NASA’s Perseverance probe landed safely and on time on Mars, at 3:55 p.m. EST, Thursday, marking another success for the U.S. space agency.  The nuclear-powered probe made its way through a harrowing landing process, deemed by some engineers as “seven minutes of terror” because it involves parachutes, powered descent and a “sky crane” that gently lowers Perseverance onto a challenging, rocky area of Martian surface. After a confirmed safe landing, members of the probe’s Mission Control erupted in applause and cheers. NASA has now successfully landed nine of 10 probes sent to the Red Planet. Minutes after touching down, Perseverance beamed back a black-and-white image from the surface as more applause broke out at Mission Control.Safe on Mars. https://t.co/heoYjkwfty— NASA’s Perseverance Mars Rover (@NASAPersevere) February 18, 2021The probe is equipped with a microphone, which should have recorded its descent. Perseverance, and its helicopter-like companion drone, Ingenuity, began the 300-million mile journey in July. Ingenuity will test if powered flight can be done in Mars’ thin atmosphere. The six-wheeled Perseverance, which looks like the other four rover probes that have landed on Mars, set down in Jezero Crater, which is believed to be an ancient lakebed and a potential source for remnants of ancient life.  Determining if Mars once hosted life is the primary goal of the probe’s two-year mission. During its search, the probe will take samples from the Red Planet’s surface and store them in its 43 sample tubes. NASA plans to send another mission to Mars to retrieve the tubes sometime in the early 2030s. Before collecting samples, NASA will spend the next weeks making sure Perseverance’s systems are all working. You can follow Perseverance’s progress on its Twitter account. 
 
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NASA and the United States have successfully landed the Perseverance on Mars after the rover left the company of spacecrafts from the UAE and China in orbit. VOA’s Arash Arabasadi reports, challenges for the rover – and potentially a treasure trove of discoveries  – await.Produced by:  Arash Arabasadi
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Pushed to the back of Gen Z anxieties by the COVID-19 pandemic, a looming stressor for many people younger than 30 remains climate change, say experts. 
 
“Natural disasters precipitated by climate change, including hurricanes, heatwaves, wildfires, and floods can lead to … increased rates of depression, anxiety, post-traumatic stress, and other mental health disorders,” according to researchers at the University of British Columbia and Simon Fraser University in Canada, and Johns Hopkins University in Baltimore. FILE – Firefighters battle the Morton Fire as it burns a home near Bundanoon, New South Wales, Australia, Jan. 23, 2020. (AP Photo/Noah Berger) 
The authors label the fear “eco-anxiety, climate distress, climate change anxiety, or climate anxiety,” writing in the respected British medical and science journal, The Lancet Planetary Health. 
 
In other words, the future is not looking bright from the perspective of many people under 30. 
 
Xiye Bastida, a student at the University of Pennsylvania, has been fighting the climate crisis since her hometown in Mexico flooded when she was 13. She calls it a pivotal moment in her environmental activism. 
 
“Sometimes we don’t realize when we actually start caring about something and acting upon it,” she said. 
 
Mexican-Chilean Bastida is one of the founding members of the New York City chapter of Fridays for Future, a strike movement that pressures public officials about climate change by protesting outside schools and government offices. She is also the co-founder of Re-Earth Initiative, which seeks to educate the public about climate issues.
 
Bastida’s generation might be more likely than adults to experience climate anxiety, the Lancet Planetary Health paper states.  
 
“They are at a crucial point in their physical and psychological development,” the authors wrote, “when … stress and everyday anxiety elevate their risk of developing depression, anxiety, and substance use disorders.”  
 
Bastida said she has experienced eco-anxiety and burnout from climate activism. She ended up in the hospital with heart palpitations because she was so stressed, she told VOA.  
 
“For me, the way I experienced and dealt with climate anxiety was just by always blaming myself for not doing enough,” Bastida explained.  
 
She continued, “If you don’t take care of yourself, if you don’t take care of your home, if you don’t take care of your well-being, you cannot take care of the world.” 
 
“Climate change is rapidly creating a less safe, less secure [food security, national security], less healthy, and less prosperous world,” Edward Maibach, director of George Mason University’s Center for Climate Change Communication (4C), wrote to VOA.  
 
“Today’s young people will be living in this world, as conditions deteriorate, unless the nations of the world rise to the challenge they currently face. 
 
