On the evening of 14 March 2006 a penumbral
eclipse was visible from the Netherlands. The greatest eclipse was at 23:47 UT. Penumbral eclipses are sometimes called "invisible" eclipses as the
moon does not enter the earth's main shadow or umbra. However, inspired by
David H. Levy's article In Praise of Penumbral Eclipses (Sky &
Telescope, Sep 2005, p 113) I decided to stay up and watch and photograph
this eclipse. It was also a good rehearsal for taking pictures during the
total solar eclipse on March 29.
|I sent the picture to David Levy, to let him know that there are others as well interested in penumbral eclipse. I also wrote to him that I always enjoy reading his Star Trails in Sky & Telescope. On the right is the friendly e-mail I received in return from David. He even included a picture he took from an airplane just after sunset.||
How to visualise a penumbral eclipse: if you were standing on the moon, you would see partial eclipse of the sun by the earth.
The 14 March 2006 event was a so-called total penumbral eclipse, where the whole moon is in the penumbra, and no part in the umbra, nor outside the penumbra, see the picture to the left. Although not spectacular, these are rare events. The next one will be on 29 August 2053, and in some centuries there are none at all. The number of total penumbral eclipse for a given length of time is governed by a period of 586 year. More information on this is given in Jean Meeus, Mathematical Astronomical Morsels, chapter 17.
The next total lunar eclipse visible from the Netherlands will be in less than a year's time on 3 March 2007.