March 2 2007 Occultation of Saturn

Dia 1 The sky looking SWW at 02h 20m UT March 2 2007.

Dia 2. The relative size of the Moon and Saturn shown close to first contact 02h 19m UT March 2 2006.

The Moon will pass in front of Saturn during the early hours of March 2 2007. (Dia. 1)

From Orkney the disappearance will take place at 02h 19m UT and the reappearance at 02h 44m UT. These times are to the nearest minute and in the case of reappearance apply to the ring system.

Dia 2 shows the relative sizes of Saturn and the Moon close to first “contact”.

An optical power of at least 40x is usually necessary in order to see the rings but with the bright Moon so close one should aim to use at least twice this magnification.

It should be possible to view the main event easily in ordinary binoculars.

The Moon being close to full phase will make naked eye observation less easy. However, Saturn is very bright at zero magnitude (brighter than Procyon for example) so that there should be little problem in good, clear skies.

March 3 2007 Total Eclipse of the Moon

This eclipse will be visible in its entirety from Orkney. In addition, the Moon at mid eclipse will be at a comfortable altitude in the constellation Leo.

It is to be hoped that the weather will be kind to us this night. Out of  nine total eclipses of the Moon only two will be visible from Orkney in the space of the next eight years.

The circumstances of the eclipse (Kirkwall) will be:

Moon enters penumbra: 20:16:16
Moon enters umbra: 21:29:52
Start of totality: 22:43:37
Maximum eclipse: 23:20:44
End of totality: 23:57:49
Moon leaves umbra: 01:11:34
Moon leaves penumbra: 02:25:14

Duration of total phase: 1h 14m 11s
Duration of umbral phase:  3h 41m 42s
Duration of penumbral phase: 6h 8m 58s

The altitude of the Moon will be:

Moon enters penumbra: 20.5°
Moon enters umbra: 28.1°
Start of totality:  33.8°
Maximum eclipse: 35.7°
End of totality: 36.7°
Moon leaves umbra: 36.0°
Moon leaves penumbra: 31.9°

All times UT (GMT)

Total eclipses of the Moon are more frequent than are eclipses of the Sun. The reasons for this should be obvious enough. The Earth’s umbral shadow can be about 2.7 times that of the apparent diameter of the Moon or Sun at a solar eclipse.

Both types of eclipse are equally unpredictable in their physical aspects. Many would argue that the appearance of the corona at a total solar eclipse is more spectacular than the appearance of the Moon at mid eclipse.

Indeed it can be very difficult to see the Moon if the Earth’s shadow is dark. Everything depends on the state of the Earth’s atmosphere at the time as seen from the Moon. Under the most favourable conditions the face of the Moon can appear a somber bronze colour. Those who have seen it will know what I mean when I say that this colour is unique as a natural celestial spectacle.

Imaging the Moon for the eclipse will require well mounted cameras using wide apertures, maximum zoom and relatively slow speeds. One cannot advise precisely on the latter since all will depend upon the conditions at the time.

In over fifty years observing I have yet to secure a satisfactory image of a totally eclipsed Moon bathed in that bronze light. Good luck!

JV 22/02/07