Correct.
NB: What I calculated before was the Earth-Sun-Venus angle. The separation of Venus from the Sun is the Venus-Earth-Sun angle, asin(0.723/1)=46.4 degrees (=90-43.7) Sorry for any confusion.
Earth’s eccentricity is 0.017 and Venus’ is 0.007. To maximize the separation, you’d want Earth to be at perihelion (its closest approach to the Sun) at (1-0.017)1AU=.983AU and Venus to be at aphelion, at (1+0.007).723=0.728 AU, yeilding a separation angle of 47.8 degrees.
I have seen it during the day with naked eye. You just have to know exactly where it is. It isn’t real easy.
But, if you have a telescope already pointing at it, you can do it.
Back to the OP, the cycle of Venus-Earth positions cycles about every 584 days. (Yes, that’s close to the sum of the length of their years but it’s just a coincidence.) That is, conjunctions, etc. occur every 584 days. The maximum elongation in the evening occurs that often as well. So that 584 days from now it will be about where it is now in the sky (from our perspective).
The Mayans were supposedly very keen on this cycle.
Thanks ftg. That coincides with my estimate from the graph of about 20 months.
Did you just know this obscure fact?
My amazement of the facts that you Dopers know (or know how to find) is boundless.
Stick around, you’ll get good at too.
For my part, I looked up the distance of each planet to the Sun. For the geometric drawing, I just created that in my head. I didn’t even draw it for myself.
All day. I have seen it morning noon and night. It has been difficult lately because there has been a lot of forest fire smoke hanging around.
I live on the desert where horizontal visibilities of 100 miles are common. In fact you can visually navigate by air from here clear over past Albuquerque without using a map. From here, when you get airborne a ways, you can see Charlston Peak just west of Las Vegas, NV. Then before you lose sight of that peak behind you, you can see Humphries Peak at Flagstaff, AZ coming up. And before losing sight of that you can see the Sangre de Cristos in New Mexico. It’s a good idea to have maps though because you cross the Continental Divide where there can be clouds which restricti visibility even on the desert.
My memory was actually 484 but I decided to check to be sure. I did a Google on “Venus Conjunction” and probably another word I’ve forgotten. I noticed the similarity to the sum of the years so I checked it:
365x = 224(x+1) gives the fraction of an Earth orbit for Venus to go around that plus 1 orbit. Multiply by 365, tada. It’s a little off from 584 but since the Earth’s year is really 365.254 (which I do remember), etc., close enough.
I also remember that Venus’s orbit is a little over .7 A.U., so I could have roughed out the other calc. in my head too.
Not an Astronomer. I just remember stuff.
Now there is an understatement. Heck, I can’t even remember stuff from yesterday. I’m impressed. (and that goes for all of you)
I happened to know the maximum elongation of Venus – though I did not know to call it that – from my astrological work, where the aspects (elongations) between any two planets can have a specific significance, particular those in multiples of 30 or 45 degrees. In my table of interpretations for Sun-Venus aspects, it tells me that the maximum separation is 48 degrees, and therefore most major aspects (60, 90, 120, 135, 180 degress) will never occur between these two.
Incidentally the maximum elongation of Mercury, according to the same table, in 28 degrees, not 36 as I stated earlier from memory. For some reason I always get it wrong that way. At least I’m consistent!
There’s the problem.