Mercury stations retrograde on April 23, 1990 at 17° Taurus, and direct on May 17 at 7° Taurus — 24 days. From the Earth, Mercury seems to back up against the stars as we overtake it, as a car passed on the highway seems to slide backward. Astrology holds it a time for crossed wires and delays. Computed from JPL's approximate orbits; the stations agree with an almanac's to within minutes.