“In my view, young people who don’t care about climate change are not paying attention,” he wrote. 
 
But many young people are paying attention and trying to effect change. The children and grandchildren of those who planted trees for the creation of Earth Day and the Environmental Protection Agency in 1970, are giving environmental justice a hard push forward.  
 
The movement has been propelled by young people everywhere.FILE – Climate change environmental activist Greta Thunberg joins Red Cloud Indian School student and activist Tokata Iron Eyes at a youth panel at the Standing Rock Indian Reservation, North Dakota, Oct. 8, 2019.Sweden’s Greta Thunberg riveted global attention as she sat outside a Swedish Parliament meeting, her expression capturing the impatient disgust of her generation with inactivity over climate change.  
 
Other famous young environmentalists include Canadian Autumn Peltier from the First Nations community, Argentinian Bruno Rodriguez, and Helena Gualinga from the Ecuadorian Amazon. FILE – Young environmental activists Ayakha Melithafa of S. Africa, Naomi Wadler of the US, Autumn Peltier of Canada and Melati Wijsen of Indonesia take part in a forum during the World Economic Forum in Davos, Switzerland, Jan. 20, 2020. 
Nikayla Jefferson is a volunteer writer for the Sunrise Movement, co-founder of the San Diego hub, and a doctoral candidate at University of California-Santa Barbara. For her, the scariest part of climate change is basic, she says. 
 
“The total loss of human life and the land that gives us our history and story,” she said. “We understand climate change science and how devastating it is to the Earth, but addressing carbon emissions is not enough,” Jefferson wrote to VOA. “We need to look at climate change through a human lens because climate change is the not the only existential threat people are facing.”  
 
Anxiety about climate change and a desire to act erases political lines, according to research from Pew, Brookings Institution and 4C. In the 2020 presidential election, climate change was among the top three issues to young voters. COVID-19, Race, Climate Change Dominate Youth Vote IssuesStudent debt polls lower in face of news events 
And 4C’s Maibach says that youth leadership about climate change has woven generations together on the issue. 
 
“Politicians and CEOs alike have every reason to want to keep young people happy, because they won’t keep their jobs for long if they don’t,” Maibach wrote. As the percentage of younger votes eclipses those of Baby Boomers, born between 1946 and 1964, the Gen Z and millennial vote becomes more powerful. 
 
“CEOs are not directly accountable to the public, but corporations are becoming increasingly sensitive to public opinion, especially that of young people, because they want to attract the best and brightest young people as employees, and they want to earn the loyalty of young customers,” Maibach wrote.  
 
While Bastida said she still worries about the future, she looks on the bright side and believes her generation can have an impact.   
 
“I think that we have to realize that that timeline is already running out,” she said. “And we cannot just keep talking about what we’re going to do, we need to actually start doing it. And when I see people actually doing things, when I see initiatives coming up, when I see companies changing their whole business model, that’s what makes me optimistic.”  
 
