[PLUG-TALK] Eclipse and "Supermoon"

[Keith Lofstrom]

Somehow, the press has gotten heated up about the astrological
"Supermoon", and the explanations focus on the moon being at
perigee tonight.  Uh, ... no.  Perigee makes the moon appear 11%
larger, and no brighter per angular area than normal.  Mostly
What's making the moon about 40% brighter is "heiligenshein". 
The surface of the moon is covered with tiny retroreflective
glass beads formed by meteoroid impact, and we are very close
to syzygy, direct lineup between sun and moon and earth.

For more, see http://server-sky.com/LunarBrightness 

Much more interesting: in about two weeks, on May 20 at about
5:00pm, the moon will have travelled a bit more than halfway
around its orbit, and we will be in exact syzygy.  The moon
will eclipse the sun.  Because the moon will be near apogee,
it will be "smaller", and the eclipse will be annular, with
the moon covering 94% of the Sun's disk along the path of
totality.  Which passes just south of Crescent city, BTW.
The Sun will appear as a circular ring of light.

Here in Portland, the eclipse will be "only" around 88% of
total, around 620pm, with the sun forming a crescent around
the "top" of the moon.  But still, it will be  a once-in-a-
lifetime show.  Even with cloud cover, close to dusk, an 88%
darkening should be spooky and way cool.  Please schedule
time around late afternoon on Saturday May 20, and support
your favorite local solar system team.  GO, PLANETS!

Besides, the TV direct broadcast satellites will also get
eclipsed, so there won't be anything on the boob tube anyway. :-)

There are links to NASA's eclipse pages on the webpage above.

Keith

-- 
Keith Lofstrom          keithl at keithl.com         Voice (503)-520-1993
KLIC --- Keith Lofstrom Integrated Circuits --- "Your Ideas in Silicon"
Design Contracting in Bipolar and CMOS - Analog, Digital, and Scan ICs