Volcanoes built much of the ground you're standing on, and they remain the planet's most dramatic reminder of who's really in charge down there. Cover the answers, lock each one in, and keep score.

Where does the word "volcano" come from?

Vulcano, a small Italian island named for Vulcan — the Roman god of fire and the forge.

In 1943, a volcano was born in a Mexican farmer's cornfield. What is it called?

Parícutin — farmer Dionisio Pulido watched it split open in his field, and within a year it had grown into a cone over 1,000 feet tall.

What happened to the town Parícutin's lava buried?

San Juan Parangaricutiro was entombed — except its church tower, which still pokes defiantly out of the black rock today.

What's the difference between magma and lava?

Location — it's magma while underground, lava the moment it erupts.

What is the largest volcano in the solar system?

Olympus Mons on Mars — about two and a half times the height of Everest, with a footprint roughly the size of Arizona.

What is the most volcanically active body in the solar system?

Jupiter's moon Io — hundreds of volcanoes, kept molten by the relentless squeeze of Jupiter's gravity.

What is the Ring of Fire?

A horseshoe of volcanoes and quake zones ringing the Pacific — home to roughly three-quarters of Earth's active volcanoes.

Vesuvius's eruption in AD 79 buried Pompeii and which other Roman town?

Herculaneum — smaller, wealthier, and preserved even more completely beneath the flows.

Why are eruptions of that type called "Plinian"?

For Pliny the Younger, whose eyewitness letters on Vesuvius are history's first detailed account of an eruption — written after his uncle died in it.

What are the famous "bodies" of Pompeii?

Plaster casts — starting in 1863, archaeologists poured plaster into the hollows victims left behind in the hardened ash.

What was the largest volcanic eruption in recorded history?

Indonesia's Mount Tambora in 1815 — it chilled the globe so badly that 1816 became the "Year Without a Summer," with June snow in New England.

Which rock floats on water?

Pumice — frothy volcanic glass full of gas bubbles, which sometimes drifts across oceans in giant rafts.

Can a volcano make its own lightning?

Yes — colliding ash particles build static charge, creating "dirty thunderstorms" that crackle inside the plume.

What did Iceland's Eyjafjallajökull do to the world in 2010?

Grounded Europe — roughly 100,000 flights were canceled in the continent's largest airspace shutdown since World War II.

Which volcano stands taller than Everest when measured from its base?

Hawaii's Mauna Kea — over 33,000 feet from seafloor to summit, most of it hidden underwater.

Keep the Parícutin story in your pocket: history records plenty of farmers who lost a crop to bad weather, but only one who lost the whole field to a brand-new mountain.