
GeoAstro Applets 
Astronomy 
Chaos Game 
Java 
Miscel laneous 
Eclipse Magnitude and Obscuration
The eclipse magnitude is defined
as the fraction of the Sun's diameter occulted by
the Moon, and the eclipse obscuration as
the fraction of the Sun's surface area occulted by
the Moon. The area covered by the the moon can
easily be computed: The
area of the segment is: The secant P_{1}P_{2}
is at: and the angles
are:
Diameters: d_{Moon}/d_{Sun}=
1.1 (total eclipse) Diameters: d_{Moon}/d_{Sun}=
0.9 (annular eclipse) Diameters: d_{Moon}/d_{Sun}=
0.9, 1.0, and 1,1 Select Data from
the menu to get this window:
Magnitudes of Solar Eclipses 2006  2010 (Fred Espeneak):

Calculating the area of the Sun covered during an eclipse 
(c) 20062023 J. Giesen
Modified: 2023, Oct 07