濮阳东方医院男科治疗阳痿价格低(濮阳东方医院男科治阳痿技术先进) (今日更新中)

After almost two years circling an ancient asteroid hundreds of millions of miles away, a NASA spacecraft this week will attempt to descend to the treacherous, boulder-packed surface and snatch a handful of rubble.The drama unfolds Tuesday as the U.S. takes its first crack at collecting asteroid samples for return to Earth, a feat accomplished so far only by Japan.Brimming with names inspired by Egyptian mythology, the Osiris-Rex mission is looking to bring back at least 2 ounces (60 grams) worth of asteroid Bennu, the biggest otherworldly haul from beyond the moon.The van-sized spacecraft is aiming for the relatively flat middle of a tennis court-sized crater named Nightingale — a spot comparable to a few parking places here on Earth. Boulders as big as buildings loom over the targeted touchdown zone.“So for some perspective, the next time you park your car in front of your house or in front of a coffee shop and walk inside, think about the challenge of navigating Osiris-Rex into one of these spots from 200 million miles away,” said NASA’s deputy project manager Mike Moreau.Once it drops out of its half-mile-high (0.75 kilometer-high) orbit around Bennu, the spacecraft will take a deliberate four hours to make it all the way down, to just above the surface.Then the action cranks up when Osiris-Rex’s 11-foot (3.4-meter) arm reaches out and touches Bennu. Contact should last five to 10 seconds, just long enough to shoot out pressurized nitrogen gas and suck up the churned dirt and gravel. Programmed in advance, the spacecraft will operate autonomously during the unprecedented touch-and-go maneuver. With an 18-minute lag in radio communication each way, ground controllers for spacecraft builder Lockheed Martin near Denver can’t intervene.If the first attempt doesn’t work, Osiris-Rex can try again. Any collected samples won’t reach Earth until 2023.While NASA has brought back comet dust and solar wind particles, it’s never attempted to sample one of the nearly 1 million known asteroids lurking in our solar system until now. Japan, meanwhile, expects to get samples from asteroid Ryugu in December — in the milligrams at most — 10 years after bringing back specks from asteroid Itokawa.Bennu is an asteroid picker’s paradise.The big, black, roundish, carbon-rich space rock — taller than New York’s Empire State Building — was around when our solar system was forming 4.5 billion years ago. Scientists consider it a time capsule full of pristine building blocks that could help explain how life formed on Earth and possibly elsewhere.“This is all about understanding our origins,” said the mission’s principal scientist, Dante Lauretta of the University of Arizona.There also are selfish reasons for getting to know Bennu better.The solar-orbiting asteroid, which swings by Earth every six years, could take aim at us late in the next century. NASA puts the odds of an impact at 1-in-2,700. The more scientists know about potentially menacing asteroids like Bennu, the safer Earth will be.When Osiris-Rex blasted off in 2016 on the more than 0 million mission, scientists envisioned sandy stretches at Bennu. So the spacecraft was designed to ingest small pebbles less than an inch (2 centimeters) across.Scientists were stunned to find massive rocks and chunky gravel all over the place when the spacecraft arrived in 2018. And pebbles were occasionally seen shooting off the asteroid, falling back and sometimes ricocheting off again in a cosmic game of ping-pong.With so much rough terrain, engineers scrambled to aim for a tighter spot than originally anticipated. Nightingale Crater, the prime target, appears to have the biggest abundance of fine grains, but boulders still abound, including one dubbed Mount Doom.Then COVID-19 struck.The team fell behind and bumped the second and final touch-and-go dress rehearsal for the spacecraft to August. That pushed the sample grab to October.“Returning a sample is hard,” said NASA’s science mission chief, Thomas Zurbuchen. “The COVID made it even harder.”Osiris-Rex has three bottles of nitrogen gas, which means it can touch down three times — no more.The spacecraft automatically will back away if it encounters unexpected hazards like big rocks that could cause it to tip over. And there’s a chance it will touch down safely, but fail to collect enough rubble.In either case, the spacecraft would return to orbit around Bennu and try again in January at another location.With the first try finally here, Lauretta is worried, nervous, excited “and confident we have done everything possible to ensure a safe sampling.”___The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content. 4807

