In the ATM section in the "Is Venus Bugging Us?" thread someone is passing on a theory that influenza outbreaks coincide with the conjuctions. As I'm kind of being ignored there I'd thought I'd ask this here.

One: What the heck is a inferior conjuntion of Venus with Earth?

Two: Do they ever occur outside of the Autumn/Winter months?

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Earth and Venus orbit the sun. At some points one planet is on one side of the sun while the other planet is on the other. Far away from eachother. Bad time to launch a probe. Or a bug.

At other points they are on the same side during their orbits and that is when they are closest to eachother.

It's where Venus passes "between" the Earth and the Sun. Due to orbital inclinations, Venus usually winds up either above or below the Sun as seen from Earth, although this wasn't the case in June, 2004.Sure. They can happen any day of the year (see above re the June, 2004 inferior conjunction). It's all a product of orbital periods and mechanics.

The bit about flu, etc., is, at best, malarky.

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Graphically, here's what an inferior conjunction of Venus in respect to the Earth looks like, as seen from above the plane of the ecliptic (the plane of the Earth's orbit). (not to scale):



Also here's what a superior conjunction looks like:



Remember, the orbital plane of Venus is not identical to Earth's, therefore Venus rarely appears to cross the Sun.

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Just for fun, I will say they always do occur inside the Autumn/Winter months.

Owing to the fact that this planet has a northern and a southern hemisphere, it is always Autumn or Winter somewhere here.

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0 1 1 0 1 0 0 1 1 0 0 1 0 1 1 0 1 0 0 1 0 1 1 0 0 1 1 0 1 0 0 1 1 0 0 1 0 1 1 0 0 1 1 0 1 0 0 1 0 1 1 0 1 0 0 1 1 0 0 1 0 1 1 0 ...

And some of us are already in line for June 2012

D'oh! You got me on that one. (What a minute, what's down there? The Prison Continent, The Land of the Hairy Potato-shaped Bird, The Big Icebox and South America. Oh okay South America counts)

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In your rush to call everyone "entrenched" or closed-minded or "limited" you fail to note that the "limit" here has a very natural boundary: that point at which the evidence stops. - JayUtah

Science fiction was never meant to be an educational tool. - Editor Amazing Tales

Yup, and my diagrams were actually from below the plane of Earth's orbit. Ha!

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Is Venus' entire orbit below the Sun's equator? Or just dips below for part of the cycle.

__________________
In your rush to call everyone "entrenched" or closed-minded or "limited" you fail to note that the "limit" here has a very natural boundary: that point at which the evidence stops. - JayUtah

Science fiction was never meant to be an educational tool. - Editor Amazing Tales

Due to Venus' orbit not being coplanar with the plane established by the Sun's equator, it is either "above" or "below" (i.e., not in) the solar equatorial plane, except for twice an orbit, when it crosses the equatorial plane of the Sun.

Here's a wiki article that elaborates on orbital inclinations.

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But is it Autumn or Winter when it's above?

Is it always June when it's "in"?

Due to the difference between the orbital periods of the Earth and Venus, Venus can be "above" on any day of an Earth year. It's not constrained by the seasons of the Earth.

One item of clarification re the transits of Venus: for the past couple of thousand years they have been occurring mainly in either June or December. This is due to the way the nodes of Venus' orbit line up as seen from Earth. For example the last non-June/December transit was on May 23rd in the year 1526 CE. This June/December pattern will continue for many more thousands of years, unless there's an event that perturbs either Venus and/or the Earth.

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The Earth Venus conjunction features interestingly in The Da Vinci Code. Because 13 Venus years are almost precisely equal to 8 Earth years, there are 13/5 = 2.6 Venus years for each 8/5 = 1.6 earth years. The common "0.6" in the two cycles means that when Venus has orbited 2.6 times, the Earth has orbited 1.6 times, so they line up exactly again with the sun. The five inferior or superior conjunctions are therefore at 1.6, 3.2, 4.8, 6.4 and 8 earth years = 2.6, 5.2, 7.8, 10.4 and 13 Venus years. For example, the inferior conjunction of Earth and Venus on 18 August 2007 was the fifth such event since the same date in 1999. These five points form a perfect pentagram in space, the divine shape of Pythagorean lore and the Vitruvian Man by Leonardo, as discussed by Dan Brown. There is reportedly a 0.0789 day slippage of this pentagram every 584 days.

Assuming a single, unambiguous definition of 'inferior conjunction' for the Moon and Venus, do such (always) occur within hours? days? a month? of the corresponding Earth-Venus conjunctions?

