Why do observers on the earth always see the same side of the moon?

Question

Why do observers on the earth always see the same side of the moon?

Answer 1

My unproven hypothesis is that in ancient times the moon and the earth collided. The rock that floats on the earth in the form of continents is material left by the moon.

This hypothesis  would explain why the dark side of the moon is so rugged and why moon rocks are similar to surface earthrocks.

The result of the collision means that one half of the moon, the earth facing side, is much larger in terms of mass. The gravitational pull exerted by the earth on the moon means that the moon is tidally locked and so faces the earth as it follows its orbital path around the earth.

Answer 2

Well, i'm not sure. but probably because the moon doesn't rotate in place.

Answer 3

The earth and the moon spin as if they were connected by a large string. That's the best way I can explain it.

Answer 4

The same side of the moon always faces the Earth. The "dark side" of the moon is not actually dark — it gets cycles of day and night just like most places on Earth — it is just so named because we never see it. The "far side of the moon" is a more correct term.

The reason that one side of the moon is never visible from the Earth is because the moon spins once on its axis in precisely the same amount of time it takes to revolve around the Earth. If its rate of rotation were slightly different than its rate of revolution, we would eventually be exposed to the entire surface of the moon. However, these two intervals have been equal for all of recorded history, and probably for millions of years or longer.

Answer 5

the moon rotates on its axis at the same speed that it orbits the Earth. It takes about 28 days for the moon to go around the Earth, and it takes the same amount of time for the moon to spin around on its axis one time. So as the moon moves around the Earth, it is also spinning to keep the same side always facing the Earth.

Answer 6

the moon doesn't spin on an axis like the earth does...i do believe that would be it.

Answer 7

Because read those squiggly lines written on the moon..God wanna show it's people something about someone really special because of who he created this Universe for. Note that the scripture written on the moon that we see from earth is in Arabic. The name is Ali in arabic.

Prophet Mohammad pbuh said "I'm like the Sun and Ali is like the Moon."

See the proof for yourself ;)

Answer 8

the moons rotation is different from earths its slower and the earths is faster so it appears to always face the earth the same way all the time you see it

Answer 9

PROBLEY BECAUSE THE THIS IS THE ONLY SIDE IT FACES US.

Answer 10

WOW

I wasn't going to answer this until I saw that 9 out of 10 answers were wrong.

The moon rotates at a rate of once per orbit, so the same side is always facing earth. This is called a tidal lock (I think). It turns out the small forces of the tide are enough to keep the moon locked into that rotation period.

Answer 11

well they do not. but however there is nothing up there. the moon is well... the moon a huge chunk of white rock that looks beautiful at nite

Answer 12

The Moon is in synchronous rotation, meaning that it keeps nearly the same face turned towards the Earth at all times. Early in the Moon's history, its rotation slowed and became locked in this configuration as a result of frictional effects associated with tidal deformations caused by the Earth.

Long ago when the Moon spun much faster, its tidal bulge preceded the Earth-Moon line because it could not "snap back" its bulges quickly enough to keep its bulges in line with Earth.The rotation swept the bulge beyond the Earth-Moon line. This out-of-line bulge caused a torque, slowing the Moon spin, like a wrench tightening a nut. When the Moon's spin slowed enough to match its orbital rate, then the bulge always faced Earth, the bulge was in line with Earth, and the torque disappeared. That is why the Moon rotates at the same rate as it orbits and we always see the same side of the Moon.

Small variations (libration) in the angle from which the Moon is seen allow about 59% of its surface to be seen from the earth (but only half at any instant).

The side of the Moon that faces Earth is called the near side, and the opposite side the far side. The far side is often inaccurately called the "dark side," but in fact, it is illuminated exactly as often as the near side: once per lunar day, during the new moon phase we observe on Earth when the near side is dark. The far side of the Moon was first photographed by the Soviet probe Luna 3 in 1959. One distinguishing feature of the far side is its almost complete lack of maria.

Answer 13

because the moon rotates in a way that the same face always faces the earth as it orbits. Its surprising really.

Answer 14

because the moon stays in the same path orbiting with the earth...the earth rotates the moon does not

Answer 15

The Moon is said to be "tidally locked" with the Earth.  In other words, the tidal effects exerted on the Moon by the Earth's gravity keep the same face constantly facing the Earth. (To be fair, it does wobble just a bit, but that effect is hardly noticeable).

Here's how it works:  The Moon is held in orbit around the Earth by the Earth's gravity, but the force of gravity drops off with the square of distance.  So the "near" side of the Moon is more strongly attracted to the Earth than the "far" side.  This differential gravitational attraction causes the Moon's rock to be stressed along an axis that points more or less toward the center of the Earth.

The Moon could have rotated with respect to the Earth in its earlier days, but every time it rotated its mass would have to stretch and compress.  That stretching and compressing takes energy out of the rotation of the Moon (very much like a slack bicycle tire makes it harder to ride), so the Moon's rotation would have slowed as energy was lost via heat.

The system reached equilibrium when the Moon's rotational period matched its orbital period.  When that happened, the bulk of the Moon was always stretched and compressed along the same axis, and it no longer had to be deformed in order to rotate.  That's pretty much how things are now.

I hope that helps.  Good luck!

Answer 16

Because the moons own rotation equals 30 days, which is also the time it takes to revolve around the earth.

That these two rates match up is thought to be a result of tidal drag.

Answer 17

...they don't..