Name: 史蒂夫-萊文博士談朱諾 - SpacePod 2011.05.31 (Dr. Steve Levin talks Juno - SpacePod 2011.05.31)
Uploaded: 2021-01-14T04:45:33.000Z
Duration: 5 min 39 s
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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.

程度副詞

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!

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.

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.

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.