Moon Libration examples

Inmykombi (Geoff) · #1 22-06-2009, 07:29 PM

Hi all,

I have taken so many Moon images over the last year, I am still organising them all.
I came across these two of almost the same phase illumination and some Libration is noticeable.
5 months apart between these two images.

I also checked out this we-site that shows images and predicted phases and libration for 2009.

http://au.video.search.yahoo.com/vid...=0001498168713

Hope you like 'em.

Geoffro.]

RB (Andrew) · #2 22-06-2009, 07:51 PM

Great shots Geoff !!
Very nice examples mate and sharp detail.

Inmykombi (Geoff) · #3 22-06-2009, 08:36 PM

Thx RB.

StephenM (Stephen) · #4 22-06-2009, 08:40 PM

That's great Geoff! I've been thinking about doing the same thing for a while, but haven't ever gotten around to it. Nice work!

Cheers,
Stephen

Inmykombi (Geoff) · #5 22-06-2009, 09:14 PM

Thx Stephen. Glad you liked 'em.

White Rabbit · #6 24-06-2009, 12:24 PM

Nice, were these taken with the exact same equipment? Or is the distance displayed between the two due to the orbit being further out on the second one?

Thanks

Quark (Trevor) · #7 24-06-2009, 04:58 PM

Well done Geoff,
Nice sharp images and a top example of libration of the Moon.
Now it would also be great to capture examples of nutation and then you have an excellent set of images to demonstrate to school kids the various motions of the Moon, that really go un-noticed by most.

Regards
Trevor

markseibold (Mark Seibold) · #8 24-06-2009, 06:53 PM

Geoff

Very nice imaging. I notice that one appears as color and the other in
B & W. I have taken many with a hand held digital over the telescope but have seen the color very greatly at times. Usually due to the height of the moon from the horizon. But also sometimes due to atmospheric smog or forest fire smoke.

Any thoughts on this?

Thanks again for any info,

Mark

Inmykombi (Geoff) · #9 24-06-2009, 10:14 PM

Quote:

Originally Posted by White Rabbit

Nice, were these taken with the exact same equipment? Or is the distance displayed between the two due to the orbit being further out on the second one?

Thanks

Hi thx for the reply.

I used the afocal method both times ( and for all my Moon images ).

If I remember correctly the eyepieces were different but the scope was the same 4.5 inch Newt, that I have used for my imaging.
I usually use an 18mm ED eyepiece but I may have also used a 20mm.
The difference in size is due to the different eyepieces and not the Earth-Moon distance.

Cheers.

Inmykombi (Geoff) · #10 24-06-2009, 10:19 PM

Quote:

Originally Posted by Quark

Well done Geoff,
Nice sharp images and a top example of libration of the Moon.
Now it would also be great to capture examples of nutation and then you have an excellent set of images to demonstrate to school kids the various motions of the Moon, that really go un-noticed by most.

Regards
Trevor

Thx for the comments Trevor,

I'll show my ignorance here and ask you to explain "Nutation" please.
I couldn't find it in the Glossary.

Cheers Geoffro

Inmykombi (Geoff) · #11 24-06-2009, 10:27 PM

Quote:

Originally Posted by markseibold

Geoff

Very nice imaging. I notice that one appears as color and the other in
B & W. I have taken many with a hand held digital over the telescope but have seen the color very greatly at times. Usually due to the height of the moon from the horizon. But also sometimes due to atmospheric smog or forest fire smoke.

Any thoughts on this?

Thanks again for any info,

Mark

Hi Mark.

When I do some very minor processing on my Moon images, I usually try and reduce the colour to almost , but not quite black and white.

These images were also aken months apart and one may have been taken through light cloud as I sometimes do.
They both were taken in the early evening and with slightly differing camera settings.

I didnt process them before posting them...hence the slight difference in contrast and colour.

Bothe Afocal though with the same 4.5 inch Meade Newt.

Geoffro.

Quark (Trevor) · #12 25-06-2009, 11:39 AM

Quote:

Originally Posted by Inmykombie

Thx for the comments Trevor,

I'll show my ignorance here and ask you to explain "Nutation" please.
I couldn't find it in the Glossary.

Cheers Geoffro

Hi Geoff,

As the Moon rotates on it's axis it exhibits small apparent oscillations or libration, your images clearly demonstrate this effect.

Nutation is an apparent slight nodding in the axis of rotation.
Tidal forces exerted by the Moon on the Earth cause the Earth to Nutate.

As the Moon orbits the Earth it experiences a variation in the inclination of it's orbit, relative to the ecliptic, of between 5 degrees and 5 degrees 18 minutes with a period of 173 days. This results in a slight apparent nodding motion of the Moons rotational axis relative to Earth, similar to nutation.

This would thus provide you with the potential to image slightly different regions near the poles.

Regards
Trevor

Inmykombi (Geoff) · #13 25-06-2009, 07:50 PM

Quote:

Originally Posted by Quark

Hi Geoff,

As the Moon rotates on it's axis it exhibits small apparent oscillations or libration, your images clearly demonstrate this effect.

Nutation is an apparent slight nodding in the axis of rotation.
Tidal forces exerted by the Moon on the Earth cause the Earth to Nutate.

As the Moon orbits the Earth it experiences a variation in the inclination of it's orbit, relative to the ecliptic, of between 5 degrees and 5 degrees 18 minutes with a period of 173 days. This results in a slight apparent nodding motion of the Moons rotational axis relative to Earth, similar to nutation.

This would thus provide you with the potential to image slightly different regions near the poles.

Regards
Trevor

Thx very much for the detailed explanation.
I now know what you mean, and have seen this " nodding" in examples of libration in the past.

Cheers....and I hope the skies are clear where you are.

Geoffro.