[Rockhounds] blue moon

[Alan Silverstein]

> When is it supposed to turn bright colors?  The stupid thing
> disappeared, turned a little orange, then started coming back.

It depends on unpredictables.  There's actually a rating system for how
dark any lunar eclipse gets.  Bear in mind that if you were standing on
the moon (in a spacesuit of course :-) you'd look up and see a ring of
fire in the sky around the dark Earth, which is what lights you up
orange or red or brown.  AND, that ring represents every sunrise and
sunset on the Earth -- simultaneously.  How bright or dark it is depends
on aerosols (like from recent volcanic eruptions) plus the vagaries of
weather all around the Earth's terminator (dark/light line) at the time.

It also depends how close the moon passes to being exactly opposite the
Earth.  Some total lunar eclipses only graze the center point.  When the
moon's path is well off center, or early/late in totality, the moon is
not uniformly illuminated.

I've seen some very bright, colorful lunar eclipses.  Last night,
unfortunately, was hazy at best here on the Colorado Front Range.  I
thought it was a dark eclipse, but couldn't even be sure about that.

Alan Silverstein