A Masai giraffe calf died on Tuesday at the Columbus Zoo in Ohio shortly after its mother, Cami, was given an emergency Cesarean section in an effort to save both the mother and calf. According to the Columbus Zoo, veterinarians and zoo staff recognized that Cami was going into labor Tuesday afternoon, but that the giraffe calf was presenting rear hooves first. The zoo said that it is rare for calves to survive when born rear hooves first.That is when a decision was made for veterinarians to enter Cami's stall. It also meant that a webcam of the birth broadcasted by National Geographic was shut off. Veterinarians from the zoo and Ohio State University first attempted to remove the calf manually. When that did not work, they performed the emergency Cesarean section.Unfortunately, their efforts were futile. "Cesarean sections in giraffes are extremely rare and typically conducted as a last resort due to the high risks involved in putting giraffes under anesthesia and successful recovery," the zoo said in a statement. "After the calf was extracted via Cesarean section, the veterinary team found that the calf had serious congenital defects and thus would not have survived even if it had been born front hooves first."The zoo said Cami’s condition was stable, but her prognosis remains guarded as of late Tuesday evening. Zoo staff will continue to monitor her condition. Tuesday's failed birth marks the second giraffe calf the zoo has lost in recent weeks. On November 17, Ubumwe, an 18-day-old calf died at the zoo. The cause of Ubumwe's death remains unknown, and a full pathology report is being conducted to determine the cause of death. According to information from the Association of Zoos and Aquariums, giraffe calves have a 25 percent mortality rate. This is compared to roughly a 50-percent mortality rate for giraffe calves born in the wild, according to the association.  2007

ALEXANDRIA, Va. -- Within a quiet lab, are scattered fragments of America’s storied past.“I never thought I'd be doing anything like this,” said Kenneth McNeill, an eight-year veteran of the U.S. Air Force.He also spent three years in the reserves and now is a part of the “Veterans Curation Program,” which provides training in archiving and archaeology.“I think one thing that happens a lot is that we just exist, and we don't think about things that happened in the past,” McNeill said.In the lab, though, the past is never out of reach.The artifacts come from the U.S. Army Corps of Engineers, who discovered the items at sites across the country during the excavation and construction of major projects, like dams and canals.“The Army Corps of Engineers had a need for people to do this curation work and the veterans have a need to find work and gain new skills and feel comfortable getting back into the workforce,” said Sarah Janesko, administrator of the Veterans Curation Program.The lab spaces are provided around the country by New South Associates, a company which specializes in archaeology and partnered with the Army Corps to train the veterans.“They feel like they're part of this larger mission to preserve our history and the cultural materials that come with it,” Janesko said.In just over 10 years, the Army Corps said the program has trained nearly 700 veterans, with 72% of them landing permanent jobs, some with the Smithsonian and National Park Service, while another 19% have gone on to further their studies in college.“It also gives us a sense of purpose, which is something I think veterans sometimes need when they separate from the military,” McNeill said. “We live in an area that has a lot of history to it. So, it's good that we are helping restore some of these things.”All of this happening, while they gain new skills, along with a deeper appreciation of the past. 1909

A woman has been charged in connection with the death of her 3-year-old daughter.Cassandra Kay Michalski, 24, has been charged in Wayne County, Michigan with felony murder and first degree child abuse for the death of Skylar Michalski.On Nov. 19, Skylar was taken to the Annapolis Hospital where she was pronounced dead.Police say she appeared to have injuries on her head, neck and back. On Feb. 2, the medical examiner determined that her death was a homicide.Cassandra's bond is set at 0,000.   528

After living in California’s Bay Area for eight years, Andrew Sanchez moved his family to Hawaii’s countryside“There are those obstacles,” he said of living in a metropolitan area. “There’s incredible amounts of traffic, pollution, crime. You know, serious things.”Sanchez and his wife are both teachers and wanted to save money and live a slower pace of life with their children. They say those were big factors in moving out of the big city.“We wanted to have an opportunity to spend more time with them and we wanted to make the right steps to watch them the best life they could,” Sanchez said.Now more people are looking to do what the Sanchez family did -- leave the big city for a smaller suburb.“It’s not surprising given the pandemic we are experiencing,” said Lawrence Yun, chief economist of the National Association of Realtors.He says due in part to the COVID-19 crisis and more companies allowing employees to work from home, there’s an exodus from downtown areas across the country.“People will say, ‘Why am I living so close job center when I can have perhaps a better affordability -- housing affordability out in the suburbs,” Yun said.According to a recent Harris Poll survey, nearly one-third of Americans are considering moving to a less densely populated area because of the coronavirus outbreak.Yun says this could impact the real estate market.“Before the pandemic, there was a housing shortage,” he said. “We knew that homebuilders needed to build significantly more to fully satisfy the demand.”Looking to help to meet that demand is housing developer Brain Levitt.“People are coming to Colorado because of lifestyle choice,” he said.Levitt is the president of Nava Real Estate Development. His company recently finished a 196-unit development called Lakehouse area outside of downtown Denver.He says a third of buyers are from out of the of area.“What we are finding, just because the cost of living or maybe new job opportunities or even just the lifestyle -- getting out of the city and getting to a place where you can work and play, it just seems like it’s attracting a lot of people,” Levitt said.That attraction of living away from a big city, however, does come at a cost.“It really required me to check my entitlements,” Sanchez said.Back in Hawaii, Sanchez said his family did have to give up several amenities when moving out of a big city.In the end, however, it was well worth it.“My kids are safe,” Sanchez said. “And you can’t put a price tag on that.” 2501

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