字幕列表 影片播放 列印英文字幕 - NASA is about to go where no one has gone before: the sun. That's right, NASA is flying a $1.5-billion spacecraft into the hottest, most violent object in our solar system, all in the name of science. (soaring orchestral music) NASA's unmanned Parker Solar Probe will come within 3.83 million miles of the solar surface. Now, that doesn't sound very close, but it's about seven times closer than any spacecraft has ever gone before and it puts the probe smack inside one of the sun's most treacherous layers: the corona, the outermost layer of the sun. Here, the temperatures fluctuate from one to five million degrees Fahrenheit and solar flares exist that are so big, they could swallow our planet whole. So, why are we going here again? It turns out the sun poses a major threat to our modern way of life. Powerful magnetic fields form near the sun's surface, where they sometimes spark violent eruptions, called coronal mass ejections. These ejections fire a surge of highly-charged particles into space that will fry any electronic circuits on impact. That includes circuits inside our satellites that control cell service, the internet, GPS, the stock exchange, and much, much more. In 2014, for example, astrophysicist Daniel N. Baker explained what may happen if one of these powerful storms hit Earth directly, explaining it "could cause widespread power blackouts, disabling everything that plugs into a wall socket. Most people wouldn't even be able to flush their toilet because urban water supplies largely rely on electric pumps." Such a strike could cost an estimated $2 trillion in damage, 10 times more than Hurricane Katrina. Now, luckily, space is a big place, which makes Earth a relatively small and tricky target. In fact, the last time a powerful storm like this struck our planet was more than 150 years ago, back in 1859. But the risk is there, and NASA predicts there's a 12% chance we could get hit within the next decade. That's where the Parker Solar Probe comes in. The probe can't prevent an ejection from happening, but it can study the corona so that we may better understand the warning signs of an impending storm. And with enough notice, we may be able to protect our satellites from harm. In addition to spying on the sun, Parker Solar Probe has another very important job: don't melt. To that end, NASA has prepped the probe with four highly-tuned sensors and an impressive heat shield that will protect the probe's instruments. The sensors are there to make sure the shield stays directed at the sun at all times. The mission will involve not one or two, but 24 dives into the sun, which are all scheduled to take place through the year 2025.
B2 中高級 美國腔 美國宇航局首次將航天器飛向太陽 (NASA Is Flying A Spacecraft Into The Sun For The First Time) 110 2 鐘燕華 發佈於 2021 年 01 月 14 日 更多分享 分享 收藏 回報 影片單字