Mars is in IAU Ophiucchus on April 17, or more accurately Scorpio, when it appears to stall before backtracking, about three-quarters of a finger-width west of Antares at transit (03:10 AEST). It crosses the Southern Hemisphere Astrology (SHA) boundary of Libra on June 2, goes ‘direct’ on June 30, and reenters Scorpio on July 29. SHA boundaries are projected across the sky by right ascension from equal divisions of the Ecliptic, originating at Iota1 Scorpii [Breamlea Zodiac]. The southern signs of Libra and Scorpio are equivalent to the northern tropical signs of Taurus and Gemini, not Scorpio and Sagittarius (northern tropical), or, heaven forbid, Libra and Scorpio (northern sidereal).
All astrologers abstract from reality. How could any prediction be otherwise? All astrological predictions, and I dare to suggest, any astrological observations, are derived from mathematical models of varying precision. This is a hidden element in the arbitrariness of orbs. My low-precision algorithms, developed with familiar mathematics to predict the arrival of stars in my ‘window’, are quite adequate for stargazing and horoscopes: within a few minutes in azimuth, and usually a minute in longitude and time. They are adequate for plotting planet positions in relation to stars, but admittedly inadequate for precisely timing conjunctions of planets.
When does Mars overtake Saturn? According to me, the conjunction on August 24 is at 19:32. Stellarium gives the topocentric ecliptic conjunction of Mars and Saturn over Melbourne at 21:27 AEST on August 24. Most sources I can find quote a geocentric conjunction at 21:26. According to high precision data from the US Naval Observatory, the geocentric equatorial conjunction (in right ascension: how SHA relates the planets to the stars) is at 03:50 AEST on August 26. Stellarium agrees. I’m not arguing, because my spreadsheet says 02:00. You will find conflicting information in these matters all over the web, because basically, people seldom acknowledge sources, and never quantify error.
The question above will be answered to my satisfaction when Saturn transits the meridian on August 26 at 18:36. Mars will be half a finger-width to the east. In these terms, Mars exits its retrograde zone on August 24, passing Antares at transit.
[At opposition on May 22, Mars is as bright as Jupiter, but will unfortunately cower in the proximity of the Full Moon. The opposition of Saturn on June 3, two days before New Moon, will not be so intimidated. It will shine as bright as Betelgeuse.]