Moon Phases with Grover

The podcast Extra Galactic discusses the phases of the moon in a friendly and helpful way. The moon's phases are caused by the sunlight illuminating different parts of the moon as it orbits the Earth. During the new moon phase, the side of the moon facing Earth is not getting any sunlight, so it appears dark. As the moon continues its orbit, it starts to receive sunlight and goes through phases like waxing crescent, first quarter, waxing gibbous, and finally full moon. The moon does not light up on its own, but reflects sunlight from the sun. After the full moon, the moon starts to lose sunlight and goes through phases in reverse until it becomes a new moon again. How often have you looked up at the sky on a clear night and saw a sliver of the moon, only to look up again a couple weeks later, and suddenly the entire moon is big, lit up, and shining brightly down on you? How is it that the moon is barely a sliver one night, then suddenly appears as a huge, round, shining, big chunk of rock in the sky? Does it magically shrink and later reappear? Could it be alien life forces that control the moonlight with a light switch dimmer commanded by the almighty Google? Well, my name is Alicia, and I'm the host of Extra Galactic, the newly created podcast for space-curious kids and grown-ups alike. Welcome to our first show. I am joined today by a very special guest who has been entertaining kids for decades and is known globally as the cute and furry little monster. Welcome to the show, Grover. Oh, thank you. Thank you so much. I am very happy to be here today. I am also very excited to share some old family recipes featuring the delicious bugs. Uh, well, uh, I'm... Did your agent tell you anything about our podcast? Wait a minute. This is a podcast and not the great Cooking with Bugs show? Mm-hmm. Yeah, this is the podcast Extra Galactic, where we discuss common space themes in friendly, funny, and helpful ways for kids and adults to understand. Oh, well. You had the cute, lovable, furry Grover at friendly. Well, you actually had me at space, but I, Grover, am quite helpful, too, so I will help you today. I am happy to help anyone who is in the business of both friendliness and space. Yay! I'm excited, too, and ready to dive into the first topic, which is all about the phases of the moon. I was recently asked to explain how moon phases appear to us from here on Earth, as well as why the moon appears to change shape so often. But first, to understand the different phases, we must look at how the Earth cycles between day and night. The Earth spins on its own axis as it circles, or orbits, around the sun every year. As Earth travels, spinning around the sun, it is constantly transitioning between day and night. Daytime occurs when the side of Earth that's facing the sun is getting direct rays of sunlight shining onto it. As Earth continues to spin, the part getting the sun starts to move away from the sun, causing darkness due to the lack of sunlight that's now shining on that side. This is what we call night. So, to recap, Earth is spinning on its own axis, as it orbits the sun, while the moon orbits Earth. Oh, man, that is a lot of orbiting. All that spinning is making me feel quite dizzy. Yeah, there is a lot of moving up in the universe. For those of you listening at home, if you'd like to see how they all orbit instead of trying to spin around your family members or friends, I posted the link to a great demonstration video in the show notes below. That, along with pictures I took to depict the different phases of the moon. Oh, great! That will be very helpful. So, let's dive into why we see different parts of the moon throughout the month as it rotates around Earth. The beginning of the moon's 28-day cycle starts with a phase referred to as a new moon. Okay, now close your eyes and imagine you are on the moon. You look over to the right and you see the sun. Ah, hey, sun! Then you look over to the left and you give a little wave to Earth. Hey, Earth! Now you are directly facing torn Earth with your back toward the sun, kind of like if you were laying on your stomach at the beach or pool and the heat from the sun is beating down on the entire backside of your body, while the front of your body remains untouched by the rays of sunlight. Oh, yes, I can see it now! I'm at the beach, laying on the cabana lounger. The front of my body is getting all sunlight, but... but... but my back is getting too hot! Ah, so I should flippity-floppity! Hmm... oh... Now my front is too hot! I must flip over again! Oh, man! Now my back is getting really hot again! I must flip again! Well, this is a conundrum! I could go on and on! Yeah, exactly! Well, aside from continuing to flip over and over, that is similar to what the moon experiences during the new moon phase. The