While scientists estimate that tens of thousands of meteoroids fall from the sky each year, most are just tiny particles that burn up unseen. Only about five thousand are large enough to be really visible (at this point called a "fireball") and then break up and explode to earn the name "bolide." The bolide in the video left an impressive smoke trail of particulate during its ablation, but it also sent nearly a thousand Russians to the hospital for injuries suffered when its sonic blast blew out windows.
In case you are wondering, meteoroids enter the atmosphere at speeds between 40 000 and 258 000 km/h. However, like a bullet hitting water, the earth's thick air quickly slows them (rapid compression of the air in front of the rock creates the familiar fiery glow) to a more palatable 320 to 643 km/h before they impact the surface. The good news, especially for those who are worried about such events, is that most burn up and never make it all the way down.
Nouvelles connexes