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[quote="jdaw1"]Good diagrams showing apparent proximity of Neptune and Sun. [/qupte]Indeed, you might also not realise that Jupiter is over 2000x the diameter of Mars, or that Saturn can pass Jupiter without colliding; However, a fully to scale drawing might be somewhat less useful to the astronomer in this context.

A shame they used a factor of 2.5x for each order of apparent magnitude; if only they had used a factor of 3 for double apparent magnitude we could all have been confused about dBs instead.

Upon further thought, DNO should go further. It is the international year of the Dwarf Planet, in that spacecraft are visiting two of them. So in 2015 DNO should attempt to observe all five: Ceres; Pluto; Haumea; Makemake; and Eris. (Apparent magnitudes: 6.64 to 9.34; 13.65 to 16.3; 17.3; 16.7; 18.7. The last will be difficult. But, mercifully, you are not expected to see Dysnomia, as its apparent magnitude is ~23.1.)

DRT wrote:I have the coordinates of Haumea for midnight tonight.

Weather?

PhilW wrote:Indeed, you might also not realise that Jupiter is over 2000x the diameter of Mars

Mass rather than diameter, surely.

jdaw1 wrote:

DRT wrote:I have the coordinates of Haumea for midnight tonight.

Weather?

Not high enough in the sky for me to be able to point at it from my viewing area.

Advice from a reliable source is "for visual a mag 17.3 would require at least a 37" scope, and to make it "easy", 40" and above would be required."

At that size a primary mirror costs roughly £1,000 per inch of diameter. the tube to hold it in costs about the same again. I am unconvinced that £74,000 to £80,000 falls into the category of "a large amateur telescope".

Astro-social media is buzzing with stories of Comet LG-Parker - no sightings yet.

jdaw1 wrote:

PhilW wrote:Indeed, you might also not realise that Jupiter is over 2000x the diameter of Mars

Mass rather than diameter, surely.

20x diameter, roughly.

DRT wrote:

jdaw1 wrote:

DRT wrote:I have the coordinates of Haumea for midnight tonight.

Weather?

Not high enough in the sky for me to be able to point at it from my viewing area.

Advice from a reliable source is "for visual a mag 17.3 would require at least a 37" scope, and to make it "easy", 40" and above would be required."

At that size a primary mirror costs roughly £1,000 per inch of diameter. the tube to hold it in costs about the same again. I am unconvinced that £74,000 to £80,000 falls into the category of "a large amateur telescope".

I don't know, that seems rather large to me...

Or are you implying that if I managed to grow my Port collection by 3x that it might be considered a professional collection?

Tell me more about Comet LGTrotter.
Will it fizzle out after delighting us with its oohs, aahs, and sparkles?

djewesbury wrote:Tell me more about Comet LGTrotter.
Will it fizzle out after delighting us with its oohs, aahs, and sparkles?

Too insignificant to be seen with the naked eye, of interest only to specialists .

This evening I arrived at a star party near Hereford in my hired motor home for the first of four nights gazing at the wonders of the Universe through various bits of expensive glass.

After setting up my telescope I did what a boy alone should do - Boeuf Bourguignon with a couple of glasses of La Rioja Alta Gran Reserva 904 2001.

Off to look at Jupiter for a while then it will be Lagavulin time

DRT wrote:This evening I arrived at a star party near Hereford in my hired motor home for the first of four nights gazing at the wonders of the Universe through various bits of expensive glass.

After setting up my telescope I did what a boy alone should do - Boeuf Bourguignon with a couple of glasses of La Rioja Alta Gran Reserva 904 2001.

Off to look at Jupiter for a while then it will be Lagavulin time

What, no Port?

A moon of Jupiter received its official name only this month. Presumably your equipment is too small for a damsel seduced by the King of the Gods (whose equipment reached magnitude 23)?

jdaw1 wrote:A moon of Jupiter received its official name only this month. Presumably your equipment is too small for a damsel seduced by the King of the Gods (whose equipment reached magnitude 23)?

Alas, even at a creditable 12", my equipment is far too small for that particular damsel

Glenn E. wrote:

DRT wrote:This evening I arrived at a star party near Hereford in my hired motor home for the first of four nights gazing at the wonders of the Universe through various bits of expensive glass.

After setting up my telescope I did what a boy alone should do - Boeuf Bourguignon with a couple of glasses of La Rioja Alta Gran Reserva 904 2001.

