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Re: (meteorobs) Fireballs
At 06:03 PM 4/17/97 -0400, you wrote:
>Here I go sounding stupid but just what are fireballs?
>
>Debby
Ah! I'm GLAD you asked that! :)
Seriously, good question Debby. Most people define a "fireball" as any
meteor which appears as bright or brighter than the brightest planet,
Venus. In practice, this means any meteor whose "magnitude" (on the
logarithmic scale astronomers use to measure brightness) is LOWER than -3.
(Lower magnitudes mean brighter objects.)
So for example, if you were lucky enough to see a meteor as bright as the
full moon (a once-in-a-lifetime event at best!), it would be about
magnitude -12, and therefore definitely a fireball! But if you see one that
is only as bright at the star Vega in Lyra (a common but lovely event),
then it would only be about magnitude 0, and so NOT a fireball.
Side Note: The human eye can see meteors as faint as magnitude 7 (I've seen
them!) But this is only right near the center of your eye's field of view,
and only in pitch-black rural skies, with no moon out.
Let the experts correct me where I stray...
Lew