An eclipse is simply the shadow cast by one body upon another, when
it passes in front of a source of light. There are two categories of
eclipse of interest to observers on the Earth, both of which owe their
existance to the fact that the Moon orbits around the Earth:
Lunar and Solar eclipses.
- A Solar eclipse occurs when the Moon passes between the
Earth and Sun; this happens at the New Moon,
and the effect is that
observers on the side of the Earth facing the Sun (i.e. the side which
is in daytime) have their view of it cut off, either partly or
- A Lunar eclipse occurs when the Earth passes between the
Full Moon and Sun (or, to look
at it another way, when the Moon passes
"behind" the Earth), and is visible at night as a shadow cast on the
Moon. A lunar eclipse can be quite beautiful; the full moon is seen
in shadow, and often appears a deep red colour.
The following pages provide more detail on the workings of
||The Earth and Moon
In order to help you understand how eclipses occur, we take a
little look at how the Earth, Sun and Moon are related
to each other, and how the phases of the Moon happen.
||Mechanics of Solar Eclipses
Solar eclipses come in several types; this page explains the types
of solar eclipses, and why they occur.
||Mechanics of Lunar Eclipses
A look at the mechanics of lunar eclipses, why they occur,
and the types of lunar eclipse.
This page looks at how often and when eclipses occur, and why
they happen when they do (and not more often!).
A different look at eclipse prediction, showing how the cycles
of the Moon dictate when eclipses occur.
The Sun is at the heart of all eclipses, but can be seen in a whole
new way during a total solar eclipse; this page explains a little of the Sun's
structure, to help you understand what can be seen during an eclipse.
Ever wondered why the Moon is bigger when it's near the horizon?
(Atmospheric refraction, right?) Or why water swirls round sinks
clockwise in the northern hemisphere (or is that anti-clockwise)? Or
why you can stand an egg on end during an equinox? Check out my
Bad Science page!
The diagrams in this section were produced using
using the KPovModeler front-end.