A study led by Prof. Oded Aharonson from the Weizmann Institute examined the question in the information sent by the LRO spacecraft
When we look to the sky, we encounter the familiar and kind look of the "man in the moon", who faithfully accompanies us. The strange coordination of the moon's movement, that is, the fact that the duration of its rotation around its axis is the same as the time it takes to circle the earth, means that the side facing the earth is constant - so that the eyes of the man on the moon are always fixed on us. Is there a reason why the moon always faces us, or is it just a coincidence that it doesn't turn its back?
In a study that included simulations and detailed analyses, Prof. Oded Aharonson from the Center for Planetary Sciences at the Weizmann Institute of Science, Prof. Peter Goldreich from the California Institute of Technology (where Prof. Aharonson initiated the current research), and Prof. Ram Seri from the Hebrew University of Jerusalem showed that the surface of the Moon - i.e. Its geophysical properties are what determine its direction in relation to the Earth. The findings of the study, supported by NASA's Lunar Reconnaissance Satellite (LRO), were recently published in the journal Icarus.
The geophysical shape of the moon is not symmetrical: the surface on its near side is covered with deep craters, in which is compressed and dark volcanic material - and they form the "human face". On the far side of the moon, however, high mountains rise. "Intuitively, we would expect that the far side of the moon - where there are mountains - would face us, and not the side where there are deep craters. In this situation, the surface of the moon was closer to the earth, and thus the energy level of the entire system is lower," says Prof. Aaronson. Nature usually prefers situations where the energy is lower. Why is this case different?
The movement of the moon can be compared to a toy train, which moves along a circular path with two hills and two valleys. The hills and valleys represent different energy levels of the directions in which the moon can be found. Because of the friction of the wheels on the track, the train gradually loses energy, to the point where it cannot climb up the hill, and gets stuck in a valley. The choice of one of the two valleys depends mainly on the height of the last hill crossed (and not on the depth of the valleys). That is, it is the maximum energy levels (the "hills") that determine the final state of the moon - and not the minimum energies (the "valleys"). Prof. Aaronson: "People are surprised by the fact that the moon always faces us, but we are also surprised by the great elegance of the principles according to which the system operates."
The energy levels calculated by the scientists for the current characteristics of the moon's surface show that there is a preference for its stabilization in the current direction. "Through changes in the model we planned - such as changes in the distribution of the moon's mass, or in other parameters related to its internal properties - we were able to control the selection of the 'valley' where the moon will be located," says Prof. Aaronson.
The moon's geophysical properties have undergone significant changes since its early days, so it is possible that in the past its direction preference was different. Various evidence points to the possibility that in the past the moon did turn its other side towards us, but at some point the system began to spin as a result of a huge impact of some object on the moon, and then stabilized and relocked in its current state - in the manner described in this study.
16 תגובות
Rami K
Your explanation is simple and clear and...
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Completely wrong
Rami K
But in the article it is stated that the moon does rotate around its axis..
Simple and clear explanation
In the past the moon was hot "and liquid" its heavy parts such as iron sank inward and toward the Earth and thus the moon cooled
In an asymmetrical way when the center of gravity - our body is close to the Earth, in this situation the Moon is gravitationally locked to us and cannot rotate around its axis, those around the Earth which is its axis,
And so the heavy side of the moon that faces us is steeped in ancient volcanic influences - the dark spots,
Therefore, a satellite orbiting the moon will approach it on its gravitationally heavy side.
lol the man on the moon?? In the way they found a face there, I can also find the Taj Mahal
point:
It really is.
What is important is the probability that two numbers drawn at random (the angular velocity of the moon's rotation around its axis and the angular velocity of its orbit around the Earth) will be the same.
The chance is zero.
This implies the existence of a law of nature that causes the phenomenon and indeed - such a law exists.
This condition of facing a fixed side towards the encircled star is characteristic of many moons in the solar system.
You can read the explanation of the phenomenon here:
http://en.wikipedia.org/wiki/Tidal_locking
Grace:
The parts of the moon that the sunlight does not reach are very small - these are only valleys located in the regions of its poles.
The rest of the moon's surface is lit and darkened by suits.
From the article it can be understood that in the past the moon did not rotate in a coordinated manner with the earth, is this really so?
For those who don't see "The Man on the Moon":
http://en.wikipedia.org/wiki/Man_in_the_Moon
(I still don't see. Precisely what the man that Chen mentioned seems much clearer).
to my parents
I think the moon is the head itself, and the two craters on the right are the eyes.
I must point out that with a simple home telescope, the observation of the moon is simply amazing! You can see the craters in an exceptional way!
As someone who was in a solar eclipse, the temperature does drop by a few degrees at the point where the eclipse passes, roughly like the transition from noon to afternoon or evening.
Am I the only one who doesn't see a face in the picture?
small question
Why doesn't the Earth's temperature drop in the middle of a solar eclipse?
Nicholas
Yes, that's exactly why something doesn't work out.
After all, I remember that there is a large part of the moon that sunlight does not reach, and therefore it is in constant darkness..
Hen, the whole moon goes through a rotation cycle around the earth, so different parts of it are illuminated at different times.
The same side of the moon faces the center of its rotation (Earth), but the part facing the sun changes.
This is the opportunity to thank Prof. Oded Aharonson for his instructive lecture given on this topic at the 59th annual conference of the Israel Astronomical Society about two months ago.
one moment
If the moon rotates on its axis, how can it be that a large part of the moon is in constant darkness?
interesting !