Why do volcanoes erupt?
Deep under the ground it is so hot that some rock melts. Melted rock is called magma, and it is lighter than solid rock, so it rises. Gas bubbles in the magma push it up harder, like a shaken fizzy drink. When it bursts out the top, we call it lava.
Transcript
Dr. Nina Byte: Chip asked me why volcanoes erupt. I'm now a kindergarten teacher, and I'd like the record to show I didn't apply.
Dr. Nina Byte: Step one. Deep under the ground, it's so hot that some rock melts.
Chip Darnell: So the Earth is a slow cooker. Somebody's been simmering it since breakfast.
Dr. Nina Byte: Step two. Melted rock is called magma, and it's lighter than solid rock, so it rises.
Chip Darnell: Rises. Like bread. So the lid is the crust, and nobody's supposed to peek.
Dr. Nina Byte: Step three. Gas bubbles in the magma push it up harder, like a shaken fizzy drink.
Chip Darnell: Oh, so it's a soda in a hot car. And the volcano is the guy who opens it.
Dr. Nina Byte: Step four. When it bursts out the top, we call it lava. There is no guy and no car.
Chip Darnell: Are there volcanoes on other planets?
Dr. Nina Byte: That's actually the right question. Yes.
Dr. Nina Byte: Per NASA, a volcano is just an opening where molten rock escapes, and Jupiter's moon Io has hundreds of them.
Dr. Nina Byte: It's the most volcanic place we know. I'm a little moved, and I resent that.
Chip Darnell: Hundreds. Does Io have a gift shop, or do you just bring your own oven mitts?