It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Friday, November 18, 2022
Hubble Views a Billowing Cosmic Cloud
A small, dense cloud of gas and dust called CB 130-3 blots out the center of this image from the NASA/ESA Hubble Space Telescope. CB 130-3 is an object known as a dense core, a compact agglomeration of gas and dust. This particular dense core is in the constellation Serpens and seems to billow across a field of background stars.
Dense cores like CB 130-3 are the birthplaces of stars and are of particular interest to astronomers. During the collapse of these cores enough mass can accumulate in one place to reach the temperatures and densities required to ignite hydrogen fusion, marking the birth of a new star. While it may not be obvious from this image, a compact object teetering on the brink of becoming a star is embedded deep within CB 130-3.
Astronomers used Hubble’s Wide Field Camera 3 to better understand the environment surrounding this fledgling star. As this image shows, the density of CB 130-3 isn’t constant; the outer edges of the cloud consist of only tenuous wisps, whereas at its core CB 130-3 blots out background light entirely. The gas and dust making up CB 130-3 affect not only the brightness but also the apparent color of background stars, with stars toward the cloud’s center appearing redder than their counterparts at the outskirts of this image. Astronomers used Hubble to measure this reddening effect and chart out the density of CB 130-3, providing insights into the inner structure of this stellar nursery.
Text credit: European Space Agency (ESA) Image credit: ESA/Hubble, NASA & STScI, C. Britt, T. Huard, A. Pagan
This cross-sectional illustration shows the farside meteorite impact observed by the Mars Reconnaissance Orbiter and the resultant propagation paths, through the mantle and along the core-mantle boundary, of seismic waves detected by the InSight seismic station. Credit: Institut de Physique du Globe de Paris/Centre National D’Études Spatiales/N. Starter
NASA's InSight lander (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) launched in 2018 with the goal of peering deep into Mars's interior for the first time to gain important information about the planet's structure and formation. To help with this task, the lander is equipped with a sensitive seismometer that allows it to detect subtle marsquake vibrations.
By recording the way these vibrations are reflected and bent as they travel through the planet, InSight has helped scientists map the layout of Mars's crust, mantle, and core. Recently, an unusual series of vibrations provided an opportunity for even deeper understanding.
In a new paper published in Geophysical Research Letters, Durán et al describe one of the largest seismic events recorded on Mars, and the farthest from InSight's location. It is the first such event with pressure waves (P waves) that reached into the lower mantle more than 800 kilometers beneath the planet's surface and all the way to the core, where they were diffracted.
After analyzing the vibrations, the authors concluded that the event, which turned out to be an impact, occurred near Mars's Tharsis volcanic plateau, on the opposite side of the planet from InSight, in agreement with satellite images showing the impact site.
The depth of the detected vibrations allowed the researchers to constrain the structure of Mars's lower mantle in more detail than has previously been available. They found that the lower mantle appears to be more variable, in terms of both its temperature and composition, than suggested by previous seismic models. However, they say, it will require more data to determine precisely how the thermal and chemical makeup of the lower mantle varies, and why.
More information: C. Durán et al, Observation of a Core‐Diffracted P‐Wave From a Farside Impact With Implications for the Lower‐Mantle Structure of Mars, Geophysical Research Letters (2022). DOI: 10.1029/2022GL100887
Australia's Great Barrier Reef might never have come to be were it not for the formation of a vast island based mostly on sand.
K'gari, also known as Fraser Island, has the honor of being the world's largest sand island, covering around 640 square miles (nearly 1,700 square kilometers) just off the southeastern coast of Queensland.
Along with the nearby Cooloola Sand Mass, the mass of forested dunes and beaches forms an unofficial base to the vast reef that sits to its north.
If this terrestrial 'launching pad' had never formed, researchers think the masses of sand carried northwards along the coast by ocean currents would have landed right where the reef now sits.
Quartz-rich sands have a way of smothering carbonate-rich sediments, which are necessary for coral development.
Without K'gari in the way to guide sediment off the continental shelf and into the deep, conditions would not have suited the formation of the world's largest coral reef, experts argue.
The Great Barrier Reef has a confusing origin story. It only formed half a million years ago, long after conditions were appropriate for the growth of coral.
K'gari might be the lost puzzle piece researchers have been searching for. Analysis and dating of sand from the many dunes on the 123 kilometer (76 mile) long island suggest the land mass formed between 1.2 and 0.7 million years ago, just a few hundred thousand years before the Great Barrier Reef came to be.
