Welcome to Overnight News Digest- Saturday Science. Since 2007 the OND has been a regular community feature on Daily Kos, consisting of science stories from around the world, sometimes coupled with a daily theme, original research or commentary. Editors of OND impart their own presentation styles and content choices, typically publishing each day near 12:00 AM Eastern Time.
Topics in this edition include:
- Reducing asteroid collision risks
- Space debris lands in Saskatchewan farm field
- Do we need to reset our understanding of the cosmos?
- 1,300-year-old letter found in Iranian cave
- Transparent glass made of bamboo
- Earth’s magnetic field nearly collapsed 600 million years ago
- New clues regarding the Roanoke “lost colony” mystery
- 50,000-year-old ice block reveals true state of CO2 now
Salon
by Theo Nicitopoulos
A rare risk of asteroid fastballs turns scientists into sluggers
On a fall evening in 2022, scientists at the Johns Hopkins University Applied Physics Laboratory were busy with the final stages of a planetary defense mission. As Andy Rivkin, one of the team leaders, was getting ready to appear in NASA’s live broadcast of the experiment, a colleague posted a photo of a pair of asteroids: the half-mile-wide Didymos and, orbiting around it, a smaller one called Dimorphos, taken about 7 million miles from Earth.
“We were able to see Didymos and this little dot in the right spot where we expected Dimorphos to be,” Rivkin recalled.
After the interview, Rivkin joined a crowd of scientists and guests to watch the mission’s finale on several big screens: As part of an asteroid deflection mission called DART, a spacecraft was closing in on Dimorphos and photographing its rocky surface in increasing detail.
Business Insider
by Jessica Orwig and Ellyn LaPoint
Astronomers say we may live at the center of a cosmic void 2 billion light-years wide that defies the laws of cosmology
Our home galaxy, the Milky Way, is just one of billions in our universe. So, in the grand scheme of things, we're not so special. But zoom in to our local cosmic neighborhood, and that story begins to change.
A growing list of observations suggests we live in the crosshairs of a giant cosmic void — the largest ever observed. Astronomers first suggested such a void in 2013 and evidence for its existence has been stacking up ever since.
But the kicker is that this giant void shouldn't exist in the first place. If it does exist, that means something is probably amiss with our understanding of the cosmos.
My Modern Met
by Jessica Stewart
1,300-Year-Old Heartfelt Letter Between Family Members Found in Iranian Cave
For four centuries, from 224 CE to 651 CE, the Sasanian Empire (aka the Sassanids) ruled over modern-day Iran and Iraq. Considered a high point of Iranian civilization, it was ended by the early Muslim conquests of the 7th and 8th centuries. Deep in Iran's central province of Delijan, a cave filled with treasures from the late Sasanian era was discovered, though it had been plundered many times over the years.
Many of the items found in Hastijan’s cave are no longer in Iran, as they were sent abroad after being looted. In fact, one of these items was the reason researchers even knew that the cave existed.
“The name of this cave was not mentioned in the archaeological map or in the archaeological reports until one of the Pahlavi language experts abroad noticed the leather writings that contained valuable information,” shares Mustafa Deh Pahlvan, head of the Research Institute of Cultural Heritage, Tourism and Handicrafts. “After following up, he found out that many of these works had left the country, and after questioning, he found out that the origin of these parchments was a cave in Central Province.”
New Atlas
by Michael Irving
Transparent bamboo: A fireproof and waterproof alternative to glass
Glass might soon have some competition from an unlikely rival – bamboo. Scientists in China have turned regular old bamboo into a transparent material that’s also resistant to fire and water, and suppresses smoke.
Silica glass, made from sand, is still the go-to building material when you need something transparent but strong, like windows. But it’s not particularly sustainable, and can be heavy and brittle.
Transparent wood has actually been muscling in on glass’s turf for a few years now. Scientists chemically remove the lignin from the wood fibers, then treat the remaining material with plexiglass or epoxy. The end result is a material that’s transparent, renewable, and as strong as or stronger than glass, while being lighter and a better thermal insulator.
There are still a few problems with using wood though. It’s way more flammable than glass, and already in high demand, with stocks taking too long to replenish. So for the new study, researchers at Central South University of Forestry and Technology (CSUFT) in China turned to bamboo instead.
