字幕列表 影片播放 列印英文字幕 [ intro ] In the last fifty years, humans have landed enough spacecraft on the Moon that, if you're not careful, the missions can start to feel… ordinary. Like, oh, more robots on the surface? Whatever, we've been doing that since the '60s! The truth is, though, those landings are hard. They often depend on thousands of steps going not just mostly right, but going perfectly. And sometimes… that doesn't happen. Last Friday, India became the latest nation to learn that firsthand when they lost contact with their spacecraft right before it landed on the Moon. Their mission, called Chandrayaan-2, was designed with three main parts: an orbiter, a rover, and a lander called Vikram. It launched in July, and its goal was to study the South Pole-Aitken Basin near the Moon's south pole. In 2009, India's first Chandrayaan mission detected ice within some of the basin's craters, which could someday support a permanent lunar base or help us understand where Earth's water came from. So the idea was to land Vikram and its rover near the area and explore the terrain up-close for the first time. Years of work went into the mission, and it was supposed to be a big, historic thing — because it also would have been India's first Moon landing. But it didn't go as planned. As the lander approached the Moon last week, it appeared to be traveling faster than expected. Then, only about two kilometers above the lunar surface, mission controllers lost contact. The next day, Chandrayaan-2's orbiting satellite captured an image of what appeared to be Vikram's landing site, but there was still no signal from it. When we filmed this episode on Tuesday, that's all that had been confirmed by ISRO, the space agency behind the mission. Reports had started to trickle out that the lander may at least be in one piece, but everything else is unclear. Stories like this are always hard, but in the world of space exploration, they're not uncommon. After all, none of the countries that have landed on the Moon were successful on their first try. In fact, the Soviet Union failed eleven times before achieving the first successful landing in 1966. And earlier this year, an Israeli lander failed in almost exactly the same way Vikram may have. So even if they never get in contact with their lander, the ISRO team isn't alone in this. And fortunately, no matter what happens, Chandrayaan-2 also won't be a total loss. The orbiter is doing great, and ISRO expects it will continue to study the Moon for as many as seven years. In that time, its instruments will study the thin lunar atmosphere and the Moon's water, and its camera will snap some really high-resolution photos. According to ISRO, that camera is actually the highest-resolution one ever sent to orbit the Moon, and it's capable of taking pictures of objects just 32 centimeters across. That will be great for studying features on the surface — and maybe even helping ISRO diagnose what happened during last week's landing. Missions are an awesome way to learn about the solar system, but we don't always need to go to space to learn something about it. Sometimes, meteors come crashing to Earth, bringing new information and the chance for new discoveries. And that's something another team of scientists has been celebrating lately! In the journal American Mineralogist, a team from Caltech recently published their study of the Wedderburn meteorite, which was discovered in Australia in 1951. It's a cool red and black rock, but the researchers confirmed something special about it: It contains a new, naturally-occurring mineral! That find came with a pretty nifty perk, too: They got to name it! By rule, only minerals known to exist in nature get their own proper names. So even though scientists have seen this one in smelters for decades, it's always been called by its chemical formula. The team chose to call this mineral edscot tite, after the American scientist Ed Scott. Who first proposed the mineral exist in the Wedderburn meteorite. At the time, though, instruments weren't advanced enough for Scott to confirm the mineral was there, so that's where this new research came in. The team from Caltech examined their sample using methods like scanning electron microscopy, which uses a beam of electrons, rather than light Those images revealed tiny pieces of edscottite squished between other minerals. And the images were detailed enough for the team to study the mineral's structure and finally confirm Scott's hypothesis from decades earlier. As for how the mineral got there? Well, it may have been surprisingly similar to how it's made in smelters on Earth. Wedderburn is an iron meteorite, which means it was most likely part of the core of a large asteroid or small planet. This object likely formed early in the solar system when a bunch of smaller rocks got crunched together. All those collisions would have added a lot of heat to the object, which would have helped its molten metal sink towards the center to form a core. “Hot metal” also sounds a lot like the conditions inside a smelter, so it all kind of fits together. Still, think about how amazing that is: A piece of an asteroid or planet that hasn't existed for millions or billions of years somehow ended up on Earth. And now, we get to study it. The researchers aren't positive why edscottite hasn't been found in other iron meteorites, so there are more questions to be answered here. But whatever the reason, it's pretty cool that something first found as industrial waste turns out to be part of the solar system's building blocks. Thanks for watching this episode of SciShow Space News! We know there's a lot of science content on the Internet, and we're thankful that you chose to watch some of ours. If you want to help us keep making episodes like this, you can learn how over at patreon.com/scishow. And to all of our current patrons: Thank you! We're glad to have you. [ outro ]
B1 中級 印度的月球登陸器怎麼了?| 科學秀新聞 (What Happened to India's Moon Lander? | SciShow News) 12 0 林宜悉 發佈於 2021 年 01 月 14 日 更多分享 分享 收藏 回報 影片單字