字幕表 動画を再生する 英語字幕をプリント [♪ INTRO] From the upcoming fiftieth anniversary of Apollo eleven to Israel's attempt at a lunar landing, the Moon has been in the news a lot lately! And one announcement that's gotten a lot of attention is NASA's new challenge from the White House: return American astronauts to the lunar surface by 2024. It's a big goal, considering how much time, effort, and equipment it takes to send people to space, but last week, one company stepped up to offer some help. And in the process, they made their own huge announcement. At a fancy press event, Blue Origin revealed that they've quietly been developing a lunar lander called Blue Moon, and they gave us our first good look at it. If you've heard of Blue Origin before, it's probably because the company was founded by Amazon's Jeff Bezos. Or maybe you've heard about their reusable, suborbital rockets, dubbed New Shepard. Either way, the company has been making big strides in the last few years. But with Blue Moon, they're venturing into new territory. Because until now, Blue Origin's most famous work has focused on suborbital launches, that is, those that go to space but don't orbit the Earth. And none of them have been crewed. At this point, their new lander is primarily designed to deliver cargo, but it can also be modified to accommodate astronauts, supposedly by 2024, which would really help out NASA. Last week, Bezos announced that their intent is to send a mission to Shackleton Crater at the Moon's south pole. It isn't totally clear when that will happen, but as far as destinations go, Shackleton Crater might be considered prime lunar real estate. Outside the crater, it's almost always daylight, which means that you could get the most out of any solar panels you brought along. Meanwhile, the inside of the crater almost never sees the Sun, so we're pretty sure it's full of water ice. That's great for drinking purposes, but it's also important because missions could use electricity to break the water molecules apart into oxygen and hydrogen gas. The oxygen gets you something to breathe, but together with the hydrogen, it also gives you power. Hydrogen is a great fuel source, and you can use oxygen to make it combust. Right now, the idea is that Blue Moon would take several trips to the lunar surface to prepare for the astronauts and deliver supplies, a few thousand kilograms at a time. Then, humans would make the journey. But even though their announcement was super exciting, Blue Origin has a lot of work to do before they're ready to go. Like, for one, they have to test a new engine. To land Blue Moon, the company's engineers have designed what they're calling the BE-7 engine, which uses liquid hydrogen and oxygen. Its first hotfire test is scheduled for this summer, and that's where they'll make sure all the electrical components work and the fuel explodes in a planned, controlled manner. Still, even if that goes a hundred percent according to plan, there's no news yet about when its first test launch will be. And that's just for the lander. Blue Origin also has to build a totally new rocket, since New Shepard is only capable of reaching suborbital altitudes. Their new vehicle will be called New Glenn, and although it's still in the design phase, it will supposedly enter service in 2021. Assuming it works, New Glenn will serve as competition against SpaceX's Falcon Heavy and NASA's future Space Launch System, both of which could also carry people to the Moon. So whatever gets us there, and however long it takes us, it looks like we're finally headed back to the lunar surface. Well, at least as far as humans go. Robots are already on the Moon, including China's lander Chang'e-4. And according to a paper published this week in the journal Nature, it's helping us figure out what the Moon is made of. Spoilers! It's still not cheese. Like the Earth's interior, the Moon has layers: a crust, a mantle, and a core. Basically, when it was super young and still molten, denser material sank toward the center, and lighter stuff rose to the surface. So far, we know that most of the lunar crust is made of a mineral called plagioclase. And based on what they've seen of the Moon's ancient lava flows, scientists think the mantle likely contains so-called mafic minerals, those rich in things like iron and magnesium. Still, it's hard to be totally sure what those mafic minerals are, because, well, it's kind of hard getting to the lunar mantle. It doesn't start until you're tens of kilometers below the surface, and we don't have any probes on the Moon that can drill that far down. So scientists have mostly had to make due hunting for rocks on the surface that somehow made their way up from the mantle. The ideal locations for this kind of work are large, deep impact craters, where huge collisions could have blasted up underground rock. And that's where Chang'e-4 comes in. This January, it and its rover, Yutu-2, landed in one of those craters. Specifically, Von Kármán crater, which is located in the enormous South Pole-Aitken basin on the Moon's far side. For the record, that basin also contains Shackleton Crater. Lunar orbiters had detected minerals in the basin that could have possibly come from the mantle, but we needed some kind of eyes on the ground to check if it was true. For the last five months, Yutu-2 has been collecting the light signature of the surrounding rocks to figure out what elements they're made of, and in what abundances. And in this new paper, scientists confirmed that this area is rich in mafic minerals! The researchers think that these minerals didn't actually come from Von Kármán, though, since it was flooded a long time ago by volcanic basalt. Instead, they think they sprinkled down from the impact that created the Finsen crater, which is much younger and located nearby. Still, no matter which crater they came from, the minerals Yutu-2 found are a lot different than the typical stuff we see on the lunar surface. They're made of minerals called olivine and low-calcium (ortho)pyroxene, which scientists have assumed were in the lunar mantle for a long time. Unfortunately, even if the evidence is promising, it's too soon to tell if these rocks actually come from the mantle and not just the lower crust. But as Yutu-2 keeps working, we'll probably get an update. Studies like this are a great reminder that we haven't learned everything there is to know about the Moon, which makes it really exciting to think about the future. Because if we're still learning so much from robotic missions, just imagine what we'll figure out when we send human scientists there! Thanks for watching this episode of SciShow Space News! If you want to keep up with the latest news in astronomy and in the space industry, you can go to youtube.com/scishowspace and subscribe. We make a new episode like this every Friday! [♪ OUTRO]
B1 中級 ブルームーンとの出会い。ブルーオリジンの月面着陸船|SciShow News (Meet Blue Moon: Blue Origin's Lunar Lander | SciShow News) 3 0 林宜悉 に公開 2021 年 01 月 14 日 シェア シェア 保存 報告 動画の中の単語