Sunday, August 22, 2021

What can we do with a captured asteroid?
There's gold in them thar asteroids — literally.


Artist's concept of the asteroid 16 Psyche, which is thought to be a stripped planetary core. (Image credit: Maxar/ASU/P. Rubin/NASA/JPL-Caltech)

By Paul Sutter 
about 10 hours ago

There's gold in them thar asteroids! Literally — asteroids have more than enough gold, plus other metals, to provide a few lifetimes' worth of fortunes. But there are plenty of other reasons asteroids are valuable.

So how do we get these metals from these faraway asteroids? Perhaps the best way is to bring the space rocks to Earth.

Photos: Asteroids in deep space

Most of the metals we use in our everyday lives are buried deep within Earth. And I mean deep: When our planet was still molten, almost all of the heavy metals sank to the core, which is pretty hard to get to. The accessible veins of gold, zinc, platinum and other valuable metals instead came from later asteroid impacts on Earth's surface.

Those asteroids are the fragmented remains of almost-planets, but they contain all of the same mixtures of elements as their larger planetary cousins. And you don't have to dig down into their cores to get it: The asteroid 16 Psyche, for example, contains roughly 22 billion billion pounds (10 billion billion kilograms) of nickel and iron, which are used in everything from reinforced concrete to mobile phones.

If we maintained our current consumption of nickel and iron, 16 Psyche alone could supply our industrial needs for several million years.

Far, far away

But the main problem with asteroids is that they are far away. Not just in space (tens of millions of miles for even the "near"-Earth asteroids), but also in speed. To launch from Earth's surface and go into orbit, a rocket needs to change its velocity from zero to 5 miles per second (8 kilometers per second). To rendezvous with an average asteroid, the rocket has to change its velocity by another 3.4 miles per second (5.5 km/s).

That requires almost as much fuel as the launch itself, which the rocket would just have to carry as dead weight, thus adding to the already-obscene cost of trying to set up a remote mining operation in the first place.

And once the asteroid were mined, asteroid prospectors would be faced with a difficult choice: They could try to refine the ore right there on the asteroid, which would entail setting up an entire refining facility, or ship the raw ore back to Earth, with all the waste that would involve

So instead of trying to mine a distant asteroid, how about we bring the asteroid back to Earth? NASA's ill-fated Asteroid Redirect Mission (ARM) was an attempt to do just that. The goal of the mission was to grab a 13-foot (4 meters) boulder from a nearby asteroid and return it to cislunar space (between the orbits of Earth and the moon), where we could then study it at our leisure.

To move the boulder, ARM would use solar electric propulsion, with solar panels absorbing sunlight and converting it into electricity. That electricity would, in turn, power an ion engine. It wouldn't be fast, but it would be efficient — and it would eventually get the job done.

Related: How it works: NASA asteroid-capture mission in pictures

Unfortunately, in 2017, NASA canceled ARM. Some of the critical technologies wound up in other projects, like the OSIRIS-REx mission to the asteroid Bennu, and NASA continues to investigate and use ion engines. When properly scaled up, a future version of ARM could potentially send large chunks of asteroids — if not entire small asteroids — into nearby outer space.

In fact, a recent study found a dozen potential asteroids, ranging from 6.6 to 66 feet (2 to 20 meters) across, that could be brought into near-Earth orbit with a change in velocity of less than 1,640 feet per second (500 m/s). And the solar electric propulsion schemes cooked up for ARM would be perfectly capable of that, although it would take a while.

Once an asteroid is in near-Earth space, many of the difficulties of asteroid mining are significantly reduced. Just compare the ease of getting to low Earth orbit, or even to the moon, versus reaching Mars. The Red Planet's extreme distance from Earth presents enormous logistical, engineering and technical challenges that we are still trying to solve, all while we've maintained a continuous human presence in low Earth orbit for over two decades.

A cislunar asteroid would be much easier to study and much easier to test different mining strategies on. In addition, its resources would be much easier to bring back to Earth.

As a bonus, any asteroid redirect mission meant for mining would also automatically become an asteroid redirect mission for saving Earth: If we can successfully change the speed and orbit of a harmless asteroid, we can potentially do it for a dangerous Earth-crossing one. The solar electric propulsion drive, for example, might be humanity's best chance to avoid calamity.

Too bad the project was canceled.

