and research workers."

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Eighty years later, the laboratory, now known as NASA’s John H. Glenn Research Center, is one of 10 centres and a leading economic contributor to the Cleveland area.

Exactly one year before the groundbreaking, the NACA formally proposed the creation of a new research lab dedicated to aero propulsion.  During the interim, the committee evaluated locations for the facility across the Midwest before selecting Cleveland, Ohio in November 1940.

The Cleveland Chamber of Commerce scheduled a full day of activities for that cold January Thursday in 1941. In the morning, the cadre of officials toured the Alcoa and the Cleveland Pneumatic Tool Company plants. The former was a key supplier of aluminium aircraft parts and the latter produced landing gears for the Douglas XB–19—then, the nation’s largest bomber.

Afterwards, the group joined 240 local businessmen in the Hotel Cleveland’s Red Room for a luncheon hosted by Cleveland’s newly elected mayor Edward Blythin and Chamber of Commerce President Frederick Crawford. The George Worthington Hardware Company presented the NACA with a chrome-plated pick and shovel to be used for the groundbreaking.

NACA officials described the site selection activities, while Crawford reminded area businesses to maintain their pledges of support to the NACA.  Lewis told the attendees, “The future of aviation as regards to speed, efficiency, and safety, will, in a very large measure, depend on the results which come from this laboratory.”

With the war in Europe on the front pages, Edward Warner of Civil Aviation Authority added ominously, “What we are doing here today may mean the difference between America’s survival and subjugation. The difference between winning a war and losing it may be the difference between a 1,000- and 2,000-horsepower motor, or the difference between the ability to fly at 20,000 feet or 30,000 feet.”

In the afternoon the group travelled out to the construction site adjacent to Cleveland Municipal Airport. Shortly after 3 p.m., Lewis struck the ground with the chrome pick to loosen the soil, which Major General George Brett, acting chief of the Army Air Corps, then scooped up. The moment was immortalized by a local newspaper photographer.

That evening, Crawford held a dinner for the dignitaries at the Union Club. Construction of the NACA laboratory began in the ensuing days. Research commenced in May 1942.

Top Image: A model of the new campus shows that it contained nine primary buildings—Administration, Flight Research, Engine Research, Technical Services, Fuels and Lubrication, Engine Propeller Research, Research Equipment, and the Altitude Wind and Icing Research tunnels.

 

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Swinburne aims high

Australian university joins space race with new technology and industry institute.

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Swinburne University of Technology's (L-R) Pascale Quester, Alan Duffy and Bronwyn Fox. Credit: Swinburne

Specialists at Melbourne’s Swinburne University of Technology are already working on an interplanetary refuelling station on the Moon and vastly improved satellite-imaging technology: just two of the projects in the stream at the university’s new Space Technology and Industry Institute, launched today.

The institute will gather world-class capabilities in astrophysics, aerospace, aviation, advanced manufacturing, artificial intelligence and education to tackle the challenges of future space exploration – a sector that’s generating economic growth – it’s projected to be worth $1 trillion globally by 2040 – in addition to technological innovation.

Swinburne’s also anticipating that the institute will inspire learning from vocational training to PhD level.

The institute’s leader will be Alan Duffy, renowned astronomer, science communicator and Lead Scientist of the Royal Institution of Australia – the not-for-profit owner of this website and Cosmos magazine.

“Space has always been a fascination from me, as my writing for the Royal Institution of Australia makes clear, [and] now being able to help bridge the expertise within Swinburne to the needs of partners outside is a joy,” says Duffy.

“I couldn’t be happier to lead our university in finding ways for industries and communities to solve their problems on Earth by using the technologies from space. Building for space brings together the very best of engineering and science to brave the challenges at the final frontier.”

Duffy, who was recently named Academic of the Year at the Australian Space Awards, says the institute is an important step forward in the ongoing growth and development of the growing Australian space industry.

“Space research, technology and education is, like the Universe itself, incredibly complex and interdependent. It requires close collaboration, targeted investment and new ways of working to succeed. Australia has the potential to be a global leader in space research and technology, as well as teaching the brightest minds.

“I’m delighted to be uniting the efforts of my colleagues at Swinburne to help achieve this and make that next big breakthrough,” he adds.

Swinburne Vice-Chancellor Pascale Quester says research and education into space technologies and their terrestrial applications had extraordinary potential for both economic and social impact.

“Our end-to-end coverage of R&D, as well as developing the people and skills needed to build new space industries of the future, means that Swinburne is perfectly positioned to enter a new frontier in space discovery and innovation,” Quester says.

“We have all the experience, equipment and thirst for knowledge under one roof to help our industry partners move into this market and capitalise on the vast potential of space.”

