Timeline of Solar System exploration

This is a timeline of Solar System exploration ordering events in the exploration of the Solar System by date of spacecraft launch. It includes: All spacecraft that have left Earth orbit for the purposes of Solar System exploration (or were launched with that intention but failed), including lunar probes. A small number of pioneering or notable Earth-orbiting craft. It does not include: Centuries of terrestrial telescopic observation. The great majority of Earth-orbiting satellites. Space probes leaving Earth orbit that are not concerned with Solar System exploration (such as space telescopes targeted at distant galaxies, cosmic background radiation observatories, and so on). Probes that failed at launch. The dates listed are launch dates, but the achievements noted may have occurred some time laterin some cases, a considerable time later (for example, Voyager 2, launched 20 August 1977, did not reach Neptune until 1989).