Paul M. Sutter is an astrophysicist at SUNY Stony Brook and the Flatiron Institute, host of "Ask a Spaceman" and "Space Radio," and author of "How to Die in Space."

Learn more by listening to the episode "What are asteroids good for?" on the "Ask a Spaceman" podcast, available on iTunes and askaspaceman.com. Ask your own question on Twitter using #AskASpaceman or by following Paul @PaulMattSutter and facebook.com/PaulMattSutter.  


Can synthetic fuels save the combustion engine?

 STEPHEN EDELSTEIN
AUGUST 22, 2021


Automakers like BMW and Porsche are investigating synthetic fuels as a way to keep internal-combustion engines alive in the face of stricter emissions standards. But Engineering Explained host Jason Fenske is skeptical of this new fuel technology.

While gasoline and diesel are refined from naturally occurring stocks of crude oil, synthetic fuels are made by combining different molecules into a substance that performs like a conventional fossil fuel in a combustion engine.


That process is supposed to be carbon neutral, because one component of most synthetic fuels is carbon extracted from the atmosphere, Fenske noted. So while burning synthetic fuel may still produce carbon emissions, they would theoretically be canceled out by the recovery of that carbon for more fuel production. Plus, unlike fossil fuels, you can always make more synthetic fuel.

In addition to keeping gasoline cars on the road, synthetic fuel also has one of gasoline's main advantages—energy density. It can't match gasoline for energy density, but it's much better than hydrogen or the lithium-ion batteries used in current electric cars, Fenske said.




Artist's impression of Haru Oni synthetic fuel pilot plant

However, synthetic fuel must be made using renewable energy in order to be cleaner than gasoline, Fenske said. That's not true of electric cars, which can still have a very small carbon footprint even when charged from the dirtiest electricity grids.

Charging an electric car is also a fairly straightforward process, whereas making synthetic fuel, transporting it, and then burning it in a combustion engine adds a lot more steps, making it inherently less efficient.

Consequently, less of the energy put into synthetic fuel actually makes it to the wheels, Fenske said, citing some recent studies. Synthetic fuels' greater energy density might make them a good fit for aviation or maritime applications, but even that would still be very expensive, Fenske concluded.

Those challenges haven't discouraged automakers from experimenting with synthetic fuels. Porsche is testing it in race cars, and is backing a pilot plant in Chile. Last year, BMW invested in Prometheus Fuels, claiming the startup would be able to sell synthetic fuel at a price comparable to gasoline.


  


  • Synthetic fuel - Wikipedia

    https://en.wikipedia.org/wiki/Synthfuel

    The Bergius process plants were Nazi Germany's primary source of high-grade aviation gasoline, synthetic oil, synthetic rubber, synthetic methanol, synthetic ammonia, and nitric acid.


    • Article: Whatever Happened to Nazi Synthetic Gas and Oil ...

      https://www.opednews.com/articles/Whatever-Happened-to-Nazi-by-Grant...

      What is not as well known is that the technology that created Nazi synthetic gas and oil is still around today and in use. In South Africa, there is a company called Sosol that utilizes the same...

    • Synthetic fuel in nazi germany | History Forum

      https://historum.com/threads/synthetic-fuel-in-nazi-germany.125367

      Event more fascinating but incredibly sad is the career of Harbor, a brilliant chemist but ironically a Jew and German patriot. His pioneering work having saved (or least extended the war for) Germany, he weaponised the use of Chlorine Gas, amongst other chemical weapons. His wife also a scientist begged him not to do so - he refused and went ahead; she committed suicide. After the War, Bosch ...






    • Mass grave from Nazi atrocity discovered in Poland's 'Death Valley'


      By Laura Geggel
      4 days ago

      Among the victims were members of the Polish resistance.






      Study researcher Dawid Kobiałka during an excavation in Death Valley. (Image credit: D. Frymark; Antiquity Publications Ltd.)

      Archaeologists in Poland have discovered a mass grave that the Nazis tried to destroy at the end of World War II, a new study finds.

      The mass grave, filled with the remains of about 500 individuals, is linked to the horrific "Pomeranian Crime" that took place in Poland's pre-war Pomerania province when the Nazis occupied the country in 1939. The Nazis killed up to 35,000 people in Pomerania at the beginning of the war, and they returned in 1945 to kill even more people, as well as to hide evidence of the prior massacres by exhuming and burning the bodies of victims.

