A fireball is another term for a very bright meteor, generally brighter than magnitude -3, which is about the same magnitude of the planet Venus in the morning or evening sky. Fireballs and bolides are astronomical terms for exceptionally bright meteors that are spectacular enough to be seen over a very wide area. Fireballs that explode in the atmosphere are technically referred to as bolides although the terms fireballs and bolides are often used interchangeably. Objects causing fireball events can exceed one meter in size. Fireballs can develop two types of trails behind them: trains and smoke trails. A train is a glowing trail of ionized and excited air molecules left behind after the passage of the meteor. Most trains last only a few seconds, but on rare occasions, a train may last up to several minutes.

Fireballs are usually observed at night, but they can also be seen during the day. Ground-based observers sometimes witness these events at night, or much more rarely in daylight, as impressive atmospheric light displays. If you happen to see one of these memorable events, you can report it to the American Meteor Society, remembering as many details as possible. Several thousand meteors of fireball magnitude occur in the Earth’s atmosphere each day. The vast majority of these, however, occur over the oceans and uninhabited regions, and a good many are masked by daylight.