Learning Center
Plans & pricing Sign in
Sign Out



									                           LUNAR ECLIPSES

In a lunar eclipse the earth casts its shadow on the moon. This can only happen at the full
moon, at night, when the moon’s orbit brings it exactly in line with the earth and the sun. Again
the shadow cast (this time by the earth) has 2 parts, the umbra and the penumbra, but this time
from earth we see these as 2 concentric circles.

        In the penumbral eclipse the full moon enters the moon’s
        penumbra, but still appears quite brightly lit.

        In a partial eclipse, part of the moon is in the umbra and
        part is in the penumbra, so we see the moon partially in

        A total lunar eclipse is when the moon is completely in the
        umbra. As the earth’s atmosphere both refracts and filters light the moon appears
        dark red.

A lunar eclipse is much easier to see than a solar eclipse – it will be seen anywhere on earth at
night where the moon is visible and can last for hours.

Total Lunar Eclipse 16 July 2000

                                                                                   In day for
                                                                                   the whole
                                                                                   eclipse, see

See the end of the        See the total lunar eclipse         See the beginning of the total
eclipse as moon                 at night                         eclipse as the moon sets
rises in East                                                            in the West

Either a solar or a lunar eclipse occurs somewhere on earth about every 6 months or so.

To top