The island's presence probably deflected northward currents, researchers explain, providing the southern and central parts of the great barrier reef the reprieve they needed to start growing thousands of kilometers of coral.
The coast of Queensland, Australia, showing sediment dispersal before the formation of K'gari and Cooloola (left) and after (right). (Ellerton et al., Nature Geoscience, 2022)
K'gari and Cooloola themselves arose from the accumulation of sand and sediment from the south.
Amid periods of ice formation and fluctuating sea levels, researchers suspect sediment around the world 'suddenly' became exposed. In successive periods of ice melt and rising oceans, that sediment then got caught up in the currents.
Along the east coast of Australia this probably meant a long northward treadmill of soil and sand tracing the continental shelf.
A slope off the southern coast of Queensland, however, makes the perfect place for sediment to accumulate, and this is right where K'gari and Cooloola are found.
Just south of the sand masses, coral reefs are conspicuously missing.
If researchers are right, that's probably because the northward currents here are too strong. K'gari and Cooloola break up the long distance dispersal, stopping quartz-rich sands from smothering developing reefs.
"Before Fraser Island developed, northward longshore transport would have interfered with coral reef development in the southern and central [Great Barrier Reef]," researchers write.
Sediment records from the southern Great Barrier Reef support this idea. About 700,000 years ago, there appears to have been an uptick in carbonate content in sediment in this region.
Research on reefs further north is now needed as well, but at least two-thirds of the Great Barrier Reef seems to owe its existence to a wall of sand to the south.
"The development of Fraser Island dramatically reduced sediment supply to the continental shelf north of the island," the authors argue.
"This facilitated widespread coral reef formation in the southern and central Great Barrier Reef and was a necessary precondition for its development."
Tue 15 Nov 2022 The combined methane emissions of 15 of the world’s largest meat and dairy companies are higher than those of several of the world’s largest countries, including Russia, Canada and Australia, according to a new study.
The analysis from the Institute for Agriculture and Trade Policy and Changing Markets Foundation found that emissions by the companies – five meat and 10 dairy corporations – equate to more than 80% of the European Union’s entire methane footprint and account for 11.1% of the world’s livestock-related methane emissions.
“That just blew my mind,” said Shefali Sharma, director of the IATP’s European office. “We can’t continue to have this handful of companies controlling this many animals.” Methane reduction is vital to achieving a 1.5C future
Methane, expelled by cows and their manure, is far more potent than carbon dioxide, trapping heat 80 times more effectively and emissions are accelerating rapidly, according to the UN.
Researchers admit in the report that a lack of transparency from the companies makes it difficult to accurately measure greenhouse gas emissions. Results were estimated based on publicly available data on meat and milk production and regional livestock practices.
The report comes as the Cop27 climate conference unfolds in Egypt, where politicians and corporate leaders are discussing the role of agriculture and face accusations they are failing to consider meaningful solutions.
If the 15 companies were treated as a country, the report noted, it would be the 10th-largest greenhouse gas-emitting jurisdiction in the world. Their combined emissions outpace those of oil companies such as ExxonMobil, BP and Shell, researchers found.
Researchers singled out individual livestock companies such as JBS, the world’s largest meat company, and the French dairy giant Danone.
JBS’s methane emissions “far outpace all other companies”, according to the report, exceeding the combined livestock emissions of France, Germany, Canada and New Zealand.
The world’s second-largest meat company, Tyson, produces approximately as much livestock methane as Russia, researchers said, and Dairy Farmers of America produces as much as the United Kingdom.
JBS did not respond to requests for comment.
Tyson and Dairy Farmers of America declined interview requests. A Dairy Farmers of America spokesperson said in an email that the report’s comparison of the company with UK emissions “is not an apples to apples comparison and is clearly an attempt to make sensationalistic headlines”. Dairy Farmers of America “is committed to being a part of climate solutions”, the organization added.
The report recommended reforms to help curb emissions and climate breakdown, including governments requiring companies to report greenhouse gas emissions and fostering a “just transition” away from factory farming by reducing the number of animals per farm. Companies should also set goals to reduce emissions and be more transparent about methane production, the report concluded.
