Have you ever wondered why we always see the same face of the moon? It’s because our Earth rotates on its axis and takes about a month to complete this cycle. This means that as it spins, one side of the Earth is facing towards the Moon, and so we only get to see one side of it. But don’t worry, if you look closely enough at any given night sky for long enough with your eyes closed, then eventually you will be able to make out both halves!
The Earth and Moon are both rotating bodies. This means the earth is spinning on its axis, which causes day/night cycles for us here on Earth to occur as it rotates around the Sun. The moon itself has an orbital rotation around the earth that also spins in line with what we see from our vantage point on Earth. Because of these two synchronized orbits, you can oftentimes only see one face of the moon because it’s always facing towards or away from us during any given cycle!
Why do we seem to constantly be seeing essentially the same side of a celestial body? When looking at stars or planets through your telescope at night, have you ever noticed them twinkling like they were made out of solid light?
As the moon orbits Earth, we only see one side of it. And because our planet’s orbit is tilted on its axis by around 23 degrees, this means that each month we catch a different glimpse of the terrain and features on the far-side surface of the moon from where we are located (i.e., Earth).
This poetic video beautifully illustrates how seeing just half the face of any object reveals so much about what it looks like. For example, with only part of a cat visible in an alleyway you might be able to tell if they have stripes or not, but no more than that; whereas with two thirds you’ll know whether there’s white fur between their eyes as well:
In the earth’s 24 hour rotation, we see all of its faces. The moon rotates around and crosses over it in what is a 27.32-day cycle. These two factors combine to make us always see essentially the same face of the moon at any given point in time.
why do we see essentially the same face of the moon at all times?
The earth has been spinning on its axis for billions of years; this motion makes one complete revolution every 23 hours 56 minutes ˜ 86 400 seconds or 366 days per year (a sidereal year). This gives rise to our seasons because when it’s summertime where you are—or springtime or wintertime ˜ there will be another hemisphere experience
How does the moon rotate?
The rotation of the Moon is quite remarkable. The Earth’s gravitational pull on the Moon exerts a tidal force that deforms and stretches it, but leaves its orbit more or less intact. This distortion produces an elongation in both directions along which you could have two separate pieces (a so-called “double whirl”). As with most satellites orbiting larger bodies, however, this one eventually falls back into line; to compensate for these distortions, as well as perturbations from other planets whose gravity pulls on it too, it spins faster than any other major planetary object: once every 27.32 days rather than once every 29 earth days like everything else in our solar system except Mercury (who also rot
This is because we are always seeing the moon from a side that can only see one face. The Moon rotates around its axis in about 27 days, but it takes 29.53 days to rotate all the way around so that the other side faces Earth and becomes visible for us to view. This means there’s an average of four hours per day when people on Earth cannot see any part of the moon (new moons). When you take into account that our planet has rotated an additional number of times since then-whether due to daylight saving time or not-it follows that we have never seen more than half of any given lunar cycle at once!
There are two variations on this explanation: either what we’re viewing is actually just The moon rotates on its axis once every 28 days, and because it takes about a month to orbit the Earth, we always see approximately the same side of the Moon. The part of this cycle that is not complete in one day corresponds to a lunar phase called the New Moon when the Sun’s rays do not reach any point on the surface of the Moon. On average there are twelve new moons per year over short periods (less than 20 years). As each 29-day period goes by from January through December, at some point we will experience all 12 phases within less than 30 months: Full Moon → New Moon → First Quarter → Half Crescent→ Third Quarter → Gibbous Waxing/WaningMoon←→Newmoon again