When the Moon orbits our planet, it always turns the same face towards us, but in reality it has a different one that seems hidden from us: the reason for this phenomenon is that it rotation period (i.e. the time it takes the moon to complete one revolution around itself) is equal to its own orbital period (i.e. the time it takes for the Earth to make one complete revolution), an effect called synchronous rotationcommon to many natural satellites of the solar system.
In this article we will discover that “hidden face” of the moon to tell what phases it was in Explorationwhat was just beginning 1959.
What's on the other side of the moon?
THE first photos Images were taken of the lunar surface opposite the Earth's direction October 7, 1959 from the Soviet investigation Moon-3. Launched from the cosmodrome Baikonur In KazakhstanThe probe was the first to fly over the far side of the moon. The images sent to Earth are obviously of very poor quality compared to the ones we have today, but they represent that the first time in which people saw the face of “hidden side” of the moonalthough it is the closest object astronomically to our planet.
The photos of Moon 3 (and later other lunar probes that observed the “far side” of the moon) showed us a surface at the same time very similar but also very different of the face we knew. There Surface of the “hidden side” it was actually similar to that of trays of the familiar face, covered with Dust which appeared in clear tone when illuminated by the light of the sun, and were marked with numerous dots crater, big and small; However, the surface was almost complete free of dark areasthe “seas” of basalt rock that characterize the face of the moon that we have always known.
The most notable feature of the Moon's “far side” is actually a large area that is barely visible to visual observation and is known as known South Pole-Aitken Basina huge depression 2,500 km wide (about the size of Western Europe) and up to 6000 meters on the southern hemisphere of the lunar surface relative to the Earth: it is a gigantic meteorite crater, the largest impact mark on the Moon and one of the largest in the solar system. Because it is a large area with poorly defined boundaries, it is difficult to observe in photographs, but it appears immediately on elevation maps of the lunar surface.
Because the two faces of the moon are different
There Explanation is probably a combination of several factors, such as: chemical composition and that Thickness of the lunar crust in the two hemispheres: This geological difference has led to a different behavior of the side closest to the Earth, exposing it to a greater number of influences magmatic outcropscreated directly on meAsteroid impact on its surface or due to intense volcanic episodes triggered by impacts on the opposite side. These are the two largest seas on the “far side” of the moon Moscow Sea and that Sea of ingenuitybut together they form it less than 3% from the surface of the far side of the moon; For comparison: the lunar seas, which can be observed from Earth more than 30 % the facial surface closest to our planet.
Consists mainly of trays olderThe “far side” of the moon is also richer than Impact craters. This is probably the best known Jackson crater (dedicated to the Scottish astronomer John Jackson), characterized by a wide Radiation system which come from the impact site and consist of brighter material thrown up by the crash of the asteroid that triggered the event.
A curiosity: There is no “hidden side” of the moon
Contrary to what we often hear, There is no “dark side” on the moon.
Or rather, like all objects in the solar system, the moon receives light from it Sun, which illuminates half of it and leaves the other half in darkness. But this “half dark” it's not always the same: change depending on which side the moon faces the sun (just like the sun does). Earthon their surface for the same reason Day and that Night). From the combination between position of the moon in relation to the earth and the Direction We observe where the sun's light comes from Moon phases: New moon, waxing moon, full moon, waning moon, then new moon again.
The idea of a “dark side” of the moon also found its way into popular culture through the title of the album “The dark side of the moon” of Pink FloydPublished in 1973 with the famous Ceiling Black with the prism that splits a beam of light into seven colors of the iris.
