Watch a Simulated Asteroid Hit the Atmosphere at 45,000 Miles Per Hour

Four years ago, an asteroid the size of a city bus screamed across the skies of Chelyabinsk, Russia, shattering glass around a 60 mile perimeter and sending 1,200 people to hospitals with related injuries. In an effort to learn more about these rare but dangerous encounters with objects from space, NASA has used a supercomputer to recreate the moment an asteroid of comparable size hits the atmosphere.


The 3D model was developed by the NASA Advanced Supercomputing (NAS) division as part of the agency’s Asteroid Threat Assessment Project (ATAP). High-fidelity simulations such as this one, which was run on the Pleiades supercomputer, can help scientists estimate the amount of damage asteroids could cause during atmospheric entry, and then plan the appropriate mitigation strategies.

The simulation above shows a cross-section of an asteroid roughly the size of the one that exploded over Russia in February 2013. When the 20-meter-wide asteroid hit the Earth’s atmosphere, it was traveling around 20 kilometers per second, or 45,000 mph.

The grey and black areas represent the rocky mass of the asteroid, while the orange and red areas represent the hot, high pressure shock wave that forms around it during entry. This shock wave, in addition to wreaking havoc below, causes the asteroid to fracture and flatten out like a pancake. Due to the irregular shape of the asteroid, the resulting aerodynamic instabilities rip away at the object, shredding it to pieces. The incoming asteroid and its fragments dispel a tremendous amount of energy into the atmosphere over a short distance, creating dangerous blast waves and thermal radiation on the ground.

Indeed, as we’re learning, the primary danger from asteroids isn’t from the impact site (if it manages to reach the surface before breaking up) or from an ensuing tsunami (should it hit a large water body), but rather from the tremendous shock wave it produces on entry. As recent studies have pointed out, approximately three-quarters of all casualties will come from the heat and wind blast produced by a large incoming asteroid.

On a more positive note, here are some pictures of cute puppies.



George is a senior staff reporter at Gizmodo.


That’s a very interesting simulation. I hope they do another that doesn’t rely on symmetry around the center of the circle to model the erosion of the material. That symmetry made the results of this simultation invalid about 8 seconds into the video when the first fragment ‘collided’ with the symmetry axis. I think we can all understand that it is incredibly unlikely that the ‘other’ side of the sphere had a fragment of the same mass, traveling at the same velocity, intersect the symmetry axis, collide with the first fragment and prevent that fragment from being ejected out the side of the shock tail.

Again, I’m glad they released this, and I want to see accurate results as much as they do. (note: accurate simulations of high speed flow are almost always ITAR controlled, so they probably couldn’t have released this video if it had been a ‘realistic’ non-symmetric simulation)


me, an aerospace engineer at a national lab.