13 Comments
User's avatar
Adrian P Conway's avatar

Of the purest kind of conjecture, William. Gratefully enlightened.

Expand full comment
William Collen's avatar

One that I did find which was highly accurate is Turner's "Moonlight, a study at Millbank", which shows a rising full moon with a very bright star next to it. What star is that? What star could possibly still be so bright when in such close proximity to the full moon? It couldn't be Venus or Sirius; they never appear so near to a full moon. Could it be Jupiter? My kids and I planned an observation of the full moon and Jupiter for Sunday morning, and behold, they were as close together as in Turner's painting and Jupiter was not washed out by the full moon's glow.

Expand full comment
Theric Jepson's avatar

I made my whole family walk outside and see this! Now that Jupiter's in the sky again (during waking hours) is it reasonable to hope for it once more or is this not an every-turn sort of thing?

Expand full comment
William Collen's avatar

It will happen approx. monthly for the next few months at least; Jupiter is rather slow-moving compared to the moon. By the way, this is my go-to resource for that sort of thing. Just plug in your zip code and you're all set to go. https://skyandtelescope.org/interactive-sky-chart/

Expand full comment
Theric Jepson's avatar

Oh, nice, thank you.

Expand full comment
Adrian P Conway's avatar

Wow. See, that's the sort of science I would've stayed awake for in school. Quick understanding check here... are you saying moon horns are often exaggerated in art compared to the reality?

Expand full comment
William Collen's avatar

Yes indeed.

Expand full comment
Adrian P Conway's avatar

Because the earth shadow truncates them due to its respective size?

Expand full comment
William Collen's avatar

Nope—there's no earth shadow involved in a crescent moon. The light / dark ratio is an effect of the moon's angle in relation to the sun.

Imagine a right triangle with the earth at the vertex and the moon and sun at either end of the long side; what you would see from earth is half the moon illuminated. If the vertex is smaller than ninety degrees, you would see less than half a moon. (It would be a lot easier to explain this if I had a flashlight and an orange.)

Expand full comment
Adrian P Conway's avatar

😂 They're never there when you need them! DM visuals did the trick, thanks. I'm fairly waxing with this new knowledge.

Expand full comment
Tam's avatar

This may be too simplistic, but surely it is more difficult to paint at night.

Expand full comment
Theric Jepson's avatar

.

I love a good pet peeve.

Expand full comment
Bob Kirchman's avatar

Wow! This is great observation to share with our paining students!

Expand full comment