 Greetings and welcome to the Astronomy Picture of the Day podcast. Today's picture for December 25th of 2023 is titled Cathedral Mountain Moon. So what do we see here? Well, here we see an alignment of three objects. And how do you get an image like this? Well, you really have to plan and set it up to get everything lined up perfectly. Now you can imagine that the cathedral in the mountain would not change a whole lot so you could move around to find the correct position that would line up the cathedral here in the foreground with the mountain behind it. What the planning involved is getting the moon in the right spot. Why is that? Well, the moon does not always rise at the same position in the sky. It changes. And I'm much like the sun. How the sun will rise farther to the north of east in the summertime and set farther to the north of west in summer. And in the winter it'll rise south of east and set south of west at least in the northern hemisphere. So just like the sun, the moon's position will change as to where it rises. So you would also have to find out exactly when the moon would be rising here and that would be something that would be much more difficult. And of course you also have to hope for good weather that day when it happens to be able to get an image like this. And it took the photographer many years to be able to get this image waiting for everything to be properly aligned and to have the perfect weather for it to be able to get the image. Now here we do see that thin crescent of a moon just rising up over the mountain here. However, the crescent there on the right-hand side is not the only part of the moon that is illuminated. That is the portion that is being directly illuminated by the sun at this time. However, the rest of the moon also is glowing. Normally you'd think that's invisible. You can't see it because it's not being directly illuminated by our sun. However, in this case, it's being illuminated by the Earth. Well, what's really happening there? Well, the Earth is reflecting sunlight to the moon which then reflects some of that light back to Earth. And that's what we call the Earth Shine or the Da Vinci Glow. And that occurs and we can see that when the moon is at a thin crescent phase. Why only at a crescent phase? Well, that is when the actual illuminated portion of the moon is small enough and not overwhelmingly bright to wash out the rest of the moon. At a higher phase of the moon, when more of the moon was directly illuminated, we would not be able to see this Da Vinci Glow even though it would still be there. So it's something that we can see but only really see when the moon is at a very thin crescent phase as it is here in the image taken just ten days ago when everything finally aligned for this photographer to be able to take this image. So that was our picture of the day for December 25th of 2023. It was titled Cathedral Mountain Moon. We'll be back again tomorrow for the next picture previewed to be Planet Web. So we'll see what that is about tomorrow. And until then, have a great day everyone and I will see you in class.