Swinburne Deputy Vice-Chancellor of Research and Enterprise Bronwyn Fox highlights the institute’s potential to collaborate with industry to build lighter, stronger and cheaper materials with faster production enabled by cutting-edge additive manufacturing processes.

“We’re opening up a world of possibilities to expand our stellar capabilities and the new institute will make the most of our globally recognised expertise in digitalisation and materials engineering,” Fox says. “We are in the midst of a space revolution, and Australia has a unique opportunity to emerge as a major player in the global space market.”

https://cosmosmagazine.com/space/exploration/swinburne-aims-high/

 

 

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Baby galaxies born big

Faint, distant fossil galaxy has a massive dark-matter halo.

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The first galaxies in the universe were likely more massive than previously thought, according to new research from MIT astrophysicists.

Dozens of dwarf galaxies orbit the Milky Way-like satellites, and some of these are so metal-poor that they must have formed billions of years ago, before the universe was producing heavy elements. These galactic “fossils” are an excellent natural laboratory for astronomers interested in studying the conditions of the early universe, including how the very first galaxies formed and evolved.

A US-led research team – with collaborators in Australia and the UK – has now shed light on the formation of one of the most primitive dwarf galaxies known. They used the Australian National University’s SkyMapper telescope to take a squiz at Tucana II, an ultra-faint galaxy around 163,000 light-years from Earth, and discovered nine previously unknown stars at its very outskirts.

These far-flung stars are surprisingly far from the galaxy’s centre but are still held fast by its gravitational pull. This provides the first evidence that the galaxy’s dark matter halo is much more extended and massive than previously thought – with similar implications for other early galaxies.

“Tucana II has a lot more mass than we thought, in order to bound these stars that are so far away,” explains co-author Anirudh Chiti, from MIT. “This means that other relic first galaxies probably have these kinds of extended halos too.”

Their results are published in Nature Astronomy.

Dark matter is a hypothetical form of matter that’s thought to make up a substantial portion of the universe – but it doesn’t emit or absorb light, heat or energy, so it can only be detected through its gravitational influence. Every galaxy is thought to be bound together by a concentration (“halo”) of dark matter; without it, galaxies would fly apart.

This result is the first to show that ultrafaint dwarf galaxies can have an extended dark matter halo.

Alan Duffy, an astrophysicist from Swinburne University, Melbourne, who wasn’t involved in the study, points out that the fact these galaxies “have vastly more dark matter around them than what we see in stars is of course not new – but it would appear that these more distant stars have revealed just how much more”.

“This probably also means that the earliest galaxies formed in much larger dark-matter haloes than previously thought,” says co-author Anna Frebel, also from MIT. “We have thought that the first galaxies were the tiniest, wimpiest galaxies. But they actually may have been several times larger than we thought, and not so tiny after all.”

In other words – baby galaxies were born big.

Follow-up observations have revealed that these stars out at the edge of Tucana II are more metal-poor – and therefore even more primitive – than the stars at its core. 

“This is the first time we’ve seen something that looks like a chemical difference between the inner and outer stars in an ancient galaxy,” Chiti says.

This stellar imbalance suggests that this ancient galaxy might be the result of a merger of two infant galaxies of different ages – perhaps one of the first mergers in the universe.

“We may be seeing the first signature of galactic cannibalism,” says Frebel. “One galaxy may have eaten one of its slightly smaller, more primitive neighbours, that then spilled all its stars into the outskirts.”

Eventually, Tucana II and other nearby fossil galaxies will be gobbled up by the Milky Way – but before then, the team hopes to study more of these ultrafaint dwarf galaxies to build a better understanding of the universe’s early years.

https://cosmosmagazine.com/space/astrophysics/baby-galaxies-born-big/

 

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Feb 2, 2021

NASA’s Psyche Mission Moves Forward, Passing Key Milestone

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Now just a year and a half from launch, the mission to explore a metal-rich asteroid will soon begin assembling and testing the spacecraft.

NASA’s Psyche mission has passed a critical milestone that moves it a step closer to launch. After an intense review of the mission’s progress in building its science instruments and engineering systems, Psyche won clearance to progress into what NASA calls Phase D of its life cycle – the final phase of operations prior to its scheduled launch in August 2022.  

Until now, the mission has focused on planning, designing, and building the body of the spacecraft, its solar-electric propulsion system, the three science instruments, electronics, the power subsystem, and the like. The successful review of those elements means the mission can now begin delivering components to NASA’s Jet Propulsion Laboratory, which manages the mission and will test, assemble, and integrate each piece..........

ASTEROID PSYCHE

 

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