Adam Frank

And every now and then you get a place where the gas is dense enough that gravity gets hold of it and it can pull it downward. So you'll start to form a protostar. And a protostar is basically the young star of this ball of gas where nuclear reactions are getting started. But it's also a disk. So as material falls inward, because everything's rotating,

As it falls inward, it'll spin up and then it'll form a disc. Material will collect in what's called an accretion disc or a protoplanetary disc. And you can simulate all of that. Once you get into the disk itself and you wanna do planets, things get a little bit more complicated, because the physics gets more complicated.

As it falls inward, it'll spin up and then it'll form a disc. Material will collect in what's called an accretion disc or a protoplanetary disc. And you can simulate all of that. Once you get into the disk itself and you wanna do planets, things get a little bit more complicated, because the physics gets more complicated.

As it falls inward, it'll spin up and then it'll form a disc. Material will collect in what's called an accretion disc or a protoplanetary disc. And you can simulate all of that. Once you get into the disk itself and you wanna do planets, things get a little bit more complicated, because the physics gets more complicated.

Now you gotta start worrying about dust, because actually dust, which is just, dust is the wrong word, it's smoke, really. These are the tiniest bits of solids. They will coagulate in the disk to form pebbles, right? And then the pebbles will collide to form rocks, and then the rocks will form boulders, et cetera, et cetera. That process is super complicated.

Now you gotta start worrying about dust, because actually dust, which is just, dust is the wrong word, it's smoke, really. These are the tiniest bits of solids. They will coagulate in the disk to form pebbles, right? And then the pebbles will collide to form rocks, and then the rocks will form boulders, et cetera, et cetera. That process is super complicated.

Now you gotta start worrying about dust, because actually dust, which is just, dust is the wrong word, it's smoke, really. These are the tiniest bits of solids. They will coagulate in the disk to form pebbles, right? And then the pebbles will collide to form rocks, and then the rocks will form boulders, et cetera, et cetera. That process is super complicated.

But we've been able to simulate enough of it to begin to get a handle on how planets form, how you accrete enough material to get the first proto-planets or planetary embryos, as we call them. And then the next step is those things start slamming into each other. to form, you know, planetary-sized bodies. And then the planetary bodies slam into each other.

But we've been able to simulate enough of it to begin to get a handle on how planets form, how you accrete enough material to get the first proto-planets or planetary embryos, as we call them. And then the next step is those things start slamming into each other. to form, you know, planetary-sized bodies. And then the planetary bodies slam into each other.

But we've been able to simulate enough of it to begin to get a handle on how planets form, how you accrete enough material to get the first proto-planets or planetary embryos, as we call them. And then the next step is those things start slamming into each other. to form, you know, planetary-sized bodies. And then the planetary bodies slam into each other.

Earth, the moon came about because there was a Mars-sized body that slammed into the earth and basically blew off all the material that then eventually formed the moon.

Earth, the moon came about because there was a Mars-sized body that slammed into the earth and basically blew off all the material that then eventually formed the moon.

Earth, the moon came about because there was a Mars-sized body that slammed into the earth and basically blew off all the material that then eventually formed the moon.

Yeah, so the temperature of the material in the disk depends on how far away you are from the star. So it decreases, right? And so there's a really interesting point. So like, you know, close to the star, temperatures are really high. And the only thing that can condense, that can kind of freeze out, is going to be stuff like metals.

Yeah, so the temperature of the material in the disk depends on how far away you are from the star. So it decreases, right? And so there's a really interesting point. So like, you know, close to the star, temperatures are really high. And the only thing that can condense, that can kind of freeze out, is going to be stuff like metals.

Yeah, so the temperature of the material in the disk depends on how far away you are from the star. So it decreases, right? And so there's a really interesting point. So like, you know, close to the star, temperatures are really high. And the only thing that can condense, that can kind of freeze out, is going to be stuff like metals.

So that's why you find mercury is this giant ball of iron, basically. Yeah. And then as you go further out stuff, you know, the gas gets cooler and now you can start getting things like water to freeze, right? So there's something we call the snow line, which is somewhere in our solar system out around between Mars and Jupiter.

So that's why you find mercury is this giant ball of iron, basically. Yeah. And then as you go further out stuff, you know, the gas gets cooler and now you can start getting things like water to freeze, right? So there's something we call the snow line, which is somewhere in our solar system out around between Mars and Jupiter.

So that's why you find mercury is this giant ball of iron, basically. Yeah. And then as you go further out stuff, you know, the gas gets cooler and now you can start getting things like water to freeze, right? So there's something we call the snow line, which is somewhere in our solar system out around between Mars and Jupiter.

And that's the reason why the giant planets in our solar system, Jupiter, Saturn, Uranus, and Neptune all have huge amounts of ice in them or water and ice. Actually, Jupiter and Saturn don't have so much, but the moons do. The