Can the Moon ever spoil the fun of watching an "in" Earth-Venus conjunction? If so, has it done so since telescopes were invented? When will it next be a party-pooper?

That part is good information.

The rest is...

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The information is all correct, I think you may be reading more in than is there.

Venus transits of the sun take a quarter day or so, and are visible from almost anywhere on the Earth that is in sunlight. They occur in pairs, mostly now, a hundred years apart. A solar eclipse by the moon doesn't last as long as that--and the eclipse is not visible from everywhere, so it wouldn't obscure the transit for everyone.

Thanks.

Any solar eclipses, somewhere in the world, during at least part of a transit of Venus?

The odds are thin. This 6000 year catalog shows only about 80 transits, that's about one per 75 years, but a lot occur in pairs about eight years apart. The pairs are over 100 years apart. This catalog of "famous" lunar eclipses probably would have included one that had a simultaneous transit.

None since 2000 BCE, and the next is not forecast until 5 April 15,232 (Dynamical Time!).
There was a near miss on 22 May 427 BCE, when a total solar eclipse ended nine hours before the beginning of a transit of Venus, and another on 4 June 1769, when a total solar eclipse started five hours after the transit of Venus ended.
(Information from Jean Meeus' Mathematical Astronomy Morsels III.)

Grant Hutchison

That 1526 transit was in May only because it was the last one before the calendar change in 1582. If we extrapolate the Gregorian calendar backward, the transit falls on June 2. Working farther backward, we find more transits fall in June and December:

1518/05/26 becomes 1518/06/05
1396/11/23 becomes 1396/12/01
1283/05/23 becomes 1283/05/30

and here we have the last transit not in June or December, even without the calendar change.

The next such is 4791/01/02.

Not it's not. The main problem is the use of the words "perfect" and "exactly".

Next conjunction I plan to move from my previous position to a location about 100 feet higher, thereby shifting the Earth's center of gravity and ruining the "perfect" pentagram as well as the "exact" alignment.

Actually I won't have to do that, since the Earth's center of gravity is constantly shifting all the time.

Same deal re the geometric center.

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Maksotov post #4 has the correct definition. Some of the other posts have it backwards. I nearly gave up trying to confirm that transits occur in inferior conjuctions. The following is partial quote from Transits of Venus at www.wickipedia.org Normally when the Earth and Venus are in conjunction they are not aligned with the Sun. Venus' orbit is inclined by 3.4° to the Earth's so it appears to pass under (or over) the Sun in the sky.[3] Transits occur when the two planets happen to be in conjunction at (or very near) the line where their orbital planes cross. Although the inclination is only 3.4°, Venus can be as far as 9.6° from the Sun when viewed from the Earth at inferior conjunction.[4] Since the angular diameter of the Sun is about half a degree, Venus may appear to pass above or below the Sun by more than 18 solar diameters during an ordinary conjunction.[3]

Also, don't forget that Venus is in a rotational resonance with the Earth such that the same hemisphere of Venus faces the Earth at each inferior conjunction. . . .

http://www.bautforum.com/questions-a...njunction.html

For some reason bautforum won't let me save the correction of www.wikipedia.org No c. Neil

The inferior conjunction of Venus occurs every 583.93 days as Venus passes between the Earth and the Sun. Most recent was 18 August 2007. The period for every fifth event is eight years minus 2.4 days, so it will happen on 16 August 2015. This regular period, due to the 13/8 relation between the orbits of Venus and Earth, also applies to the superior conjunction (Venus behind Sun), the dates of change to forward and retrograde motion, and the dates when Venus is at maximum apparent angle of 45-47 degrees each side of the sun. Venus was recently at maximum angle on 9 June 2007 and went retrograde on 30 July. In eight years, it will reach these positions on 7 June 2015 and 27 July 2015 respectively, 2.4 days before the corresponding days this year.

For the ancients, the date when Venus as evening or morning star changed direction could have been a main temporal marker, observed 2.4 days earlier against the zodiac stars every eight years. I would be interested in any information on this - did the ancients monitor the apparent 2.4 day precession of the position of Venus each eight years? This movement is certainly much easier to observe than the precession of the zodiac recorded by Hipparchus in the second century BCE.

The ten points of the apparent change of direction of Venus (five each for the evening and morning stars) form two pentagons, each evenly spaced around the zodiac. These pentagons precess with an orbital period of about 1217.5 years, as do the inferior and superior conjunctions. The Pythagorean School of ancient Greece used the pentagon as its symbol, (http://en.wikipedia.org/wiki/ Pythagoreans. They had a strong interest in the mathematics of celestial observation, and had cultural affinity to the themes of beauty and love symbolized by Venus/Aphrodite. For these reasons, I imagine it is likely the Pythagoreans monitored this nearly exact eight year cycle. Would their secrecy mean we will never know?

