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  • Narrator: Jupiter, where weather is one continuous planetary super-cane and many of the gas giant's swirling

  • secrets remain hidden beneath its cover of clouds.

  • Ben: So let's just start with the basics of what is the Juno mission? Or is it mission Juno?

  • Because the shirt says Mission Juno. So is it Mission Juno or Juno Mission?

  • Dr. Steve Levin: Either one is fine. Mission Juno or Juno Mission.

  • And, well, Juno is a mission to Jupiter. What we're trying to do is understand the origin ...

  • the main thing we're trying to do is to try to understand the origin of Jupiter and by understanding that,

  • understand how planets form and how solar systems form.

  • And Jupiter, as the largest planet in the solar system by far, - it's more than twice the mass of

  • all the other planets combined - is our key to understanding how do planets form and how did the solar system form.

  • Narrator: A new armored force will battle through Jupiter's supercharged radiation field and atmosphere

  • to unlock new mysteries of our solar system!

  • Dr. Levin: Because it formed first, because it's the biggest, it influenced the formation of everything else.

  • And partly because it's so big, there's actually a lot we don't know about Jupiter.

  • What you see when you look at Jupiter from the Earth or with visible light, what you see is the tops

  • of the clouds. It's a gas giant. What you're seeing is the very top of its atmosphere.

  • We don't know that much about what's down inside!

  • We know some things, but for example, all the theorists say there ought to be a dense core down in the middle of Jupiter.

  • Maybe three times the mass of the Earth, maybe up to twenty times the mass of the Earth.

  • We don't have any direct evidence for that core!

  • Juno will measure that.

  • I have a background in radio astronomy. I've worked with our P.I., Scott Bolton,

  • he's the principal investigator on the project, I've worked with Scott for a long time.

  • One of the things we did was modeling synchrotron radiation from Jupiter.

  • That's radio waves given off by the high-energy electrons trapped in Jupiter's magnetic field.

  • Narrator: Juno!

  • Dr. Levin: Jupiter has an ocean of liquid-metallic hydrogen. And what that means if you think about it,

  • hydrogen is the lightest element there is. If you filled a balloon with hydrogen here on the Earth,

  • it would float up into the sky. On Jupiter, the pressure is so high, the temperature conditions are so high

  • it's so intense that that hydrogen is squeezed down so much that not only is it squeezed down to become a liquid,

  • but the electrons are squeezed right off the atoms. It conducts electricity, so what you have is a liquid metal of hydrogen!

  • That's a huge ocean of liquid metallic hydrogen. Much bigger than the Earth.

  • And it's the patterns in that liquid metallic hydrogen that generate Jupiter's huge magnetic field.

  • Narrator: Juno, with it's suite of sophisticated science instruments and majestic solar panels ...

  • Juno, with it's protective radiation vault ...

  • Dr. Levin: It's really hard to pick one part of the Juno spacecraft and say this is my favorite piece

  • because all of the pieces work together. I think the way I would say it is that there's one instrument on

  • Juno, all the instruments are great, they all do lots of exciting things, there's one instrument that

  • does things a little bit different than we've done before, especially at a giant planet.

  • That would probably be the microwave radiometer instrument.

  • It's 6 different radio channels. They're looking deep into Jupiter's atmosphere.

  • We're taking advantage of our orbit to look at each place at different angles with six different frequencies

  • and see, because it's 6 different frequencies, it's 6 different depths because it's a whole range of angles.

  • Each spot on the planet gets seen from a whole range of angles.

  • That's going to let us understand the composition of Jupiter's atmosphere.

  • It's a kind of measurement we haven't done before at the outer planets.

  • Narrator: Juno - it's smart!

  • Dr. Levin: Most scientists sort of fall into one of two camps - either a theorist or an experimentalist,

  • or observationalist depending. And as you might guess, they tend to have a slightly different slant on things.

  • So, if I were a theorist, I would be looking at "Oh, I really want to see that my theory is right!"

  • As an experimentalist, I would really love for us to discover something that just makes all the theorists

  • have to throw everything out and start over.

  • That's just in many ways more exciting. That's letting the universe teach you.

  • The way science works is the universe teaches you about itself.

  • You do measurements, you do observations, you look at what you can figure out based on what

  • you've measured, what you've observed, what you can see and touch and even taste and so forth.

  • So if the universe teaches us something new, if it says "Here's this new fact, throw out all those theories

  • you've got to start over!", that would be really exciting.

  • Narrator: Juno, unraveling the history of our solar system and conquering the gas giant.

Narrator: Jupiter, where weather is one continuous planetary super-cane and many of the gas giant's swirling

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史蒂夫-萊文博士談朱諾 - SpacePod 2011.05.31 (Dr. Steve Levin talks Juno - SpacePod 2011.05.31)

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    shaellot 發佈於 2021 年 01 月 14 日
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