Crater - Definition, Examples, Quiz, FAQ, Trivia
Discover how craters form on Earth and other planets
What is a Crater?
A crater is a bowl-shaped depression, or hole, usually made by something hitting the surface or by volcanic activity. Craters can be found on Earth, the Moon, and other planets.
Think of a crater like a dent in the surface of a planet or moon. Just like when you drop a heavy object into soft mud and it makes a hole, craters form when meteorites hit planets or when volcanoes erupt and collapse.
Science Fact!
The word "crater" comes from the Greek word meaning "cup" or "bowl" because of their distinctive shape!
Types of Craters
There are two main types of craters:
Impact Craters
Formed when a meteorite, asteroid, or comet strikes a planet or moon at high speed
Volcanic Craters
Formed by volcanic activity, either by explosion or collapse of the volcano
Impact craters are usually more circular with raised rims, while volcanic craters can have different shapes and often have volcanic vents inside them. Some craters can also form when underground spaces collapse, creating sinkholes.
How Craters Form
The formation of impact craters happens in stages:
Approach
A space object enters the atmosphere at high speed
Impact
The object hits the surface with tremendous force
Explosion
Kinetic energy creates a powerful explosion
Ejection
Material is thrown out, forming the crater rim
Formation
The crater takes its final shape with central peak
Volcanic craters form differently. When a volcano erupts, it can blast material out from the top, creating a depression. Sometimes the top of the volcano collapses inward after an eruption, forming a much larger crater called a caldera.
Impact Energy!
The meteorite that formed Arizona's Meteor Crater was traveling at about 26,000 miles per hour when it hit!
Famous Craters
Here are some famous craters from Earth and beyond:
Meteor Crater
Arizona, USA - Best preserved impact crater on Earth
Crater Lake
Oregon, USA - Formed by collapsed volcano (caldera)
Tycho Crater
Moon - Young crater with visible rays of ejected material
Lonar Crater
India - Impact crater now filled with saltwater lake
Crater lakes form when water collects in a crater over time. The most famous is Crater Lake in Oregon, which formed about 7,700 years ago when Mount Mazama collapsed. It's now the deepest lake in the United States at 1,949 feet deep!
Crater Quiz
Test your crater knowledge with this quiz! Answer all 5 questions to see how much you've learned.
Frequently Asked Questions
Here are answers to common questions about craters:
Crater Trivia
Discover amazing facts about craters!
Moon Craters
The Moon has over 300,000 craters larger than 1 km across! The largest is the South Pole-Aitken Basin, which is 1,600 miles wide and 5 miles deep.
Ancient Impact
The oldest known impact crater on Earth is the Yarrabubba crater in Australia, formed about 2.2 billion years ago - that's almost half the age of Earth!
Dinosaur Extinction
A massive crater buried under Mexico's Yucatán Peninsula (called Chicxulub) is believed to be the impact site that caused the extinction of dinosaurs 66 million years ago.
Mars Mystery
Mars has the largest volcano in the solar system (Olympus Mons) which has a crater 50 miles wide at its summit! This crater formed from volcanic activity.
