Completely eclipsed in French Polynesia

A total eclipse of the Moonwill take place on Wednesday January 31st 2018.

A lunar eclipse at full Moon takes place when the Sun, the Earth and the Moon are sufficiently well aligned : when that happens, the Moon passes through the shadow cone created by the Earth and is then totally eclipsed.

The eclipse will be total at 13h29 UTC (at 14h29 in Paris French standard time FST). Consequently, it will not be observable from the France, since the full Moon can only be seen at night. However, the total eclipse can be seen from, for example, Tahiti and New Caledonia.

If the meteorological conditions are good, the astronomical "show" will be remarkable : the Moon will have a large apparent diameter and a coppery color.

Super Moon

Moving on an eccentric orbit, the Moon’s distance from the Earth is different each month, varying from about 356 000 km to 406 000 km.

It is at perigee when, during its elliptic orbit, it is at its closest point to the centre of the Earth.

Although there is no official definition of the super Moon,this istacitly taken to occur when its distance from the Earth at the moment of full Moon is less than 356 600 km.

In fact, on January 31st 2018, the Earth-Moon distance will be 358 995 km, only just obve this limit.

In metropolitan France, the Moon will be fully illuminated, but just a little larger than usual, in fact about 7 % larger than the average Moon, so that it will be possible to see easily with the naked eye the dark regions and the contrasts.

Blue Moon

2018 will be a year with 13 full Moons, two of which will be blue.

Does that mean that we will see an unusually blue Moon ? Not at all:the expression « blue Moon » is once again taken from our Anglo-Saxon neighbors …

It apparently goes back to the XVIth century,when it originally referred to the stupidity of something one said : it is just as absurd to say that the Moon is blue as to say that black is white. Since then, its meaning has changed. In English, it can be found in the well known expression « once in a blue moon » whose equivalent in French is « chaque 36 du mois », meaning a particularly rare happening.

En astronomy, the blue Moon refers to the second full Moon which can take place in the same month.

This will happen both in January and in March 2018. This exceptional situation is due to the fact that the month of February 2018 will have only 28 days.

When a blue Moon takes place in January, there is necessarily a second blue Moon in March and there is no full Moon in February. This is the only case when two blue Moons can occur in the same year. The next one will be in exactly 19 years, in 2037. Note finally the following curiosity of the calendar:because of the time difference,certain regions on the Earth will be already in the month of February at the time of the next full Moon.

To know more :

Information bulletin of the IMCCE : https://www.imcce.fr/lettre-information/archives/141