Retrograde Venus transits the Sun: graphical explanation

Following on from the detailed  3-Dimensional graphics I created to `show’ the way Earth & Moon move around, and how their different positions create the shadows we we (Eclipses), I thought Venus transit deserved a graphics too 🙂

Every diagram in the internet shows `what we will see. .. a picture of the Sun-disc, and Venus as a black spot moving from top-left  across the sun to the right.  But no one has said why?

Normally – from our Earth’s point of view (if we take north pole as `up’) planets move `clockwise’  around the Sun.  If Venus moved that way too, then from our point of view- we will see the transit as going from right hand to left hand part across the Sun.

But of course, at the moment, Venus is `retrograding’. This means it’s going backwards. Not really but it `seems’ that way to us on Earth.  A good example is if you are in a train that’s just leaving the station, and you look out…and  you see another train leaving the station at next platform.  But if your train’s speed is faster than he other train, that one will suddenly look like it’s going `backwards’ – even though both train are going forward. This is an optical illusion of relative perspective of two objects. Same is happening with Earth going around Sun, and Venus.

(You can imagine the headache Albert Einstein must have had, trying to imagine light beams and other objects travelling in space..  as he came up with those Theories of Relativity!)

So Venus IS seemingly going backwards, and so we see the transit of venus across the Sun …from left to right- only for the 6th June 2012. 🙂



Also read about Data for Venus transit

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