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Old November 2nd 17, 03:36 PM posted to sci.astro.amateur
Chris L Peterson
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Default The First Known Interstellar Comet

On Thu, 2 Nov 2017 07:04:54 -0700 (PDT), Gerald Kelleher
wrote:

When Venus reaches its widest point after it emerges as an evening appearance it will then turn back in front of the Sun and move from left to right until it overtakes us and becomes a morning appearance once more.


What do "left" and "right" mean? If I walk outside today and look up
at the Sun while facing south, Venus will be on its left. If I'm
facing north, Venus will be on its right. It only makes sense to use
these terms when considering very specific viewpoints. In most cases,
they are ambiguous and non-useful. That's why we have astronomical
coordinate systems.