字幕表 動画を再生する 英語字幕をプリント So, exciting news: SciShow now makes science kits! To learn more, stick around until the end of this video. [ ♪ Intro ] When astronomers study the universe, they're often using telescopes that cost millions or even billions of dollars to build. And they're exactly what you'd want if you're trying to peer back at the dawn of time. But, luckily, we don't need to be a gazillionaire to see amazing things in space. Even the smallest telescope can do the trick, like the one you probably got for your birthday that's been hiding in the back of your closet for the last three years. If you live somewhere with a lot of light pollution, looking at the Moon and planets like Jupiter or Saturn is probably your best bet. Seriously, seeing Saturn's rings for yourself might make you drop everything and become an astronomer. But if you can sneak out to somewhere dark, well, there is a whole universe to discover. And here are three things you won't want to miss. First, few things are cooler, or easier to find, than the Orion Nebula. Shockingly, it's located in the constellation Orion, which is best seen during winter in the Northern Hemisphere and summer in the southern hemisphere. To find it, look just down from the three stars that make up Orion's belt. You should see a more vertical line of three objects. And that's called Orion's sword, and the nebula is the middle spot. With even the smallest telescope, you'll be able to see it as a faint, wispy structure, even though the nebula is more than a 1000 light-years away. Add a little more magnification, and you'll spot four stars so famous that they have their own name: the Trapezium. These bright-blue stars are just 30,000 years old, making them real babies on the cosmic scale. For comparison, the Sun is about four and a half billion years old, and it's still only halfway through its current phase of life. Like many young stars, those in the Trapezium are pouring energy into the surrounding gas and dust. That energy blasts electrons off molecules in a process called photoionization, and it turns the molecules into charged ions. Then, those ions release light at specific wavelengths, which creates the glow astronomers call an emission nebula. Famous pictures of the Orion Nebula, like this one from the Hubble Space Telescope, are awash in reds and purples, which indicate the presence of hydrogen. And that's not surprising. The Orion Nebula is the closest star-forming region to Earth, and stars are mostly hydrogen. Regions like this one are incredibly important because they enable scientists to study stars in the many phases of their birth. It's a process too slow to play out in a human lifetime, so astronomers piece the story together from many examples. And the Orion Nebula is full of examples. Hubble images have revealed dozens of so-called protoplanetary disks in the Nebula. That's the name given to baby star systems in their earliest stages of formation. And within those pockets, stars and maybe even planets are being born all the time. You won't be able to see those disks through your telescope, though. And if you see any color at all, it will probably be hints of green, not red. That's because our eyes are much more sensitive to green light than red. And that green tells astronomers there's oxygen in the nebula, too. Now, if you're in the northern hemisphere and winter seems far away, don't panic: There are great things to see in northern summer, too! First, start by finding Vega and Arcturus. They're two of the brightest stars in the summer sky, so are pretty easy to find. Between them, you can find the constellation Hercules. And within that lies what's sometimes called the Hercules Cluster. Its official name, though, is M13, because it was the thirteenth thing added to astronomer Charles Messier's catalog of interesting objects. M13 is only visible in the Northern Hemisphere, and although you can see it year-round, it's best seen during the summer because it's high in the sky. Through a small telescope, you'll probably see it as kind of a smudge, and if that doesn't seem all that exciting, know that your reaction is probably similar to those of astronomers throughout history. In fact, when Messier cataloged M13, he didn't think it contained a single star. But he could not have been more wrong. M13 is actually made of hundreds of thousands of stars, so many that the light blends together into a fuzzy spot. It's what astronomers call a globular cluster, a type of structure found throughout the Galaxy. These are regions packed with an incredible density of stars. Like, the center of M13 has more than 5000 times as many stars as the same-sized area around the Sun. In fact, there are so many that when astronomer Frank Drake sent the first radio message attempting to contact alien life in 1974, M13 was his target of choice. If life does exist in a place like this, it might have been around for a very long time too, since evidence also suggests that globular clusters contain some of the oldest stars in the Galaxy. With a small telescope, you won't be able to pick out many of those details, but if you ever upgrade to a larger one with more magnification, you'll start to see some of those individual stars. That means M13 is an object that can grow up with you as your observing skills improve! And finally, some of the sky's most amazing sights don't actually require a telescope. In the Southern Hemisphere, you can look up and see the Large Magellanic Cloud with the naked eye. It's one of the Milky Way's satellite galaxies, and it's around 160,000 light-years away. Without any equipment, the Cloud looks like a faint smudge, and with just a pair of binoculars, you'll also be able to see the basic structure. So even if you don't have a telescope yet, there's a lot to explore. Of course, if you do have a telescope, things get a lot more interesting. The coolest thing you'll spot is probably the massive Tarantula Nebula, a star-forming region similar to the one in Orion. Except, it's huge. It's more than a thousand light-years in diameter, and is the largest star factory found in any nearby galaxy. And those babies are bright. If you placed the Tarantula Nebula at the same distance from Earth as the Orion Nebula, it would shine so brightly in the night sky that it would actually cast shadows. What? And the Orion Nebula is still more than 1000 light-years from here. So, like, I'm glad that's not out my window as I try to sleep. Of course, one side effect of creating so many new stars is that the Tarantula Nebula is also a good spot to watch many stars die. After all, not everything lives as long as the Sun. In fact, one area, called Hodge 301, has three giant stars that could explode in a powerful supernova at almost any time. Who knows, maybe it's already happened and we just don't know yet because the light waves haven't made it here! And these are just three of a nearly-uncountable list of things you can see with a small telescope. Which is a good reminder that the night sky doesn't belong only to those with giant telescopes. All of us can get in on the fun. And that general idea is actually true for all kinds of science. Like, you don't need to have a million-dollar chemistry lab to learn how acids and bases work. You can discover a lot on your own, and that's why we are super excited to announce that we've launched a line of science kits! They're called Universe Unboxed, and they're great for everyone from elementary-aged kids on up. The kits are full of experiments that teach basic science concepts, but they also explain how those ideas apply to real research. We made a bunch of videos to go along with each kit where Hank explain how the activities work and why they matter. We've been having a ton of fun working on these and right now, we have kits about all kinds of topics from physics to chemistry, and we're excited to share them with you. To learn more and buy a kit for yourself or someone in your life, you can go to UniverseUnboxed.com. [ ♪ Outro ]
B2 中上級 新しい望遠鏡でチェックすべき3つの驚くべき天体 (3 Amazing Objects to Check Out with Your New Telescope) 2 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