Question re moons orbit

[Loti]

Okay not sure where to post this so please bump to the right place if needs be.

and I am sure it is a stupid question but if you don't ask ....

The moon seems to be particularly low in the sky at the moment, as the sun sets around 7:30ish it is barely visible over the hedge and then it rises slowly in a low arc to a few feet about the hedge line, I am sure I have read somewhere it has something to do with its current orbit, but can't put my finger on it exactly.

Anyone help on this one?

[Jamie]

Loti where is you location?

[Loti]

I am on the Beds/Bucks border just off J12 of the M1

[Jamie]

Hmmm.

I am in Glasgow and you have to wait till about 2am for the moon to rise to its highest point during

this lunar cycle. In this case its quite high up.

You might have to stay up a little later to see it but its worth it.

[Loti]

If its clear tonight I'll see how it looks as it gets later, if I can stay awake.

[GordonCopestake]

Loti, i find it useful to use a planetarium program like The Sky or Stellarium to see when the moon is favourable for viewing and then wake up at night to view (the missus hates me)

[OXO]

From your location the Moon is at around 40 degrees up at 1.00am Loti

[Greg]

Loti,

Here'a a Starry Night Pic for you for your location..

As you can see the moon reaches it's highest at about 0230 and is as approximatly 45 degrees in the South East.

Greg

[GazOC]

A rule of thumb is high in winter, low in summer.

[tenbyfifty]

A rule of thumb is high in winter, low in summer.

What sort cycle is the moon following ? I just had a look in Starry Night Pro and there doesn't seem to be an annual

pattern ie the moon's position on sep 15 at 2.00 am this year is not the same at the same time next year ?

How long does it take the moon to return to the same spot ? Is there a pattern to it?

[The Warthog]

The moon follows roughly the path of the ecliptic in its orbit. The ecliptic is the path 'followed' by the sun across the sky during the year. The moon is a little higher than the ecliptic in the northern part of its orbit, and a little lower in the southern part of its orbit.

The full moon is always opposite the sun, so that in summer when the sun is high in the sky, the full moon is low in the sky - very low, in fact, because it is a few degrees below the ecliptic.

During any lunation, the moon is at the low point in its orbit at some phase or other, so in summer, when the full moon is low in the sky, the crescent moons will be high in the sky, and the opposite in winter.

If the moon appears particularly low right now, it is because it is in the far southern reaches of its orbit.

This month and next month, the full moon will rise in the middle part of its orbit, and because the ecliptic is tilted at a low angle to the horizon, it will rise at about the same time for several nights in a row - the 'Harvest Moon" phenomenon. That's a little hard to understand, and you have to kinda draw yourself a picture. It took me a while to straighten that one out.

[tenbyfifty]

The moon follows roughly the path of the ecliptic in its orbit...

Thanks for that. I can see that there's a rough annual pattern but you would think there would be some kind of cycle

whereby the moon returns to the exact coords after some calculable period of time - unless there's some other variable/s

which makes this difficult to predict?

[The Warthog]

Yes, there is. The cycle is about eighteen years, but I don't know all the details of that. I'm not sure where I read that recently.

[Kaptain Klevtsov]

I noticed last night that the moon came up over the "wrong" end of our block of four houses. It usually comes over the south gable of our house. How does that happen?

Captain Chaos

[GazOC]

The Moons orbit is very complicated, it gets pulled by the Earth and the Sun.

How this affects it's position in relation to your gable end.....dunno....

[Astroman]

In addition to the ~23º inclination of the Earth's orbit around the Sun, the Moon's orbit is inclined ~5º with respect to the equator. This tilted orbit "precesses", that is it moves around the Earth in a 17 year cycle. This is why the position of eclipses moves around the Earth and why the elevation of the Moon changes with respect to CC's gable ends. During the summer, the Moon's orbit was at a low point, dipping below the ecliptic the full 5º. The orbit is now drifting, precessing further, so the angle of viewing is changing along with it. It's extremely difficult to repeat any particular Sun angled photo or observation because of the complexity of the Moon's orbital mechanics. It's one reason it's fascinated mankind since we became mankind.

[Loti]

Thanks everyone this has been a great help.

Greg, thanks for the picture helps me to see it clearer, haven't quite got the hang of the angles bit yet, but I will. Going to try installing some software tonight to help.

the 'Harvest Moon" phenomenon.

Thank-you thats what its called, I knew there was a name for it. I shall now search out more details, I've got the gist of what you are saying WH, I just need to think it over a bit. Had to chose something complex to try to get my head around.

In addition to the ~23º inclination of the Earth's orbit around the Sun, the Moon's orbit is inclined ~5º with respect to the equator. This tilted orbit "precesses", that is it moves around the Earth in a 17 year cycle.

Thanks Astroman, even though I could do with a 3D image for this one, I understand the theory but am struggling to picture. I will what I can find.