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  • [♪ INTRO]

  • 2019 is almost over, and it has been another really good year for exploring the universe.

  • I mean we took the first ever picture of a black hole,

  • landed our first robot on the far side of the Moon, and explored our farthest-yet object in the solar system.

  • But some discoveries were even bigger than those.

  • I mean, maybe not more important, but, like, literally bigger, brighter, and just generally more.

  • This is our annual superlatives episode,

  • so let's take a look at the some of the coolest breakthroughs of 2019.

  • What better place to start than with the brightest object ever discovered in the early universe,

  • not just in 2019, we're talking ever.

  • Scientists announced its discovery almost a year ago

  • at the annual meeting of the American Astronomical Society,

  • and it's an object that looks 600 trillion times brighter than the Sun.

  • This thing has a super gnarly name, I'm not going to say the whole thing, I'm just going to call it J04.

  • It's what astronomers call a quasar, the incredibly bright center of an ancient galaxy.

  • And all that light is created by the supermassive black hole lurking at the galaxy's center.

  • Well, the black hole itself isn't emitting any light.

  • But its powerful gravity has trapped an enormous disk of material in its orbit.

  • As all that gas and dust swirls around, bits smash into each other,

  • and that generates friction that heats up the disk until it's glowing white-hot.

  • It turns out, though, that J04 is getting a bit of a helping hand.

  • This quasar is nearly 13 billion light-years away,

  • so, on its own, astronomers would never be able to see it.

  • But fortunately, there's another galaxy perfectly lined up between us and J04,

  • creating what scientists call a gravitational lens.

  • Gravity from this lensing galaxy is bending extra light from J04 our way,

  • boosting its brightness by a factor of 50.

  • It's that magnification that gives the quasar its apparent brightness of 600 trillion Suns

  • and enables astronomers to spot it from half a universe away.

  • And that's a big deal because, even though astronomers have long thought that lensed quasars

  • should be common in the universe,

  • this is the first one they've actually been able to find.

  • And because looking this far away is also looking back in time

  • because it's taken billions of years for that light to travel to us,

  • it could provide critical details about a key phase in history,

  • the period when the first stars and galaxies were being born.

  • Next, in September, astronomers announced they'd found another object that,

  • while not quite as bright, is just as impressive.

  • It's about 4600 light-years away, and it's got another gibberish name.

  • So let's call this one J07.

  • This object is likely the most-massive example of a neutron star we've ever seen.

  • A neutron star is the leftover core of a massive star that died in a supernova explosion.

  • During that detonation, the core is crushed under such extreme pressure

  • that the electrons and protons in its atoms are forced into one another,

  • canceling out their opposite charges and leaving only neutrons behind.

  • The end result is a substance that's ludicrously dense.

  • Like, one cubic centimeter of neutron star material would weigh a billion metric tons.

  • But even among neutron stars, J07 is an oddball.

  • It clocks in at 2.14 times the mass of the Sun,

  • which is, like, really pushing the theoretical maximum on how big neutron stars can get.

  • Although it is still a little unclear, physics suggests the absolute heaviest one of these things can be

  • is around 2.17 solar masses.

  • Once that limit is crossed, the star should collapse directly into a black hole.

  • So at 2.14, J07 is right on that edge.

  • What's more, this star is orbited by a white dwarf;

  • if they were to collide, it would literally be lights out.

  • The extra mass would make the combined object so dense that gravity would just like...

  • and just collapse it into a black hole.

  • For now, though, J07 will have to settle for being the biggest neutron star on the block.

  • And along the way, it will likely help scientist learn more about how massive these things can become.

  • Finally, SpaceX set a new mark for landing rockets this year.

  • When we filmed this episode in mid-December, the company had landed 15 rockets in 2019.

  • That's 3 more than in 2018, and 6 more landings than any of NASA's space shuttles ever did

  • in a single year.

  • And it's not like they launched all brand-new rockets, either.

  • They've been reusing them.

  • Like, in November, they launched and landed a single booster for a record-breaking fourth time.

  • And the rocket, called the Falcon 9 Block 5,

  • is designed to launch at least 10 and up to 100 times before being discarded.

  • SpaceX also successfully caught and re-flew a rocket's nose cone, called the fairing,

  • for the first time this year.

  • Although this is cool for the company and everything, all these efficiencies are great

  • for the space industry as well.

  • Because they could easily add up to tens of millions of dollars in savings on a rocket

  • that's already the cheapest of its kind.

  • And that's what's really exciting here.

  • Because cheaper rockets could mean more missions and more exploration!

  • A decade ago, when NASA selected the MAVEN satellite to orbit Mars,

  • it budgeted almost $500 million for the spacecraft

  • and almost $200 million to launch aboard an Atlas V rocket.

  • Today, launching a Falcon 9 costs a third of that.

  • That's $100 million of extra money, that we can spend on scientific instruments or

  • entirely new missions.

  • It's worth remembering that SpaceX isn't the only company making reusable rockets.

  • But thanks to work like this, the industry is moving forward.

  • And a decade from now, maybe we'll have lots of new science to talk about as a result.

  • So, yeah, it's been a great year for astronomy.

  • And here's to hoping 2020 is even better!

  • If you want to help us make more content like this in the next decade,

  • you can check us out on Patreon.

  • Our patrons make up a community of thoughtful, super smart people, and without them,

  • SciShow Space would not have lasted a year, let alone five and a half.

  • If you're already a patron, thank you so much for everything you do for SciShow

  • and for our viewers here on YouTube.

  • And if you want to learn more about supporting the show and joining that community,

  • we would love to have you.

  • Check it out at patreon.com/scishow.

  • [♪ OUTRO]

[♪ INTRO]

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2019年最亮、最大的航天新聞! (The Brightest, Biggest Space News of 2019!)

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    林宜悉 發佈於 2021 年 01 月 14 日
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