The moon is the only natural satellite of the Earth. There are always many secrets and mysteries associated with this celestial body, and today we will talk about one of them. At school lessons, from parents, watching educational programs, we learned as a child that the Moon always faces the Earth on one side, and no matter how hard we try, we will never see the other from our planet. In this article, we will explore why this is so. What is the name of the side that we cannot see? How is it different from the other side of the moon?
Meanings of the word "terminator"
You might be wondering what the cult action movie was all about, but that's right. The word "terminator" has several meanings.
Firstly, this concept is present in the characteristics of DNA. Terminator - a sequence of DNA nucleotides that are recognized by RNA polymerase, and a signal is received to stop the synthesis of an RNA molecule and the dissociation of the transcription code.
Secondly, in electronics this concept is called an energy absorber located at the end of a long line, and its resistance is equal to the waveline resistance.
Third, the terminator is Russian military equipment (tank).
And, fourthly, the concept is used in astronomy. The terminator is the line of separation of light, which separates the illuminated from the unilluminated part of the satellite (or other celestial body). This line never has a clear border, the dark and light parts are separated by a smooth transition. The Moon's Terminator cannot be seen as it grows and ages.
Dark Side of the Moon
As mentioned above, only one hemisphere of a natural satellite is always visible from the Earth. Why is this happening? It's all about rotation: the Moon's periods of rotation around its axis and around the Earth are very similar. Both last 27 days.
However, the reverse side has been photographed many times by satellites and space stations, the first being Luna 3, which belonged to the Soviet Union. It happened in 1959, on October 7th. Landings have not yet been made on the "dark" hemisphere, but Chinese scientists claim that in 2018 their AMS will land there.
What does the Moon look like on the other side that we cannot see from Earth? The part visible to us is covered with a very large number of seas (more than 30), there are not very many craters there. There are only two seas on the other hemisphere, the rest of the surface is strewn with craters, because space debris most often crashes into it.
Conclusion
So, we found out that the Earth's natural satellite, the Moon, has two completely different hemispheres in its structure. The one thatwe see a smoother one, it has many seas and few craters, and the invisible part of the Moon is covered with many craters. The article also discusses several meanings of the word "terminator", one of which refers to astronomy.
