Moon and its phases
It is always fascinating to see objects that are visible in the night sky and there is hardly anyone who is not attracted towards its beauty. I always get fascinated with the objects like stars, moon etc. shinning in the night sky. As usual once I was sitting at night and was just observing bright shining objects in the night sky suddenly few children from my neighbourhood came to me. As I knew that whenever they come to me they always throw curious questions at me. This time they had questions related to Moon. One of the kid asked me can we go on moon another kid asked is there life on moon then someone asked why moon shines so much someone else asked why its shape keeps on changing and there questions were endless and were coming at me at speed of light without letting me to answer. At last I had to calm them down by saying I will answer everyone’s questions. When things got under control, I asked everyone to look up in the night sky and find the moon it wasn’t a difficult task everyone find it quite easily as Moon is the easiest thing to locate in the night sky as it is the second brightest object in the sky after sun. Moon is also called as Luna, while everyone was looking at moon I told them it is the earth’s natural satellite. Moon takes almost 28 days to rotate on its axis and almost same number of days to orbit the earth this is the reason why we always see the same side of the moon when viewed from earth, at that time someone interrupted and asked me to explain it, to explain them in a better way I used some images:
The side of the moon which is visible from the earth is called as near side and the other side is called as far side this side is never visible to us from earth because the time taken by the moon to rotate on its axis and to revolve around earth is same. So if you look at the image above you will notice only one side always faces the earth. Kids got exited after knowing this as they never knew it. Suddenly someone interrupted and asked had there any mission to moon I answered yes in the year 1969 Nasa launched first manned mission to moon and named it as” Apollo 11”and the first person to walk on the Moon was the American astronaut, Neil Armstrong. Moon is the only object in our solar system that man has landed on after our earth. This was a giant step and this mission was successful. Do you know there are various things which are different on moon as compared to earth like If you’re on the Moon you’ll feel much lighter, so here’s the place to go if you want to feel like you’re weightless you’ll weight about one sixth of your weight on Earth, suppose if your weight is 100 kg on Earth then on moon your weight will be 17 kg. Someone asked why so this is because the gravity on the moon is very less as compared to earth and there is very little gravitational force which will be acting, In fact, you can take big leaps on moon by putting very less pressure just like you can jump high on a trampoline. Isn’t it a cool place to visit. Another very astonishing fact about moon is that The Moon has no atmosphere, wind and water, because no wind blows on moon so we can still see the damage caused billions of years ago even the footprints left by the astronauts who landed on moon even there footprints will be there today as well. All the kids were very happy to know all this, I can see some are surprised can’t believe that the moon which they see is such an exciting place. A small kid asked me how far is moon from us and how much time it will take for us to reach on moon I smiled and answered him the distance from the Moon to the Earth is 3.5 lakh kilometres. However not possible but just suppose If you had to drive from the earth to the moon at a speed just over 100km/h it would take you 153 days driving non-stop 24 hours a day to reach moon. That would be quite a trip. Everyone now knew that it’s very far away from us.
Its late in the night now but no one was willing to leave I saw a very curious kid looking confused I asked him what happened, the moment I asked him he suddenly threw a very good question at me he said everything what you said is fine but one thing I can’t understand that why moon disappears for few days and why its shape keeps on changing, suddenly now everyone has the same question in their mind, to explain the reason behind it I will be introducing some new terms as well so be ready and listen carefully one thing we know that moon revolves around the earth, the earth revolves around the sun now one important question that everyone missed is why the moon shines from where the moon gets this light or is this the moons own light let me make it clear for you, it is the sun‘s light that the moon reflects and this is the reason why it shines let me show you a picture for better understanding in the image below we see how the moon is rotating around the earth and how the sunlight is falling on the moon and the earth, other thing which is noticeable is that how with the motion of the moon different areas on moon receives sunlight and this is the reason for the moon disappearing and changing shapes as well.
