June 3 is a hinge date for Venus.
See the end note about enlarging illustrations.
It’s the event rather dully called “inferior conjunction.” It’s the passage of Venus from an evening performance to a morning performance.
The space diagram, from page 42 of my forthcoming Venus book, shows Venus swinging through inferior conjunction (the red-labeled moment).
In the famous eight-year cycle, Venus repeats its movements (not exactly) in each eighth year. I find it more helpful to treat the cycle not as eight Earth-years but as ten Venus apparitions – five in the evening sky and five in the morning sky – so that they make five apparition pairs. (I’ve tried, so far unsuccessfully, to think of a neater term than “apparition pair.”)
The apparition pair of the present type (2020-2021, which will repeat in 2028-2029) is a notable one. It includes, in the evening, the Pleiades passage and the northernmost moment, which we’ve just seen. And then this inferior conjunction, the hinge of the apparition pair, is a special one. Whereas, at the other four, Venus passes well north or south of the Sun, at this one its latitude is smallest. That is, it almost crosses the Sun. At the previous two occurrences, 2012 June 6 and 2004 June 8, it did cross the Sun. The great Transits, when we watched the black dot crawl across the blazing disk!
The close passage of the Sun happens because Venus is at or near one of the nodes, the moments when it crosses the ecliptic plane in which the Sun lies. It happens to be the descending or southward node. This has the result that Venus was, before this moment, more northward than the Sun and therefore visible, for north-hemisphere people, till only a few days before the conjunction; but from tomorrow onward it will be more southerly than the Sun.
These two sky scenes try to show the possible glimpses of Venus close to the Sun: the last chance before the conjunction and the earliest chance after. The glimpser would have to have a clear horizon and binocular skill.
Last glimpse of an evening apparition?
First glimpse of the coming morning apparition?
In these pictures, Venus’s position is shown by a dot; its slender sunlit crescent is exaggerated 150 times in size; and an arrow shows its movement over five days, against the starry background.
Among features drawn but not visible in the bright sky are the Milky Way and Uranus and – what are those streaks across the morning picture? My program, if I let it, draws them to indicate meteor showers, and these are the Daytime Arietids that peak about June 7. And they are quite abundant, but are for radar, not the eyes.
Mercury is high above Venus in the late-May picture, and will be at greatest evening elongation, nearly 24 degrees from the Sun, on June 4. A good Mercury performance: you can see that it is passing north of the northernmost point on the ecliptic (labeled “solstice point”).
The Moon doesn’t appear in our near-to-the-Sun pictures, because it is on the opposite side of the sky:. It will be Full on June 5. And it will suffer an eclipse, but only a penumbral one. That is, Earth’s almost imperceptible outermost shadow will sweep only the southern half of it. And this will be when it is in the sky for lands around the Indian Ocean.
So:
Venus is about to pull out into the morning sky. It may become findable about June 9, then will shine higher and brighter at each following dawn. And the book – Venus: a Longer View – will be announced by then, or sooner, I hope. (There have been maddening technical delays…)
Stray Thoughts Department
We came here (this part of England) when the cherry trees were in flower. Not such a galaxy as the dogwoods of South Carolina, but an inspiration to English and Japanese poetry. A few weeks later, it was April snow: blossom still seemingly as abundant on the trees, but myriads of petals on the ground. They seem to lie random, but every time there is an eddy of breeze you see them in orderly spirals.
Now after weeks of blue sky the grass is yellow. Has the blue been lifted out of the green?
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Bye bye Venus we shall miss you,well at least it exited our evening skies letting Mercury take centre stage for a few nights although it was hard to see in the sun’s after glow.however all is not lost as Jupiter in the south east at about 00:30hrs and west of it I’ve been able to pick Antares out.
And Saturn and Mars before and during dawn, as well, if you get up early enough. Do they look non-stellar in your tiny monocular?
If I recall correctly the 5×10 Zeiss miniquick monocular resolves Mars, Mercury and Saturn into tiny discs and you can tell they are not stars.Jupiter is an easy disc and Venus a blur when high but as it starts to leave our skies and it packs less glow it becomes a crescent at 5x.Uranus is an easy point of light.now Neptune I haven’t seen in the 5×10 but bigger monoculars like 8×25,8×36 and 10×42 pick it up.i don’t know what the limiting magnitude of 5×10 is guessing about 7 under dark skies so Neptune is probably beyond it.
It’s amazing that such a small aperture and low magnification makes such a difference compared to no optical aid.
