What is the likely explanation if a bright light seen in the sky is extremely fast and transient, lasting only a second or two?

Answer

A fireball or bolide

If the light is incredibly fast and fleeting, lasting only briefly before disappearing, it is likely a fireball, which is a particularly large or bright meteor.

What is the likely explanation if a bright light seen in the sky is extremely fast and transient, lasting only a second or two?

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