Calling all Medway Graemes

[ChrisGreaves]

Graeme, you're a lucky man, because we live where we live, and were we to meet Midway, in a manner of speaking, we would get very wet.
Also, you are lucky that I am too miserly to make long-distance telephone calls.
Which means a form of email, like this.
Still lucky because I am a slow two-fingered typist.

But if I were in GB I would rent a car and a tent and camp out for a week, to ask you questions about your equipment.

Instead I have to compose what I hope are simple questions like this one:-

I know that you can photograph the surface of the moon (given near-ideal weather), so if you were charged with taking an image of a specific object on the moon's surface (a crater, a rock, a lunar-lander etc.), what is the smallest object you could image that would convince someone that you had succeeded?

Untitled.png

This image was on a news web site today, and the image is grainy, but still of sufficient quality to pass as IM-1 or Odyssey or whatever it is called.
We are not looking for top-quality as much as enough-quality-to-identify-the-object.

Of course I am curious about how good your equipment is, but suppose you were asked to image a specific crater in the equatorial zone of The Moon, what's the smallest crater you could image that would include enough detail (variations on the rim, or its central mound, or whatever) that would satisfy another lunar astronomer?

Thanks, Chris

[HansV]

Also, you are lucky that I am too miserly to make long-distance telephone calls.

I hope I'm not opening a Pandora's Box here, but: calls in WhatsApp and Signal are free, all over the world...

[ChrisGreaves]

I hope I'm not opening a Pandora's Box here, but: calls in WhatsApp and Signal are free, all over the world...

Thanks, Hans. Funny you should mention it, but this past week I had reason to reflect on the Real Cheap phone calls I used to make across North America back in the late 1990s; one had to dial a local number, and then the long-distance number, and it was in this way that I chatted with a school-teacher friend in Prince Rupert BC (from Toronto).

I was speaking a bit tongue-in-cheek when I spoke of telephone calls. There really is no solution to this problem, because every time Graeme answers one of my questions, he prompts in me ten more questions.
He's a Rotten Teacher

Cheers, Chris

[Graeme]

what's the smallest crater you could image that would include enough detail (variations on the rim, or its central mound, or whatever) that would satisfy another lunar astronomer?

Dunno.

I've done some Lunar photography but I've not really studied the specifics of the images.

Here's an image I captured of the Rupes Altai. The wiggly white line is an escarpment 430km in length.

190410-Moon-Rupes_Altai.jpg

Below the Altai (north (I didn't get round to inverting my image)) is Mare Nectaris, a flat lava flooded plane. Above the Mare is the impact crater Fracastorius (124km diameter). The northern wall of this crater is missing, so the crater looks like a bay off the Mare. If you zoom in on my image you can see some very small impact craters on the floor of Fracastorius, these include Fracastorius L and M which are 5km and 4km across respectively.


https://en.wikipedia.org/wiki/Fracastorius_(crater)


This is about as good as it gets. I could put a x2 or x3 Barlow lens in front of the camera and increase magnification but I'm not sure if the trade off with increased magnification would give much improvement in clarity. Perhaps I'll give it a go.

Great question. I didn't know the answer till I studied my image to find out!

Graeme

[PJ_in_FL]

...
Dunno.

I've done some Lunar photography but I've not really studied the specifics of the images.

Here's an image I captured of the Rupes Altai. The wiggly white line is an escarpment 430km in length.

...
Great question. I didn't know the answer till I studied my image to find out!

Graeme

Amazing imagery, as always,

Thank you for sharing!

[Graeme]

Cheers PJ. My Lunar imaging has usually been for a specific Lunar thing, like the Lunar X and V last month. And I've not spent much time on things like focus and processing. But I was quite pleased with the Rupes Altai image even with its too high contrast.

There's a challenge in the Astronomy Now Magazine this month to capture the detail of the Lunar North shadows on the 18th. Focus and processing would be crucial! I'm planning on having a go without the focal reducer if the skies stay clear.

Graeme

[BobH]

Great lunar photo, Graeme. It's enlightening to have distances associated with parts of the image. It changes my perspective about the size of lunar objects.

Given that the moon has so many craters, presumably from the impact of objects, one wonders why the Earth's surface is not similarly cratered. Again, presumably, Earth's atmosphere protects it from some impacts; but the difference in numbers seems staggering. Having grown up in central North Carolina, I'm aware of pocosin-filled craters across the Eastern parts of the state and South Carolina. I think they were created by meteor impacts around about the same geologic era, but I don't know anything more about them. We also have a huge area called craters of the moon. Again, though, Earth's surface seems not to have anything like the number of impacts that Earth's moon has.

[HansV]

Yes, the Earth's atmosphere protects us from a large majority of meteors. Plus, the dynamic nature of our geology and biology has hidden older impact craters partially or entirely.

[Graeme]

And the Moon has no atmosphere or plate tectonics so a meteor impact will cause a crater to be formed that will stay there for billions of years.

On the Earth there have been even more meteors because the Earth is bigger. But most burn up or explode in the atmosphere. The craters that are formed by those that hit the Earth are eroded by the wind and rain etc and also subducted (is that the right word?) into the Earth's mantel in the process of plate tectonics.

