Trying to plan some outreach events where guests can observe the red spot on Jupiter. I am having a heckuva time getting consistent results for the GRS transit timing from among several resources.
I am in MDT zone, offset -6 from UTC.
An example of the discrepancies for the evening of June 24, 2019, for example:
8:48 PM - Sky Safari Pro 6 (minor body orbit data updated today)
9:19 PM - Sky and Telescope calculator https://www.skyandte...great-red-spot/
8:47 PM - Project Pluto https://www.projectp...om/jeve_grs.htm (UTC 14:47 on June 25)
9:02 PM - http://www.acquerra....re/jupiter.html
Is there an accepted "gold standard" for these timings?