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  • The universe is a tantalizing realm of billowing galaxies, terrorizing black holes, mysterious

  • planets, and then...we get to asteroids.

  • These lone grey worlds seem to have all the hype right now and, if we have so much going

  • on in the universe, why are we so focused on sending spacecraft to these drifting rocks?

  • I mean theyre not exactly easy to explore.

  • Japan’s Aerospace Exploration Agency learned that the literalhard waywhen their

  • spacecraft, Hayabusa2, had to launch a “bulletinto the rocky surface of asteroid Ryugu.

  • (Of course it was for data collecting purposes) but it was never supposed to be that way.

  • JAXA scientists anticipated the asteroid to have regolith, or a powdery surface of pulverized

  • material of ice, and dust This would be easy for Hayabusa2 to collect a sample of and add

  • to the regolith material that was brought back from asteroid Itokawa on the first Hayabusa

  • mission.

  • But upon arrival, they were met with the opposite; a graveled hard terrain.

  • With some quick thinking, scientists made adjustments to their collection tactics before

  • our buddy H2 made its landingand in doing so, here on earth, they entirely replicated

  • the surface of an asteroid and shot it with a copy of their sampling instrument.

  • All their testing proved successful when, on February 22nd, 2019 the spacecraft blasted

  • the surface of Ryugu, collecting a piece of the asteroid, which is now is on its way back

  • to us.

  • We expect H2’s valiant return in 2020.

  • 5.

  • But that’s not the only sample were expecting to arrive to Earth in the coming years.

  • NASA’s OSIRIS-REx spacecraft is on a mission as well, to investigate another asteroid named

  • Bennu.

  • Scientists recently discovered by chance that this is a rare class of asteroid, which ejects

  • its own mass into space leaving a trail of tinier rocks in its wake.

  • 6.

  • But Hayabusa2 and Osiris-rex didn’t travel so far to check if asteroids are bullet-proof

  • and watch them throw up.

  • I mean they did, but more importantly NASA says that asteroids are time capsules of our

  • solar system, and these investigative missions are a way to unravel a few mysteries we still

  • have about how it all formed and how we got here.

  • 7.

  • Like one of the biggest asteroids may have delivered the elements of life to Earth.

  • Scientists believe that asteroids like Bennu which are carbon-rich, collided with our planet

  • during its formative years.

  • And while the rocks didn’t have oceans on them, they could have had water molecules

  • lurking within its mineral structure, and helped begin the vast life we now know and

  • love.

  • There’s also the idea that while earth might have been given life from an asteroid, they

  • may have also supplied the foundations for the planets themselves.

  • 8.

  • In the early beginnings of our solar system, there were just tiny particles of dust, made

  • of rock, metal, and ice swirling around our young sun.

  • But as time passed some bits fell into the sun and others stuck together; creating asteroids,

  • but maybe also getting bigger into planetary bodies.

  • We have evidence that previous asteroids weve visited with NASA’s Dawn spacecraft, Vesta

  • and Ceres, were internally layered with materials, with the core being the densest part.Indicating

  • both asteroids were growing to be planets but they never gathered enough material to

  • do so.

  • So an asteroid could be a leftover relic from that early evolution period of our solar system

  • that were still trying to figure out.

  • 9.

  • But now that I’ve explained some ways asteroids are awesome, there’s always a little disclaimer

  • and this one is that asteroids can be hazardous to earth.

  • We actually have a program called the Planetary Defense Coordination Office and they use a

  • collection of instruments in the Near-Earth Object (NEO) Observations Program to keep

  • tabs on any and all asteroids that flyby, or enter our atmosphere.NASA is even working

  • on a redirect mission called DART where Bruce Willis takes a team of oil riggersjk,

  • There’s no Bruce, but this is a real mission.

  • And emerging research like this simulation from John Hopkins University shows that it’s

  • much more difficult to destroy an asteroid than we previously thought.

  • So this all may be new to you, but weve actually been hunting asteroids for a while

  • now.

  • Back in the early 2000’s, NASA’s NEAR Shoemaker was the first spacecraft to orbit

  • and land on an asteroid.

  • Now missions like this are standard when going to small bodies with OSIRIS REx, Hayabusa1

  • and 2, Rosetta/Philae, and New Horizons.

  • And theyve taught us so much already.

  • Hayabusa2, although not back yet with its sample, has already detected that the Ryugu

  • asteroid is drier than anticipated and that it’s quite young, only around 100 million

  • years old.

  • This suggests that wherever it stemmed from was probably devoid of water, too.

  • Which might change our current understanding of what the universe looked like 100 million

  • years ago.

  • And OSIRIS RE-x, remember lucked out with Bennu being anactive asteroid.”

  • Out of the 8,000 asteroids discovered, there have been just 12 observed releasing their

  • material into space.

  • So all observations from Bennu are valuable and it has plenty of time to prepare for its

  • sample mission in July 2020.

  • But what is in store for the future?

  • Let me introduce Mission Psyche.

  • NASA wants to send a spacecraft, for the first time, to a nearly entirely metal asteroid

  • named Psyche.

  • Psyche is special because it might be a piece of a metallic core that’s similar to Earth’s

  • that we can ACTUALLY study.

  • Earth’s core is way too hot to investigate and now it’s our opportunity to do so and

  • understand how Earth and other rocky planets formed.

  • Plus, the center of our magnetic field is our metallic core, sooo this might help us

  • understand that too.

  • (hopefully) NASA’s estimated arrival to Psyche will be in 2026.

  • So floating space rocks such as asteroids, are unique to our understanding of our universe.

  • They may hold the key answers to our burning questions and all we have to do is capture

  • them.

  • One spacecraft at a time.

  • Still wanna know more about the missions ahead?

  • Comment down below on the specifics youre looking for and check out this video about

  • Oumuamua, the mysterious interstellar asteroid that flew right by us.

  • Subscribe for more science in your day and thanks for watching seeker.

The universe is a tantalizing realm of billowing galaxies, terrorizing black holes, mysterious

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我們為什麼要向小行星發射 "子彈"? (Why Did We Just Shoot A “Bullet” At An Asteroid?)

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    林宜悉 發佈於 2021 年 01 月 14 日
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