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Malawi will reopen schools on Monday (Feb 22), five weeks after President Lazarus Chakwera suspended classes due to a surge in COVID-19 cases. Malawi’s Presidential Task-Force on COVID-19 determined it is safe to resume classes after a drop in the rate of infection.Co-Chairperson of the Presidential Task-Force on COVID-19 Khumbize Kandodo Chiponda said in a televised address Wednesday night the infection rate is at 16%, down from 30% in January, when classes were suspended.She said, “Actually what we wanted is that once we reopen the schools our children should be safe because we know that when we were closing the schools, some teachers were COVID-19 positive and were on quarantine.  So we wanted to give them enough time to recover.”However, Kandodo Chiponda, who is also minister of health, said some schools will require students to produce COVID-19-negative certificates to be allowed into class.She asked parents to comply with such a requirement, saying the government has enough COVID-19 test kits in all public hospitals in the country.She said, “I would like to ask schools with such a requirement not to suspend learners with positive COVID-19 results but reverse their places and give them enough time to recover.”Critics say the decision to resume classes has been rushed and many schools, especially in rural areas, are not ready to reopen.They say unmet requirements include on-the-campus water sources for hand washing and enough classrooms for proper social distancing when learning.   But Education Minister Agness Nyalonje says everything is set and that the ministry has allocated about $6 milion for the reopening of schools.Nyalonje said part of the money will be used to drill 400 boreholes in primary schools and 240 in secondary schools to improve sanitation.“My ministry has made money [available] directly to schools through zonal accounts for them to procure soaps, to procure masks, to procure buckets where buckets need replacing, to make sure that when schools open, these things are in place,” she said.She said the challenge is to find tents for additional classrooms in highly congested schools.“Because it so happens that globally, the scramble for tents is very, very high but we are very advanced to get tents and we are hopeful that we will find tents and probably within a week,” said Nyalonje. Nyalonje also said the government has recruited 2,275 auxiliary teachers to ease pressure on permanent teachers. 
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The latest NASA probe to Mars is set to land Thursday after a journey that began last July.Perseverance’s entry into the Martian atmosphere was set to start at 3:55 p.m. EST, starting a seven-minute process that scientists hope will be successful. During the landing, NASA has no ability to control the probe.The elaborate landing process involves parachutes, powered descent and a “sky crane,” which is expected to lower Perseverance onto the Martian surface using cables.”I can tell you that Perseverance is operating perfectly right now, and that all systems are go for landing,” Jennifer Trosper, a NASA deputy project manager for the rover mission, said during a press briefing Tuesday.Perseverance is targeting a landing in Jezero Crater, which is believed to be an ancient lakebed. There, it will search for signs of ancient life.The terrain around the landing site is rocky, making landing difficult, but NASA said the probe is up to the challenge.“When the scientists take a look at a site like Jezero Crater, they see the promise, right?” said Al Chen, who is in charge of the entry, descent and landing team at NASA’s Jet Propulsion Laboratory in Pasadena, California, according to The Associated Press. “When I look at Jezero, I see danger. There’s danger everywhere.”NASA has successfully landed eight of nine probes on Mars.Perseverance is similar in appearance to other Mars rovers, but it carries a helicopter-type drone, Ingenuity, which will test if powered flight on Mars is possible.
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President Joe Biden’s administration has pledged to improve the delivery of COVID-19 vaccines in the U.S. This week, the first federally supported mass vaccination sites opened in California. Matt Dibble reports.
Camera: Matt Dibble     Producer: Matt Dibble
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The U.N. secretary-general called on the world’s largest economies Wednesday to create a task force to plan and coordinate a global COVID-19 vaccination plan.  “The world urgently needs a global vaccination plan to bring together all those with the required power, scientific expertise and production and financial capacities,” Antonio Guterres told a high-level virtual meeting of the U.N. Security Council on the global vaccine rollout. “I believe the G-20 is well-placed to establish an emergency task force to prepare such a global vaccination plan and coordinate its implementation and financing.” He said the task force should include the World Health Organization (WHO), the global vaccine alliance Gavi, international financial institutions, as well as the international vaccine alliance COVAX, and all countries that have the capacity to develop vaccines or produce them if licenses are available. “The task force would have the capacity to mobilize the pharmaceutical companies and key industry and logistics actors,” Guterres added. Leaders of the G-7 are holding a virtual summit this Friday, and Guterres said they could use that session to create momentum to mobilize the necessary financial resources. “The rollout of COVID-19 vaccines is generating hope,” he noted, but warned that people affected by conflict and insecurity are at risk of being left behind. US to pay WHO U.S. Secretary of State Antony Blinken made his international debut at the online meeting. He said the Biden administration will work with partners to expand COVID-19 vaccine manufacturing and distribution capacity, and increase access, including to marginalized populations.   He also said Washington would pay over $200 million in assessed and current obligations to WHO by the end this month. Funding stopped to the organization last year under the Trump administration, which did not like how WHO handled the coronavirus pandemic.   “This is a key step forward in fulfilling our financial obligations as a WHO member,” Blinken said. “It reflects our renewed commitment to ensuring the WHO has the support it needs to lead the global response to the pandemic, even as we work to reform it for the future.”   India to vaccinate UN peacekeepers Security Council member India, which is a major pharmaceutical manufacturer and is currently producing two vaccines, one of which it developed, announced it would contribute 200,000 COVID-19 vaccine doses to the U.N. peacekeeping division to inoculate their troops and police. The United Nations has about 95,000 peacekeepers, which means double doses could be available to all of them. Britain presides over the 15-nation Security Council this month and organized Wednesday’s session, which drew nine foreign ministers and one prime minister.   British Foreign Secretary Dominic Raab called for a U.N. Security Council resolution to facilitate COVID-19 vaccines to millions of people in conflict areas.     “Local cease-fires are going to be essential to enable lifesaving vaccinations to take place, and they are essential to protect the brave health workers and humanitarian workers working in incredibly challenging conditions in conflict zones,” Raab said.   He said that more than 160 million people are at risk of not receiving COVID-19 vaccinations because of instability and conflict in places including Yemen, Syria, South Sudan and Ethiopia.   In July, after three months of negotiations, the council adopted a resolution supporting the U.N. secretary-general’s global cease-fire to assist international containment efforts. It was not immediately clear Wednesday whether the British proposal for smaller cease-fires would have the council’s full support.   China’s foreign minister also participated. Beijing has been the subject of some international criticism for its handling of the coronavirus and for a lack of transparency about its origin in the city of Wuhan. “We need to resist prejudice, respect science and reject disinformation and attempts to politicize the pandemic,” Wang Yi said. “In this regard, members of the Security Council should lead by example.”  He also said China would help realize vaccine accessibility and affordability in developing countries.   “At the request of the WHO, China has decided preliminarily to donate 10 million doses of Chinese vaccine to help developing countries,” he announced.    The U.N. says progress on vaccinations has been extremely uneven and unfair, with just 10 countries having administered 75% of all COVID-19 vaccines, while more than 130 countries have not received a single dose.  
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German Health Minister Jens Spahn said Wednesday the so-called British variant of COVID-19 is spreading quickly in his country, now accounting for more than 20 percent of all tested cases, and nearly four times the rate of two weeks earlier. Speaking to reporters in Berlin, Spahn said that rate of spread indicates the variant virus strain, first identified in Britain, roughly doubles each week, as has been seen in other countries where it has been found. He said he expects it will soon become the dominant strain found in Germany. FILE – German Health Minister Jens Spahn speaks at the lower house of parliament Bundestag on the start of the coronavirus vaccinations, in Berlin, Germany, Jan. 13, 2021.Spahn said the good news is that overall, the number of new infections is decreasing, a sign that preventive measures, including the current lockdown, are working. He said German health officials will have to be exceptionally careful regarding the British strain when the country starts to ease restrictions. 
 
