The question of when a meteor last struck Earth touches on the fundamental processes of our solar system and the protective nature of our planet’s atmosphere. Every day, countless pieces of space rock intersect with Earth’s orbit, but the vast majority never reach the ground. Understanding the true frequency of these events requires distinguishing between the microscopic dust that constantly settles and the larger objects that create atmospheric explosions. Scientific observation has provided a clear answer to when the last major celestial body entered our atmosphere and affected the surface.
Clarifying Terminology
The terms used to describe space rocks are often confused, but their definitions depend entirely on their location relative to Earth. A meteoroid is the object itself, a piece of rocky or metallic debris that is still traveling through space, ranging in size from a grain of sand to a small asteroid. When this space rock enters our atmosphere, it begins to heat up due to friction, producing a bright streak of light known as a meteor or “shooting star.” Most of these meteors burn up completely high above the ground.
If the object survives the atmospheric journey to land on Earth’s surface, the surviving remnant is then called a meteorite. Extremely bright meteors that explode violently in the atmosphere are known as bolides. The detonation of a bolide releases a massive amount of energy, often accompanied by a loud sonic boom.
The Most Recent Significant Airburst Event
The last widely documented and significant event involving a large celestial body occurred on February 15, 2013, over Chelyabinsk, Russia. An object estimated to be about 17 to 20 meters (56 to 66 feet) in diameter entered the atmosphere at a high speed, becoming a brilliant superbolide. The object was traveling at approximately 19 kilometers per second (42,000 miles per hour) before it fragmented.
The object did not strike the ground but instead detonated in an airburst at an altitude of roughly 30 kilometers (18.6 miles). The blast released a tremendous amount of energy, estimated to be equivalent to 440 to 500 kilotons of TNT. This energy release was approximately 30 times greater than the atomic bomb dropped on Hiroshima.
The resulting shockwave was powerful enough to reach the ground, causing widespread damage. Over 7,200 buildings across six cities were damaged, and the blast shattered windows for hundreds of square miles. Nearly 1,500 people sought medical treatment, mostly due to injuries from flying glass, making it the largest documented impact event to injure a significant number of people in more than a century.
The Reality of Daily Impacts
While the Chelyabinsk event was the most recent large-scale airburst, the Earth is constantly bombarded by countless smaller pieces of space debris every day. Scientists estimate that between 48.5 and 100 tons of meteoric material falls toward Earth daily. The vast majority of this incoming material is composed of micrometeorites, which are tiny dust-sized particles that drift down to the surface unnoticed.
Nearly 95% of the material that enters our atmosphere burns up completely due to atmospheric friction, creating the familiar streaks of light we call meteors. Even objects up to a few meters in size will typically disintegrate harmlessly before any fragments reach the ground.
The most frequent impacts are routine, silent processes that add a small amount of cosmic material to our planet daily. This constant bombardment contrasts sharply with the rare, massive impacts that shape planetary history. The Earth’s atmosphere acts as a highly effective shield, preventing all but the largest or most durable objects from causing significant damage.
How Scientists Track Impact Events
The detection of incoming space objects relies on a combination of ground-based and space-based technologies. These combined efforts provide a comprehensive system for both early warning and post-event analysis of impact events. Scientists use several methods to track and analyze these events:
- Dedicated all-sky camera networks, such as the NASA All Sky Fireball Network, continuously scan the night sky to record the paths of bright meteors (fireballs). These networks calculate the object’s trajectory and speed, sometimes predicting where potential meteorites might have landed.
- A global network of infrasound sensors monitors for large airburst events. When a bolide explodes, it creates extremely low-frequency sound waves that these sensors can detect from thousands of miles away.
- Satellite observation systems, often operated by governments, monitor for the sudden, intense flashes of light and heat produced by atmospheric detonations.
- Sky surveys, such as the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) or the Asteroid Terrestrial-impact Last Alert System (ATLAS), are designed to find and track Near-Earth Objects (NEOs) before they pose a threat. These powerful telescopes monitor large areas of the sky, creating a catalog of celestial bodies whose orbits might intersect with Earth’s path.