Understand what happens when different shapes and sizes of meteorites impact the Earth with this fun activity.
The STEM Behind the Fun
What's the difference between an asteroid and a meteorite?
An asteroid is a rock-like object that orbits around the sun. A meteorite is what we see flashing through the sky when a piece of an asteroid breaks off and enters Earth’s atmosphere. An asteroid is classified as a meteorite if it impacts the Earth. Meteorites do not usually stay intact after impacting the Earth, so scientists estimate their original size by observing the crater and the ejecta – the particles that were ejected (forced out or thrown out) because of the meteorite’s impact.
What is bigger, the meteorite itself or the crater it makes?
As you noticed, the crater is always bigger than the meteorite itself. The biggest crater discovered was almost 200 km in diameter, and its meteorite was the one that, many scientists believe, caused the dinosaurs to go extinct 65 million years ago! But don’t worry, the odds of an asteroid this size impacting us again are minimal.
How big are asteroids?
Asteroids vary in size and are smaller than a planet but bigger than the meteorite that hits Earth. Asteroid Bennu is the biggest asteroid that has a risk of impacting the Earth in a couple hundred years, and it is 500 metres in diameter. The OSIRIS-REx mission, which Canada is part of, consists of bringing a small sample from Bennu back to Earth. This will allow scientists to see what this asteroid is made of, and get more information to help us prevent a collision with our planet!
How many layers does Earth's surface have?
Earth’s surface consists of 4 layers. In order from closest to the surface, those are crust, mantle, core, and inner core. On top of the crust is where you’ll find the soil (for example) that we walk on.
Did You Know:
While falling through the sky toward Earth, meteorites race through the air a hundred times faster than an airplane.
Did You Know:
Travelling as fast as they do makes meteorites very hot – more than 1000℃!
Did You Know:
All that speed and heat makes meteorites shine like a star – which is why people sometimes call them “shooting stars”.
Let's Simulate a Meteorite Hitting the Earth's Surface
Materials
- Modelling clay of a few different colours (ideally brown, black or white – colours that a meteor might be)
- Large shallow pan/tray with edges
- White baking flour (or any white powder: baking soda, coconut flour, etc.)
- Cocoa powder (or any coloured powder: dry drink powder, coffee, etc.)
- Flour sifter or a fine sieve
- Small dinosaur toys (optional)
Procedure
Pour a thick layer of flour (or other white powder) evenly into your pan or tray. This will simulate Earth’s crust. Make sure your pan is on a surface like a kitchen table, which will be easy to wipe down if any of the flour splashes off the tray.
With the sifter, dust a thin layer of cocoa powder (or other coloured powder) over the flour. This represents the soil of the planet.
If you’d like, add some dinosaurs to recreate Earth, 65 million years ago!
To build our meteorites, mix the colours of modelling clay with your hands to build three meteors of different shapes and sizes.
Hold your first meteorite 40 cm to 50 cm above the pan, then drop it! Carefully remove the meteorite and observe the crater (the hole) created. Remember that the material that was ejected is called “ejecta.”
Make a prediction: which one of your meteorites do you think will create the largest crater? Which will eject the most material? Test it out, repeat step 2 with your other meteorites. What do you notice about any patterns, or anything different between the impact and sizesE