      Despite this elaborate Nazi cover-up, archaeologists have now found abundant evidence of one of these mass graves after examining archives, interviewing locals and conducting extensive archaeological surveys, the researchers said.

      Related: Photos: Escape tunnel at Holocaust death site

      The 1939 Pomeranian Crime was the first large-scale atrocity of World War II in Poland. This includes 12,000 people who were killed in the forests around the village of Piaśnica and 7,000 people who were buried in the forests near the village of Szpęgawsk in 1939. Some historians say the massacres were a prelude to the later Nazi atrocities committed during the Holocaust, the researchers said.


      So many people were killed in 1939 and 1945 in one area of Pomerania, near the outskirts of the town of Chojnice, it became known locally as Death Valley. One witness, who testified after the war, recalled seeing that "a column of approximately 600 Polish prisoners from Bydgoszcz, Toruń, Grudziad̨z and neighboring villages, under the escort of the Gestapo, was taken to Death Valley during the second half of January 1945," the researchers wrote in the study. "They were executed there, and the witness speculated that the bodies of the victims were burned to cover up the evidence."




      An aerial photo of Death Valley taken in July 2020. (Image credit: D. Frymark; Antiquity Publications Ltd.)


      A researcher uses a metal detector to search for artifacts at the mass grave site. (Image credit: D. Frymark; Antiquity Publications Ltd.)

      After the war, in 1945, exhumations at that spot in Death Valley unearthed the remains of 168 people. But it was evident from the exhumation reports and the witness' testimony that there were more burials to be found, the researchers said.

      "It was commonly known that not all mass graves from 1939 were found and exhumed, and the grave of those killed in 1945 was not exhumed either," study lead author Dawid Kobiałka, an archaeologist and cultural anthropologist at the Polish Academy of Sciences, said in a statement.

      To investigate, Kobiałka and his colleagues used noninvasive techniques to study the area, including with lidar (light detection and ranging), which uses lasers shot from an aircraft flying overhead to map the topography of the ground. The lidar work revealed trenches that the Polish army had dug in 1939 in anticipation of a war with the Third Reich. But just a few months later, the Nazis used these trenches to hide the bodies of their victims, the researchers said.

      "Executions took place at the trenches," they wrote in the study. "The victims fell into the trenches or their bodies were thrown there by the perpetrators. Later, the trenches were backfilled with soil."

      At the trench site, the team performed surveys on the soil underground with ground-penetrating radar, electromagnetic field analysis and electrical resistivity, and found many anomalies hidden in the soil underground. Metal-detector surveys also revealed many artifacts, which led the researchers to excavate eight of the trenches. Since then, they have found more than 4,250 artifacts, many from 1939 and 1945, that included bullets, shell casings and charred wood that was likely used to burn the bodies.

      Image 1 of 4



      Photos of (A-B) the funeral of people murdered in Death Valley; (C) the gateway to the Cemetery of the Victims of Nazi Crimes in Chojnice; and (D) one of the mass graves in the Cemetery of the Victims of Nazi Crimes in Chojnice. (Image credit: Historical-Ethnographic Museum of Julian Rydzkowski in Chojnice; D. Kobiałka; Antiquity Publications Ltd.)



      Pieces of charred wood: (A-B) used to build a stack on which the bodies of victims were burned; (C) blue stains on the wood left by a flammable substance; (D) fragments of burned human bones preserved on the surface of the wood. (Image credit: J. Rennwanz; Antiquity Publications Ltd.)



      The wedding ring of Irena Szydłowska, a courier with the Polish resistance. (Image credit: A. Barejko; Antiquity Publications Ltd.)



      Personal belongings from victims murdered at Death Valley in 1945, including (A) a wristwatch; (B) a badge with crest of Toruń; (C) a woman's earring; and (D) a holy medal. (Image credit: A. Barejko; Antiquity Publications Ltd.)


      The team also found cremated bones and jewelry, including a gold wedding ring, suggesting the victims were not robbed when they were killed. The researchers identified the ring's owner as Irena Szydłowska, a courier in the Polish Home Army. "Her family was informed about the finding, and the plan is to return the ring to them," Kobiałka said.




