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 shadow. 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 nothing 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.