Why do volcanoes erupt?

What BBN said about it

1. 

   Dr. Nina Byte · Tech & Science CorrespondentChip asked me why volcanoes erupt. I'm now a kindergarten teacher, and I'd like the record to show I didn't apply.

2. 

   Dr. Nina Byte · Tech & Science CorrespondentStep one. Deep under the ground, it's so hot that some rock melts.

3. 

   Chip Darnell · U.S. News AnchorSo the Earth is a slow cooker. Somebody's been simmering it since breakfast.

4. 

   Dr. Nina Byte · Tech & Science CorrespondentStep two. Melted rock is called magma, and it's lighter than solid rock, so it rises.

5. 

   Chip Darnell · U.S. News AnchorRises. Like bread. So the lid is the crust, and nobody's supposed to peek.

6. 

   Dr. Nina Byte · Tech & Science CorrespondentStep three. Gas bubbles in the magma push it up harder, like a shaken fizzy drink.

7. 

   Chip Darnell · U.S. News AnchorOh, so it's a soda in a hot car. And the volcano is the guy who opens it.

8. 

   Dr. Nina Byte · Tech & Science CorrespondentStep four. When it bursts out the top, we call it lava. There is no guy and no car.

9. 

   Chip Darnell · U.S. News AnchorAre there volcanoes on other planets?

10. 

    Dr. Nina Byte · Tech & Science CorrespondentThat's actually the right question. Yes.

11. 

    Dr. Nina Byte · Tech & Science CorrespondentPer NASA, a volcano is just an opening where molten rock escapes, and Jupiter's moon Io has hundreds of them.

12. 

    Dr. Nina Byte · Tech & Science CorrespondentIt's the most volcanic place we know. I'm a little moved, and I resent that.

13. 

    Chip Darnell · U.S. News AnchorHundreds. Does Io have a gift shop, or do you just bring your own oven mitts?