      (A) Study author Dawid Kobiałka interviews Urszula Steinke, who lost her father in 1939 in Death Valley; (B) Alojzy Słomiński, the father of Urszula Steinke; (C) An interview with Aleksandra Lubińska, who lost her father in 1939 in Death Valley; and (D) Władysław Kręcki, the father of Aleksandra Lubińska. (Image credit: D. Frymark; U. Steinke’s private archive; A. Lubińska’s private archive; Antiquity Publications Ltd.)
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      Their historical investigation revealed that some of the killed prisoners were part of the Polish resistance.

      "A series of specialized analyses of the finds is taking place right now," Kobiałka said. "It is believed that more victims killed in Death Valley will be identified soon, and their families will be informed about what really happened to their beloved ones."

      The team also hopes to identify some of the victims with DNA analysis. After the researchers are done examining the site, "the remains will be reburied in Death Valley and the site will become an official war cemetery," they wrote in the study.

      The study was published online Wednesday (Aug. 18) in the journal Antiquity.

      Originally published on Live Science.

      What color is the universe?

      A colorful shot of nebula and stars in deep space. (Image credit: Shutterstock)

      When you look up at the night sky, it's easy to think that the universe is a never-ending sea of blackness. But if you measured the visible light from all of the luminous celestial bodies out there, what would the average color of the universe be?

      Let's get this out of the way first: It's not black.

      "Black is not a color," Ivan Baldry, a professor at the Liverpool John Moores University Astrophysics Research Institute in the U.K., told Live Science. "Black is just the absence of detectable light." Instead, color is the result of visible light, which is created throughout the universe by stars and galaxies, he said. 

      In 2002, Baldry and Karl Glazebrook, a distinguished professor at the Centre for Astrophysics and Supercomputing at the Swinburne University of Technology in Australia, co-led a study published in The Astrophysical Journal that measured the light coming from tens of thousands of galaxies and combined it into a singular spectrum that represented the entire universe.

      In doing so, the pair and their colleagues were able to work out the average color of the universe.

      The cosmic spectrum 

      Stars and galaxies emit waves of electromagnetic radiation, which is separated into different groups based on the length of the waves emitted. From shortest to longest wavelength, the groups include gamma-raysX-raysultraviolet light, visible light, infrared radiationmicrowaves and radio waves

      Visible light makes up a tiny portion of the electromagnetic spectrum in terms of the range of wavelengths, but it is the only part the naked eye can see. What we perceive as colors are actually just different wavelengths of visible light; reds and oranges have longer wavelengths, and blues and purples have shorter wavelengthsThe visible spectrum of a star or a galaxy is a measure of the brightness and wavelengths of light that the star or galaxy emits, which, in turn, can be used to determine the average color of the star or galaxy, Baldry said.

      In 2002, Australia's 2dF Galaxy Redshift Survey — which was the largest survey of galaxies ever carried out at the time — captured the visible spectra of more than 200,000 galaxies from across the observable universe. By combining the spectra of all these galaxies, Baldry and Glazebrook's team was able to create a visible light spectrum that accurately represented the entire universe, known as the cosmic spectrum.

      The comic spectrum "represents the sum of all the energy in the universe emitted at different optical wavelengths of light," Baldry and Glazebrook wrote in a separate non-peer-reviewed online paper in 2002 based on their discovery. The cosmic spectrum, in turn, allowed them to determine the average color of the universe.  

      Color conversion 

      The researchers used a color-matching computer program to convert the cosmic spectrum into a single color visible to humans, Baldry said.

      Our eyes have three types of light-sensitive cones, each of which helps us perceive a different range of visible light wavelengths. This means that we have certain blind spots where we cannot properly register certain colors of wavelengths between these ranges, Baldry and Glazebrook wrote in their online paper. The colors we see also depend on what our reference for white light is as we are observing an object. For instance, the color of an object may appear different in a brightly lit room compared with the outdoors on an overcast day.

      Related: What color is the sunset on other planets?

      However, the CIE color spaces, created by the International Commission on Illumination in 1931, compensate for our visual limitations by attributing a color to different wavelength combinations as seen by a standardized human observer, which is what the team's computer models used.

      The team determined that the average color of the universe is a beige shade not too far off from white. Although this is a rather boring finding, it is not a surprising one, considering that white light is the result of combining all the different wavelengths of visible light and the cosmic spectrum includes such a wide range of wavelengths.

      The new color was eventually named "cosmic latte," based on the Italian word for milk, after a poll of the whole research team. Other suggestions included cappuccino cosmico, Big Bang beige and primordial clam chowder. 


