Watch This Space

Mike Hewson
Mike Hewson
Moderator
Joined: 1 Dec 05
Posts: 6,042
Credit: 105,756,245
RAC: 52,518

This is a GIMP'ed for an oil

This is a GIMP'ed for an oil painting effect :

Cheers, Mike.

I have made this letter longer than usual because I lack the time to make it shorter. Blaise Pascal

Mike Hewson
Mike Hewson
Moderator
Joined: 1 Dec 05
Posts: 6,042
Credit: 105,756,245
RAC: 52,518

Now there is another one in

Now there is another one in nearly 6 months time - hey, an extra half circuit of the Earth around the Sun, right ? :-) :-)

If you compare the plots of the two :

.... you will note that while the Moon just recently slid through the part of Earth's shadow on the south side of the ecliptic, in October it will go through on the north side of the ecliptic.

Now if you draw a line through all the Moon's on each diagram ( as I have in red ) you will see a slight inclination of the Moon's orbital plane with respect to the ecliptic ( which is Earth's orbital plane around the Sun ). They intersect within a few Moon's widths on the left/eastern side. As the Moon subtends about 1/3rd of a degree of arc, this will be about a degree or so away on the sky. Hence these eclipses occur when the Moon is on the opposite side of the Earth from the Sun nearby the point of the intersection of it's orbital plane with Earth's orbital plane.

Hey! Maybe that's why they've called it the ecliptic ? :-) :-)

By eye the relevant angle b/w the two planes is about 5 degrees. Over long periods of time this will vary.

The Moon progresses - as always - in the sky from West to East. I saw it rising while standing upon a rotating platform going eastwards, and the Moon was moving east through the starfield also. But they were all appearing to go west ie. rising in the sky toward my local zenith ( straight above my head ). So this is roughly my view on the night :

So my 'nice ambience' shot was when the Moon was about position U3 on the diagram.

Cheers, Mike.

I have made this letter longer than usual because I lack the time to make it shorter. Blaise Pascal

Mike Hewson
Mike Hewson
Moderator
Joined: 1 Dec 05
Posts: 6,042
Credit: 105,756,245
RAC: 52,518

Of course. Optical infinity

Of course. Optical infinity is when the telephoto is out on the far stop. The camera normally auto-focuses by shifting the aperture lens back and forth ( motorised mechanical rotation of the lens barrel ). It finds the position of best focus by averaging to least blur ( least rate of change of phase at the focal plane minimum ie. Fermat's Principle Of Least Time ). But if it's already wound out maximally, it can't do the 'wind further out' part of it's algorithm. So it does nothing. No shutter movement. No exposure. No shot.

Cheers, Mike.

I have made this letter longer than usual because I lack the time to make it shorter. Blaise Pascal

MAGIC Quantum Mechanic
MAGIC Quantum M...
Joined: 18 Jan 05
Posts: 1,269
Credit: 384,967,444
RAC: 102,174

It will make another

It will make another appearance on October 8 of this year, and April 4 and September 28 of next year.

Miss those, and you'll have to wait until 2032.

I hope to have better luck in October as far as a clear sky but you never know here until that night.

And I rather not have to wait until September of next year let alone 2032!!

 

Mike Hewson
Mike Hewson
Moderator
Joined: 1 Dec 05
Posts: 6,042
Credit: 105,756,245
RAC: 52,518

RE: It will make another

Quote:

It will make another appearance on October 8 of this year, and April 4 and September 28 of next year.

Miss those, and you'll have to wait until 2032.


I might even be an old man by then .... :-)

Quote:

I hope to have better luck in October as far as a clear sky but you never know here until that night.

And I rather not have to wait until September of next year let alone 2032!!


I got my kids up from the city to watch, letting them know how infrequent it is. The last time ( in the 90's ) they were young children.

