Science Megathread

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So the water that first gave us our oceans didn't just come from random comets early in Earth's geologic history, but mainly from one cataclysmic collision:

All Water On Earth Originated From The Moon’s Formation, Says Study

Life exists on Earth thanks to two things: water and the moon. Without both of these, it's likely that life would not have developed on the planet.

Now, new research from the University of Münster in Germany reveals that the origins of these two are inextricably linked. It turns out that a single crash gave birth to both the moon and water on Earth.

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CO2 isn't just plant food -it turns out we can also use it as (liquid) fuel by mimicking nature through artificial photosynthesis:

Artificial photosynthesis transforms carbon dioxide into liquefiable fuels

Chemists at the University of Illinois have successfully produced fuels using water, carbon dioxide and visible light through artificial photosynthesis. By converting carbon dioxide into more complex molecules like propane, green energy technology is now one step closer to using excess CO2 to store solar energy—in the form of chemical bonds—for use when the sun is not shining and in times of peak demand.

Plants use sunlight to drive chemical reactions between water and CO2 to create and store solar energy in the form of energy-dense glucose. In the new study, the researchers developed an artificial process that uses the same green light portion of the visible light spectrum used by plants during natural photosynthesis to convert CO2 and water into fuel, in conjunction with electron-rich gold nanoparticles that serve as a catalyst. The new findings are published in the journal Nature Communications.

"The goal here is to produce complex, liquefiable hydrocarbons from excess CO2 and other sustainable resources such as sunlight," said Prashant Jain, a chemistry professor and co-author of the study. "Liquid fuels are ideal because they are easier, safer and more economical to transport than gas and, because they are made from long-chain molecules, contain more bonds—meaning they pack energy more densely."

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Nearby supernovae (plural) exploding like firecrackers almost simultaneously in the Milky Way Galaxy (so right in our neighborhood) millions of years ago helped spur human evolution, according to this:

Exploding stars led to humans walking on two legs, radical study suggests
Scientists say surge of radiation led to lightning causing forest fires, making adaptation vital

(...) The benefits of standing tall in the African savannah are broadly nailed down, but what prompted our distant forebears to walk upright is far from clear. Now, in a radical proposal, US scientists point to a cosmic intervention: protohumans had a helping hand from a flurry of exploding stars, they say.

According to the researchers, a series of stars in our corner of the Milky Way exploded in a cosmic riot that began about 7m years ago and continued for millions of years more. The supernovae blasted powerful cosmic rays in all directions. On Earth, the radiation arriving from the cataclysmic explosions peaked about 2.6m years ago.

The surge of radiation triggered a chain of events, the scientists argue. As cosmic rays battered the planet, they ionised the atmosphere and made it more conductive. This could have ramped up the frequency of lightning strikes, sending wildfires raging through African forests, and making way for grasslands, they write in the Journal of Geology. With fewer trees at hand in the aftermath, our ancient ancestors adapted, and those who walked upright thrived.

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Closest-known ancestor of today’s Native Americans found in Siberia

Indigenous Americans, who include Alaska Natives, Canadian First Nations, and Native Americans, descend from humans who crossed an ancient land bridge connecting Siberia in Russia to Alaska tens of thousands of years ago. But scientists are unclear when and where these early migrants moved from place to place. Two new studies shed light on this mystery and uncover the most closely related Native American ancestor outside North America.

(...) Based on the time it would have taken for key mutations to pop up, the ancestors of today’s Native Americans splintered off from these ancient Siberians about 24,000 years ago, roughly matching up with previous archaeological and genetic evidence for when the peopling of the Americas occurred, the team reports today in Nature.

Additional DNA evidence suggests a third wave of migrants, the Neo-Siberians, moved into northeastern Siberia from the south sometime after 10,000 years ago. These migrants mixed with the ancient Siberians, planting the genetic roots of many of the area’s present-day populations.

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If they are going to be doing this, then it makes sense to extend the life of the International Space Station from 2024 to 2030:

NASA is opening the space station to commercial business and more private astronauts

Today, NASA executives announced that the space agency will open up parts of the International Space Station to more commercial opportunities, allowing companies unprecedented use of the space station’s facilities, including filming commercials or movies against the backdrop of space. NASA is also calling on the private space industry to send in ideas for habitats and modules that can be attached to the space station semi-permanently.

A new interim directive from NASA allows private companies to buy time and space on the ISS for producing, marketing, or testing their products. It also allows those companies to use resources on the ISS for commercial purposes, even making use of NASA astronauts’ time and expertise (but not their likeness). If companies want, they can even send their own astronauts to the ISS, starting as early as 2020, but all of these activities come with a hefty price tag.

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Massive Alien Hunt Finds No Sign Of Extraterrestrial Life In 1,300 Stars Closest To Earth

Scientists have been searching for aliens for centuries, but new research reveals that if intelligent extraterrestrial life exists, it's likely not anywhere nearby.

