Next, let's turn our attention to the biggest planet in our solar system, the planet Jupiter.  And Jupiter is enormous.  It is so big, it's really difficult to comprehend.  Here's a picture.  The first picture in the gallery shows the scale of the Earth and Jupiter on the same picture.  So you can see how much bigger Jupiter really is compared to the Earth.  If you were to take the whole sphere of Jupiter and just start putting Earths in it, how many earths do you think you could fit into one Jupiter?  Maybe ten?  A hundred thousand?  You could actually fit 1,300 Earths into just one Jupiter.  Isn’t that incredible?  It's how big this planet is.


Jupiter is the first as we move outward of what we call the gas giants.  Now these planets are fundamentally different than the four planets in the inner solar system.  They are, first of all, so big, in part because they have enormous atmospheres.  Basically, the whole planet is atmosphere. 


How does this happen?  What's going on?  Well, because these planets are so far away from the Sun, it's colder out there.  And because it's colder, ice can form.  So these planets are all past what we call the snow line in the solar system.  That's a place where snow can form where these gases basically sort of crystallize and form ice crystals.  


The other piece is, because it's cold out there, the particles of gas are not moving as quickly.  You know, when things are warm, they move around really, really fast and when they're cold, they move more slowly.  And as a result, when things are moving more slowly, it's easier to hold on to them with gravity.  So as these larger objects are out there, they have gravity, they're getting more and more material to stay because it's colder.  And the more material that stays, the more gravity it gets.  And so it attracts more material.  And so you have this process that allows you to accumulate a very, very large planet.


So what are these things?  So when we see the beautiful patterns on Jupiter, here's another picture, the second picture in the gallery, is a closer up photo of Jupiter, we're not looking at the surface of a planet, we're looking at its atmosphere at its clouds.  What is this like?  Well, these clouds are made up of ice crystals, tiny little ice crystals.  And in the process, it looks like clouds you might experience here on Earth, but there's just way more of them and many, many layers of clouds.  


So if you were to try to jump into these clouds and maybe parachute in, you know what would happen as you made your way in?  Okay, of course, you need a spacesuit because you'd be freezing cold, you'd need air to breathe, because there's no air that we could breathe in these clouds.  But as you made your way down through the clouds, what happened is you went down, down, down, down, down?


Well, what happens is the clouds get thicker, the pressure gets greater, you’d need a very strong space suit so you didn't get crushed by the by the pressure.  But the idea is you keep falling down, down, down, it gets thicker and thicker and thicker, you get slower and slower and slower, until eventually you will just get stuck, suspended in the clouds.  You'd never land on any surface, you wouldn't just pass right through it, you would just eventually just get suspended there in the muck of this atmosphere.  It’s an amazing in different kind of place.

Now this atmosphere is beautiful to see up close.  I mean, when I see these pictures from spacecraft that flew by, I would just stare.  I would want to just sit up close and watch the beautiful swirls as this planet rotates and as the storms are moving around.  And we can see that with some of our telescopes.  I wish I could see it with my eyes, but we could see it with telescopes.  


So this is the third picture in our gallery.  It’s actually a little animation.  And it shows the entire atmosphere.  It's like a map of the entire globe of Jupiter that's been stretched out.  And what this shows over time is how the clouds on Jupiter are moving in opposite directions and at great speeds. So let me just go through these real briefly here so you get a sense of this motion.


So you see, these bands that are moving.  These bands, dark and light bands, are often moving in opposite directions because Jupiter is rotating so fast that these clouds are also moving really, really fast.  In fact, on Jupiter, and Saturn, these clouds move well over 100 meters per second.  A hundred meters per second, that's like, super, super fast that these guys are flying around.  And as a result, because these clouds are moving in opposite directions, you get all kinds of these spirally patterns, these kind of like hurricanes that seem to form in the atmosphere of Jupiter.


The largest one of these, you can see right here, is the Great Red Spot.  And this is a large hurricane that's been going for well over 100 years, in fact, basically, as long as we've been observing Jupiter through a telescope, we've seen this large hurricane in the clouds of Jupiter.


And more than that, spacecraft have seen other kinds of atmospheric features that we see in our atmosphere on Earth, like lightning.  Lightning has been recorded on Jupiter, and even the Northern Lights, you know, like the glow that you see, as particles fly into our atmosphere, you can see those on Jupiter, as well.  So the atmosphere obeys the same kinds of rules as our atmosphere does.  In fact, that's one of the reasons that scientists study the atmosphere of these giant planets is that it allows us, you know, we can use the same laws of nature to study these atmospheres as we do to predict weather and climate in our own atmosphere.  


