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  • 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 ]

So, exciting news: SciShow now makes science kits!

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B2 中高級

用新望遠鏡觀察3個神奇的天體。 (3 Amazing Objects to Check Out with Your New Telescope)

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    林宜悉 發佈於 2021 年 01 月 14 日
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