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Rain Fell for the First Time on Greenland’s Summit. Here’s Why It Matters. – Sierra Magazine



Earlier this month, instead of snow, rain fell on Greenland’s tallest point. It was the first time on record, and it was only the fourth time that temperatures there—an ice-capped expanse two miles above sea level, located in the very center of the Arctic island’s interior—had risen above freezing. For two days following the rain, 337,000 square miles of the territory’s ice sheet experienced surface melting. In total, 7 billion tons of water flooded the summit. 

That rain has fallen in one of Earth’s most reliably frozen regions is an “unprecedented shock to the system,” says John Walsh, a professor at the University of Alaska Fairbanks and a scientist with the International Arctic Research Center. “This has never happened before. Something is going on in the atmosphere that’s taking us into uncharted territory.”  

Greenland is a linchpin within the world’s climate system. Weather that happens there has global implications, Walsh says.  

The Labrador and Greenland Seas, which wrap around the island’s eastern, southern, and western coasts, play pivotal roles in driving what Walsh calls “the global conveyor belt” of ocean currents. These seas are the world’s main centers for deep convection, a process in which colder, denser ocean water sinks and warmer water rises to the surface. This churning action fuels the flow of the world’s oceans, which in turn helps stabilize global temperatures and rainfall.  

But deep convection is impeded by freshwater. Less dense than saltwater, it rests atop the ocean’s surface like a lid. When ice melts into the ocean, not only do sea levels rise, but also the convection process slows, leading to extreme weather around the globe.  

“Like a pan of water boiling on the stove, you turn the heat up, and all sorts of chaotic circulations take place.”

This has happened before. The last ice age, which lasted from 110,000 to 15,000 years ago, was hardly a uniform global freeze. Instead, temperatures fluctuated rapidly all over the world; the Northern and Southern Hemispheres alternated between long stretches of warming and cooling. In 2016, scientists found evidence that suggested this out-of-sync, drastic weather was caused in large part by a major slowing of the oceans’ currents at the time, particularly those near present-day Greenland. 

“The more that Greenland melts, the more freshwater will sit on top,” Walsh says. “The evidence now seems to be suggesting that we’re already seeing a slow-down of the conveyor belt. The combination of freshening and warming are a double whammy and a real concern.”

This feedback loop contributed to the rain event at Greenland’s summit. Ocean waters have been warmer and fresher than normal this summer, which primed the air moving inland for rain instead of snow. 

The distinction between ice and snow is significant in the Arctic, says John Moore, a geophysicist specializing in glaciology and a professor at the University of Lapland. In locations like Greenland’s interior summit, where rain had never fallen before, “ice” is technically a misnomer. The topography is really composed of layers and layers of snow, which over time, and under great weight, has become densely packed, though still with tiny pockets of air. 

But now, meltwater and rain are freezing into solid layers of ice that take many weeks, if not months, to naturally break up. Nobody lives near the Greenland summit, but in other parts of the Arctic, these freezing rain events are wreaking havoc on both natural and urban ecosystems.  

Thousands of reindeer, unable to dig through frozen rain to reach the vegetation they eat, have starved in the past few years. And Indigenous communities throughout the Arctic, who depend on reliable freezing and melting seasons, and on animals who migrate according to weather, find transport across ice sheets—rather than snow—incredibly challenging. 

The rain event at Greenland’s summit occurred just five days after the Intergovernmental Panel on Climate Change released its Code Red for Humanity climate report and coincides with sweeping wildfires throughout Greece and Turkey, historic drought in both southern Africa and the American West, and record-high temperatures worldwide. According to Moore, Greenland’s rain and these events are interconnected. 

“Like a pan of water boiling on the stove, you turn the heat up and all sorts of chaotic circulations take place,” says Moore. “What happened in Greenland is evidence of this chaos.” 

“The Greenland rain event is something not even scientists expected,” Walsh says. “So what else is out there? That’s the real concern here. There could be some surprises that we’re not anticipating at all.”

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Scientists may have accidentally detected dark energy – CTV News



Dark energy, a mysterious force believed to be causing the universe to expand at an accelerated rate, may have been detected by scientists for the first time.

In a new study, published Wednesday in the journal Physical Review D, the authors suggest certain unexplained results from an experiment designed to detect dark matter could have been caused by dark energy.

“Despite both components being invisible, we know a lot more about dark matter, since its existence was suggested as early as the 1920s, while dark energy wasn’t discovered until 1998,” Sunny Vagnozzi, of the University of Cambridge’s Kavli Institute for Cosmology, said in a story posted by the university. “Large-scale experiments like XENON1T have been designed to directly detect dark matter, by searching for signs of dark matter ‘hitting’ ordinary matter, but dark energy is even more elusive.”

Nearly everything we can see and interact with, from bacteria to entire galaxies, is considered ordinary matter and energy, and makes up about five per cent of our universe, according to scientists. The rest is made up of dark matter (27 per cent), an invisible attractive force that holds the cosmos together, and dark energy (68 per cent), a repulsive force considered to be responsible for the accelerating expansion of the universe.

The XENON research project is a collaboration of 160 scientists from around the world who have come together to perform a series of experiments aimed at detecting dark matter particles. These experiments involve the use of ultra-pure liquid xenon, a colourless, dense, odourless noble gas found in trace amounts in Earth’s atmosphere.

Experiments are performed at the Gran Sasso National Laboratory, the largest underground laboratory in the world, located approximately 1.4 kilometres beneath the Gran Sasso mountains in central Italy, about 120 kilometres northeast of Rome.

