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Old January 25th 19, 09:44 PM posted to sci.astro.amateur
Gerald Kelleher
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Default Mercury in direct motion

The direct/retrogrades of Venus and Mercury are much more intricate to discern if people insist on using the background stars, however, it doesn't detract from the beautiful spectacle of those planets passing in front and behind the Sun like Jupiter's satellites are seen to run a circuit of their parent planet.

https://www.youtube.com/watch?v=L74B98ITKEA&t=145s

As the Earth moves slower hence the background stars change their position from left to right, when Venus and Mercury run from left to right, they are moving faster than the change in position of the stars from left to right (retrograde motion)and as they run behind the Sun in the opposite direction (direct motion) to the change in the stars from left to right.

The slower moving planets in that time lapse will always be seen to move direct as those planets don't show the centre of their retrograde motions until the Earth has overtaken them until the Earth is between them and the Sun..

The 'planets today' website doesn't match what is actually seen so it is omitted in lieu of animation that screens out a celestial sphere. This honours the work done by the original Sun centred astronomers who did not have the ability screen out the central Sun's glare as we look inwards to our parent star and the faster moving planets.

Celebrate something good for a change as though you could actually appreciate what is in front of you. It doesn't matter anyway as wider society already does even in an incomplete form.