Smithsonian Magazine
by Tara Wu
Earth’s Magnetic Field Nearly Collapsed 600 Million Years Ago. Then, Weird and Complex Life Evolved
Earth’s magnetic field sustains life on our planet, protecting us from solar winds, radiation and extreme changes in temperature. But around 591 million years ago, it almost collapsed. According to a new study, this near-disaster may have actually been the key to a burst of evolution, which paved the way for larger and more varied life forms to develop.
Published in the journal Communications Earth & Environment this month, the study found that a drastic weakening of Earth’s magnetic field that lasted for 26 million years corresponded with a period of the planet’s history called the Ediacaran. During this time, a large amount of oxygen in Earth’s atmosphere and oceans allowed for the first multicellular, oxygen-using organisms to arise from the sea.
The creatures that evolved during the Edicaran hardly resembled anything seen today, however, taking on disc-like forms and shapeless masses—some of which exceeded three feet in size. These fronds and fans include Earth’s earliest known animals, such as the blob-like Dickinsonia.
Scientists theorize that without the protection of the magnetic field roughly 600 million years ago, solar radiation pounded the Earth’s atmosphere, stripping away hydrogen and other light gases from the atmosphere. This left behind an abundance of free-floating oxygen atoms for organisms to use.
New Atlas
by Bronwyn Thompson
This 50,000-year-old block of ice reveals the true state of CO2 levels now
Despite an ever-growing body of evidence indicating we're now living beneath unprecedented levels of atmospheric greenhouse gases, a lack of thorough historical knowledge has hindered our ability to put present-day CO2 emissions into a concrete, long-term context. So what if we're able to use the planet's own record-keeping to fill in those important blanks?
This is the bold approach taken in a new study from Oregon State University (OSU) and University of St Andrews scientists, who, working with the US National Science Foundation, have unlocked a 50,000-year timeline of atmospheric carbon dioxide – thanks to tiny bubbles trapped in Antarctic ice, frozen in time miles below the Earth's surface.
“Studying the past teaches us how today is different," said Kathleen Wendt, an assistant professor at OSU and the study’s lead author. "The rate of CO2 change today really is unprecedented."
Using frozen samples from the West Antarctic Ice Sheet (WAIS) Divide ice core, which were extracted by drilling two miles (3.2 km) deep, the team conducted chemical analysis on the little pockets of preserved gases in the ice blocks to get a clear picture of atmospheric CO2 changes over the many, many years.
CBC Canada
by Jason Warick
Chunk of space debris lands in Sask. farm field
Farmer hopes to sell the 2-metre wide piece of burnt metal to raise money for local hockey rink.
As a farmer in rural Saskatchewan, Barry Sawchuk is used to removing rocks and weeds from his fields.
But he recently discovered a two-metre wide, 40-kilogram heap of twisted, burnt metal.
"My oldest son and I were out driving around just checking fields," said Sawchuk, who farms near Ituna, Sask., about 250 kilometres southeast of Saskatoon. "We came across this object. We thought originally it was just garbage."
Sawchuk said the multiple layers of charred composite fibres and webbing made him suspect it was space debris.
"But I had no idea. I don't build spaceships for a living. I farm," he said.
The Debrief
by Micah Hanks
ARCHAEOLOGISTS UNEARTH NEW CLUES THAT COULD HELP SOLVE CENTURIES-OLD “LOST COLONY” MYSTERY
In 1587, John White and a group of approximately 115 English settlers landed on Roanoke Island off the coast of present-day North Carolina. The colony they sought to establish marked the second attempt to create a long-term presence in the New World under the direction of Sir Walter Raleigh, who instructed them to establish a city bearing his name in the vicinity of the Chesapeake Bay. However, much like the earlier failed effort under Governor Ralph Lane in 1585, White and his fellow colonists soon began to face challenges that included strained relations with the region’s Indigenous inhabitants.
With hopes of garnering additional support for the colony, White sailed back to England, leaving his daughter Eleanor Dare, her husband Ananias Dare, and their infant daughter Virginia—the first English child born in America—behind on Roanoke Island. By the time he returned in 1590, following delays imposed by the Anglo-Spanish War, White found the settlement had been deserted. The only potential clues regarding the whereabouts of the colonists had been an inscription of the word “CROATOAN” carved into a palisade, along with the letters “CRO” found carved into a nearby tree, seemingly in reference to a nearby island located 50 miles to the south.
[…]
Recent excavations by the First Colony Foundation, a North Carolina 501(c)(3) non-profit organization formed in 2004, have reportedly unearthed evidence of a farmstead near the Elizabethan Gardens in Manteo. The farmstead is believed to be associated with the Indigenous Algonquian village of Roanoke.
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