**ECLIPSES OF
MOON**

Data from Wikipedia and NASA (C)

A lunar
eclipse happens when the Moon passes in the cone of shadow of the Earth and in
such a way it darks totally or partially. This situation can only happen in the
phase of full Moon, when the Moon and the Earth are in conjunction as seen from
the Sun. The penumbral cone is external to that one of shadow, and much more is
extended than this last one.

**TYPE OF ECLIPSES**

Exist 4
type of lunar eclipses :

Total,
happens when the Moon is completely darkened from the earth shadow. The disc of
the Moon passes totally in our cone of shadow, with a consequent strongly
decrease of brightness; sometimes the phenomenon is therefore "deep"
that the lunar disc disappear totally to our vision. Other times assume a red color.

Partial,
it happens when the Moon passes only partially in the cone of totality shadow.
The brightness decrease is inversely proportional to the distance of the Moon
from the center of the earth shadow.

Penumbral,
happens when the Moon passes in the cone of penumbra of the Earth; our planet
blocks only a small part of the sunlight and therefore our satellite appears
still very illuminated; this type of eclipse is very little visible to naked eye
in how much the brightness case is minimal.

Partial
penumbral: also the lunar eclipses of penumbra can be partial; that happens
when the Moon does not enter totally in the earth penumbra.

**TECHNICAL NOTES**

The
lunar cycle is approximately 29,5 days, therefore the
Moon returns in "the full" phase nearly every month. But why the Moon
eclipses are not never repeated then with the same
frequency? The answer is in the lunar orbit, that it is tilted of beyond 5°
regarding the earth orbit. This inclination makes yes that not always Moon
Earth and Sun are aligned, in order the Moon must pass in the so-called
ascending node or the descendant of its orbit. That only happens from 2 to 4
times to the year. The Moon eclipses, with the exception of those solar ones,
are visible from the entire earth hemisphere that is not turned towards the
Sun. Of all the eclipses that happen 35% are of penumbral type, 30% are partial
and remaining 35% total. Although during the total eclipses the Earth blocks
the sunlight, a small part of it filters and illuminates our satellite of a
red-orange-yellow in how much only the red frequencies of the light pass from
our atmosphere. To this light sum the light reflected from our same planet.

All the total
eclipses begin with a penumbral phase followed from a partial phase whose
durations depend on how much the Moon pass near to the center
of the earth shadows.

For the
lunar observations they do not need filters of protection of the eyes of no
type. Indeed, modest binoculars or telescope can offer exceptional shows.

Saying **γ** (gamma) __the minimal distance from the center of the axis of the earth shadow to the center of the Moon__, in unit of earth equatorial radius

·
if
γ > 0 the
moon passes to north of the axis of the shadow

·
if
γ < 0 the
moon passes to south of the axis of the shadow

Saying **u **the radius of the cone of shadow of
the Earth in the fundamental plan

σ = 1.2848 + u it is the radius of the penumbra
to the distance of the Moon

σ = 0.7403 + it is the radius of the umbra to
the distance of the Moon

In the
case of penumbral eclipses the maximum magnitude in the place of better
visibility on the Earth, that it is more close to the axis of the shadow is

1,5573+u-|γ|

------------

0,545

while for the shadow it is

1,0128-u-|γ|

------------

0,545

**SEVERAL DATA ON THE SUN ECLIPSES**

All the
data that follow are based on the French Rule of Connaissance
des Temps of Paris.

The
number of lunar eclipses in a year varied from 2 to 5. There will be

The
eclipses of shadow (and from in ahead we will define here as shadow eclipse is
those totals that those partial ones) can be 0,1,2 or
3. From 1500 to 2499 there are 191 years with 0 eclipses of shadow, 105 with 1,
676 with 2 and 28 with 3. The next event with

4
successive eclipses can be all totals.

In
period 0-2999 there will be 7249 moon eclipses, of which 2089 totals, 2536
partial and 2620 penumbral.

The
maximum magnitude in shadow for this century is 1,88 on

Sometimes
there aren’t total eclipse for 3 consecutive years,
the next cycle will be in 2160-61-62.

Don exist 2 consecutive years with only penumbral eclipses.

The
extreme diameters of the Moon are 1763" at apogee and 2012" at the
perigee. The radius of earth penumbra varied 1888"to 1952".

Total eclipses
of penumbra, in the period

The
magnitude of the total eclipses varied from 1,001 to 1,094.

During an
eclipse the Moon can also hide stars. Such events are rare in the case of luminous:
Regulus will come hidden during the total eclipse on

Also the
planets can be hidden during a eclipse:

Mars in
the total of

Jupiter
in the partial on

Saturn
in the total on

Uranus
in the total on

Length
of an eclipse: in period

If we
consider also the phase of partiality the duration it can arrive nearly to 4
hours. The longest on

Considering
the phase of penumbra the duration arrives to 379.11 minutes on

Tetrad:
4 consecutive total eclipses, in period

Every
how much happens the eclipses of Moon shadow? Every 5, 6, 11,
12, 17 or 23 lunations.