As part of the decade-long $100 million Breakthrough Listen initiative funded by Russian billionaire Yuri Milner, researchers conducted the most comprehensive Search for Extraterrestrial Intelligence program ever undertaken. The team led by University of California, Berkeley astrophysicist Danny Price looked at 1,327 nearby stars across billions of frequency channels in an attempt to detect signs of intelligent life.

Results of their search was released in a paper published in the Astrophysical Journal with the researchers revealing that they came up empty.

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Considering how much we blame human-induced climate change, there are actually other factors contributing to the decline of coral reefs.  Factors we may find easier to control:

Sewage, Fertilizers Contribute To Coral Death, Study Finds

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Ecologically-friendly air-conditioning.  Quite timely, too:

New Cooling System Reduces Temperatures In Crowded City Buildings Without Electricity

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Allow me to introduce the parrot from hell, the kind that stood 3 feet tall and was a cannibal:

This toddler-size parrot was a prehistoric oddity
The flightless 'squawkzilla' stood three feet tall and was twice the weight of the kakapo, the heaviest parrot alive today.

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And while we are on the subject of giant, flightless, prehistoric birds, here is yet another:

This monster penguin was as big as humans. And it once swam the oceans, scientists say

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It is now raining plastics....literally:

Scientists make troubling discovery in rain falling over portion of US

Plastic has become more than just a part of humans' daily lives; it’s now a part of the environment. Scientists in two very different places have made similar, startling observations in precipitation that demonstrate how plastic is finding its way into every facet of life on the planet.

In the Rocky Mountains, United States Geological Survey (USGS) scientists took samples of rainwater and accidentally found particles of microplastics. They originally had set out to analyze the samples to study rainwater for nitrogen pollution levels. Instead, they found something much more tragic.

According to the National Oceanic and Atmospheric Administration (NOAA), microplastics are pieces of plastic debris that are less than 5 millimeters in length. NOAA explains that microplastics, microbeads and microfibers pose a dangerous threat to aquatic life.

If these particles are ingested or marine wildlife get entangled in them, the plastics can cause injury, alter behaviors and drastically impact important populations. This could throw the balance of the entire ecosystem off kilter.

Does anyone think this is a bigger crisis than human-induced climate change?  Should it be given priority in terms of government resources? 

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16,000 year-old artifacts found near an Idaho river suggest that humans not only lived in the Americas before the opening of the ice-free corridor, but that they arrived by water along the Pacific coast.  Thereby driving one more stake into the heart of the Clovis-first theory, which should by all rights ought to be stone-cold dead by now:

16,000-Year-Old Stone Artifacts Unearthed in Idaho

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There are planets out there beyond our solar system that may not only harbor conditions conducive to life, but that may be even more conducive than our own planet:

Study shows some exoplanets may have greater variety of life than exists on Earth

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NASA'S Hubble Finds Water Vapor On Habitable-Zone Exoplanet For the First Time

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Highly Energetic Explosion Occurred in Milky Way’s Center 3.5 Million Years Ago

About 3.5 million years ago, a Seyfert flare from Sagittarius A*, a supermassive black hole in the center of the Milky Way Galaxy, created two enormous ionization cones that sliced through our Galaxy, beginning with a relatively small diameter close to the black hole, and expanding vastly as they exited the Galaxy.

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MIT engineers develop a new way to remove carbon dioxide from air
The process could work on the gas at any concentrations, from power plant emissions to open air.

A new way of removing carbon dioxide from a stream of air could provide a significant tool in the battle against climate change. The new system can work on the gas at virtually any concentration level, even down to the roughly 400 parts per million currently found in the atmosphere.

Most methods of removing carbon dioxide from a stream of gas require higher concentrations, such as those found in the flue emissions from fossil fuel-based power plants. A few variations have been developed that can work with the low concentrations found in air, but the new method is significantly less energy-intensive and expensive, the researchers say.

The technique, based on passing air through a stack of charged electrochemical plates, is described in a new paper in the journal Energy and Environmental Science, by MIT postdoc Sahag Voskian, who developed the work during his PhD, and T. Alan Hatton, the Ralph Landau Professor of Chemical Engineering.

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It seems Botswana is the motherland of modern humans, according to this latest study:

Controversial new study pinpoints where all modern humans arose
The research reignites a long-simmering debate about how and where our species emerged.

(...) Now, a controversial new study in Nature argues that this oasis, known as the Makgadikgadi–Okavango wetland, was not just any home, but the ancestral “homeland” for all modern humans today. The researchers studied mitochondrial DNA—genetic material stored in the powerhouse of our cells that is passed from mother to child—of current residents across southern Africa. Then they layered the genetic data with an analysis of past climate and modern linguistics, as well as cultural and geographic distributions of local populations.

The study’s results suggest that shifts in climate allowed branches of the ancient population to spread from the wetland to newly formed zones of green. Thousands of years later, a small population of these wanderers’ kin eventually would leave Africa and ultimately inhabit every corner of the world.

