Variation in probe coordinates as viewed by a common terrestrial receive aperture. The variation in the longitude and latitude (in arcseconds in an ecliptic coordinate system) for 26 probes launched at 30-day intervals is shown. The origin corresponds to the angle of Proxima Centauri when viewed from the initial launch site. Each elliptical trajectory is due to the parallax effect of the receiver orbit about the Sun over a period of 2.21 yr, which corresponds to a probe's travel 10% farther than the star. The general drift of the probe positions is due to the star's proper motion, presenting a moving target for the various probes.