One
of the more interesting lights in the sky come from a series of communication
satellites called Iridium.
These satellites have an antenna that is similar to a dressing mirror in
size, shape, and reflectivity. So what? Well, from 485 miles
up, if that mirror is aligned just right, it will reflect the sun towards
you, becoming the brightest thing in the sky. In astronomical parlance,
these Iridium Flares can be as bright as magnitude -7 (brighter
than Venus ever gets). They last for only a few seconds at a time.
So, how do you know when and where an Iridium Flare will happen?
Well, there's an excellent web site called Heavens-Above
that will happily calculate the Iridium flare
schedule for any place on Earth. You can go
to their site (which can also show you when ISS and many other
satellites will be overhead), or you can check out the schedules for San
Diego or Los
Angeles. Note that the more precise you are about your location,
the more accurate the flare prediction will be.
Heavens-Above now has an excellent
tool that lets you nail down your latitude and longitude quite precisely.
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One
of the more interesting lights in the sky come from a series of communication
satellites called Iridium.
These satellites have an antenna that is similar to a dressing mirror in
size, shape, and reflectivity. So what? Well, from 485 miles
up, if that mirror is aligned just right, it will reflect the sun towards
you, becoming the brightest thing in the sky. In astronomical parlance,
these Iridium Flares can be as bright as magnitude -7 (brighter
than Venus ever gets). They last for only a few seconds at a time.