Ok, so I get that the moon orbits the Earth. But I don’t know how exactly to picture it. I mean how to understand why it appears in different areas of the sky.
Sometimes it’s right overhead, sometimes it’s off to the east. Southeast, actually.
I know it doesn’t orbit the equator or any other arbitrary path, but it’s there any way to visualize the orbit if viewed from, say, Wisconsin?
Thanks for any help
Some of the astronomical sky viewing apps use a phone’s compass and accelerometers to work out where the phone is pointing. They then render the sky on the screen showing what would be visible in the sky, as a form of simple augmented reality. What is fun is using it in the day, or, pointing at the ground, where it shows you what would be visible if the Earth were not in the way.
So, trivially you can use it to follow the moon, and even if the moon is below the horizon, it will show you where the moon is relative to you.
This isn’t quite what you asked for, but in some ways might actually be superior. In same way as it tracks the moon it will show you the position of the sun and the other planets. So you can see the nature of the ecliptic and the plane of orbits around the sun.
The app I use is SkyView. There are others, but this one does what I describe.
You can have a play with this. Use the slider at the top to show where the moon is at any time of day.
You can adjust the location or date.
Basically the moon’s orbit is very close to the ecliptic (the sun’s path). So it will appear pretty much where the sun does.
And the moon rises (and sets) 50 minutes later each day.
Um…no.
re degrees per day, it’s kinda easy. 360 degrees in a month – right around 12 degrees a day, or 24 moon-widths. (Sun and moon are about 1/2 degree in the sky.)
That means the moon moves its own width (west to east) in an hour.
You can actually watch that happen with the naked eye, when the moon occults a particularly bright star.
Get to know the Zodiac, also known as the ecliptic. That is the path of the Sun around the sky (or the path of the Earth, as seen from the Sun). The Moon’s orbit around the Earth is almost in the same plane as the ecliptic, so the Moon moves through the same constellations of the Zodiac that the sun moves through. Since it goes through 12 signs of the Zodiac in about 27 days, it takes about 2 days to get through each one. Since the moon has to get around the sky once a month, it moves a bit less than one hour per day. Thus the moon rises about 50 minutes later every day.
My advice is to take note of the Moon’s position in the stars every clear night for a full month. This will start to give you some intuition about its motion.
And do so at the same time each night when you do.
Whether the moon appears in the east, overhead or west has principally to do with the earth’s rotation, rather than the moon’s orbital motion.
Can you explain instead of giving a dismissive, “um…no”? As I understand what’s written, yeah, that seems to be true. When I was tracking the moon to figure out when to get a moonrise photo, moonrise times changed about 40-50 minutes forward from the night before, so there was only a window of one or two days when moonrise coincided with just the right lighting levels I wanted (not quite pitch black.) Is it the “50 minutes” figure that you have issue with or something else?
You know, thank you for drawing my attention back to that post. My “Um…no” was reading it as if he was saying the moon rose and set 50 minutes after the Sun did. The paragraph just didn’t parse very well to me - on second reading, he was definitely saying that moon itself rises (and sets) 50 minutes later each day than it rose (or set) the day before.
My apologies.
Does the moon have an analemma if you account for the 40 minute difference every night?
ETA: Yep
The left/right (east/west really) of an analemma is caused by orbital eccentricity. The up/down (north/south really) of an analemma is caused by the orbital plane of the body not being aligned with the Earth’s equator.
Both Moon and Sun score positive on both those counts.