Dates of the full moon phases. Why does the moon come in different shapes?

As you know, the Moon does not emit light, but only reflects it. And therefore, only that side of it that is illuminated by the Sun is always visible in the sky. This side is called the day side. Moving across the sky from the west to the east, the Moon over the course of the month catches up and overtakes the Sun. There is a change in the relative positions of the Moon, Earth and Sun. In this case, the sun's rays change the angle of incidence on the lunar surface and therefore the part of the Moon visible from the Earth changes. The movement of the Moon across the sky is usually divided into phases directly related to its modification: new moon, new moon, first quarter, full moon and last quarter.

Moon observations

The Moon is a celestial body of spherical shape. That is why, when it is partially illuminated by sunlight from the side, the appearance of a “sickle” appears. By the way, by the illuminated side of the Moon you can always determine in which direction the Sun is located, even if it is hidden behind the horizon.

The duration of the complete change of all lunar phases is usually called a synodic month and ranges from 29.25 to 29.83 Earth solar days. The length of the synodic month varies due to the elliptical shape of the lunar orbit.

During the new moon, the Moon's disk is completely invisible in the night sky, since at this time it is located as close as possible to the Sun and at the same time faces the Earth with its night side.

Next comes the new moon phase. During this period of time, the Moon becomes visible in the night sky for the first time in the synodic month in the form of a narrow crescent and can be observed at dusk a few minutes before its setting.

Next comes the first quarter. This is the phase in which exactly half of its visible part is illuminated, as in the last quarter. The only difference is that in the first quarter the proportion of the illuminated part at this moment increases.

The full moon is the phase in which the lunar disk is clearly and completely visible. During the full moon, for several hours you can observe the so-called opposition effect, in which the brightness of the lunar disk noticeably increases, while its size remains the same. This phenomenon is explained quite simply: for an earthly observer, at this moment all shadows on the surface of the Moon disappear.

There are also phases of the waxing, waning and old moon. All of them are characterized by a very narrow crescent of the Moon with a grayish-ash color typical for these phases.

From all of the above we can conclude that, in fact, nothing obscures the Moon. The angle of its illumination by the sun's rays simply changes.

The sun has just set. Against the background of the reddish dawn, a narrow shiny sickle emerges brightly, its hump turned towards the setting Sun. It doesn't take long to admire them. Soon it will follow the Sun below the horizon. At the same time they say: “A new moon is born.”

Photo: V.Ladinsky. A new moon was born.

The next day, at sunset, you will notice that the crescent has become wider, it is visible higher above the horizon and does not set so early. Every day the Moon seems to grow and at the same time moves away from the Sun further and further to the left (to the east). A week later, the Moon appears in the south in the evening in the form of a semicircle with a convexity to the right. Then they say: “The moon has reached its phase first quarter».

The best time of year to observe the young Moon in the Northern Hemisphere of the Earth is spring, when the crescent of the new Moon rises high above the horizon. In the first quarter phase, the Moon rises highest above the horizon in late winter - early spring.

In the following days, the Moon continues to grow, becomes larger than a semicircle and moves even further to the east, until after another week it becomes a full circle, i.e. will come full moon. While the Sun will go below the western horizon on the western side, the full Moon will begin to rise on the opposite, eastern side. By morning, both luminaries seem to change places: the appearance of the Sun in the east finds the full Moon setting in the west.

The full Moon is highest above the horizon in the first half of winter, and on short summer nights it can be found around midnight low in the southern sky.

Photo: V.Ladinsky. Full Moon rising on July 21, 2005.

Then, day after day, the Moon rises later and later. It becomes more and more truncated, or damaged, but on the right side. A week after the full moon, you will not find the Moon in the sky in the evening. Only around midnight it appears in the east from behind the horizon and again in the form of a half circle, but now with its hump directed to the left. This last(or, as it is sometimes called, the third) quarter. In the morning, the semicircle of the Moon, with its hump facing the rising Sun, can be seen in the southern side of the sky. A few days later, the narrow crescent of the Moon appears over the horizon in the east just before sunrise. And a week later, after the last quarter, the Moon completely ceases to be visible - it comes new moon; then it will appear again on the left side of the Sun: in the evening in the west and with its hump again to the right.