Graeme

[ChrisGreaves]

… these include Fracastorius L and M which are 5km and 4km across respectively.

Fracastorius	Diameter
D	28 km
A	18 km
Z	9 km
M	4 km

OK. I’ve thought about this; it’s an excellent way to get to sleep. I am never the first one to think of something, so I can state confidently that there must be a scale somewhere, created by a committee of astronomers.

I think of individuals as owning, controlling, and using a Black Box. Graeme’s black box is a camera, computer, lenses, filters, software and, I learned last week, a strip of aluminium foil. Bob’s black box is a camera and a telescope and, we trust, a solar filter. Chris’s black box is a LGK30 smart phone How might these three individuals rate themselves? By a public scale of objects.

Lunar: Craters, ridges, mares, mountains etc ranging in size from 1,000 Km down to 1m. My stolen image in this post above is in the 1-9m class. Graeme’s “wiggly white line" is in the 400-500Km class, while his Fracastorius L and M are in the 1-9Km class.
Bob cannot hope to get a clear image of “wiggly white line” so Bob and I are not in the Lunar Grade.

Planetary: (Mars through Pluto) this scale runs from 1,000 Km down to 10m and includes moons, craters, Giant Red Spots and whatever else can be distinguished from Earth. I suspect that Graeme is in the Planetary Grade. Bob is not, and Chris can only identify Venus on account of it being visible at sunrise and sunset!

Galactic: I am out of my depth at scales here, especially when it comes to Km, but I would place Graeme in the Galactic scale because I believe that he can capture Sirius (as a composite of Sirius-A and Sirius-B) and I expect that, were he but to try, he could capture an image of Sirius-A and the (even smaller?) Sirius-B.
My lack of knowledge of galaxies means I cannot list galactic features that fit on a scale.

Universal: Andromeda, …

(1) The intention is not to be able to identify every object on the moon/planets/galaxies etc, but to have a committee establish a basic set of objects to which photographers can aspire. Fracastorius might be too close to a pole to be of use, but there must be a set of equatorial objects available at full moon.
(2) The lunar scale runs from 1,000Km to 1 metre (100,000, 90,000, 80,000, 70,000, 60,000, 50,000, 40,000, 30,000, 20,000, 10,000, 1,000, 900, 800, 700, 600, 500, 400, 300, 200, 100, 90, 80, 70, 60, 50, 40, 30, 20, 10, 1 metres) and has a large number of steps to encourage a photographer’s progress through the scale. The planetary scale is sparser, as are the Galactic and Universal scales.
(3) The Earth itself provides a scale (so that folks like me aren’t pushed to one side) ranging from one metre down to, perhaps, 0.1 mm. Unless you don’t have a camera of any make, you are automatically in the Earth Class. Congratulations! (I am glad to see Ken by my side)
(4) There is then a sub-Earth class that passes through bacteria and virus but not to molecular and atomic. Molecular and Atomic are the domain of rich agencies. Super-Universe class objects are as yet figments of mathematicians imaginations.
(5) Lunar and Martian humans will have access to an Earth scale 100Km to 1m

The objects selected for each class will be identified and fixed publicly.
There is of course no reason to have a judging committee; this is an informal scale, and as shown in my post above, any fool can steal an image and claim it as their own.

We would have to have a better acronym than the LPGU-scales or the GELAS-scale⁽¹⁾
Language mavens can start their own topic about why the adjectives Universal, Galactic, Planetary and Lunar provide disparate endings -al, -ic, -ary and -ar.

Cheers, Chris
⁽¹⁾ Great Eileen’s Lounge Astrophotograpical Scale.

[ChrisGreaves]

Amazing imagery, as always,

Agreed! I spent far too much time using Ctrl+] in Firefox yesterday. Chris

[ChrisGreaves]

... the detail of the Lunar North shadows on the 18th.

So Astronomy Now Magazine would be a great source of object definitions for such as scale.
( I have a feeling that before I finish typing this you will be back at me with:-
Chris, the following thirty-three scales are ...
Cheers, chris

[stuck]

Instead of theorising, how about you pick up the phone and call your local astronomy experts, here:
    http://www.stjohnsrasc.ca/

They'll be your best mates and wanting to camp out in your back yard when you tell them you are are in Bonavista.

Ken

[Graeme]

Planetary: (Mars through Pluto)

Pluto's not a planet.

Graeme

[ChrisGreaves]

They'll be your best mates and wanting to camp out in your back yard when you tell them you are are in Bonavista.

I dunno Ken, I emailed them five minutes ago and they haven't got back to me.
Their web site gives you some idea of the attitude of folks from The Big Smoke - they would rather drive an extra 15 minutes (each way!) and be NOT on the centre-line of totality, than accept a cup of coffee or tea from me, I s'pose.

I pointed out the benefits of Bonavista:
P.S. Why are y'all traveling to Gander when Bonavista is
(a) 15 minutes closer and
(b) On the path of totality and
(c) Will be the last land to experience a total eclipse in North America until ...