Spahn said he expects Germany’s vaccination program to “significantly pick up speed” in the next several days. He said vaccination centers are becoming more efficient, and by the end of next week, they should have delivered 10 million additional doses.The health minister urged all those whose turn it is to receive the vaccine do so as soon as possible, so the largest number of people can be protected. He also sought to reassure those reluctant to get vaccinated because of safety concerns.”If a vaccine is approved by the European Union following a rigorous approval process, then it is safe and effective,” he said. Spahn said those who wait also make the situation worse for everyone.”Reason dictates that people should get vaccinated in a pandemic and those who wait risk a serious illness and spreading the virus,” he said. 
 
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A historic winter storm and frigid temperatures that have gripped at least half the United States has left more than 2.5 million Texans without power. Snow and record cold continued Wednesday in the southwestern state where temperatures are forecast to remain at or below freezing. The unusual winter weather created a huge demand for electricity that caused the state’s independently-run power system to fail, exposing issues with its structure.  In an interview, Harris County Judge Lina Hidalgo — whose county includes the city of Houston — said some of the outages are caused directly by the weather, and many of those problems are being repaired.  Customers, whose homes are without electric power, wait in line to purchase food and snacks at a gas station in Pflugerville, Texas, Feb. 16, 2021. (Ricardo B. Brazziell/via Reuters)But she said much of what the state is dealing with is a “man-made disaster” stemming from how the electricity grid is managed by the Electric Reliability Council of Texas (ERCOT). She said residents statewide deserve answers. ERCOT President Bill Magness said the system tried to prepare for the storm, but as conditions worsened Monday into Tuesday, several power plants went offline.  Some politicians in the oil- and natural-gas-producing state blamed the problems on green energy sources, saying iced wind turbines were the cause. Magness said some turbines were frozen, but he said twice as much power was wiped out at natural gas and coal plants. He said forcing controlled outages was the only way to avert an even more dire blackout in Texas. As of Wednesday, Magness said ERCOT could not offer a firm timetable for when power might be fully restored. Texas Republican Gov. Greg Abbott called for an investigation of the agency.  Cold and wintry weather is forecast to continue for at least the next few days in Texas and much of the eastern half of the United States. 
 