The most favorable time of year for observing the Moon in the phases between the last quarter and the new moon is early autumn.

This is how the appearance of the Moon in the sky changes every four weeks, or more precisely, 29.5 days. This lunar, or synodic, month. It served as the basis for compiling a calendar in ancient times. This lunar calendar has been preserved among some eastern peoples to the present day.

The change in lunar phases can be summarized in the following table:

During the new moon, the Moon is between the Earth and the Sun and faces the Earth with its unlit side. In the first quarter, i.e. After a quarter of the Moon's revolution, half of its illuminated side faces the Earth. During a full moon, the Moon is on the opposite side to the Sun, and the entire illuminated side of the Moon faces the Earth, and we see it in a full circle. In the last quarter, we again see half of the illuminated side of the Moon from Earth. Now it is clear why the convex side of the crescent moon always faces the sun.

For several days after (or before) the new moon, you can observe, in addition to the bright crescent, the part of the Moon not illuminated by the Sun, but faintly visible. This phenomenon is called ashen light. This is the night surface of the Moon, illuminated only by solar rays reflected from the Earth.

Thus, the change in the phases of the Moon is explained by the fact that the Moon revolves around the Earth. The time it takes for the Moon to orbit around our planet is called sidereal month and is 27.3 days, which is less than 29.5 days, during which the phases of the Moon change. The reason for this phenomenon is the movement of the Earth itself. As it revolves around the Sun, the Earth carries with it its satellite, the Moon.

On a new moon, when the Moon is between the Earth and the Sun, it can block it from us, then a solar eclipse will occur. During a full moon, the Moon, being on the other side of the Earth, can fall into the shadow cast by our planet, then a lunar eclipse will occur. Eclipses do not occur every month because the Moon revolves around the Earth in a plane that does not coincide with the plane (the ecliptic plane) in which the Earth revolves around the Sun. The plane of the Moon's orbit is inclined to the plane of the ecliptic at an angle of 5° 9". Therefore, eclipses occur only when at the moment of the new moon (full moon) the Moon is near the ecliptic, otherwise its shadow falls “above” or “below” the Earth (or the earth’s shadow “ above" or "below" the Moon).

Phase is the ratio of the area of ​​the illuminated part of the disk of a celestial body to the area of ​​the entire disk. In the new moon phase Ф = 0.0, in the first and last quarter phase = 0.5, in the full moon phase = 1.0.

The mental line drawn through the tops of the horns of the crescent moon is called the line of horns. It is often said that the line of horns points to, or below, the point of south. Perpendicular to the line of the horns indicates the direction to the Sun.

If the horns of the lunar month are directed to the left, then the Moon is growing, if to the right, then it is aging. However, this rule is reversed when observing the Moon from the southern hemisphere of the Earth, as shown in the figure:

Tasks and questions:

1. The moon is at new moon. In what phase will the Earth be visible from the Moon? The earth will be in the “full earth” phase, because... the phases of the Moon when observed from the Earth and the phases of the Earth for a lunar observer change the other way around and are in antiphase.

2. Is the Earth visible from the Moon in “New Earth”? Yes, it is visible in the form of a crescent due to the fact that the Earth's atmosphere refracts sunlight.

3. On December 25 of such and such a year, the Moon was in the first quarter phase. In what phase will it be visible in a year? To solve this problem, let’s take the synodic month of the Moon, equal to approximately 29.5 days. Multiply 29.5 by 12 months and get 354 days. Subtract the resulting value from 365 (the number of days in a year) and get 11 days. Considering that the first quarter occurs after 7 - 8 days, then by adding the resulting value (11) to 7 (or 8), we obtain the age of the Moon in a year equal to 18 or 19 days. Thus, a year later the Moon will be in a phase between the full moon and the last quarter.

4. What time will the Moon culminate in the first quarter? The first quarter moon will culminate over the point south at approximately 6 p.m. local time.

Moon phases in 2012 Time indicated is Universal (MSK - 4 hours)

The lunar disk shining in the night sky has always attracted people's attention. Legends were written about the moon; it was worshiped no less than the Sun. Already in ancient times, people realized that the moon influences earthly life. And its influence is due to phase changes.

The Moon is positioned so that it reflects the Sun all the time. The whole moon or some part of it may be illuminated, and sometimes the moon is completely plunged into darkness. This change in the state of illumination of the moon is called lunar phases.