Cheers, Chris

[ChrisGreaves]

Pluto's not a planet.

Maybe, maybe not. But it does start with the same letter as the word "pedantic". Also "Picky".
My teacher at Merredin Junior High School told me in the first term that Pluto was a planet, and he was right about all the others.
Besides, I am too old now to lean another mnemonic.
Cheers, Chris

[Graeme]

When you were at Merredin Junior High School and Pluto was discovered it was assumed it was a planet because we didn't know about the Kuiper Belt. It's not a case of pedantry on my part, it's that now we are more informed. The Kuiper Belt contains many objects that are similar to and behave like Pluto does. None of the eight solar system planets orbit the Sun like Kuiper Belt objects do. Pluto was the first Kuiper Belt object to be discovered and it is a thing of beauty, but it's not a planet.

It was the same when Ceres was discovered in the Asteroid Belt. Ceres is not a planet either.

Graeme

[ChrisGreaves]

Pluto's not a planet.

Chris’s submission for correction/evaluation.
I found this page and this page as I explored the Planetary Scale for Black Box Evaluation. The first page has a lovely diagram on the first page, I think a logarithmic scale.

The innermost planet Mercury orbits the sun in 0.2 years, the outermost planet Neptune orbits in 165 years. I visualize the solar system roughly from above The Earth’s north pole.

Orbits.png

Inner planets
To photograph any part of Mercury (represented by the silver circle) from Earth (green) we⁽¹⁾ are looking into or adjacent to the sun, which presents a challenge. We might photograph the Transit of Venus across Mercury if the alignments are correct; we can photograph the planet Mercury in its Transit of the sun, but we would be hard-pressed to photograph any structural detail of Mercury from Earth. Mercury has no moons, so I am lacking knowledge of any more objects related to Mercury that might be photographed. The scale for Mercury is therefore near-empty.
Similar arguments hold for Venus – no planets, no Transits but perhaps the occasional occultation of Mercury by Venus.
Outer planets.
Using Neptune as the outermost planet (from Earth) I would expect the easiest photographs to be taken when Neptune is in full light from the sun, and that suggests that Neptune, Earth, and Sun would be in a straight-line (in the sense of some plane of orbit). Compared to Earth Neptune is close to not-orbiting-the-sun. Earth orbits the sun 165 times during an orbit of Neptune. But this is approximate, for each Earth year Neptune will have moved an extra 1/65th (slightly more) along its orbital path. Nonetheless we can think of maximum opportunity as being a little bit more than once each Earth year.
Moons of planets: Neptune has 14 moons, so each moon might be considered as a visible object for capture. On the planetary scale then I suggest that Neptune donates fourteen points along the scale. I think of photographing a moon as it orbits off to the side of Neptune, or transits across Neptune, or the moon’s shadow ON Neptune, so perhaps 3x14 possibilities.
There are listed 2+92+83+27+14 giving 218 satellites of the outer planets, so 354 opportunities for moons on the Planetary scale.

Object on planets surface: There are five outer planets, so that adds another five surfaces, some of which have identifiable objects; Jupiter’s Red Spot comes to mind.
The orbit period of Mars (Earth’s closest neighbor in terms of planetary orbits away from the sun) is about two years which, I think, translates to Mars being in the optimum position every 1.5 Earth years.

All of this is, as usual, prompted by Graeme’s professional opinion that Pluto is NOT a planet. As a solar object orbiting the sun, Pluto orbits every 248 years. This would make Pluto about 1.5 times as bad as Neptune in orbital opportunity alone.

Which made me think of a weighting system for these scales, then I woke up to find a fresh layer of 2 cm of snow, which brought me back to Earth.

And made me think of the Moon, especially the bleak lunar surface. The Lunar surface seems by far to be the best scale. Whatever the optimum viewing time is for objects on the moon, they come around every month ( ) and with the exception of eccentricities like “X” and “O” must be always available each month. A bad-weather day at full moon is still surrounded by two or three days for most objects, and a cancellation means a wait of only one month, as distinct from one year.

Thanks again to Graeme for pushing me to the outer limits of my knowledge, and (probably!) beyond.

⁽¹⁾ By "we" I mean individual observers, and not government-funded agencies and commercial entities.

Cheers, Chris

[BobH]

A bit of doggerel to remember the order of planets of the solar system by distance from the Sun (courtesy of my Old Dad who was born not in the last century but the one before):
"Mercury, Venus, the Earth, Mars
Jupiter the largest of the stars
Saturn, Uranus, Neptune, too
Far away and hard to view."

Dad was upset when they added Pluto to the list, I think because he couldn't fit it to the rhyme. I think he always knew that Pluto wasn't a planet.

[GeoffW]

A bit of doggerel to remember the order of planets of the solar system by distance from the Sun (courtesy of my Old Dad who was born not in the last century but the one before):
"Mercury, Venus, the Earth, Mars
Jupiter the largest of the stars
Saturn, Uranus, Neptune, too
Far away and hard to view."

Dad was upset when they added Pluto to the list, I think because he couldn't fit it to the rhyme. I think he always knew that Pluto wasn't a planet.

I guess he just didn't planet properly.