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Japan began its long-awaited coronavirus vaccination program Wednesday. The first shots took place at a Tokyo hospital just hours after the hospital received the Pfizer-BioNTech vaccine.  As many as 40,000 doctors and nurses across the nation will receive the first doses of the vaccine, with the eventual goal of inoculating a total of 3.7 million medical personnel by March, followed by about 36 million citizens 65 years of age and older.   Japan’s vaccination program is off to a slow start, with health authorities only formally approving use of the two-dose Pfizer-BioNTech drug on Sunday. Officials asked Pfizer to carry out further tests on the vaccine in addition to earlier tests that had been conducted in several other countries. Taro Kono, the country’s vaccine minister, told reporters Tuesday the additional testing was conducted to reassure the Japanese people of its safety.  Vaccinations are not compulsory in Japan, and while Kono voiced confidence he could reach front-line workers and elderly people, he acknowledged he needed to formulate a plan for successfully reaching younger people and encourage them to get the shot.A medical worker fills a syringe with a dose of the Pfizer-BioNTech coronavirus disease (COVID-19) vaccine as Japan launches its inoculation campaign, at Tokyo Medical Center in Tokyo, Feb. 17, 2021.Along with Pfizer-BioNTech, Japan has also signed contracts to procure millions of doses of the vaccine from AstraZeneca and Moderna, enough in all for 157 million people. The country is hoping to get enough people vaccinated in time for the postponed Tokyo Summer Olympic Games, which are scheduled to begin in July. Japan is the last member of the Group of Seven (G7) industrialized nations to begin the shots.  Meanwhile, about 80,000 doses of the new COVID-19 vaccine developed by U.S. drugmaker Johnson & Johnson arrived in Johannesburg, South Africa, late Tuesday night. The government will begin administering the Johnson & Johnson vaccine to health care workers later this week as part of an observational study. A total of 500,000 doses are expected to be shipped to South Africa within the next few weeks, along with another 20 million doses of the Pfizer-BioNTech vaccine. South Africa had purchased 1 million doses of the two-shot vaccine developed by AstraZeneca and Oxford University, but abandoned plans to use the drug after a study revealed that the vaccine was less effective against a variant of the coronavirus found in the country. Health Minister Zweli Mkhize told parliament Wednesday that South Africa will share the AstraZeneca-Oxford vaccine with the African Union, which will distribute it throughout the continent.   The single-dose Johnson & Johnson vaccine has not been formally approved for use by any country, but the company says results of a late-stage clinical trial shows it is 85% effective in preventing serious illness or death from COVID-19, even against the South African variant. In the United States, President Joe Biden said Tuesday night the country will have more than 600 million doses of coronavirus vaccines, enough to inoculate “every single American” by the end of this July.  Biden made the pledge during a question-and-answer session in Milwaukee, Wisconsin that was televised on cable news network CNN.  When asked by moderator Anderson Cooper when the United States will return to normal, Biden said by next Christmas “we’ll be in a very different circumstance, God willing, than we are in today.”  The White House announced earlier Tuesday that the federal government will increase the amount of COVID-19 vaccines that states receive each week from 11 million doses to 13.5 million doses. The president also said that states should prioritize public school teachers in their vaccination efforts as part of a strategy to reopen schools to full-time in-person classes.   
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It’s as if the world has been turned upside-down, or at least its weather. You can blame the increasingly familiar polar vortex, which has brought a taste of the Arctic to places where winter often requires no more than a jacket. Around the North Pole, winter’s ultra-cold air is usually kept bottled up 15 to 30 miles high. That’s the polar vortex, which spins like a whirling top at the top of the planet. But occasionally something slams against the top, sending the cold air escaping from its Arctic home and heading south. It’s been happening more often, and scientists are still not completely sure why, but they suggest it’s a mix of natural random weather and human-caused climate change. This particular polar vortex breakdown has been a whopper. Meteorologists call it one of the biggest, nastiest and longest-lasting ones they’ve seen, and they’ve been watching since at least the 1950 s. This week’s weather is part of a pattern stretching back to January. “It’s been a major breakdown,” said Jennifer Francis, a climate scientist at the Woodwell Climate Research Center on Cape Cod. “It really is the cause of all of these crazy weather events in the Northern Hemisphere.” “It’s been unusual for a few weeks now — very, very crazy,” Francis said. “Totally topsy-turvy.” Record cold in warmer placesRecord subzero temperatures in Texas and Oklahoma knocked millions off the power grid and into deep freezes. A deadly tornado hit North Carolina. Other parts of the South saw thunder snow and reports of something that seemed like a snow tornado but wasn’t. Snow fell hard not just in Chicago, but in Greece and Turkey, where it’s far less normal. Record cold also hit Europe this winter, earning the name the “Beast from the East.” “We’ve had everything you could possibly think of in the past week,” said Northern Illinois University meteorology professor Victor Gensini, noting that parts of the U.S. have been 50 degrees (28 degrees Celsius) colder than normal. “It’s been a wild ride.”A man walks at Filopapos hill as snow falls, with the ancient Acropolis hill and the Parthenon temple, in background, Athens, on Feb. 16, 2021.It was warmer Tuesday in parts of Greenland, Alaska, Norway and Sweden than in Texas and Oklahoma. And somehow people in South Florida have been complaining about record warmth that is causing plants to bloom early. In the eastern Greenland town of Tasiilaq, it’s been about 18 degrees (10 degrees Celsius) warmer than normal, which “is a bit of a nuisance,” said Lars Rasmussen, a museum curator at the local cultural center. “The warm weather makes dog sledding and driving on snow scooters a bit of a hassle.” Several meteorologists squarely blamed the polar vortex breakdown or disruption. These used to happen once every other year or so, but research shows they are now close to happening yearly, if not more, said Judah Cohen, a winter storm expert for Atmospheric Environmental Research, a commercial firm outside of Boston. The spinning top gets toppledThe polar vortex spends winter in its normal place until an atmospheric wave — the type that brings weather patterns here and there — slams into it. Normally such waves don’t do much to the strong vortex, but occasionally the wave has enough energy to push the spinning top over, and that’s when the frigid air breaks loose, Gensini said. Sometimes, the cold air mass splits into chunks — an event that usually is connected to big snowstorms in the U.S. East, like a few weeks ago. Other times, it just moves to a new place, which often means bitter cold in parts of Europe. This time it did both, Cohen said. There was a split of the vortex in early January and another in mid-January. Then at the end of January came the displacement that caused cold air to spill into Europe and much of the United States, Cohen said. Both Cohen and Francis said this should be considered not one but three polar vortex disruptions, though some scientists lump it all together.  