Watching the Sky Fall: Visualizing a Century of Meteorites

Watching the Sky Fall: Visualizing a Century of Meteorites

Astrophysicist Neil DeGrasse Tyson once said “The chances that your tombstone will read ‘Killed by an Asteroid’ are about the same as they’d be for ‘Killed in Airplane Crash’.”

Part of the reason for this is the Earth’s atmospheric ability to burn up inbound space rocks before they reach the surface, a process that ensures that most meteors never become meteorites.

Of the 33,162 meteorites found in the past 100 years, only 625 were seen. Today’s visualization from data designer Tiffany Farrant-Gonzalez groups these 625 observed meteorites by the year they fell, classification, mass, and landing location on Earth.

Asteroid, Meteoroids, Meteors, and Meteorites

Not all flying space rocks are the same. Their origins and trajectories define its type.

Asteroid: A large rocky body in space, in orbit around the Sun.
Meteoroid: Much smaller rocks or particles in orbit around the Sun.
Meteor: If a meteoroid enters the Earth’s atmosphere and vaporizes, it becomes a meteor, or a shooting star.
Meteorite: If a small asteroid or large meteoroid survives its fiery passage through the Earth’s atmosphere and lands on Earth’s surface.
Bolide: A very bright meteor that often explodes in the atmosphere, also known as a fireball.

Classification

This graphic classifies meteorites into four types based on their composition: stony, stony-iron, iron and other.

Top 5 Meteorites by Size

While half of all observed meteorites weighed less than 2.5 kg (5.5 lbs), there are a few exceptional ones that stand out. The graphic highlights the five largest meteorites ever observed, and when they fell:

Each category differs in their amount of iron-nickel metal and what they reveal about the early solar system.

Fireballs in the Sky: Bolides

Small asteroids frequently enter and disintegrate in Earth’s atmosphere randomly around the globe, creating fireballs known as bolides. NASA’s Near-Earth Object Program mapped data gathered by U.S. government sensors from 1994 to 2013.

Source: NASA

The data indicates that small asteroids impacted Earth’s atmosphere, resulting in a bolide (or fireball), on 556 separate occasions over a 20-year period. Almost all asteroids of this size disintegrate in the atmosphere and are harmless.

A notable exception was the Chelyabinsk event in 2013, which was the largest known natural object to have entered Earth’s atmosphere since the 1908 Tunguska event. A house-sized asteroid entered the atmosphere over Chelyabinsk at over 11 miles per second, and blew apart 14 miles above the ground.

The explosion released an energy equivalent to ~440,000 tons of TNT, generating a shock wave that shattered windows over 200 square miles—damaging several buildings and injuring over 1,600 people.

Look Out Above

While the night sky appears to be a beautiful tableau of the cosmos, these two visualizations paint a dramatic galactic battle. Rocks inundate our planet as it moves through the darkness of space. The resiliency of Earth’s atmosphere to erode these invaders has allowed life to flourish⁠—until the next big one comes through.

Remember the Dinosaurs?