moon's back is getting the sun shining on it, while the front remains dark and out of view of the sun. Earth is mostly unable to see the moon during this phase as we are facing the side of the moon that isn't getting any sunlight to reflect on it. It's also important to note that the moon, as well as all other planets in our solar system, do not light up on their own. According to space.com, the only illuminating mass within our vicinity is the sun. So even though the moon appears to be lit up, it isn't. But rather, it reflects light emitting from the sun. Ah! Very interesting! Go on! Okay. The moon is still on the go at this point, as it never stops. Again, it only has roughly 28 days to fully circle the Earth. So it's got to hustle! Shortly after the new moon, the sun rays start to make their debut on the moon again and begin to shine on a small sliver of the moon. This is the second phase of the cycle and is referred to as a waxing crescent. I have another visual to help understand. Imagine you have a protractor and Earth is the center point with the moon being the rotating arm holding the pencil, slowly gliding around the Earth from phase to phase. The position of the waxing crescent moon would be approximately a 45 degree angle from the new moon. Why is it called a waxing? I didn't think the moon has hair or that the sun would make wax. Hmm. That is a good question, Fred. Rest assured, though, the moon is not hairy and the sun does not create wax of any kind. It's referred to as waxing because during the first half of the moon's cycle, light illuminating from the sun gradually increases on the moon's surface. This is considered a waxing phase because waxing means gaining or to gain and the moon is gaining more sunlight as it continues through the first half of the cycle. The name of crescent comes from the small amount of light we see reflecting off the moon and it appears in the shape of a crescent. Now, back to our nifty-difty protractor. Ah, yes, the handy-dandy protractor. Okay, so the moon is still on the move and the light from the sun is starting to illuminate larger portions of light on the surface of the moon as it makes its way around the Earth. We'll now pause at the 90-degree mark with our protractor, which is the next phase of the moon we refer to as the first quarter. About half of the moon is illuminated by the light of the sun and appears as though the moon has been split in half. Ah! No, not the moon! The poor, cray-trailed man in the moon! How did he get split in two? Where is his other half? Does he grow back? Don't worry, Grover, the moon isn't really cut in half. There's no harm to the moon during its cycle around Earth. It only appears to be half because half of the moon still isn't getting any light from the sun. A lot of people think this phase is called a half moon because the moon looks like it's half a full. However, it's called a first quarter moon because at this point, it is a quarter through its cycle around the Earth. Now, we continue on our voyage on the moon cycle and our protractor will stop at a 145-degree angle. We are now able to see even more of the moon's surface lit up as it is being exposed to more sunlight. This phase is called a waxing gibbous. Deborah Bird, a writer for Earth Sky, explains that the waxing gibbous shows a little more light than the first moon, but less light than a full moon. So the name of this moon phase implies the moon is waxing, gaining more light, and illuminating more of the gibbous to circle around us. Well, that is an interesting name, gibbous. Who would have thought it would be named after a monkey? I can understand why that would remind you of the familiar gibbon monkey, although no monkeying around. We are now halfway through the moon cycle. At this next phase, the moon is reflecting the light straight on from the sun, covering the entire surface of the moon's side that's facing Earth. This is called a full moon. Our protractors should now be at a 180-degree angle, which is the halfway point of the moon's entire orbital cycle around Earth. This is the time when the moon's surface is fully lit up by the sun and viewable to us here on Earth. I'm going to take us back visually to the beach or pool and imagine you are laying on your back. The front of your body is reflecting light illuminated by the sun, and the backside of your body is now the dark side with no exposure to the sun. This is how a full moon appears to us. Its front part is lit up and reflecting the sun, while the other side gets no sun. If we go back to the beginning of the cycle during the first phase, the new moon was completely dark, with the surface part facing Earth and not receiving any light rays. While the moon is now halfway through the cycle, its surface is receiving all the sun rays from the sun, causing light to reflect