While both the vortex and the wave that bumped it are natural, and polar vortex breakdowns happen naturally, there is likely an element of climate change at work, but it is not a sure thing that science agrees on, Cohen, Gensini and Francis said. Warming in the Arctic, with shrinking sea ice, is goosing the atmospheric wave in two places, giving it more energy when it strikes the polar vortex, making it more likely to disrupt the vortex, Cohen said. “There is evidence that climate change can weaken the polar vortex, which allows more chances for frigid Arctic air to ooze into the Lower 48,” said University of Georgia meteorology professor Marshall Shepherd. Pattern has been observed for decadesThere were strong polar vortex disruptions and cold outbreaks like this in the 1980s, Cohen said. “I think it’s historic and generational,” Cohen said. “I don’t think it’s unprecedented. This Arctic outbreak has to be thought of in context. The globe is much warmer than it used to be.” It also feels colder because just before the outbreak, much of the United States was experiencing a milder-than-normal winter, with the ground not even frozen on Christmas Day in Chicago, Gensini said. The globe as a whole is about the same temperature as the average was from 1979 to 2000 for this time of year, according to the University of Maine’s Climate Reanalyzer. That’s still warmer than the 20th-century average, and scientists don’t think that this month has much of a chance to be colder than the 20th century average for the globe, something that hasn’t happened since the early 1980s. One reason is that it will soon warm back up to normal when the polar vortex returns to its regular home, Cohen said. As for people thinking this cold outbreak disproves global warming, scientists say that’s definitely not so. Even with climate change, “we’ll still have winter,” said North Carolina state climatologist Kathie Dello. “What we’re seeing here is we’re pretty unprepared for almost every type of extreme weather. It’s pretty sad.” 
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Sixty-six million years ago, a huge celestial object struck off the coast of what is now Mexico, triggering a catastrophic “impact winter” that eventually wiped out three-quarters of life on Earth, including the dinosaurs. A pair of astronomers at Harvard say they have now resolved long-standing mysteries surrounding the nature and origin of the “Chicxulub impactor.”  Their analysis suggests it was a comet that originated in a region of icy debris on the edge of the solar system, that Jupiter was responsible for it crashing into our planet, and that we can expect similar impacts every 250 million to 750 million years. The duo’s paper, published in the journal Scientific Reports this week, pushes back against an older theory that claims the object was a fragment of an asteroid that came from our solar system’s Main Belt. “Jupiter is so important because it’s the most massive planet in our solar system,” lead author Amir Siraj told AFP. Jupiter ends up acting as a kind of “pinball machine” that “kicks these incoming long-period comets into orbits that bring them very close to the sun.” So-called “long-period comets” come from the Oort cloud, thought to be a giant spherical shell surrounding the solar system like a bubble that is made of icy pieces of debris the size of mountains or larger.  The long-period comets take about 200 years to orbit the sun and are also called sungrazers because of how close they pass. Because they come from the deep freeze of the outer solar system, comets are icier than asteroids, and are known for the stunning gas and dust trails that they produce as they melt. But, said Siraj, the evaporative impact of the sun’s heat on sungrazers is nothing compared to the massive tidal forces they experience when one side faces our star. “As a result, these comets experience such a large tidal force that the most massive of them would shatter into about a thousand fragments, each of those fragments large enough to produce a Chicxulub-size impactor, or dinosaur-killing event on Earth.” Siraj and co-author Avi Loeb, a professor of science, developed a statistical model that showed the probability that long-period comets would hit Earth that is consistent with the age of Chicxulub and other known impactors. The previous theory about the object being an asteroid produces an expected rate of such events that was off by a factor of about 10 compared to what has been observed, Loeb told AFP. ‘A beautiful sight’  Another line of evidence in favor of the comet origin is the composition of Chicxulub — only about a tenth of all asteroids from the Main Belt, which lies between Mars and Jupiter, are made up of carbonaceous chondrite, while most comets have it. Evidence suggests the Chicxulub crater and other similar craters, such as the Vredefort crater in South Africa that was struck about two billion years ago, and the million-year-old Zhamanshin crater in Kazakhstan, all had carbonaceous chondrite. The hypothesis can be tested by further studying these craters, ones on the moon, or even by sending out space probes to take samples from comets. “It must have been a beautiful sight to see this rock approaching 66 million years ago, that was larger than the length of Manhattan Island,” said Loeb, “though ideally, we’d like to learn to track such objects and devise ways to deflect them, if necessary.” Loeb added he was excited by the prospect of the Vera Rubin Observatory in Chile becoming operational next year. The telescope might be able to see tidal disruption of long-period comets “and will be extremely important in making forecasts for definitely the next 100 years, to know if anything bad could happen to us,” he said. Though Siraj and Loeb calculated Chicxulub-like impactors would occur once every few hundreds of millions of years, “it’s a statistical thing,” said Loeb. “You say ‘on average; It’s every so often,’ but you never know when the next one will come.”  “The best way to find out is to search the sky,” he concluded. 
 