Ancient signs and superstitions were replaced by scientific observations, from which it became clear that changing lunar phases really affects our lives. The gravitational field of the moon creates ebbs and flows on Earth and affects plant growth. Every gardener uses the lunar calendar, according to which there are favorable and unfavorable days for planting and fertilizing seedlings. Moreover, the moon has a direct effect on human health and mental state. It has long been noted that during the full moon the number of accidents and crimes increases, and financiers even came to the conclusion that world market indices depend on the change in lunar phases.

In a word, the moon is not only a satellite of the Earth, but also a satellite of our entire life. Who knows what would have happened to our life and whether it would have arisen at all if there were no moon.

Knowing about the influence of lunar phases and lunar days on our lives is useful and especially necessary for those who want to control their destiny. Modern knowledge about the moon is no longer legends, speculations and omens, but the results of long scientific research and observations. However, it would be wrong to reject the experience and our ancestors. When interpreting the influence of the moon, we take into account the symbols and sacred images that ancient people awarded the night star.

Four lunar phases

It is generally accepted that in 29 days the moon goes through four phases - new moon, first quarter, full moon and third quarter. During the new moon, the moon is completely darkened and hidden from our eyes. Then the moon turns into a thin crescent, it is called a young or growing moon. After this, we already see half of the moon - this is the first quarter. During the full moon, the Earth's satellite is fully illuminated - we see a bright disk in the sky. Then the moon wanes. In the third quarter, we again see half the moon, and then again a narrow crescent, but already facing the other direction - this is the aging moon.

If you watch the moon closely, you will realize that it goes through other stages between phases, moving from the first quarter to the full moon and from the full moon to the last quarter. The days when the moon appears in the sky as a narrow crescent are also important in the lunar cycle. Therefore, we propose to consider the lunar month as a sequence of eight periods - four quarters, two critical points (new moon and full moon) and two transition phases. This is the sequence in which the eight states of the moon change:

• first phase - crescent moon (young, growing);
• second phase - gibbous moon - the moon is almost completely illuminated, except for a thin crescent-shaped stripe;
• the third phase - the scattering moon - the same convex moon, but already waning;
• the fourth phase is the balsamic moon (aging) - the moon in the form of a thin sickle, like after a new moon, but facing the other direction.

To avoid confusing the periods of the balsamic and crescent moons, there is a mnemonic rule. If the moon R waxing, its sickle is curved like the bow in the letter R. When the moon WITH is aging, its sickle looks like the letter C.

That is, the boundary between the illuminated and unilluminated parts of the Moon’s disk moves, which causes a change in the outlines of the visible part of the Moon.

The Moon itself does not glow, and we see it only when it is illuminated by the Sun. Since the Moon is a spherical body, and the positions of our planet and the Sun are constantly changing in space, situations arise when the Moon is partially illuminated from the side, which leads to a characteristic picture resembling a slice of cheese or a sickle - the month.

The curved side of the month always points towards the Sun, even if it is in a completely different part of the sky or hidden behind the horizon.

In phases of the Moon close to the new moon (at the beginning of the first quarter and at the end of the last quarter, with a very narrow main crescent), the unlit part forms the so-called. ashen light of the Moon - the visible glow of a surface not illuminated by direct sunlight of a characteristic ashen color. Ash light is sunlight scattered by the Earth, and then again and reflected by the Moon to Earth (that is, the route of the photon of the Moon’s ashen light: Sun->Earth->Moon->eye of the observer on Earth),

In many, including famous works of art depicting the Moon, as well as in heraldry depicting sickles, astronomical errors are often made in drawing the phases of the Moon, such as:

• an image of stars inside a ball described around the crescent of the month - which is physically impossible, since in this place there is an unlit part of the Moon, obscuring all the stars located in this direction.
• drawing the wrong orientation of the month: the “horns” of the sickle are directed towards the horizon, despite the fact that the picture depicts night. Since the illuminated part of the moon is directed towards the sun, the horns can only be directed towards the horizon during the day.
• Image of the crescent moon with its horns facing the sun.
• The location of the moon or month in the northern sky. (Which is only possible in the southern hemisphere)
• Fabricated photographs show mismatches in the phase of the moon in the sky and in reflective surfaces.