onto that full rocky circle in the sky. Wow! I never knew the moon was so magical! It doesn't even light up on its own! I suppose it does look magical, but no magic is involved. Just good old science. The moon is now halfway through the phases cycle, but it's still fully lit up. Does it just get dark and start all over now? How do you think it gets back to the beginning of the cycle to restart as a new moon? Hmm, I believe it teleports back to the starting point in between the Earth and sun. Or maybe it runs really fast, just like Super Groover! Well, that would be super cool, but I don't think we've quite figured out how to do that yet, so I'll try to explain it from how we understand it through the lens of science. Oh, I did not think about the lens of science! Yes, go on! After the full moon, it continues moving its way counterclockwise around the Earth, and as it makes its way back toward the sun, it starts to lose some of the sun rays because of the surface becoming less exposed to the light rays from the sun. Now, our protractors are on the move again and making a quick stop at the next phase, the waning gibbous, which is now approximately 225 degrees from the beginning of the moon cycle. Waning means to lessen, and we know gibbous means a circle or round object. So what do you think the waning gibbous moon phase looks like, Groover? Uh, um, I know! Is it less light being illuminating, uh, on the moon's surface? Yes, Groover! The moon is now in the second half of the cycle known as waning, meaning the light reflecting off the moon will keep getting less as the moon starts to finish its cycle around the Earth. Uh, yeah, that's just what I just said. We'll move the protractor now to 270 degrees around the Earth from the beginning of the new moon. Does this look familiar to you, Groover? Ah, yes! The old man in the moon is only half the man in the moon! But he was not harmed in the process! The moon is not cut in half, nope! The next phase of the moon cycle is called the third quarter. Can you guess what the next phase of the moon cycle is, Groover? I'll give you a hint, though. The name is comprised of words we've already heard today, and they're already used in the cycles. Hmm, is it a waning croissant? Oh, you were so close! I will give you partial credit, though, because a croissant does resemble a crescent. The final phase of the moon cycle is called a waning crescent. As we enter the final phase of the moon cycle, the moon continues to lose the sun's light reflecting off the surface, and the sliver of illuminated light on the moon continues to get smaller. It is similar in appearance to the waxing crescent, but instead of gaining light reflection, the amount of light shining on the moon's surface decreases by about 49%. At this point, our protractor would be at the 315-degree point of our circle, and the moon's orbit around Earth, nearly complete. When it finally makes its way fully around the Earth, it will complete the moon cycle in about 27.3 days, and then start the cycle all over again as a new moon. So let's make that last pivot on our protractors and stop at the 360-degree mark, with the moon taking its place back between Earth and the sun, with one side facing Earth and the other facing the sun. Well, gosh, all that talk about moving in circles while light is beaming down sure did make me hungry. I am so thankful for the next show I will be helping on, called, uh, Cooking with Bugs. Ha ha! Those are my favorites, you know. Yeah, you've mentioned that before a time or two, Grover. So, Grover, we are almost done. We've gone over the entire moon cycle, and we're ready to do a recap. The phases listed in order are new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, third quarter, and a waning crescent turning back into a new moon. Thanks so much, everyone, for joining us on a journey into space to learn more about moon phases. I hope you enjoyed it and learned a little something. If you liked our podcast, please subscribe and share with your friends and family as we are supported by viewers like you. Thank you again for joining us, and watch out for future episodes. This is Alicia signing off from Extra Galactic. Bye! Bye, everyone! Now go eat some delicious bugs! Ho, ho, ho! Oh, wait, wait! Oh, oh, well, what is it, Grover? I forgot to tell you a really funny joke. Would you like to hear it? Oh, would I? Yes. Okay, okay. So, why is the moon always so hungry? I don't know. Why? Because it's only full once a month! Oh, yes! I love that, Grover. That was a great one. Okay, okay, I have one for you. Why is the man on the moon so fond of Darth Vader? Oh, man. I do not know why, because that man is quite creepy. Well, it's because he also has a dark side. Oh, yes, that was not too funny. Okay, we are officially signing off. Take care and stay curious. Bye!