“We all came from the same homeland in southern Africa,” says Vanessa Hayes of the Garvan Institute of Medical Research in Australia, who led the new research.

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This newly discovered trove of fossils found in Colorado fills a crucial gap in our understanding of how life recovered in the one million-year period immediately after the extinction of the dinosaurs, leading to the subsequent rise of mammals, eventually including us:

Extraordinary fossils show how mammals rose from the dinosaurs’ ashes

Read more: https://www.newscientist.com/article/2221128-extraordinary-fossils-show-how-mammals-rose-from-the-dinosaurs-ashes/#ixzz63zSprtwM

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Apparently the distant ancestors of native Americans were clever and wily enough to use traps to hunt and kill mammoths:

Two Traps Where Woolly Mammoths Were Driven to Their Deaths Found in Mexico
The discovery may offer rare evidence that humans were actively hunting the great creatures

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Scientists extract hydrogen gas from oil and bitumen, giving potential pollution-free energy

Scientists have developed a large-scale economical method to extract hydrogen (H2) from oil sands (natural bitumen) and oil fields. This can be used to power hydrogen-powered vehicles, which are already marketed in some countries, as well as to generate electricity; hydrogen is regarded as an efficient transport fuel, similar to petrol and diesel, but with no pollution problems. The process can extract hydrogen from existing oil sands reservoirs, with huge existing supplies found in Canada and Venezuela. Interestingly, this process can be applied to mainstream oil fields, causing them to produce hydrogen instead of oil.

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The remains of a forest from the Devonian period have been found in a quarry in the Catskills in upstate New York, making it the oldest forest on earth:

World’s Oldest Forest Reveals Modern Trees Emerged Earlier Than Thought

A research team of faculty from Binghamton University in New York revealed surprising evidence Thursday that the transition to the everyday forests we know today began much earlier than previously thought.

Researchers have uncovered an extensive root system while sifting through fossil soils in the Catskill region near Cairo, New York. The roots belonged to 385-million-year old trees that existed during the Devonian Period, an interval of the Paleozoic era. These incredibly well-preserved root systems show evidence of the presence of trees with leaves and wood at the peak of their growth – a fascinating feat considering both features are common in modern seed plants, which did not exist until roughly 10 million years later.

The findings, which will be published this week in the journal Current Biology, is the first piece of evidence discovered to hold evidence that the transition toward modern forests began earlier than previously thought.

 

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One other factor not mentioned in the article is the absence of any predators large enough to seriously threaten them once they grow to become full behemoths.  The (definite) extinction of the Megalodon (Discovery Channel mocumentaries aside) allowed whales the space to grow as large as their food-sources would allow them to.  Not even the Great White Shark or the Orca have (yet) filled that predator vacuum left by the extinction of that giant shark:

How Whales Got So Large -- And Why They Aren’t Even Bigger
The bigger the whale, the tougher it is to find a decent meal.

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Apparently those Amazon women warriors mentioned in Homer's Iliad were real after all, and not just a figment of Greek mythology:

Ancient Amazon warrior women discovered in Russia

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Not only can asteroids cause mass extinctions if they are large enough -they can even change our global climate:

World’s Oldest Known Impact Crater Confirmed in Australia

A 70-kilometer-wide (43-mile) impact structure in the Australian Outback has been dated to 2.2 billion years old, making it the oldest known asteroid crater on Earth. Fascinatingly, this asteroid likely plunged into a massive ice sheet, triggering a global-scale warming period.

New research published today in Nature Communications confirms the Yarrabubba crater in western Australia as the oldest accepted impact crater on Earth. At an estimated 2.229 billion years old, it’s nearly 210 million years older than the 200-kilometer-wide (120-mile) Vredefort Dome in South Africa and 380 million years older than the 180-kilometer-wide (112-mile) Sudbury impact structure in Ontario, Canada.

The first author of the new study, Timmons Erickson from NASA Johnson Space Center and Curtin University in Australia, along with his colleagues, also presented evidence suggesting the 7-kilometer-wide asteroid that formed the Yarrabubba crater hit a massive ice sheet, sending tremendous amounts of water vapor into the atmosphere and potentially warming the climate around the globe.

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Skulls from ancient North Americans hint at multiple migration waves

But genetic data tells a very different story.

The earliest humans in North America were far more diverse than previously realized, according to a new study of human remains found within one of the world's most extensive underwater cave systems.

The remains, discovered in the caverns of the Mexican state of Quintana Roo, represent just four of the earliest North Americans, all of whom lived between 9,000 and 13,000 years ago. They're important because North American remains from the first millennia of human habitation in the Americas are rare, said study leader Mark Hubbe, an anthropologist at The Ohio State University. Fewer than two dozen individuals have been discovered, he added.

What makes the four individuals from Mexico interesting is that none of them are quite alike. One resembles peoples from the Arctic, another has European features and one looks much like early South American skulls, while the last doesn't share features with any one population.

"The differences we see among these Mexican skulls are on the same magnitude as the most different populations [globally] nowadays," Hubbe told Live Science.