Good that people do this

https://apod.nasa.gov/apod/ap160915.html

There is a lovely satisfaction in seeing that people do make the distinction between retrogrades as they apply to the inner and outer planets depending on whether it is seen from a faster or slower moving Earth.

The direct/retrograde motion of the inner planets gauged against the background stars are just a normal consequence of the inner planets running their circuits one way and then the other as they swing out from behind the Sun to their widest point before moving in the opposite direction as they turn in front of the Sun -

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

Take some satisfaction that things are heading the right way and that is all that matters.

In case people wish to develop it further there are a few intricate details which distinguish observations and conclusions when dealing with the inner and outer planets.

With the outer planets it is possible and indeed vital to maintain the fixed background of stars in order to discern direct/retrograde motion and ultimately the faster Earth overtaking the slower moving outer planets thereby accounting for their motions -

https://apod.nasa.gov/apod/ap160915.html

This is impossible for the inner planets as they run their tighter circuits.. The emphasis of the inner planets coming out from behind the Sun to their widest point before turning back in front of the Sun disallows a fixed stellar background as the orbital motion of the Earth causes the background stars to periodically disappear behind the Sun as a line-of-sight observation -

It is the orbital motion of the planets themselves which create the observations that the inner planets move in one direction against the stars and then the other as plainly seen in the graphical clip therefore direct/retrograde motions of the planets and their 'wandering' motions are not homogeneous by perspective.

On Sunday, August 27, 2017 at 11:13:56 AM UTC-7, Gerald Kelleher wrote:

With the outer planets it is possible and indeed vital to maintain the fixed background of stars in order to discern direct/retrograde motion and ultimately the faster Earth overtaking the slower moving outer planets thereby accounting for their motions -

https://apod.nasa.gov/apod/ap160915.html

This is impossible for the inner planets as they run their tighter circuits.

Well, just because we can't always see the background stars because they are lost in the glare of the Sun does *not* mean that we don't know where they are with respect to those inferior planets, Venus and Mars. Although Venus may appear to be in about the same place in the sky each evening, its motion with respect to the distant stars can be quite rapid. Check out this crude but effective representation of the planets' movements WRT the Sun *and* the distant fixed stars...

http://www.nakedeyeplanets.com/movements.htm

.... and see for yourself how both Venus and Mercury move in retrograde WRT each.

The emphasis of the inner planets coming out from behind the Sun to their widest point before turning back in front of the Sun disallows a fixed stellar background as the orbital motion of the Earth causes the background stars to periodically disappear behind the Sun as a line-of-sight observation -

Nevertheless, we know *exactly* how to describe the motion of the planets WRT the stars, and it is not what *you* think it is.

It is the orbital motion of the planets themselves which create the observations that the inner planets move in one direction against the stars and then the other as plainly seen in the graphical clip therefore direct/retrograde motions of the planets and their 'wandering' motions are not homogeneous by perspective.

True inspirational works like music compositions can be understood in general without having to know the details and likewise astronomical insights such as this one only needs the attention of the observer and little else.

I am delighted that some people understand that the direct/retrograde motions of the planets are not homogeneous but are split apart by perspective with the two inner planets of the solar system moving one way against the background stars and then the other as they run their smaller circuits as we see them from a slower moving and a more expansive orbital circumference of the Earth.

The phases of Venus and its size increase as it approaches our slower moving planet are gathered together to create the narrative and from their the fine points can be worked out such as the role the background stars play, the motion of the Earth, the central Sun and a number of other factors.

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

How we see Venus move one way and then the other against the background stars from the Earth is then accounted for differently than the outer planets and people not only recognize this enjoy it.

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


Major innovations can be understood in general without having to be bogged down with details so this is a celebration of contemporary imaging and graphics. The dull neither understand things in general or in detail.

On Monday, August 28, 2017 at 12:27:36 AM UTC+1, palsing wrote:


http://www.nakedeyeplanets.com/movements.htm

... and see for yourself how both Venus and Mercury move in retrograde WRT each.


Watching the Sun dance to the tune of RA/Dec is unsightly so the major adjustment for observers is to watch the stars move from an evening to morning appearance parallel to the Earth's orbital plane -

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

This observation dovetails with the rotation of the North and South poles to the orbital plane but isolating the motion of the inner planets as we see them from the expansive orbital circumference of the Earth should be a joy to behold.

On Monday, August 28, 2017 at 10:30:30 PM UTC+1, Gerald Kelleher wrote:

This observation dovetails with the rotation of the North and South poles to the orbital plane but isolating the motion of the inner planets as we see them from the expansive orbital circumference of the Earth should be a joy to behold.

You are ON one of the inner planets. One of your favourite examples of retrograde motion, Mars, is also an inner planet.

The term you should use is "inferior planets".

On Tuesday, 29 August 2017 10:43:52 UTC+2, wrote:
On Monday, August 28, 2017 at 10:30:30 PM UTC+1, Gerald Kelleher wrote:

This observation dovetails with the rotation of the North and South poles to the orbital plane but isolating the motion of the inner planets as we see them from the expansive orbital circumference of the Earth should be a joy to behold.

You are ON one of the inner planets. One of your favourite examples of retrograde motion, Mars, is also an inner planet.

The term you should use is "inferior planets".

That might give 1461 an inferiority complex.
Amongst all his other mental "problems."

I am certainly not among adults because planets closer to the Sun than our planet is are inner planets while those further out are outer planets but because of human advancement, inner and outer are relative terms as the Earth becomes an inner planet seen from Mars with all the attributes of an inner planet such as phases and the same direct/retrograde motion as Venus and Mercury have.

I can't shake myself from people who lack common sense and especially those who nobody will respond to otherwise and certainly not the British. That being said it is the only place available to outline the enjoyable distinction which exists in the direct/retrograde motion between the inner and outer planets.

Hostility is one thing, mediocrity is something else and unfortunately comments are plagued with the latter.

https://apod.nasa.gov/apod/ap160915.html

Ultimately people have taken notice and rightfully assigned that direct/retrograde motions of the outer planets are different from the inner planets. Of course it is not always possible to immediately focus on what causes the inner planets to circle the Sun and thereby move in one direction against the background stars and then the other but there is nothing in this that makes it in anyway difficult to accept and understand -

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

The partitioning of perspectives is never going to leave humanity and in respect to the original Sun centered astronomers who didn't quite get the full picture -


"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

There is no difficulty explaining the requirement for different perspectives, the only issue is how to get it into wider circulation.