The XENON1T experiment was the latest phase of the project. About a year ago, it detected an unexpected signal, or excess, over the expected background profile.

“These sorts of excesses are often flukes, but once in a while they can also lead to fundamental discoveries,” Luca Visinelli, researcher at Frascati National Laboratories in Italy, said. “We explored a model in which this signal could be attributable to dark energy, rather than the dark matter the experiment was originally devised to detect.”

The researchers created a physical model that used a type of screening mechanism known as chameleon screening to show that dark energy particles produced in the Sun’s strong magnetic fields could explain the XENON1T signal.

“It was really surprising that this excess could in principle have been caused by dark energy rather than dark matter,” Vagnozzi said. “When things click together like that, it’s really special.”

A discovery such as this would mean that experiments designed to detect dark matter, including those performed during the XENON project, could also be used to detect dark energy. But further research is required to confirm these findings.

“We first need to know that this wasn’t simply a fluke,” Visinelli said. “If XENON1T actually saw something, you’d expect to see a similar excess again in future experiments, but this time with a much stronger signal.”

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'Happy' SpaceX tourist crew spend first day whizzing around Earth –



Graphic on the four all-civilian passengers on SpaceX’s mission to orbit around the Earth, lauched September 15 from Florida.

SpaceX’s all-civilian Inspiration4 crew spent their first day in orbit conducting scientific research and talking to children at a pediatric cancer hospital, after blasting off on their pioneering mission from Cape Canaveral the night before.

St Jude tweeted its patients got to speak with the four American space tourists, “asking the questions we all want to know like ‘are there cows on the Moon?'”

Billionaire Jared Isaacman, who chartered the flight, is trying to raise $200 million for the research facility.

Inspiration4 is the first orbital spaceflight with only private citizens aboard.

Earlier, Elon Musk’s company tweeted that the four were “healthy” and “happy,” had completed their first round of , and enjoyed a couple of meals.

Musk himself tweeted that he had personally spoken with the crew and “all is well.”

By now, they should have also been able to gaze out from the Dragon ship’s cupola—the largest space window ever built, which has been fitted onto the vessel for the first time in place of its usual docking mechanism.

Most humans in space

The Inspiration4 mission also brings the total number of humans currently in space to 14—a new record. In 2009, there were 13 people on the International Space Station (ISS).

There are currently seven people aboard the ISS, including two Russian cosmonauts, and three Chinese astronauts on spaceship Shenzhou-12, which is bound home after its crew spent 90 days at the Tiangong space station.

Isaacman, physician assistant Hayley Arceneaux, geoscientist Sian Proctor and aerospace data engineer Chris Sembroski are whizzing around the planet at an altitude that at times reaches 590 kilometers (367 miles).

That is deeper in space than the ISS, which orbits at 420 kilometers (260 miles), and the furthest any humans have ventured since a 2009 maintenance mission for the Hubble telescope.

Their ship is moving at about 17,500 mph (28,000 kph) and each day they will experience about 15 sunrises and sunsets.

Their high speed means they are experiencing time slightly slower than people on the surface, because of a phenomenon called “relative velocity time dilation.”

Apart from fundraising for charity, the mission aims to study the biological effects of deep space on the astronauts’ bodies.

“Missions like Inspiration4 help advance spaceflight to enable ultimately anyone to go to orbit & beyond,” added Musk in a tweet.

The adventure bookends a summer marked by the battle of the billionaires Richard Branson and Jeff Bezos to reach the final frontier.

But these flights only offered a few minutes of weightlessness—rather than the three full days of orbit the Inspiration4 crew will experience, before splashing down off the coast of Florida on Saturday.

Explore further

SpaceX’s tourist crew ‘healthy, happy and resting’

© 2021 AFP

‘Happy’ SpaceX tourist crew spend first day whizzing around Earth (2021, September 17)
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Chinese astronauts return after 90-day mission to space station – Al Jazeera English



Shenzhou-12 mission carrying three Chinese men landed safely in the autonomous region of Inner Mongolia in northern China.

Three Chinese astronauts have returned to earth after a 90-day visit to an unfinished space station in the country’s first crewed mission since 2016.

In a small return capsule, the three men – Nie Haisheng, Liu Boming and Tang Hongbo – landed safely in the autonomous region of Inner Mongolia in the north of China at 1:34pm (05:34 GMT), state media reported.

The Shenzhou-12 mission was the first of four crewed missions planned for 2021-2022 as China assembles its first permanent space station. The process requires 11 missions, including the launches of the station’s three modules.

Construction kicked off in April with the launch of the Tianhe module, the future living quarters of the space station. Slightly larger than a city bus, Tianhe was where Nie, Liu and Tang have stayed since mid-June, marking China’s longest spaceflight mission.

While in orbit, the astronauts conducted spacewalks, validated Tianhe’s life-support system, tested the module’s robotic arm, and sorted supplies for upcoming crewed missions.

The second crewed mission is planned for October, with the next batch of astronauts expected to stay on Tianhe for six months.

Ahead of that Shenzhou-13 mission, China will send an automated cargo spacecraft – Tianzhou-3 – to Tianhe carrying supplies needed by the next crew.

Tianzhou-3 will be launched in the near future, state media said recently.

Blocked by US law from working with NASA and by extension on the US-led International Space Station (ISS), China has spent the past 10 years developing technologies to construct its own space station.

China’s space station, expected to be completed by the end of 2022, will be the sole alternative to the 20-year-old ISS, which may be retired in 2024.

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