The US has resisted regulating farm methane emissions, choosing instead to offer voluntary incentives to farmers and companies for reducing greenhouse gasses. But change is unlikely unless the Environmental Protection Agency is allowed to regulate those emissions, said Cathy Day, climate policy coordinator with the National Sustainable Agriculture Coalition.
“There’s a narrative to focus on incentives only, to focus on environmental problems by paying people to solve them rather than requiring people to solve them,” she said. “My opinion is we don’t get there without regulatory solutions.”
The 15 companies studied are based in 10 countries, five of which have increased livestock methane emissions in the past decade, the report said. China’s emissions have increased 17%, far more than other countries.
While it would be helpful for people to eat fewer meat and dairy products, Sharma said, the true solution to curbing methane emissions was to end factory farming.
“We’re not saying people need to go vegan or vegetarian,” Sharma said. “We’re just saying we need to do it better.”
Video: Protesters set fire to Iran’s ex-supreme leader Ayatollah Khomeini's home
Iranian protesters set fire to the old home of former supreme leader Ayatollah Ruhollah Khomeini as protests over Mahsa Amini's death have been raging in the country, entering their third month. The home-turned-museum of the Islamic Republic’s founder in Khomein was set on fire using petrol bombs as per videos shared on social media. Slogans against Iran’s clerical leaders were also heard in the videos.
“This year is the year of blood, (Supreme Leader Ali Khamenei) will be toppled,” protesters in Tehran can be heard saying in a video posted by 1500tasvir as fire can be seen behind the distinctive arches of the museum.
Protests raged in at least 23 cities of Iran on Thursday as the authorities scramble to control the demonstrations. Rights groups have said that over 300 people have been killed till now in the protests as reports suggest that the regime is planning to turn to more violent tactics to stem the demonstrations.
The protests have become a major challenge for the country since the 1979 Islamic Revolution.
General Hossein Salami, head of the Revolutionary Guards, said that Iran is facing a "conspiracy" from the western countries. "The United States, England, Germany, France, Israel, Saudi Arabia and their allies are preparing to fight God, his prophet and the martyrs,'" General Hossein Salami said.
Iranian protesters set fire to
Ayatollah Khomeini’s ancestral
home
Social media images show what is
now a museum commemorating
the Islamic Republic founder
ablaze as protests continue
Iran protests: footage appears to show late ayatollah's ancestral house on fire – video
The house in the city of Khomein in the western Markazi province was shown ablaze late on Thursday with crowds of jubilant protesters marching past, according to images posted on social media, verified by AFP.
Khomeini is said to have been born at the house in the town of Khomein – from where his surname derives – at the turn of the century.
He became a cleric deeply critical of the US-backed shah Mohammad Reza Pahlavi, moved into exile and then returned in triumph from France in 1979 to lead the Islamic revolution.
Khomeini died in 1989 but remains the subject of adulation by the clerical leadership under his successor, Ayatollah Ali Khamenei.
The house was later turned into a museum commemorating Khomeini. It was not immediately clear what damage it sustained.
Iran’s Tasnim news agency later denied there had been a fire, saying the “door of the historic house is open to visitors”.
“The counter-revolutionary media tries to create turmoil by spreading lies and false information. The burning down of Imam Khomeini’s historic house, a place with spiritual value to Iranians, was one of those lies,” the deputy goveronor of Markazi province, Behnam Nazari, was quoted as saying.
The protests sparked by the death of Mahsa Amini, who had been arrested by the morality police, pose the biggest challenge from the street to Iran’s leaders since the 1979 revolution.
They were fuelled by anger over the obligatory headscarf for women imposed by Khomeini but have turned into a movement calling for an end to the Islamic republic itself.
Images of Khomeini have on occasion been torched or defaced by protesters, in taboo-breaking acts against a figure whose death is still marked each June with a holiday for mourning.
Hundreds of mourners flocked to the city of Izeh in south-western Iran for the funeral of Kian Pirfalak, according to footage posted online.
His mother said at the funeral ceremony that Kian was shot on Wednesday by security forces, although Iranian officials insisted he was killed in a “terrorist” attack carried out by an extremist group.
“Hear it from me myself on how the shooting happened, so they can’t say it was by terrorists because they’re lying,” his mother told mourners, according to a video posted by the 1500tasvir activist Twitter account. “Maybe they thought we wanted to shoot or something and they peppered the car with bullets … plainclothes forces shot my child. That is it.”
