The moon is an opaque star, without its own light, that revolves around the earth and accompanies it on its path around the sun. That is why it is said to be its only natural satellite. This satellite lacks water and atmosphere. Because of its size, 49 times smaller than the earth, it exerts a much smaller attraction on the bodies on its surface; that is, there is less gravity. An astronaut who weighs 60 kilos on earth would only weigh 10 on the moon.
What is the moon
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This star is one of the largest satellites in the entire Solar System, it has a diameter of 3,476 km, and an average distance from the earth of 382,171 km. Its formation is rocky, it does not have rings or other bodies trapped in its orbit.
Scientists believe that the origin of its formation dates back to about 4.5 million years ago, when a body traveling through space of similar dimensions to those of the planet Mars collided with the Earth, which expelled millions of debris, from which the moon was formed. After that (about a hundred million years) the magma would melt, thus forming the lunar crust.
The moon is trapped in the gravitational field of the earth, directly affecting some natural phenomena of the same, or causing them, as in the case of tides. Also this satellite helps to moderate the movement of the planet on its axis, giving stability to the world's climate.
Characteristics of the Moon
This natural and unique satellite of planet earth is characterized by:
- Have a mass of 7.35 x 1022 kilograms.
- Its volume is about 2.2 x 1010 cubic kilometers.
- It has a density of 3.34 g / cm3.
- Its diameter is 3,476 kilometers, which represents a quarter of the earth's diameter.
- Temperatures on the lunar surface range between -233 and 123 degrees Celsius, depending on your exposure to the Sun.
- The structure of the Moon is solid, rocky and has craters on its surface, caused by the collision of meteorites that occurred millions of years ago.
- It has practically no atmosphere, and that is why it has no natural protection against meteorites and asteroids. The craters formed in it have remained intact, as there are no forces such as wind and rain to modify its structure.
- The only atmospheric activity is small winds that cause dust storms, product of the impacts.
It has inactive volcanoes for millions of years, since in the past it had an ocean of magma, which disappeared and the Moon today has remains of water ice, dust and rocks on its surface.
- Orbit at a distance from the earth of about 384,400 kilometers, in which 30 planets earth would fit. There are testimonies that this star and the earth were closer in the past and move apart at the rate of a few centimeters per year; so it is presumed that about 17 billion years ago they must have been in contact.
Movements of the Moon
This satellite, like the earth, performs two movements:
Translation movement
This movement allows this satellite to rotate around the earth in a space of approximately one month, so it makes the moon move in our sky about 12 degrees per day. This means that if the earth did not rotate, we would see this satellite in the sky for two weeks, disappearing for two more weeks, since it would be seen on the other side of the planet.
Because of this fact, until recent times it had not been possible to observe or investigate its “hidden face”. Today we know it from the photographs taken by astronauts, the first time that the dark side of the moon was shown to the world in October 1959.
Its elliptical orbit produces the points of perigee (shortest distance between the moon and Earth, 365,500 kilometers) and apogee (greater distance between them, 406,700 kilometers).
Rotatory motion
the moon performs the rotation movement on itself, and whose period lasts 27 days, 7 hours, 43 minutes and 11 seconds, coinciding with the translation around the earth, so it always presents the same face to our planet. This period of time is called the sidereal month.
Moon phases
The light with which we see the lunar star shine is a part of that which comes from the sun, reflected on its surface. As the moon moves around the earth, its relationship with the movements of the same, and the movements of this around the sun, the areas of the moon illuminated by the sun are changing, these changes of lighting that it presents are known as phases.
New Moon
Also known as novilunio or interlunio, it is when the star is between the earth and the sun, so that the illuminated hemisphere or “face” cannot be made visible from the earth, giving the illusion of “no moon”. This stage marks the first moon phase and its visibility can range from 0 to 2%.
This is one of the phases during which the tides are at their highest and lowest. This phase is also called the "visible" new moon.
If in this phase there is an alignment of the moon and the earth with the sun, a lunar or solar eclipse will occur, although it is important to mention that not always when a new moon is generated there will be an eclipse, but if one arises, then it must exist a new moon. In a lunar eclipse, according to the incidence of sunlight on the moon affected by the earth's atmosphere, reddish colors may be projected on the surface of the satellite in a phenomenon known as a blood moon or red moon.
Crescent moon
It is the phase in which the satellite begins to be seen in the sky 3 to 4 days after the new moon, and this phase is considered to last from 3 to 34% of the surface of the star. From the earth.
This phase can be easily seen after sunset, being observed in the northern hemisphere of the earth on the right side and in the southern hemisphere on the left side.
Crescent quarter
This phase is characterized in that half of the lunar disk is visualized when it is illuminated by the sun, and can be observed after noon until midnight, distinguishing between 35 and 65% of its surface.
Crescent gibbous moon
During this phase, more than half of the lunar surface can be seen, approximately three-quarters of it, with a viewing percentage of between 66 to 96%. The time when it can be observed is before sunrise.
full moon
Or full moon, is the phase where the surface of the satellite can be completely observed, since it presents 100% of its illuminated face. At this time, the earth, the moon and the sun are almost completely aligned, as in the new moon phase, with the difference that it is 180º from its initial place in the first phase.