Earth-Moon-Sun System

The Moon, on its way around the Earth, is illuminated by the Sun; it itself does not glow. 1. new moon, 3. first quarter, 5. full moon, 7. last quarter.

Consistent changes in the visible moon in the sky

The moon can be seen during the day

The moon goes through the following phases of illumination:

• new moon - a state when the Moon is not visible (state 1 in the figure)
• Neomenia is the first appearance of the Moon in the sky after the new moon in the form of a narrow crescent.
• first quarter - state when half of the moon is illuminated (state 3 in the figure)
• full moon - a state when the entire Moon is illuminated (state 5 in the figure)
• last quarter - state when half of the moon is illuminated again (state 7 in the figure)

To distinguish the first quarter from the last, someone in the northern hemisphere can use the following mnemonic rule. If the month looks like the letter “C”, then it is Aging, that is, it is the last quarter. If it is turned in the opposite direction and then, mentally placing a stick on it, you can get the letter “R”, then the month is “Growing”, that is, this is the first quarter.

The waxing month is usually observed in the evening, and the aging month in the morning.

It should be noted that near the equator the month is always visible “lying on its side”, and this method is not suitable for determining the phase, and in the southern hemisphere the phases of the moon occur in the reverse order.

Links

• lunar calendar with moon waxing phase, setting and lunar eclipse for more than 1200 cities around the world (English)

Moon
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Lunar surface	Selenography Visible side Far side Sea Impact crater Basin South Pole - Aitken Shackleton Ice Peak of eternal light Space weather Short-term lunar phenomena
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See also: Solar system Satellites of planets ((AMS Lunar Research))

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See what “Moon phases” are in other dictionaries:

Moon phases ... Wikipedia

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Consecutive changes during the month in the visible shape of the Moon, depending on its position in relation to the Sun and Earth ... Big Encyclopedic Dictionary

Sevastopolsky Avenue in Moscow just after sunset. In the distance you can see the thin crescent of the new moon, which points its curved side to the Sun, which has already disappeared behind the horizon. In a short time, it will also go below the horizon... Wikipedia

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>What are the phases of the moon?

Moon phases– change in the level of illumination of the Earth satellite. Description of the new moon, waxing and waning moon, full moon with photos of solar and lunar eclipses.

From Earth you can watch the Moon go through a series of phases. Of course, it's all about the incidence of the sun's rays. The satellite orbits the Earth, which revolves around the Sun. We see only part of the Moon, but one half of it is always illuminated. The orbital path takes 27.3 days.

During the lunar phases, we encounter the Waxing Moon - the brightness increases and the Waning Moon - the brightness decreases. Let's take a closer look at the phases of the moon.

• – the illuminated side is located away from us. The satellite and star line up along one side, so we see the hidden half. At this moment, you can observe a solar eclipse if the Moon passes in front of the star and casts a shadow on the earth's surface.
• Crescent– the first observed arc. For the northern hemisphere, the light edge will be located on the right.
• The first quarter is half illuminated. That is, the satellite and star form a 90-degree angle with respect to us.
• – more than half is illuminated, but not yet full.
• – maximum brightness. We see that the satellite is fully illuminated and can guarantee lunar eclipses.
• – a little more than half is illuminated, but the radiance is falling.
• Last quarter– half is illuminated, but already the opposite side.
• Crescent– completion of the lunar cycle.

If you live in the southern hemisphere, the satellite begins to be illuminated from the left. Interestingly, the alignment of the Sun, Earth and Moon results in amazing phenomena.

If we encounter a full moon passing through the earth's shadow, then this is a lunar eclipse. The satellite is darker and filled with a bloody glow. If this is a new moon between a planet and a star, then we have a solar eclipse.

It seems like we should be seeing these amazing phenomena every month, but that's not true. The lunar orbit is tilted relative to the sun, so most of the time the satellite is located above or below the star. In the bottom photo you can study the phases of Venus.

Surprisingly, Venus also goes through phases. If the planet is located on the other side of the star, then we are observing an almost complete disk. If she is on our side, then a thin crescent appears. On our website you can always find out the phases of the Moon today or use a special lunar calendar, where the phases of the satellite are scheduled for the whole year.