I've been thinking of how hard it would have been in ancient times to have sufficient information continuity across generations so that such long cycle patterns could be divulged. I think one can understate the difficulty of achieving that, in amongst the hurly-burly of short term societal changes ( war/famine/plague/migration .... ), and thus how hard won our celestial understandings actually are.

These objects like the Moon etc are so stable within human lifetimes and history, hence one is really looking at the same things that the ancients did.

Apropos annular solar eclipse next week : If the weather holds today I will investigate a little used observation platform with a westward aspect up a bush track I know of. Being on a mountain crest it should have a good view to the horizon, plus few people know of it ! :-)

Cheers, Mike.

I have made this letter longer than usual because I lack the time to make it shorter. Blaise Pascal

MAGIC Quantum Mechanic
MAGIC Quantum M...
Joined: 18 Jan 05
Posts: 1,269
Credit: 384,967,444
RAC: 102,174

No doubt about it

No doubt about it Mike,

Imagine just 100 years ago when things like cars and electricity in a house was only for the few.

And 150 years ago nobody had those things so you needed a clear sky and just happen to be awake to see it happen.

Yeah I will be 74 in 2032 and even now I am not out on a cold night like I used to be all the time.

But I live on the NE side of the Olympic mountains so there are many places to get a good view and even at home it is dark outside since the only lights I can see are my house lights.

I get a good open view out in the front since my lawn is 3 acres by itself so when I go out in the center none of the trees block the view of the sky.

I used to get my son out to look at the night sky and showed him a comet back when he was fairly young but now that he is in his 30's he probably doesn't remember that and I doubt he ever looks at the night sky.

I used to take 8mm videos of things like the comet and Mars and the Moon and even some meteor showers (and lightning storms) but I doubt anyone will ever watch them after I am gone.......in another 100 years .......ok that is another dream!

 

Mike Hewson
Mike Hewson
Moderator
Joined: 1 Dec 05
Posts: 6,042
Credit: 105,756,245
RAC: 52,518

Weather is even odds for

Weather is even odds for tomorrow evening. On the up side I have found a terrific viewing spot. The eclipse is not being publicised as being non-total they want to keep eye injuries down : there is no safe direct view for this one.

[ Well there is never really any safe direct viewing of the Sun, it's just that one can be fooled by degrees of occlusion. We have no inbuilt mechanism to do this always without error, and it may only take the briefest exposure to cause irreparable damage. ]

Cheers, Mike.

( edit ) Actually I've never looked directly at the Sun with any eclipse even during totality, about 20 degrees off central view is the closest I get : so that way if I get it wrong then I won't have fried my fovea - the retinal part with highest acuity.

( edit ) And you may be thinking : "I've done it plenty of times without any bother". Then there's a spot there for you, down at any eye clinic or blind institute, sitting on a bench next to others who have thought exactly the same thing.

I have made this letter longer than usual because I lack the time to make it shorter. Blaise Pascal

Mike Hewson
Mike Hewson
Moderator
Joined: 1 Dec 05
Posts: 6,042
Credit: 105,756,245
RAC: 52,518

Ghastly weather. Missed

Ghastly weather. Missed it.

Cheers, Mike.

I have made this letter longer than usual because I lack the time to make it shorter. Blaise Pascal

Mike Hewson
Mike Hewson
Moderator
Joined: 1 Dec 05
Posts: 6,042
Credit: 105,756,245
RAC: 52,518

OK, in theory this evening

OK, in theory this evening shortly after sunset I ought catch a total lunar eclipse. Right now it is overcast and drizzling ......

Cheers, Mike.

I have made this letter longer than usual because I lack the time to make it shorter. Blaise Pascal

Mike Hewson
Mike Hewson
Moderator
Joined: 1 Dec 05
Posts: 6,042
Credit: 105,756,245
RAC: 52,518

Darn, a washout. Cheers,

Darn, a washout.

Cheers, Mike.

I have made this letter longer than usual because I lack the time to make it shorter. Blaise Pascal

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.