And so it's a way to test whether we understand those rules.  We can say, well, it works pretty good here on Earth; let's see how it works at predicting what would happen in Jupiter.  And if we can tweak the model and make it better, they can help us better understand our own climate and weather and atmosphere here on the earth.


One of the coolest things about the gas giant planets and Jupiter in particular is its moons.  And so here's an amazing photograph from a spacecraft that shows one of Jupiter's moons against the backdrop of Jupiter itself.  Just imagine what this would be like, if you were standing on this moon, and you looked up in your sky.  


When we look at the sky, you see the moon, it's a little circle, you could block it with your thumb if you wanted to.  But if you were standing on this moon, looking at the sky, you know, you'd see the sun, and you'd see you'd see the stars, but then Jupiter would fill like, you know, a third of your entire sky, you just see this huge Jupiter in your sky and you'd watch it rotate, you'd see its clouds.  Can you imagine seeing that?  Wouldn’t that be an amazing place to live to see that kind of thing in your night sky.  It's impossible to even imagine.


Jupiter's moons are some of the most fascinating places in our solar system. They're moons, but they're quite large.  They're bigger than our moon.  And there's four in particular that are really big, really big.  And like the planets in the inner solar system, these moons have surfaces that you could walk on, that you could potentially land a spacecraft on and study up close.  Some of those moons are covered in what appears to be ice.  They just have cracks over the whole surface.  You don't see any craters; you just see what looks like a giant ice planet.  Others have bizarre, like a black surface with light bright spots on it, you should really check out Jupiter's moons, but one particular I want to show you.  I think it's the most bizarre place in the whole solar system.  And that is the moon of Jupiter called Io.  Io.  Just Io. 


And this is what it looks like; the last picture in the gallery.  It is a bizarre place.  Now it doesn't really look like our moon.  It doesn't have any craters.  Instead, all these little pits you see on the surface are volcanoes.  So this moon is an extremely geologically active place.  Now we've talked about how Mars and Mercury and the moon are geologically dead.  They don't really have a lot going on inside the planet.  Well, Io has a lot going on.  It constantly has erupting volcanoes. 


How can this particular moon have so much geologic activity?  Well, because it's so close to Jupiter, and Jupiter is so big and has so much gravity, Jupiter is constantly tugging and twisting and pushing, and crashing, this moon with its gravity.  These are called tidal forces.  It's like if you took a little rubber ball, and you constantly, like over and over again, you squeezed it really fast, that rubber ball would start to get really warm.  And that’s basically what's happening to Io.   Jupiter's gravity is squeezing it and stretching it, and squeezing it and stretching it.  And inside, it's getting really warm, and that heat has to escape, and it does through volcanic explosions.  As a result, you'll see we don't see any craters over the surface of this moon.  So it tells us that the whole surface has been reshaped by these volcanic eruptions and the lava that flows out.  It’s an amazing place.


When I look at a picture like this of Io, or when I consider the moons of Jupiter and what their sky must look like if you were sitting on one of those moons, I can't help but think about all the places not only in our solar system, but in the whole galaxy, or even the whole universe, these moons or planets that have beautiful sights.  I mean, imagine watching a sunset from one of these moons and as the sun is sinking low, you know, Jupiter is rising on the other side of the sky? 


Isn't that just… I mean, there's no one there to see that.  No one is there to see and appreciate that.  And then there's these other planets we don't even know of around other stars, which may have these amazing sights, with multiple stars that they orbit, like maybe there's two stars setting at the same time and, and a planet with rings is in the distance that they can see the rings with just their eyes.  I mean, these places exist, but we can't see them.  No person can see them.  And I can't help but think about well, why has God made these places?  No human is there to see them or appreciate them, right?


God must find some pleasure in that.  In so many ways, I think this whole universe has been created for God's pleasure; that He could see the work of His hands and enjoy interacting with it. And in light of that, it's always amazing to me that God chooses to spend any of His time with us, that He loves us when He has created these amazing, beautiful places that He could just be you know, in a sense sitting in a hammock at you know, sipping some coconut water watching this beautiful site.   He chooses to spend time in the mess of our lives.  It shows just how loving our God really is. 


Okay, we'll see you next time.



Última modificación: lunes, 2 de octubre de 2023, 12:25