Off to look at Jupiter for a while then it will be Lagavulin time

What, no Port?

Surely if you're in Hereford you are not there to be just gazing at the night sky. What's the forecast for Friday morning like?

AHB wrote:What's the forecast for Friday morning like?

It is looking good at the moment but the forecast seems to change every few hours.

AHB wrote:Surely if you're in Hereford you are not there to be just gazing at the night sky. What's the forecast for Friday morning like?

indeed, I'm surprised you (collectively) are that far south. I'll be in Perth; though in meetings all morning, I'm hoping to get a brief break to head outside; it's been foggy and clouded over here all day though, hoping for better on Friday.

Very sunny here today but a misty start early on.

PhilW wrote:I'll be in Perth … hoping for better on Friday.

Good luck with that.

There is a reason why I came south…

djewesbury wrote:Very sunny here today but a misty start early on.

It was lovely here today. T-shirt weather with a nice clear blue sky and a few hours looking at the prominences and surface features on the Sun through my new Hydrogen-Alpha telescope.

But now it's cloudy

On Friday I am joining a group of astro-geeks at a place called Madley to view the eclipse. I think it is an old airfield but it seemingly has a very flat horizon which means the Sun will be above any pesky hills for the whole event. There will be 150 10 to 12 year old school children there and we have all agreed to let them look through our telescopes as part of a science project they are doing. Perhaps I should have brought as few bottles of Port and a spit bucket along and I could have started their education in the finer things in life? Perhaps not.

DRT wrote:education

I am doing an astronomy talk tomorrow at my daughter’s school. Part of it will be a rant about the inaccurate mural; part will be seeing planets and moons to scale.

jdaw1 wrote:

DRT wrote:education

I am doing an astronomy talk tomorrow at my daughter’s school. Part of it will be a rant about the inaccurate mural; part will be seeing planets and moons to scale.

Please try really hard not to be Julian. Do you remember the garden? You were rewarded for that effort. Be nice, and don't scare them away from astronomy.

DRT wrote:Please try really hard not to be Julian. Do you remember the garden? You were rewarded for that effort. Be nice, and don't scare them away from astronomy.

Easy peasy lemon squeasy. Tell children that their school has got something utterly wrong, and they love it.

jdaw1 wrote:

DRT wrote:Please try really hard not to be Julian. Do you remember the garden? You were rewarded for that effort. Be nice, and don't scare them away from astronomy.

Easy peasy lemon squeasy. Tell children that their school has got something utterly wrong, and they love it.

Hmmm?

"Dear children, your teachers are idiots." — "Mummy, an old man in cream chinos and a checked shirt spoke to us at school today and told us that teachers are idiots. I'm not doing my homework tonight because my teacher is an idiot." — {999} "Which service, please?"

Perhaps a better way would be to explain why some things are shown in an easy to understand {schematic} form (such as the London Underground) but that the reality is somewhat more complex?

There is a reason why the mural (and thousands like it) are to the scale they are. It is because the human mind finds it difficult, if not impossible, to comprehend the mind-boggling distances and relative sizes involved. Knowing the maths isn't the same as comprehending, it's just knowing the maths.

Don't leave the children thinking their teachers are idiots.

Please video it and post it.


Sent from my iPhone using Tapatalk

jdaw1 wrote:

DRT wrote:Please try really hard not to be Julian. Do you remember the garden? You were rewarded for that effort. Be nice, and don't scare them away from astronomy.

Easy peasy lemon squeasy. Tell children that their school has got something utterly wrong, and they love it.

[tears] "Mummy, the teacher brought a strange man into the class today and he said the space picture I helped to paint is all wrong!" [more tears]

Please, Julian, be really, really Julian. I want to hear about this on the BBC.

The teacher in attendance said that it was excellent. The children seemed to enjoy it and comprehend it — ‘it’ being such minor ephemera as Jupiter being more than 4 Jupiter diameters from the sun. They seemed to get it. A win for everybody.

And one pupil asked several really excellent questions. Such as “How did the rings of Saturn form?”.

Though the Deputy Headmistress did ask me not to describe the mural as “rubbish”.

Yes, I realise that there are constraints about what can be painted on a wall. But there’s also ignorant rubbish. Neptune is not smaller than the Earth. Saturn has one large moon, not four. The planets can hint at being smaller than the distances between them. Asteroids are much smaller than the Earth’s moon. Etc. There are even dynamical errors that can be avoided: must all of the Galilean moons be shown on the same side of Jupiter?

jdaw1 wrote:must all of the Galilean moons be shown on the same side of Jupiter?

