A Chinese Lunar Probe Returns to Earth With the World's First Samples from the Far Side of the Moonhttps://english.aawsat.com/varieties/5033995-chinese-lunar-probe-returns-earth-worlds-first-samples-far-side-moon
A Chinese Lunar Probe Returns to Earth With the World's First Samples from the Far Side of the Moon
China’s Chang’e-6 probe after it landed on the surface of the moon on June 4. China National Space Administration / Xinhua / AP
China's Chang'e 6 probe returned to Earth on Tuesday with rock and soil samples from the little-explored far side of the moon in a global first.
The probe landed in northern China on Tuesday afternoon in the Inner Mongolian region, The Associated Press said.
“I now declare that the Chang’e 6 Lunar Exploration Mission achieved complete success," Zhang Kejian, Director of the China National Space Administration said shortly in a televised news conference after the landing.
Chinese scientists anticipate the returned samples will include 2.5 million-year-old volcanic rock and other material that scientists hope will answer questions about geographic differences on the moon's two sides.
The near side is what is seen from Earth, and the far side faces outer space. The far side is also known to have mountains and impact craters, contrasting with the relatively flat expanses visible on the near side.
While past US and Soviet missions have collected samples from the moon's near side, the Chinese mission was the first that has collected samples from the far side.
The moon program is part of a growing rivalry with the US — still the leader in space exploration — and others, including Japan and India. China has put its own space station in orbit and regularly sends crews there.
China's leader Xi Jinping sent a message of congratulations to the Chang'e team, saying that it was a “landmark achievement in our country's efforts at becoming a space and technological power.”
The probe left earth on May 3, and its journey lasted 53 days. The probe has drilled into the core and scooped rocks from the surface.
The samples “are expected to answer one of the most fundamental scientific questions in lunar science research: what geologic activity is responsible for the differences between the two sides?” said Zongyu Yue, a geologist at the Chinese Academy of Sciences, in a statement issued in the Innovation Monday, a journal published in partnership with the Chinese Academy of Sciences.
China in recent years has launched multiple successful missions to the moon, collecting samples from the moon’s near side with the Chang’e 5 probe previously.
They are also hoping that the probe will return with material that bears traces of meteorite strikes from the moon’s past. With the successful reentry of the probe, scientists will begin studying the samples.
5 Things We Know and Still Don’t Know about COVID, 5 Years after It Appearedhttps://english.aawsat.com/varieties/5097458-5-things-we-know-and-still-don%E2%80%99t-know-about-covid-5-years-after-it-appeared
A medical worker takes a swab sample from a worker of the China Star Optoelectronics Technology (CSOT) company during a round of COVID-19 tests in Wuhan in central China's Hubei province, Aug. 5, 2021. (Chinatopix via AP, File)
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5 Things We Know and Still Don’t Know about COVID, 5 Years after It Appeared
A medical worker takes a swab sample from a worker of the China Star Optoelectronics Technology (CSOT) company during a round of COVID-19 tests in Wuhan in central China's Hubei province, Aug. 5, 2021. (Chinatopix via AP, File)
Five years ago, a cluster of people in Wuhan, China, fell sick with a virus never before seen in the world.
The germ didn't have a name, nor did the illness it would cause. It wound up setting off a pandemic that exposed deep inequities in the global health system and reshaped public opinion about how to control deadly emerging viruses.
The virus is still with us, though humanity has built up immunity through vaccinations and infections. It's less deadly than it was in the pandemic's early days and it no longer tops the list of leading causes of death. But the virus is evolving, meaning scientists must track it closely.
Where did the SARS-CoV-2 virus come from? We don’t know. Scientists think the most likely scenario is that it circulated in bats, like many coronaviruses. They think it then infected another species, probably racoon dogs, civet cats or bamboo rats, which in turn infected humans handling or butchering those animals at a market in Wuhan, where the first human cases appeared in late November 2019.
That's a known pathway for disease transmission and likely triggered the first epidemic of a similar virus, known as SARS. But this theory has not been proven for the virus that causes COVID-19. Wuhan is home to several research labs involved in collecting and studying coronaviruses, fueling debate over whether the virus instead may have leaked from one.