Lets understand it more clearly now one thing we know that the moon shines because it reflects sun’s light another thing also which we know is that the moon revolves around the earth in an orbit and because of this the angle at which the sun’s rays falling on the moon also changes so that means the amount of moon you see in the sky is actually the amount it is lit up by the sun and there is word given to this called as ‘phase’ and the different shapes are therefore known as phases of the moon. I told you I will be introducing new terms so change in shapes and sizes of the moon is known as “phases of the moon” in all there are eight phases. Before we learn about these phases let me tell you few more things, As the moon circles the Earth, we can only see a portion of the lit up side. The phases of the moon work in a cycle starting with the new moon it is a phase when we can’t see any of the lit up side in simple terms moon is between you and sun. As the New moon begins its orbit and we see more and more of the moon, this is called Waxing. When we can see 100% of the lit up side, this is a full moon. After the full moon we start to see less and less of the moon. This is called Waning (shrinking), hopefully you won’t mind the introduction of the new terms. For better understanding let me show you a picture which explains you waning and waxing phenomena.
In the above picture we can clearly see how the waning and waxing happens and now it is good time to tell you the names of the different phases of the moon
The phases of the moon starting with the New Moon are:
- New Moon(dark moon)
- Waxing Crescent
- First Quarter
- Waxing Gibbous
- Full
- Waning Gibbous
- Third Quarter
- Waning Crescent
- As you can see in the picture moon at different positions with respect to the sun and the earth because the position of the moon keeps on changing with respect to the sun, moons different parts are lit up .Now let’s understand about different phases in more detail we already know about New moon this is the phase when no side of the moon is lit up when seen from earth. In the above picture also we can notice that the part of the moon which is facing earth is dark and the far side is lit up this is the reason no moon is visible to us on earth and we called it as new moon or dark moon.As we know after the new moon, moon starts waxing means we start seeing more and more of the moon so the next phase is termed as crescent moon but it is a waxing so it is called “waxing crescent moon” let’s understand it and other phases as well;
- Waxing crescent moon: A waxing crescent moon is when the Moon looks like crescent and the crescent increases (“waxes”) in size from one day to the next.
- The first quarter moon (or a half moon) is when half of the lit portion of the Moon is visible after the waxing crescent phase.
- A waxing gibbous moon occurs when more than half of the lit portion of the Moon can be seen and the shape increases (“waxes”) in size from one day to the next. The waxing gibbous phase occurs between the first quarter and full moon phases.
- A full moon is when we can see the entire lit portion of the Moon. The full moon phase occurs when the Moon is on the opposite side of the Earth from the Sun. A lunar eclipse can only happen at full moon.
- A waning gibbous moon occurs when more than half of the lit portion of the Moon can be seen and the shape decreases (“wanes”) in size from one day to the next. The waning gibbous phase occurs between the full moon and third quarter phases.
- The last quarter moon (or a half moon) is when half of the lit portion of the Moon is visible after the waning gibbous phase.
- A waning crescent moon is when the Moon looks like the crescent and the crescent decreases (“wanes”) in size from one day to the next.
Let me show you another picture in which you will see the moon’s monthly cycle on daily bases. Also if you want to know exactly how the moon will look on particular date in particular
Now that we know almost everything about moon and after knowing that the moon orbits the earth and the earth orbits the moon do you know sometimes moon comes exactly between earth and the sun and sometimes earth comes exactly between moon and sun and these two phenomena usually happens on new moon and full moon phase. Anytime there are three bodies (the sun, the moon, or planet) in straight line such that one blocks the light from another, we call that an eclipse and there are two kinds of eclipses look the picture below:
During a solar eclipse, moon is between sun and earth, so the moon blocks the sunlight. During a lunar eclipse, Earth is between sun and the moon, so the earth blocks the sun’s light that normally lights up the moon. Since we are standing on Earth, what we see is that the moon gets dark. To make it more clear let me show you another picture which will clear out any of your doubt if there is any.
Isn’t it a great thing next time try to find out when either of the eclipse is going to happen. Well everyone seems to be very astonished and happy all the kids are now in talk with each other regarding what they learnt today but as its late in the night so I had to stop all discussions for the next time although no one was willing to leave however with the promise that we will meet again everyone left and with this my great experience with those wonderful kids came to an end, hope you might also have learnt a lot, see you again next time.