Fifty years of Venus Dates

Inferior Conjunction; 10/11/1970; 18/6/1972; 24/1/1974; 28/8/1975; 6/4/1977; 8/11/1978; 15/6/1980; 21/1/1982; 25/8/1983; 4/4/1985;
5/11/1986; 13/6/1988; 19/1/1990; 23/8/1991; 2/4/1993; 3/11/1994;
11/6/1996; 17/1/1998; 20/8/1999; 30/3/2001; 31/10/2002; 8/6/2004;
14/1/2006; 18/8/2007; 28/3/2009; 29/10/2010; 6/6/2012; 12/1/2014;
16/8/2015; 25/3/2017; 27/10/2018;

Eight Year Cycle of Inferior Conjunction illustrating precession: 10/11/1970; 8/11/1978; 5/11/1986; 3/11/1994; 31/10/2002; 29/10/2010; 27/10/2018

Superior Conjunction: 30/8/1971; 6/4/1973; 10/11/1974; 16/6/1976;
21/1/1978; 27/8/1979; 3/4/1981; 7/11/1982; 14/6/1984; 19/1/1986;
25/8/1987; 1/4/1989; 5/11/1990; 12/6/1992; 17/1/1994; 23/8/1995;
30/3/1997; 3/11/1998; 9/6/2000; 14/1/2002; 20/8/2003; 27/3/2005;
31/10/2006; 7/6/2008; 12/1/2010; 18/8/2011; 25/3/2013; 29/10/2014;
4/6/2016; 9/1/2018; 13/8/2019;

Evening star maximum angle: 7/9/1970; 9/4/1972; 15/11/1973;
19/6/1975; 26/1/1977; 30/8/1978; 6/4/1980; 12/11/1981; 16/6/1983;
24/1/1985; 27/8/1986; 4/4/1988; 10/11/1989; 14/6/1991; 22/1/1993;
25/8/1994; 2/4/1996; 8/11/1997; 11/6/1999; 19/1/2001; 22/8/2002;
30/3/2004; 5/11/2005; 9/6/2007; 17/1/2009; 20/8/2010; 28/3/2012;
3/11/2013; 7/6/2015; 14/1/2017; 18/8/2018;

Morning star maximum angle: 20/1/1971; 28/8/1972; 5/4/1974;
7/11/1975; 16/6/1977; 18/1/1979; 25/8/1980; 2/4/1982; 4/11/1983;
14/6/1985; 15/1/1987; 23/8/1988; 31/3/1990; 2/11/1991; 12/6/1993;
13/1/1995; 21/8/1996; 29/3/1998; 30/10/1999; 9/6/2001; 10/1/2003;
18/8/2004; 26/3/2006; 28/10/2007; 7/6/2009; 8/1/2011; 16/8/2012;
24/3/2014; 26/10/2015; 4/6/2017; 6/1/2019

Average Days between aspects: 583.93
Year x 8/5: 584.4 days
Days lost per eight year cycle: 2.4
Years lost per 8 yr cycle: 0.0065708
Cycles per precessional rotation: 152.19
Years per Precessional rotation: 1,217.5
Years per pentagon point precession: 243.5

Attached shows pentagonal pattern of inferior conjunctions from 1970 to 2018.

Attached Images

Venus Inferior Conjunction.JPG (138.1 KB, 305 views)

My astroware says max was at 2007 Jun 09 02:45 45° 23' 27" and will be at 2015 Jun 06 18:29 45° 23' 40", about 2.34, and next is 2023 Jun 04 11:00 45° 23' 57", about 2.31, and then 2031 Jun 02 03:33 45° 24' 11", again about 2.31. That's affected by the tilt of Venus's orbit, and the eccentricity of the Earth's, but 2.4 is close to an average value I believe.

Sorry about that. Precession of 2.32 days every eight years (about 0.079398%) is far from exact and perfect. The imperfection is quantified in subsequent posts.

Big Don,

One:
The phrase "inferior conjunction of Venus with Earth" is a mis-use of astronomical terminology. What I was talking about was an "inferior conjunction of Venus with respect to the Sun [as viewed from earth]."

Thanks for catching the problem. [My bad!] Corrections are being made.

Two:

They can occur any time of the year.

I have a webpage that shows calculated dates for them from 1874 thru 2017 at: http://www.datasync.com/~rsf1/vel/1918ics.htm

Bob Fritzius