It's a difficult scientific puzzle to crack in the best of circumstances. The effort has been made even more challenging by political sniping around the virus' origins and by what international researchers say are moves by China to withhold evidence that could help.
The true origin of the pandemic may not be known for many years — if ever.
People attend an exhibition on the city's fight against the coronavirus in Wuhan in central China's Hubei province, Jan. 23, 2021. (AP)
How many people died from COVID-19? Probably more than 20 million. The World Health Organization has said member countries reported more than 7 million deaths from COVID-19, but the true death toll is estimated to be at least three times higher.
In the US, an average of about 900 people a week have died of COVID-19 over the past year, according to the US Centers for Disease Control and Prevention.
The coronavirus continues to affect older adults the most. Last winter in the US, people aged 75 and older accounted for about half the nation’s COVID-19 hospitalizations and in-hospital deaths, according to the CDC.
"We cannot talk about COVID in the past, since it’s still with us," WHO director Tedros Adhanom Ghebreyesus said.
What vaccines were made available? Scientists and vaccine-makers broke speed records developing COVID-19 vaccines that have saved tens of millions of lives worldwide – and were the critical step to getting life back to normal.
Less than a year after China identified the virus, health authorities in the US and Britain cleared vaccines made by Pfizer and Moderna. Years of earlier research — including Nobel-winning discoveries that were key to making the new technology work — gave a head start for so-called mRNA vaccines.
Today, there’s also a more traditional vaccine made by Novavax, and some countries have tried additional options. Rollout to poorer countries was slow but the WHO estimates more than 13 billion doses of COVID-19 vaccines have been administered globally since 2021.
The vaccines aren't perfect. They do a good job of preventing severe disease, hospitalization and death, and have proven very safe, with only rare serious side effects. But protection against milder infection begins to wane after a few months.
Like flu vaccines, COVID-19 shots must be updated regularly to match the ever-evolving virus — contributing to public frustration at the need for repeated vaccinations. Efforts to develop next-generation vaccines are underway, such as nasal vaccines that researchers hope might do a better job of blocking infection.
This undated electron microscope image made available by the US National Institutes of Health in February 2020 shows the Novel Coronavirus SARS-CoV-2, yellow, emerging from the surface of cells, pink, cultured in the lab. (NIAID-RML via AP, File)
Which variant is dominating now? Genetic changes called mutations happen as viruses make copies of themselves. And this virus has proven to be no different.
Scientists named these variants after Greek letters: alpha, beta, gamma, delta and omicron. Delta, which became dominant in the US in June 2021, raised a lot of concerns because it was twice as likely to lead to hospitalization as the first version of the virus.
Then in late November 2021, a new variant came on the scene: omicron.
"It spread very rapidly," dominating within weeks, said Dr. Wesley Long, a pathologist at Houston Methodist in Texas. "It drove a huge spike in cases compared to anything we had seen previously."
But on average, the WHO said, it caused less severe disease than delta. Scientists believe that may be partly because immunity had been building due to vaccination and infections.
"Ever since then, we just sort of keep seeing these different subvariants of omicron accumulating more different mutations," Long said. "Right now, everything seems to locked on this omicron branch of the tree."
The omicron relative now dominant in the US is called XEC, which accounted for 45% of variants circulating nationally in the two-week period ending Dec. 21, the CDC said. Existing COVID-19 medications and the latest vaccine booster should be effective against it, Long said, since "it’s really sort of a remixing of variants already circulating."
Employees disinfect streets and shops inside Istanbul's famous Grand Bazaar to prevent the spread of coronavirus. (EPA)
What do we know about long COVID? Millions of people remain in limbo with a sometimes disabling, often invisible, legacy of the pandemic called long COVID.
It can take several weeks to bounce back after a bout of COVID-19, but some people develop more persistent problems. The symptoms that last at least three months, sometimes for years, include fatigue, cognitive trouble known as "brain fog," pain and cardiovascular problems, among others.
Doctors don’t know why only some people get long COVID. It can happen even after a mild case and at any age, although rates have declined since the pandemic's early years. Studies show vaccination can lower the risk.
It also isn't clear what causes long COVID, which complicates the search for treatments. One important clue: Increasingly researchers are discovering that remnants of the coronavirus can persist in some patients’ bodies long after their initial infection, although that can’t explain all cases.
