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[Centaur]

The Dark Moon will be in geocentric longitudinal conjunction with the Sun on 2008 JAN 08 at 11:37 UT. Since we've passed the winter solstice, New Moon spotting is becoming easier for northern hemisphere observers. That will be especially true during February through May. The timing of the conjunction this month makes it impossible for northern hemisphere observers to spot the Moon aged less than 24 hours, despite otherwise improved conditions. But the Moon on the 9th aged 1.5 days and near Mercury should be a pretty sight.

I’ve created a graphic previewing the southwestern sky as viewed from Chicagoland 30 minutes after sunset on the 9th. Mercury will be about 3° to the lower right of the Moon. The graphic should well serve most North American observers. It and another graphic demonstrating the current apparition of Mercury as an evening star can be seen by clicking: www.curtrenz.com/astronomical.html

Photos or descriptions of the January New Moon would be welcome additions to this thread. Below is a picture I took on 2007 MAY 17 of the Moon aged 30:42 hrs and near Mercury.

[Maddad]

What do you mean by the Moon being aged"

[Centaur]

maddad said:

What do you mean by the Moon being aged"

The Moon's "age" is the period of time since its last conjunction with the Sun. Normally, conjunction is considered to occur at the moment that both the Moon and Sun share the same geocentric ecliptical longitude, as illustrated at the top of my diagram seen below.

Calendar makers typically label the day of conjunction as that of the New Moon. More traditionally, however, that would be called the Dark Moon and the term New Moon would refer to the slim crescent Moon that first appears in the western sky after sunset after it has aged a day or two since conjunction. That leads to an ambiguity regarding the term New Moon. I prefer the more classical usage and refer to the conjunction as the time of the Dark Moon and the first sighting of the Moon afterward as the New Moon. The photo you see above in my initial post in this thread shows the phenomenon caused by earthshine that is called "The Old Moon in the New Moon's Arms".