On Wednesday, July 20, 2016 at 6:14:34 AM UTC+1, palsing wrote:
On Tuesday, July 19, 2016 at 8:56:43 PM UTC-7, Gerald Kelleher wrote:
On Wednesday, July 20, 2016 at 4:37:50 AM UTC+1, palsing wrote:
On Tuesday, July 19, 2016 at 1:23:53 PM UTC-7, Gerald Kelleher wrote:
http://apod.nasa.gov/apod/ap160717.html

The racetrack analogy applies to Mercury as it does to Venus although Venus gives observers a clearer view as it runs its circuit along with its phases -

http://www.popastro.com/images/plane...ary%202012.jpg

An evening appearance of Mercury represents its orbital course when it emerges out from behind the Sun to its widest point seen from a slower moving Earth before turning back in while a morning appearance is when it passes in front of the Sun and moves to its widest point in the opposite direction.

The people at NASA/APOD need to grow into adults as Mercury doesn't "trail or lead the Sun", the Sun is stationary and the planet moves .

Gerald, you need to keep in mind that this photo shows the position of Mercury over several successive evenings with respect to the Sun. As explained in the text, each photo was taken when the Sun was 10 degrees below the horizon. This photo shows how Mercury swings around the Sun. Isn't it pretty?

This photo does emphatically NOT show the motion of Mercury with respect to the fixed stars, and that motion would be vastly different. Of course, we can't actually see the stars while the Sun is only 10 degrees below the horizon, but we certainly know exactly where they are.

With respect to the stars the retrograde of Mercury would look something like this...

https://michellegregg.files.wordpres...ment.jpg?w=593

Very different, eh?

After all, it is all a matter of perspective, which is always the case.

People are not barbaric and can appreciate the closed loops of Mercury and Venus with the Sun always at the center with Mercury passing in front of the Sun recently as it overtook the Earth at what we see are the center of retrogrades -

https://www.youtube.com/watch?v=PhO6Ufw9h_s

The open-ended loops of the outer planets never have the Sun at the center as the faster Earth overtakes them -

http://astrobob.areavoices.com/files...el_bigANNO.jpg


I only know too well you don't have a feel for inner planetary motion as a planet moves front the left to the right of the Sun or from a twilight appearance to a dawn appearance while appreciating a central Sun and a slower moving Earth. Maybe 1 in 10 or 1 in 100 will experience the thrill of an insight which divides the perspectives between inner and outer planets seen from a moving Earth but this is due to the dominance of celestial sphere guys and their identification exercise bounded by their local horizon.

Too bad you remain blind to reality, Gerald. It is not all that difficult to understand that the motion of the inferior planets relative to the Sun is different than their motion against the stars, but you are incapable of that understanding.

There is a lot that you don't understand. A LOT. We all know this because you spread your ignorance here multiple times daily. You have no capacity to learn. Sad.

I will give you credit that you do not put words in my mouth that I wouldn't say unlike others.

Not even Galileo or the original heliocentric astronomers got the perspectives for the inner planets right and they were superb astronomers with or without telescopes -

"Now what is said here of Jupiter is to be understood of Saturn and Mars also. In Saturn these retrogressions are somewhat more frequent than in Jupiter, because its motion is slower than Jupiter's, so that the Earth overtakes it in a shorter time. In Mars they are rarer, its motion being faster than that of Jupiter, so that the Earth spends more time in catching up with it. Next, as to Venus and Mercury, whose circles are included within that of the Earth, stoppings and retrograde motions appear in them also, due not to any motion that really exists in them, but to the annual motion of the Earth. This is acutely demonstrated by Copernicus" Galileo

The wonderful sequence of images of Mercury which appeared on the APOD website a few days ago shows Mercury running its circuit as it reaches it widest point seen from a slower moving Earth -

http://apod.nasa.gov/apod/ap160717.html

Unlike the outer planets where relative speeds are everything, the Earth's orbital motion supplies a fixed reference of the central Sun by using the incremental change in the position of the stars from night to night -

https://www.youtube.com/watch?v=MdFrE7hWj0A

What is seen in the graphic is replicated in actual imaging apart from the role the Earth's motion plays in the symphony of motions seen from the surface of the Earth. Not only does it show Mercury running its circuit but also how to prove the Earth orbits the Sun as the stars moving behind the glare of the Sun move from a twilight appearance to a dawn appearance.

What is it that you, as a group, hope to prove ?.