Enter an asteroid size and speed. Find out if it ruins your day, your city, or civilization.
A 50-meter asteroid hitting Earth at 20 km/s releases about as much energy as the Hiroshima bomb. It creates a crater about 1 kilometer wide and destroys everything within 2 kilometers. People 10 kilometers away would see a bright light and feel the shockwave.
A 1-kilometer asteroid is a civilization-level event. It releases energy equivalent to hundreds of thousands of nuclear bombs. The impact winter that follows could last years, blocking sunlight and killing crops. This is the size that killed the dinosaurs: about 10 kilometers.
The Chelyabinsk meteor in 2013 was only 20 meters. It exploded in the air over Russia, injuring 1,500 people with broken glass. It never even reached the ground. A 50-meter asteroid like the one that made Meteor Crater in Arizona would hit the ground hard enough to make a crater a mile wide.
NASA tracks near-Earth asteroids larger than 140 meters. Anything bigger than that could cause regional devastation. So far, no known asteroid has a significant chance of hitting Earth in the next 100 years. That is reassuring. For now.
About 10 kilometers. It hit Mexico 66 million years ago, releasing energy equivalent to 10 billion Hiroshima bombs. The crater is 180 kilometers wide. 75% of all species on Earth went extinct.
About 50 meters. The Tunguska event in 1908 was caused by an asteroid about 50-60 meters wide that exploded in the air over Siberia. It flattened 2,000 square kilometers of forest. If it hit a city, that city would be gone.
Between 11 and 72 km/s. The minimum is Earth's escape velocity (11.2 km/s). The maximum is for objects on retrograde orbits hitting us head-on (72 km/s). Typical asteroid impacts are around 20 km/s, or about 72,000 km/h.
NASA's DART mission successfully deflected an asteroid in 2022. The plan is: find it years in advance, hit it with a spacecraft, and change its orbit just enough to miss Earth. The harder problem is finding it early enough. Most asteroid surveys focus on objects larger than 140 meters.