      The color 'cosmic latte' (Hex triplet = #FFF8E7).

      The color 'cosmic latte' (Hex triplet = #FFF8E7) (Image credit: NASA)


      Unshifting the red 

      A key concept of the cosmic spectrum is that it represents the light of the universe "as originally envisaged," Balrdy and Glazebrook wrote in their online paper. This means that it represents the light as it was emitted throughout the universe, not just as it appears to us on Earth today.

      Like all waves, light gets stretched over vast distances because of the Doppler effect. As light gets stretched, its wavelength increases and its color moves toward the red end of the spectrum, known by astronomers as redshift. This means that the light we see is not the same color it was when it was first emitted.

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      Cosmic latte is, therefore, the color you would see if you could look down on the universe from above and see all the light coming from every galaxy, star and gas clouds all at once, Baldry said.
      "We removed the effect of redshift from the spectra of the galaxies," Baldry said. "So, it is the spectra of the galaxies when they emitted the light."

      Originally published on Live Science.

      Insurance industry seeks to limit fossil fuel exposure amid growing climate threat

      In the past 3 years, 9 insurers have ended or limited

       insurance for the Canadian oilsands

      Of all the institutional investors, insurance companies have perhaps the most on the line when it comes to climate change.                                                               (Jason Franson/The Canadian Press)

      With global climate change threatening to wreak havoc on their industry, insurance companies are increasingly looking to limit their exposure to the fossil fuel sector.

      "This was not an issue that was central in the insurance sector, even 7 years ago," said Robin Edger, national director of climate change for the Insurance Bureau of Canada. "But now it is moving at light speed."

      In the past three years, 23 major global insurance companies have adopted policies that end or limit insurance for the coal industry, and nine insurers have ended or limited insurance for the Canadian oilsands.

      Other insurance companies are making changes on the asset side of their books, divesting fossil fuel investments and adding green energy to their investment portfolios. In July, eight of the world's largest insurance companies — including Swiss Re, Zurich Insurance Group and Aviva — committed to transitioning their portfolios to net-zero greenhouse gas emissions by 2050.

      The "sustainable finance" movement — which seeks to use the power of investment capital to move toward a lower-carbon economy — also includes pension funds, banks, and mutual funds. But of all the institutional investors, insurance companies have perhaps the most on the line when it comes to climate change.

      According to the Insurance Bureau of Canada, the average annual cost of claims for property damage or losses due to severe weather has more than quadrupled over the last decade to $2.4 billion in 2020.

      That figure is expected to keep growing. An alarming report from the United Nations earlier this month said the world will cross the 1.5-degree-Celsius warming mark in the 2030s, resulting in more floods, fires and heat waves.

      On the hook for more payouts amid ever-escalating risk, the global insurance industry has been lobbying for years for governments to take more action on climate change. But it is only recently that insurers have begun taking a critical look at their own investments in fossil fuel companies.

      In Europe — where the disclosure of fossil fuel investments is mandatory for public companies — insurers are moving faster than their North American counterparts, said Victor Adesanya, lead author of a recent DBRS Morningstar report on the topic.

      But even in the U.S. and Canada, where the disclosure of fossil fuel holdings is not required, the issue is gaining momentum, Adesanya said. Manulife Financial, for example, has committed to assessing its own $39.8-billion portfolio with the goal of getting to net-zero by 2050.

      "For them (North American insurers) to just turn off the taps and stop investing right away, I don't see that happening," Adesanya said. "But there's a trend that has started, and it will begin to ramp up."

      Environmental groups are also increasingly putting pressure on the insurance industry, demanding that they stop underwriting coal mines, coal-fired power plants, and other fossil fuel projects.

      They have had some success — a handful of global insurers stated publicly this year they would not provide coverage to the TransMountain pipeline expansion.

      "To me it illustrates a real shift in the sector," said Mary Lovell, who leads insurance campaigns for the San Francisco-based environmental group Rainforest Action Network. "These insurers understand the reputational risk of being involved with a project as contentious as TransMountain, as well as the material risk of constructing a new pipeline during a climate crisis."

      Edger, with the Insurance Bureau of Canada, said the industry will be closely watching the COP 26 UN Climate Summit in Glasgow in November, where the issue of sustainable finance is expected to be a major topic.