It can be seen from sunset to sunrise, and the visibility percentage is 97 to 100%. During this cycle and that of the new moon, the phenomenon called Supermoon can be generated, which is when one of these two phases coincides with the perigee.
Waning gibbous moon
Similar to the crescent gibbous phase, since its observation ranges from 96 to 65% of the surface, only this time, the percentage of illumination is gradually decreasing.
The appearance of light and shadow will look opposite to the rising phases; that is, in its decreasing phases the illuminated side is observed in the northern hemisphere to the left and in the southern hemisphere to the right.
Last quarter
It is the opposite phase to that of the crescent quarter, because despite looking similar in appearance due to the percentage of visualization (from 65 to 35%), that is, a half moon is observed, and its illuminated side is the opposite of the fourth growing. It can be viewed from midnight until sunrise.
waning moon
This phase, also known as the waning crescent, corresponds to the final phase of the lunar cycle, in which the last days of viewing the lunar star in the sky are observed. Its visualization percentage is between 34 and 3%, and at the end of the period the period is concluded, starting the next one, with the new moon, repeating the cycle.
Black moon
This term can refer to three ideas or concepts.
1) It is related to the presence of two phases of the new moon within the same month of the Gregorian calendar.
2) The absence of a full moon phase in the same period.
3) The exact 180º alignment between the earth, the lunar star and the sun during the new moon phase, with a total absence of the visibility of its surface, and in this sense, it is also called the astronomical moon. This phase occurs right at the midpoint of the new moon, when the satellite and the sun are in exact union.
blue Moon
This phenomenon is the opposite of the black or astronomical moon, since it is the presence of two phases of the full moon in the same month of the Gregorian calendar, which takes place approximately every 2.5 years and, originally, at the third full moon when in a season of the year there are four full moons instead of three.
The fact that it is possible that there are two full moon phases in the same month is due to the fact that the lunar cycle is fulfilled every 29.5 days, so if the full moon occurs on the first or second day of that month, there are great chances of a second appearing in recent days.
Their terminology does not mean that the satellite is stained with some variation of indigo; however, according to certain atmospheric conditions, it is likely that it could appear slightly bluish.
Moon's calendar
It is the way in which the years are projected according to the cycles of the satellite. In the lunar almanac, the periods where the star is in exactly the same phase are shown, whether it is waning or waxing. These periods are grouped in what is known as the lunar month.
Since time immemorial, man has had observation of this satellite, around which innumerable stories and myths have originated about its presence, its symbolism or its influence on the daily activities of the human being, and even on spiritual phenomena.
These beliefs range from simple to more complex topics. It is said to influence hair growth and care; or that it influences mental health as erratic behaviors are allegedly developed during the full moon phase (hence the term "lunatic"); It is also said that if it is cultivated in the full moon phase, the crops will grow more rapidly; or that due to the coincidence of the duration of the lunar periods with the menstrual cycle of the woman, it influences the fertility of the same and the ideal moment to give birth.
Although it is true that it affects animal behavior in the full phase, due to the greater presence of moonlight, it has not been proven to influence the howls of wolves. Nor is it true that it has a dark side, since the side not visible from the earth spends the same time illuminated as the face that can be seen from here.
One of the most curious beliefs supported by astrology is the influence of the lunar phases on man, and his decision to marry. Astrology says that getting married during the full moon represents a good omen (prosperity and abundance); and the crescent would be the second option to do it according to this belief ("everything grows and develops").
Although they are not scientifically proven facts, they are beliefs that have endured over time. In case you plan to get married soon, make a radical change of look or undertake a project and your beliefs extend beyond what science can explain, take note of the following lunar calendar.
Arrival of the first man on the Moon
The first man to step on this satellite was the American astronaut Neil Armstrong in 1969. Since then, scientific research on this star has not stopped. The existence of life has not been found, nor has fossils or evidence of life in previous stages been found, but the existence of seismic and volcanic activity has been found.
The vehicle that made this trip possible was the Apollo XI, in which Armstrong traveled with pilots Michael Collins and Edwin “Buzz” Aldrin. This amazing journey began on July 16, 1969, during the administration of United States President John F. Kennedy. Four days later, on July 20, Commander Armstrong would become the first man to set foot on the Moon; observed before the astonished gaze of millions of people around the world through a television broadcast.
In this two-hour expedition, the crew members carried out activities on the lunar surface for which they were entrusted, such as taking samples, photographs, the installation of a device to measure the distance between the Earth and the Moon, a seismograph to measure the telluric movements of the lunar surface and another device for measuring the solar wind.
This trip has generated controversy over the years, as there is a current of skepticism that denies that this has been possible. At the time, there was strong competition from the United States with the USSR in terms of achievements in the space field (space race), a dispute that lasted from 1955 to 1975.
Moon Images
In ancient times thanks to direct observation or telescopes, expert observers managed to immortalize the satellite with a Moon drawing or lunar map; However, with the passing of the years and with technological advances, the quality of images collected from the natural satellite has been increased, so it has been possible to have a better observation. Here are some iconic images of the natural satellite.