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The European Space Agency (ESA) said Tuesday it is recruiting new astronauts for the first time since 2008 and encouraging women and people with disabilities to apply.The announcement Tuesday came in a virtual news briefing that included ESA Director General Jan Worner and current agency astronauts. Worner said while ESA still has astronauts from the last selection process, it needs new astronauts to “secure a continuity” and ensure a smooth transfer of knowledge from one class to another.Worner said the agency is looking to add up to 26 permanent and reserve astronauts. And it is strongly encouraging women to apply, as well as people with disabilities to its roster to boost diversity among crews. The agency has launched a “parastronaut” program designed to examine what is needed to get disabled astronauts onto the International Space Station.ESA astronaut Samantha Cristoforetti said if technology can allow other humans to work and thrive in space, it can do so for the disabled as well. “When it comes to space travel, we are all disabled. You know, we all have a disability because we were just not meant to be up there. So, what brings us from being, you know, disabled, to go to space to being able to go to space is technology.”Requirements for an astronaut job at ESA include a master’s degree in natural sciences, engineering, mathematics or computer science and three years of post-graduate experience. But the agency says it is looking for “all-arounders,” not specialists.The application process begins March 31 with all details available on the ESA website. The period will run until May 28 of this year with the outcome expected to be announced in October 2022. 
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