I do most of my skywatching with 10×42 image stabilized binoculars and a 60 mm f/5.5 apochromatic refractor. Friends in my astronomy club laugh when they see my little telescope, but I can easily carry the telescope and a simple altazimuth mount up the nearby hill on foot, and it only takes a couple of minutes to set up and break down. At star parties, while others are struggling with huge optical tubes, counterweights, power supplies, collimation, alignment, and software gremlins, I’ve already been observing for an hour. Then when they’re finally set up, I saunter over and have a look through their eyepiece! It’s true that aperture matters, and there’s nothing like the view through a well collimated large Newtonian reflector, but ease of use also matters.
5×10 is a pretty significant improvement over the human eye.an extra 5mm of light,or 3mm for someone who’s pupil dilates to 7mm,and obviously a 5x increase in magnification.the Zeiss one uses very high quality optics but low quality’ pen telescopes’are hopeless although not many are sold or made.ive done a Zeiss miniquick Messier marathon in the past and here’s what I recall seeing;m’s31,2,38,36,37,44,67,41,39,29,35,13,50,42,15,3,34,47,46?,22,24,33?,11,5,45,27.scorpius and Sagittarius are low for me but if they where higher I’d have no problems with ones like m8,m7, etc.because of the lack of light gathering power diffuse objects like m33 and m46 which I put the ?by are a challenge and I can’t be 100 percent sure if it’ll pick them up or if my mind paints them in?
Kevan, your Messier list is impressive! Just imagine what you could see with a 10×25 monocular — if you could manage the extra weight and volume. ;-)
I don’t have 10×25 but I have a few 8×25 and you can see quite a lot i have sighted;M’s 51,101 and 66 on the galaxy front with m1 I can’t be 100 percent certain but I think that 8×25 just does it?m1 is clear by the time you get up to 10×42.to be honest 8×25 monoculars have much more in common with my 8×36 and 10×42 than they do with the 5×10 as generally anything you can see in them is visible in the 8×25 but fainter but with 5×10 there just isn’t enough light being captured.
I didn’t know this until today. Every time Venus passes the Earth, it shows the same face.
https://apod.nasa.gov/apod/ap200603.html
To quote from my book:
117: the Venus day, as from a sunrise to a sunrise.
225: the Venus year, in which it goes around the Sun.
243: the rotation period, in which it spins once.
365: the Earth year, around the Sun.
584: the synodic period, as from one inferior conjunction to the next.
The shortest and longest of those reveal one further surprise: 584 / 117 is almost exactly 5. In other words, as Venus goes around from one inferior conjunction to the next, it rotates 5 times – and thus presents the same face to Earth! At each transit of Venus across the Sun, for instance, we have been looking at the same darkened hemisphere of Venus.
Does this mean that Venus, like the Moon, is locked in a tidal resonance with Earth? That has been a hypothesis, but has been rejected. The correspondence is not quite exact, and will evolve away, like the eight-year cycle.
The book sounds wonderful. Can’t wait to get a copy.
Dear Guy,
This has nothing to do with Venus; apologies! However I didn’t want to send you a normal e-mail, because someone seems to have hacked your and Tilly’s e-mail account and is sending phish messages as replies to Amnesty newsletters that I’ve sent! Hope you are all well and can deal with it. Best, Wayles in Ithaca
I think of the apparition pairs as horns. The horns of Venus. One appears at dusk one appears at dawn.
Maybe “apparition cycle”.
It seems like Venus goes into hiding for a shorter period at inferior conjunction compared to superior conjunction. Venus’ orbital speed is fairly constant but around inferior conjunction the angle between Venus and the sun changes faster because Venus is much closer to the Earth than at superior conjunction.
My last view of Venus as the evening star was on 26 May, a full week before inferior conjunction. Haze and clouds prevented later sightings.
If the curfew continues, as seems likely, I won’t be able to walk up the hill to see Mercury at greatest eastern elongation.
By the way, there is a typo in the paragraph that begins, “The apparition pair of the present type”. The last transit of Venus was on 2012 June 6, not 2022 June 6.
Thanks, corrected.
I saw Venus on May 30 from Tulsa with 25×100 binoculars, and showed a friend. But on 31st it was not seen.
Re: (I’ve tried, so far unsuccessfully, to think of a neater term than “apparition pair.”). A frivolous suggestion: “appairition”.
Your mention of the Daytime Arietids reminds me of last year. I had been curious if a few earth-grazers from that shower might be visible before twilight set on. Alas, in spite of clear skies and a favorable West Texas viewing site, I saw none. It was a rather good morning for sporadics, though.
Looking forward to your Venus book.