And you refrained from calling it rubbish?

djewesbury wrote:And you refrained from calling it rubbish?

No.

jdaw1 wrote:

djewesbury wrote:And you refrained from calling it rubbish?

No.

I see. The Deputy Head's imprecation arrived too late to stop you doing what you had already done. Good work.

jdaw1 wrote:There are even dynamical errors that can be avoided: must all of the Galilean moons be shown on the same side of Jupiter?

That isn't an error. They often are all on the same side.

DRT wrote:There will be 150 10 to 12 year old school children there and we have all agreed to let them look through our telescopes as part of a science project they are doing. Perhaps I should have brought as few bottles of Port and a spit bucket along and I could have started their education in the finer things in life? Perhaps not.

"Middle-aged man in caravan offers 11 year olds alcohol and a spit bucket."
I think not.

DRT wrote:They often are all on the same side.

Observe that when Ganymede and Europa are together (in conjunction as seen from Jupiter), Io is the opposite side of Jupiter.

Compare and contrast with


But good job about having four moons of Jupiter.

Probably best not to start talking about Ganymede in a thread where Derek has announced his intention to welcome 11-year-olds into his caravan and give them port.
Move along please.

jdaw1 wrote:Observe that when Ganymede and Europa are together (in conjunction as seen from Jupiter), Io is the opposite side of Jupiter.

But if Jupiter was being observed from a point at either four or ten o'clock in this image the three moons would be on the same side of a two dimensional image. It happens frequently, and also with the fourth moon.

djewesbury wrote:Probably best not to start talking about Ganymede in a thread where Derek has announced his intention to welcome 11-year-olds into his caravan and give them port.
Move along please.

Behave yourself. I am inclined to seek a Jeremy Clarkson style retraction of that outrageous slur on my good name.

DRT wrote:

djewesbury wrote:Probably best not to start talking about Ganymede in a thread where Derek has announced his intention to welcome 11-year-olds into his caravan and give them port.
Move along please.

Behave yourself. I am inclined to seek a Jeremy Clarkson style retraction of that outrageous slur on my good name.

Sorry. I forgot the spit bucket.

DRT wrote:But if Jupiter was being observed from a point at either four or ten o'clock in this image the three moons would be on the same side of a two dimensional image. It happens frequently, and also with the fourth moon.

I fold.

The following single frame, as seen by an observer on our left, would see all three moons on the same side.

Eclipse forecast, south London:

Same here.

DRT wrote:

jdaw1 wrote:Observe that when Ganymede and Europa are together (in conjunction as seen from Jupiter), Io is the opposite side of Jupiter.

But if Jupiter was being observed from a point at either four or ten o'clock in this image the three moons would be on the same side of a two dimensional image. It happens frequently, and also with the fourth moon.

I just realised I forgot to post the image. Here it is...
And this will happen in just a few hours from now...

I took this out of focus picture with my iPhone through my new H-alpha telescope this afternoon...
The prominences on the top right are each around 30,000 miles high. The detached prominence seems to be quite a rare sight and lots of people were talking about it here today.

If I can get a picture similar to this during the eclipse I will be very pleased

DRT wrote:I took this out of focus picture with my iPhone through my new H-alpha telescope this afternoon...

2015-03-19 13.47.57.jpg

The prominences on the top right are each around 30,000 miles high. The detached prominence seems to be quite a rare sight and lots of people were talking about it here today.

If I can get a picture similar to this during the eclipse I will be very pleased

But I don't see where the Galilean moons are in this lovely picture of Jupiter that Julian painted on a school wall

AHB wrote:But I don't see where the Galilean moons are in this lovely picture of Jupiter that Julian painted on a school wall

That's because they are behind the Sun. It's a Galilean eclipse. Have you not been paying attention in class, or is your teacher an idiot?

Cloudy this morning.

Cloud is broken in the South, more blanket-like in the North; I could see the sun 10 minutes ago. We are getting the 95% here, it would be good to think we'd get to see the whole wonder of the spectacle and not just get a bit dark..

South London has 100% cloud. Currently light-grey cloud. It might darken.

Cloud has filled in here as well. Rats.

Oh, this is clearly set to be a rollercoaster ride of an eclipse. Sun out again.