Eclipses of the sun occur when the moon passes directly in front of the
sun. This can only happen at the time of a new moon and only at certain points in the moon's orbit around the earth. Contrary to popular opinion, solar
eclipses are not rare; it is not unusual for there to be two solar
eclipses in any one year. In some years, such as the year 2000, there
are as many as four.
A total eclipse occurs when the moon completely covers the face of the
sun. It is, however, rare for a total eclipse to be seen at any particular
location because the path of totality on the earth's surface
is typically only 100 kilometres wide. This probably gives rise to
the perception that solar eclipses are rare - for anyone not able to travel
a total ecipse would indeed be a very rare event.
During a total eclipse, the sky becomes dark, the stars
shine and the beautiful corona (the outer atmosphere) of the sun shines
like an irridescent halo around the black moon. This is a truly
awe inspiring event and certainly worth travelling to see. For this reason,
there are now quite popular tours to see a total eclipse from the
best possible location.
Partial eclipses of the sun are much more common. During the eclipse
the moon will move slowly across the face of the sun which will appear
as if a very neat bite has been taken out of it. From the time that
the moon first starts to go in front of the sun to the time it moves
right away may take several hours. During a partial eclipse, the sky may
darken slightly and the sun's light might appear to be more yellowish
than usual.
REMEMBER that it is UNSAFE to view the sun directly at any time. However,
the sun's image can be projected from a telescope onto white card or a
pin hole camera can be constructed.
The picture shows a bite taken out of the sun during the Nov 24, 1995
solar eclipse. The image is taken from the IPS/USAF solar observatory
in Learmonth, located near Exmouth in Western Australia.
Educational